Ram Concrete Analysis

RAM Concrete Gravity AnalysisV8i (SELECTseries 6)

User Manual

Last Updated: October 09, 2013

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RAM Concrete Gravity Analysis 3 User Manual

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Table of Contents

Chapter 1: Introduction .......................................................................................................9Chapter 2: RAM Concrete Gravity Analysis ........................................................................ 112.1 Invoking the Concrete Module ............................................................................................................................................112.2 The RAM Concrete Analysis Status .................................................................................................................................... 112.3 The Toolbars ................................................................................................................................................................................11

2.3.1 The 3-D Viewer Toolbar .....................................................................................................................................112.3.2 The Gravity Analysis Mode Toolbar ..............................................................................................................12

2.4 Mode ................................................................................................................................................................................................132.5 Criteria .......................................................................................................................................................................................... 13

2.5.1 Code ............................................................................................................................................................................ 132.5.2 Analysis ..................................................................................................................................................................... 132.5.3 Column Forces ........................................................................................................................................................192.5.4 Sidesway .................................................................................................................................................................... 202.5.5 Effective Length ..................................................................................................................................................... 212.5.6 Bracing .......................................................................................................................................................................22

2.6 Assign .............................................................................................................................................................................................222.6.1 Assign Column ........................................................................................................................................................232.6.2 Assign Beam ............................................................................................................................................................ 242.6.3 Assign Beam Lines ................................................................................................................................................24

2.7 Process ........................................................................................................................................................................................... 262.7.1 Analyze ...................................................................................................................................................................... 262.7.2 Results - FE Model Information ...................................................................................................................... 272.7.3 Results - Vertical Reactions .............................................................................................................................. 302.7.4 Results - Member Forces ................................................................................................................................... 312.7.5 Results - Displacements ..................................................................................................................................... 33

2.8 Reports ...........................................................................................................................................................................................342.8.1 Report Destination ............................................................................................................................................... 342.8.2 Reports ...................................................................................................................................................................... 34

2.9 View .................................................................................................................................................................................................342.9.1 Gravity Loads ..........................................................................................................................................................342.9.2 Beam Lines ...............................................................................................................................................................352.9.3 Beam Line Numbers (only on the toolbar) ................................................................................................ 352.9.4 Model Colors / Design Colors toggle ............................................................................................................ 35

2.10 Exiting RAM Concrete Analysis .......................................................................................................................................... 36Chapter 3: Technical Notes ................................................................................................373.1 Concrete Design Code .............................................................................................................................................................373.2 Analytical Model ....................................................................................................................................................................... 37

3.2.1 Geometry .................................................................................................................................................................. 383.2.2 Model Boundary Conditions .............................................................................................................................383.2.3 Member Fixity Conditions ..................................................................................................................................393.2.4 Models with Hanging Columns ....................................................................................................................... 403.2.5 Models with Offset Beams and Columns .....................................................................................................403.2.6 Material Properties .............................................................................................................................................. 41


3.2.7 Section Properties ................................................................................................................................................ 423.3 Gravity Loads ............................................................................................................................................................................. 45

3.3.1 Load Properties ..................................................................................................................................................... 453.3.2 Self-Weight Calculations .................................................................................................................................... 463.3.3 Effects of Sloping Framing ................................................................................................................................ 473.3.4 Effects of One Way Slab Deck Orientation ................................................................................................. 483.3.5 Loads on Two-way Slab Deck .......................................................................................................................... 493.3.6 Loads on Slab Edges ..............................................................................................................................................493.3.7 Openings and Penetrations .............................................................................................................................. 513.3.8 Live Load Reduction ............................................................................................................................................ 533.3.9 Live Load Reduction in RAM Concrete ........................................................................................................ 543.3.10 Skip Loading .............................................................................................................................................................55

3.4 Analysis ..........................................................................................................................................................................................563.4.1 Global Coordinate System ................................................................................................................................. 563.4.2 Local Coordinate System ................................................................................................................................... 563.4.3 Element Formulations ........................................................................................................................................ 573.4.4 Wall Openings and Meshing .............................................................................................................................583.4.5 Two-way Slab Deck ..............................................................................................................................................593.4.6 One-Way Deck ........................................................................................................................................................ 603.4.7 Transfer Columns on One-Way and Two-Way Slabs .............................................................................603.4.8 Hanging Columns off One-Way and Two-Way Slabs ............................................................................. 603.4.9 Transfer Walls on One-Way and Two-Way Slabs ................................................................................... 613.4.10 Rigid Floor Diaphragm ........................................................................................................................................ 613.4.11 Multiple Diaphragms ...........................................................................................................................................613.4.12 P-Delta Effects ........................................................................................................................................................ 623.4.13 Rigid End Zones ...................................................................................................................................................... 623.4.14 Analysis Error Messages ....................................................................................................................................65

3.5 Gravity Design Forces .............................................................................................................................................................663.5.1 Column Gravity Forces ....................................................................................................................................... 663.5.2 Beam Gravity Forces ............................................................................................................................................683.5.3 Wall Gravity Forces ..............................................................................................................................................71

3.6 Deflections ...................................................................................................................................................................................733.7 References ................................................................................................................................................................................... 77Chapter 4: RAM Concept Column and Wall Force Integration ..............................................79Chapter 5: RAM Concrete Gravity Analysis Reports ........................................................... 855.1 General Comments on Reports ...........................................................................................................................................855.2 Concrete Model Data ...............................................................................................................................................................865.3 Member Analysis Properties ............................................................................................................................................... 875.4 Vertical Reactions .....................................................................................................................................................................875.5 Analysis Criteria ........................................................................................................................................................................875.6 Beam Load Diagram ................................................................................................................................................................ 885.7 Beam Line Force Envelope ................................................................................................................................................... 885.8 Beam Deflection ........................................................................................................................................................................ 885.9 Column Forces ........................................................................................................................................................................... 895.10 Concept Column Forces ......................................................................................................................................................... 895.11 Wall Forces ..................................................................................................................................................................................895.12 Concept Wall Forces ................................................................................................................................................................90


Introduction 1RAM Concrete Gravity Analysis is used to calculate all gravity concrete beam and column forces. Thegravity forces are calculated using finite element analysis of each floor in a structure. The reactions fromeach floor's analysis are carried down and automatically applied to the analysis of the floor below. Aquadrilateral finite element mesh is generated for a floor if it contains a two way deck within a slab edgeloop on that floor. The program automatically considers skip loading for live loads on the beam lineslying under one way decking if desired. A beam line lying under a two way deck can have skip loadingcases only if line and point live loads are applied directly on it. Currently, the surface loading applied totwo way decks does not generate any skip loading cases on beam lines. The live load reduction may alsobe applied if desired and can be applied to beams, columns and walls. For concrete columns, the forcesinclude the effect of skip loading at the top and bottom of the column. For beams, the envelope of all theskip-loaded live loads is obtained. These column and beam gravity forces can then be combined withlateral forces from RAM Frame and used for design in the RAM Concrete Column and Beam modes.Chapter 2 provides an overview of the program and its commands, and gives a brief description of theoutput reports available. It explains basic principles of the RAM Concrete Gravity Analysis.Chapter 3, Technical Notes, provides an explanation of the technical issues, assumptions, and codeinterpretations implemented in RAM Concrete Gravity Analysis. It is critical that the engineer studiesand understands this chapter very well to gain insight into how these assumptions affect the analysis.Chapter 4 discusses the integration of column and wall forces from RAM Concept into the RAM ConcreteAnalysis.Chapter 5 provides a description of the information in the Reports in this mode.


Introduction

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RAM Concrete Gravity Analysis 2RAM Concrete Gravity Analysis allows the engineer to obtain concrete beam and column forces from allgravity loads applied to the structure, using finite element analysis.This chapter is an overview of the Concrete Gravity Analysis mode (hereafter referred to as the ConcreteAnalysis Mode) along with a brief discussion of its use. More specific information on each of thecommands is available in the on-line help.

2.1 Invoking the Concrete ModuleImage Description

The RAM Concrete Analysis mode is accessed through the RAM Manager. This canbe accomplished by clicking the RAM Concrete button on the Module toolbar orby selecting RAM Concrete from the Design Menu.

2.2 The RAM Concrete Analysis StatusThe RAM Concrete Analysis mode makes use of data from the RAM Modeler, RAM Steel and RAM Frame.For this reason, any changes to the model from either of these modes will affect the RAM ConcreteAnalysis status.Issuing the command File Model Status will bring up a dialog box that explains the current status ofthe model. If the model is in a state such that it cannot be analyzed or that the beam and column post-processors cannot be accessed, then an explanation of the reasons for the current status is provided.For more information on Model Status, see the RAM Manager manual Model Status chapter.

2.3 The Toolbars

2.3.1 The 3-D Viewer Toolbar

The top toolbar in the RAM Concrete Gravity Analysis mode is common among all the RAM Concretemodes and the 3D-Viewer. For more information on this toolbar, please see the 3-D Viewer Manual.


2.3.2 The Gravity Analysis Mode Toolbar

Image Menu Item

Concrete Mode

Assign - Column Size

Assign - Beam Size

Assign - Concrete Gravity Beam Fixity

Assign - Beam Line Numbers - Automatic

Assign - Beam Line Numbers - Manual

Assign - Column Sidesway

Assign - Column Effective Length

Analyze

Results - View Finite Element Model

Results - View Vertical Reactions

Results - View Member Forces

Results - Displacements

View - Gravity Loads

RAM Concrete Gravity AnalysisThe Toolbars


Image Menu Item

View - Beam Lines

Display Beam Line Numbers (toolbar only)

2.4 ModeThe Mode menu is used for changing between the Concrete Analysis, Concrete Beam, Concrete Columnand Concrete Shear wall modes. A checkmark appears beside the mode that is currently active. Thedrop-down combo box located on the tool bar can be used for this purpose as well.

2.5 CriteriaThe criteria set in the criteria dialog boxes are global criteria that affect all structural members unlessthey are overwritten using one of the assign commands or the View/Update dialog box.When any criteria are changed, it invalidates the analysis and any design that was done in ConcreteColumn or Concrete Beam. Designs that were "frozen" in Concrete Beam or Concrete Column will besaved and checked against the new criteria when the next design is performed.

2.5.1 Code

The code selection option is made in the RAM Concrete Analysis mode. To change the design code, selectCode under the Criteria menu.

2.5.2 Analysis

Select Criteria-Analysis to display the analysis criteria dialog box. Analysis criteria allow the usercontrol over the analytical model that is created, as well as the number of load cases that are generated.These criteria also control the quantity of forces that are extracted for the design modes as describedbelow. For detailed technical information refer to the technical chapter of this manual.AnalysisStations

An analysis station is a single location along the length of a beam at which forces arecalculated for consideration in the beam design mode (see Section 3.5.2). The user cancontrol the number of stations along each concrete beam. These stations are also thelocations at which the design checks will be performed. The larger the number ofstations the more forces are saved and checked in design for each beam.

RAM Concrete Gravity AnalysisMode


The number of stations on any span will be based on the controlling of the two criteriain this frame (see example below). For beams spanning between columns, the stationsare always calculated based on the clear length (face-to-face of columns). For beamssupported on girders the stations are calculated based in the center-to-center spanlength.Minimum number of stations per beam : Specify the minimum number of stations perspan of each physical beam. For a cantilever beam the cantilever and back-span areconsidered separate spans for the purposes of these criteria.Maximum spacing between stations : Specify the maximum spacing the user wantsbetween any two adjacent stations.ExampleMinimum number of stations per beam = 10Maximum spacing between adjacent stations = 12" (250mm)

Resulting number of stations on the cantileverEnglish: maximum( 10, 72"/12" + 1 ) = 10SI: maximum (10, 1800mm/250mm + 1) = 10Resulting number of stations on the back-spanEnglish: maximum( 10, 288"/12" + 1 ) = 25SI: maximum( 10, 9000mm/250mm + 1 ) = 37For the cantilever span the minimum number of stations controls the number ofstations, for the back-span the maximum spacing criteria controls the number ofstations.The number of stations will have an effect on the force diagrams produced asillustrated in figure below.

RAM Concrete Gravity AnalysisCriteria


Rigid EndZones

Whether or not to consider the effects of rigid end zones is declared in the Rigid EndZone box. The engineer may choose to ignore these effects by clicking the Ignore Effectsoption button. To include the effects, click the Include Effects option and either enter apercent reduction (between 0 and 100%) in the edit box or accept the default value of0%. The percentage provided reduces the rigid end zone from the full length (fulllength is considered to be half the column dimension in the direction of the beam). Seethe Chapter 3 for more information on Rigid End Zones.

Loading The loading criteria directly relates to the number of load cases that are generated bythe program and applied to the analysis of each story. Note that the larger the numberof load cases the longer the analysis time.Skip load the live load on beam line beams : Select this option to skip load the liveload on beams that have assigned beam line numbers. (See Section 2.6.3 for adescription of beam lines.) When selected, the program creates one load case perunique live load type (storage, reducible, un-reducible and partition) per beam span.Dead load and Roof live load are not skip-loaded. Also, for beam lines in the two wayregions only live loads applied directly to the beams is considered for skip loads.Skip load the live load on non-beam line beams : Select this option to skip load thelive load on beams that do not have beam line numbers. This option can be selected toobtain skip loaded concrete column forces where the concrete column supports beamswithout beam line numbers. Selecting this option could increase the number of loadcases generated (and hence increase the analysis time).Consider Live Load Reduction : Select this option to have the live load reductionapplied to the forces calculated from each span. The program calculates a live loadreduction factor for each live load type (roof, reducible and storage) on each member(beam and column). Refer to the RAM Steel manual for a description of the differentload types (reducible, unreducible, storage, roof and partition).The analysis is performed for each live load type independently (i.e. different loadcases) if this option is selected. This is to allow the program to reduce the resultingmember forces by its corresponding live load reduction value before combining. Whereno live load reduction is to be considered all live load types on a beam span can beapplied in a single load case for analysis, and no reduction is made to the resulting



forces. Refer to the technical chapter for details on how live load reduction iscalculated.Consider Load Polygons as Load Cases on Two-way deck (for pattern loading) :Select this option to skip-load the surface live loads on two-way regions. Whenselected, the program creates one load case per unique live load type (storage,reducible and un-reducible) per surface load polygon. Dead load and Roof live load arenot skip-loaded. Also, if there are any partition surface live loads they are treatedsimilar to un-reducible live load by the program and they show up in un-reducible liveload component.ExampleAll loads are live loads and beam self wt (dead load) is also applied. The table belowshows the number of load cases that will be generated based on the user selected skipload and live load reduction criteria.

Number of load cases generated (based on the user selected criteria)SkiploadbeamLines

ConsiderLiveLoadReduct.

DLa LLb roof LLreduce.

LL unred. LLStorage

Total

Yes Yes 1 1 2c 2 2 8No Yes 1 1 1d 1d 1d 5Yes No 1 1 2e 0 0 4No No 1 1 0 1f 0 3

a. Never skip load dead loadb. Never skip load roof live loadsc. Both LL reducible loads applied in one load case per spand. Each live load type is its own load case to allow for live load reduction to beconsidered. (see Section 3.5 for more information on Design Forces)e. All live load types applied in one load case per span as LL reduction is not beingconsideredf. All live loads from all spans are in one load case as no skip loading or live loadreduction is being considered.



BeamTorsionStiffness

There are several references that indicate that concrete members will typically exhibitsignificantly less torsional stiffness than might be calculated using the full crosssectional properties (see Section 3.2.6 For more information on the references). In RAMConcrete the torsional stiffness J is calculated based on the dimensions of the web ofthe beam (not including flange overhangs).The torsional stiffness of the beam can then be reduced on a beam-by-beam basis basedon the torsion cracked factor assigned to the member in the RAM Modeler OR theengineer can select to reduce the torsion stiffness for all concrete beams by themagnitude specified in this dialog. Note if using the value specified in this dialog thegross member torsion stiffness will be multiplied by (1.0 - Specified reduction %) todetermine the final beam torsion stiffness. Note that for all other stiffness properties(flexure and axial stiffness) the cracked factor assigned to the both beams and columnsin the Modeler are considered to reduce the associated stiffness value.

Design Consider slenderness(Option in ACI Only,Always applies toBS8110, CP 65)

Per ACI318-02 ( 10.12, 10.13(.5) ), BS8110 3.8.3 columnforces must be increased where a slender column exists. Byselecting this option column slenderness will be checkedand where necessary column forces will be magnified. Theengineer should ensure that beams on slender columnshave sufficient capacity to resist the required increase inend moments.

AnalysisConstraints

Several options are available to the user to control finite element model that is createdin the RAM Concrete Gravity Analysis.Pin base ofconcrete gravitycolumns

The analysis of each story (per ACI318-02 8.8.3, BS81103.2.1.2.1, AS 3600, EN 1992) fixes the ends of the concretecolumns above and below each story that is analyzed. However,the user can choose to pin (release) the gravity concrete columnswhere they are at the foundation. This option will result in lessrotational stiffness than would otherwise be calculated at thejoints above these columns.

Pin base ofcolumn onTransferMember

The engineer has the option of considering the base of a gravitycolumn as pinned (released) when it sits on transfer beam orwall. Selecting this option will consider the gravity concretecolumn pinned at its base in this situation.

Pin Top ofConcrete GravityColumns

A column that is continuous at its top that has gravity beams thatare pinned and supported on the column will induce bendingmoments in the top of the column due to the eccentricitybetween the beam end positions and the column centroid (referto the Technical Section for more information). To remove anymoment being induced in the top of the column the engineer canselect this option to pin the top of the gravity columns (forbending). Note that if all the members framing into the columnare also released for flexure a situation of instability could arise.At least one member must provide stiffness in each of the sixdegrees of freedom to prevent an instability.

Remove RigidDiaphragm

The rigid diaphragm constraint is applied in a horizontal planeeven for a sloped floor. For members not located in the



Constraint onSloped Floors

horizontal plane of a floor the rigid diaphragm constraint mayintroduce unrealistic bending moments and torsion forces. Notethat this behavior is not a program error but rather an inherentfinite element limitation of applying a horizontal rigid diaphragmconstraint to nodes not located in the plane of the diaphragm.This option is provided to remove the horizontal rigid diaphragmconstraint on the floor for sloped diaphragms. When selected ifany node in a diaphragm (single slab edge) is not located at theelevation of the story then none of the nodes in that diaphragmwill be constrained (slaved to a master node).

Ignore wallstiffness abovestory

This option may be selected to ignore the stiffness of the walls atthe level above. This selection will result in a more flexibleanalysis.

Include Out-of-Plane Stiffnessfor One-WayDecks in HybridSlabs

This option may be selected to include the out-of-plane stiffnessfor one-way decks in hybrid slabs. The default selection is alwaysyes.

Speed SaveResults fordisplaypurposes

An option is available in the RAM Concrete Analysis module to allowthe user to speed up the analysis if desired. By selecting Save resultsfor display purposes (the default) the program will save all displayresults and will not experience any difference in speed or functionalityover previous versions. If unselected the program will not save displayresults during the analysis. That is, the program will not save memberforces, reactions etc that were used to allow the user to view theresults of the analysis on the screen. The design forces are still savedand all reports as well as the column and beam design modules willfunction as before. However, there will be no on-screen displayavailable through the Process Results menu command. This optionshould significantly increase the time to complete the analysisparticularly for structures with significant number of load cases.

AnalyticalModel Merge NodeTolerance

This value is used to set a tolerance for merging close nodes afterthe mesh is generated. Any two nodes closer than this specifiedtolerance is assumed to be the same node and they are merged.

MeshControls MaximumDistance

AllowedbetweenNodes

This option allows the user to define the maximum distancebetween nodes in slab decks and walls. Note that the program maygenerate some nodes closer than user entered value, but it is neverallowed to be larger than that.

GeometricTolerance

This value is used to set a tolerance for geometric calculations. Thistolerance is required while performing various geometriccomputations prior to meshing i.e. finding if the point is inside apolygon or point is same as another point etc.



Hard NodeDensity Factor

This factor is used to determine mesh density around hard nodeswhich are always located inside slab decks. A hard node is definedas a node where a column, beam or a wall is attached. For mostcases, a value of 1.0 is a good estimate to obtain relatively goodmesh density around hard nodes.

Solver Type Several types of solvers are offered in the program. Basically they are categorized intwo flavors: in-core and out-of-core solvers. With in-core solvers, the global buildingstiffness matrix is assembled, stored and solved in the physical memory (RAM) of thecomputer. As long as there is enough memory available for the solution of the models,this choice always gives the best performance/solution time. However, for very largemodels, the in-core solver might run into out-of-memory errors. If this is the case, it issuggested to switch to out-of-core direct solver. With the out-of-core solver, theprogram assembles stores and solves building stiffness matrix using files that arestored on the hard-drive of the computer. Thus, it involves repeated access to the harddrive, which may substantially increase analysis time. It is always recommended thatmodels should first be run with the in-core solvers and if an out-of-memory error isdetected, then the out-of-core should be used. Also, one should note that the resultsremain unchanged whatever solver is used in the analysis.Use In-CoreDirect Solver

User may select this option for a moderate size problem.

Use Out-of-CoreDirect Solver

While not a common occurrence should a large model experiencean out-out-of-memory error during analysis the engineer canselect this option to activate the use of the out-of-core solver. Asmentioned this solver will utilize the hard drive in its solutionprocess so while it may be a little slower it will be able toeffectively analyze larger structures.

Use In-CoreSparse Solver

User may select this option for all types of problems. This is thefastest solver in the library if the required RAM is available forusage.

Use Out-of-CoreSparse Solver

This solver provides another out of core option to be used whenthe model runs out of memory. This solver is substantially fasterthan the out-of-core direct solver.

HangerColumnLoadIteration

Convergence Tolerance (% Change)This convergence tolerance value is used to determine the termination of hangingcolumn load iteration. The load iteration is performed to achieve convergence in theload coming through hanging column from level below to the level above. The smallerthis tolerance gets the program may take more number of iterations to converge. Thedefault value of this tolerance is set to 5%.

2.5.3 Column Forces

RAM Concept column forces can be integrated into the concrete gravity analysis but only for levelswhich are not affected by hangers. The interaction between RAM Structural System and RAM Concrete



occurs through the RAM Model. To track the current state of the forces and the interaction between theprograms select the Criteria-Column Forces command to display the Column Design Forces dialog.Please note that the levels which are affected by hanger column forces are not shown in the dialog box.To use RAM Concrete Gravity Analysis column forces (ignore any RAM Concept forces) select the UseRAM Concrete Analysis Forces at all levels. If RAM Concept forces are available to be used the user canselect the Use RAM Concept Analysis Forces at Selected Levels.The columns of the table provide the following information:Use : Select the stories for which Concept forces are to be used. Note that only stories with a green oryellow status (see description of status below and in technical notes) can be selected.Story : The RAM Structural System story.Source Story : This represents the story that was originally read by RAM Concept and whose analysisresults were exported to this story. RAM Concept can export member forces into any story that is of thesame layout type as the story it originally imported. For example if 2nd and 3rd story in the RAMStructural model use floor type A, then Concept can read the data from story 2nd, analyze the floor andprovide forces back to both stories 2nd and 3rd in the Structural System (even though no data was everimported from story 3rd into Concept).Read : This represents the time that RAM Concept last imported the major information (geometry) fromthis story.Saved : This represents the time that RAM Concept last exported member forces for this story.Concept File : The name and path of the Concept file that was used to produce the forces sent back tothe RAM Structural System.Status : Indicates the current state (synchronicity) between the RAM Structural System model and theRAM Concept model. Only stories whose status is Current (green) or Not Current (yellow) can beselected to have their forces integrated with RAM Structural System. Stories that have a state of NotAvailable (red) cannot be selected. If the use RAM Concept force is selected, clicking on any of the statusdots will report the reason for the current state. Refer to the RAM Concept Column and Wall ForceIntegration Chapter for more detailed information.

2.5.4 Sidesway

Selecting the Criteria -Sidesway command will cause the Column Sidesway dialog box to appear. Thisdialog box is used to specify globally (for the entire structure) if the columns are braced or unbracedagainst sidesway (sway or non-sway columns). The third option, "partially braced", refers to the casewhere a structure is braced against sidesway in only one direction e.g., a moment frame in the x-direction and a shear wall in the y-direction. An example of a partially braced setting is provided below.Note that this criterion is not utilized unless the user has selected to consider column slenderness in theCriteria-Analysis dialog box (see Section 2.5.2). The side sway affects the column slendernesscalculation determining if the column is a sway (unbraced)) column (ACI 10.13, BS8110 3.8.1.6.1,EN1992 5.8.3.2 (3)) or a non-sway (braced) column (ACI 10.12, BS8110 3.8.1.6.1, AS3600 10.1.3.1,EN1992 5.8.3.2 (3)).Clicking OK will save the Sidesway setting. Modifying the Sidesway criteria after an analysis or codecheck has been performed will invalidate the results of that analysis and/or code check.Clicking Cancel will close the dialog without changing the Sidesway criteria.



The engineer can also assign sidesway on a member-by-member basis, overriding the global criteria,using the Assign-Column-Sidesway command.Example Partially Braced ColumnsA "partially braced" structure is one that is braced against sidesway in only one direction.To consider ONLY the columns in the Global X OR Global Y directions as being braced against sidesway:Select the Partially Braced option button.Check Global X +/- check box OR the Global Y +/- check box.Accept "0" as the number of degrees in the Degrees box.To include frame columns which are rotated off the Global X OR Global Y axes as being braced againstsidesway:1. Select the Partially Braced option button.

Check Global X +/- check box OR the Global Y +/- check box.Enter the appropriate angle in the Degrees box. NOTE: The degrees angle refers to the angle betweenthe global axis indicated and the lateral member's local major-axis.

For example: To consider Column A (see Figure below) to be braced against sidesway in its major axis,and B in its minor axis:1. Select Partially Braced2. Check Global X +/-3. Enter 20 in the Degrees box.

X

Y

AB

20

Notice that the 20 degrees refers to the angle between the global axis and the local major or minor axesof the columns. This will result in Column A being braced against sidesway in the major axis and ColumnB in the minor axis.

2.5.5 Effective Length

Selecting the Criteria - Effective Length command will cause the Column Effective Length dialog box toappear. Note that this criterion is not utilized for ACI unless the user has selected to consider columnslenderness in the Criteria-Analysis dialog box (see Section 2.5.2). The Effective Length affects thecolumn slenderness calculation in accordance with ACI318-02, BS8110 3.8.1.6.1.and AS 3600 10.5.3.



Per ACI 10.13.1 The Effective Length Factor for sway frames will be limited to a value larger than orequal to 1.0 when the nomograph is selected in the Effective Length Factor Criteria Dialog Box. Crackedsection properties as defined by the user in the RAM Modeler are considered when calculating memberstiffness for the purpose of calculation of effective length (k) factors using the nomograph approach.The Effective Length Factor can be indicated in one of two ways: entering specific values for the majoraxis and minor axis or allowing the program to choose these values. To enter Major or Minor axis valuesfor columns, click the Use button and then enter values in the edit boxes. To have the program calculatethe Effective Length Factors based on the Nomograph Values, click the Use Nomograph Values button.Effective Length Factor can also be set in a column by column basis by selecting Assign-ColumnEffective Length Factor command. If Use Nomograph (ACI) or Use Sec 2.5:BS8110:Part2 (BS8110) isselected, the effective length will be calculated based on the nomographs of 10.12.3 (ACI), the sameformulas are used for the AS3600 design, or equations of BS8110:Part2:1985 Section 2.5 (BS8110)depending on if the column is sway or non-sway in the axis being calculated.Clicking OK will save the settings. Modifying this criterion after an analysis or code check has beenperformed will invalidate the results of that analysis and/or code check.

2.5.6 Bracing

Selecting the Criteria - Bracing command will cause the Column Bracing Criteria dialog box to appear,with the current default settings shown.The bracing of a column in a particular direction affects the analytical model that is created. The dialogis used to set criteria by which the program will calculate the stories at which the columns are braced ineach axis by beams and/or the slab. An option is provided for the slab to automatically brace thecolumn. When selected, the column will be considered braced if it falls within the slab at a particularlevel.Additionally, beams framing into columns may cause the columns to be braced. The maximum angle (0 -90 degrees) for which a beam braces a column may be specified in the edit box provided. If the anglebetween a given column axis and the beam exceeds the value specified, the beam does not providebracing to that column in the axis specified.Refer to Section 3.2.2 of this manual for more information on the affect of column bracing on theboundary conditions of the finite element model.This criterion is used to determine the bracing for all concrete columns. Steel and other columns arebraced according to the bracing criteria for steel members specified in the RAM Steel Column Mode.Refer to the RAM Steel Column Mode for more information.To change the bracing criteria, click on the desired bracing options and/or enter a new maximum anglein the edit box. Clicking the Cancel button will cancel any changes made. To accept the changes, click theOK button.

2.6 AssignThe assign commands are for overriding the global criteria. Most assign commands can be issued inSingle, Fence or All mode.

RAM Concrete Gravity AnalysisAssign


When a command is issued in Single mode, the arrow cursor turns into a target cursor for the selectionof the desired member. In Fence mode, the arrow cursor turns into the rectangle cursor that allows theselection of multiple members at a time. In All mode, the cursor remains the arrow cursor but theassignment is made to all members.

2.6.1 Assign Column

ColumnSize

Using the Assign Column Size, sizes can be assigned to any concrete column. The sizelist in the dialog box displays the column sections available for assignment to columns.Concrete column sections are defined in the RAM Modeler. Clicking on a section in the listbox selects it for assignment. Clicking the Single, Fence or All buttons closes the dialog boxin the selection mode as described above. The status bar displays a prompt that tells theuser what needs to be done to make the size assignment.

Sidesway Selecting the Assign-Column-Sidesway menu command causes the Sidesway dialog box tobe displayed. From this dialog box the engineer can override on a member-by-memberbasis (concrete only) the global sidesway criteria specified under Criteria-Sidesway (see Section 2.5.4). This criterion is not utilized unless the user has selected to considercolumn slenderness in the Criteria-Analysis dialog box (see Section 2.5.2).The sidesway affects the column slenderness calculation by determining if the column is asway (braced) column (ACI 10.13, BS8110:Part2:1985:Sec2.5, AS3600 10.5./10.1.3.1) or anon-sway (unbraced) column (ACI 10.12, BS8110:Part2:Sec2.5, AS3600 10.5). Select theappropriate sidesway criteria for each local axis of the member (or specify that the globalcriteria are to be used for that axis).After the appropriate values are specified the engineer can assign the criteria to a singleconcrete member (click on Single), to multiple members (click on Fence) or to all concretemembers (click on All). If Single is selected the dialog box will close and a target cursorwill be made available. Click on each member to which the criteria should be applied. IfFence is selected the dialog box will close and a fence cursor will be made available. Clickand drag a rectangle around all the members to which the criteria should be applied. Notethat the criteria are only assigned to concrete members. To return to the dialog box toselect a different sidesway criteria click the right mouse button.To view which member axes are using the global criteria and which have been overriddenselect the appropriate option from the View-Members Dialog box.

EffectiveLengthFactor

Selecting the Assign-Effective Length Factor menu command causes the Assign EffectiveLength dialog box to be displayed. From this dialog box the engineer can override, on amember-by-member basis (concrete only), the global effective length factors specified inthe Criteria- Effective Length dialog box. This criterion is not utilized unless the user hasselected to consider column slenderness in the Criteria-Analysis dialog box.Select the appropriate values from the dialog box (see Section 2.5.5 for more informationon the various options). The engineer can choose to override the global criteria in one orboth axes of the member. The criteria are applied to the columns local axes.After the appropriate values are specified the engineer can assign the criteria to a singlemember (click on Single), to multiple members (click on Fence) or to all members (clickon All). If Single is selected the dialog box will close and a target cursor will be madeavailable. Click on each member to which the criteria should be applied. If Fence is



selected the dialog box will close and a fence cursor will be made available. Click and draga rectangle around all the members to which the criteria should be applied. Note that thecriteria are only assigned to concrete columns. To return to the dialog box to select adifferent effective length criteria click on the right mouse button.To view which member axes are using the global criteria and which have been overriddenselect the appropriate option from the View-Members Dialog box.

2.6.2 Assign Beam

Beam Using the Assign Beam Size, sizes can be assigned to any concrete beam. The size list inthe dialog box displays the concrete sections available for assignment to beams. Concretebeam sections are defined in the RAM Modeler. Clicking on a section in the list box selects itfor assignment. Clicking the Single, Fence or All buttons closes the dialog box in theselection mode as described above. The status bar displays a prompt that tells the userwhat needs to be done to make the size assignment.

GravityBeamFixity

Gravity concrete and material type Other beams can be manually assigned fixity forconsideration in the finite element analysis in RAM Concrete. In RAM Concrete Analysismode the user can assign beam fixity conditions to the gravity concrete beams by selectingthe Assign Beam Fixity menu command. Gravity, concrete beam fixities can also beassigned along with the beam line number in the Assign Beam Line Manual orAutomatic menu command as previously described in the Assign Beam Lines Section.

Note: Beam end fixity impacts the beam design envelope but does not directly impact the reinforcementlayout. The reinforcement is designed without regard to beam end fixity.

2.6.3 Assign Beam Lines

Automatic Selecting the Assign-Beam Lines-Automatic command causes the Assign Beam Linesdialog box to display. This dialog box allows the user to establish criteria by which theprogram will automatically assign beam lines to all concrete beams on all stories.Beam lines and beam line numbering are a fundamental concept utilized throughout theprogram. Only concrete beams with assigned beam line numbers can be designed in RAMConcrete Beam. Beam lines can also be assigned and modified manually using the Assign-Beam Lines-Manual command.Note that the gravity beam fixities can be assigned to the gravity concrete beams at thesame time the beam line numbers are assigned or manually at any later time. Select theappropriate assignment of fixity from the Assign Beam Line Dialog.Include Beams with Variance Angle Less Than : The angle specified in this edit boxdefines the maximum angle, between two contiguous beams, for them both to be assignedthe same beam line number. Any angle larger than this and the beams will be assigneddifferent beam line numbers.



Beam offset to accept as continuous : This distance defines the offset that can existbetween two continuous beams for them to be assigned the same beam line number. Thebeams in this case need not be truly continuous as some offset exists between the ends ofeach, but they will be designed as one continuous beam.ExampleThe beam line numbers shown below will be generated for the indicated criteria.Criteria:

Include Beams with Variance Angle Less Than 40 DegreesBeam Offset to accept as continuous = 3 inches

Note that the beams offset 3 inches are assigned the same beam line number, but notthose offset 6 inches. Also the beams that are within 40 degrees of each other are assignedthe same beam line number.

Manual Selecting the Assign-Beam Lines-Manual command causes the Select Plan dialog box todisplay. (If the model is already shown in plan view, then the Select Plan dialog will not beshown.) The selected story will then be displayed and the Assign Beam Lines Manualdialog will open. This dialog box allows the user to create new beam lines or modifyexisting beam lines.Beam lines and beam line numbering are a fundamental concept utilized throughout theprogram. Only concrete beams with assigned beam line numbers can be designed in RAMConcrete Beam.There are rules associated with assigning and deleting beam line numbers to and frombeams. If any of these rules are violated the program will issue a detailed description andprevent the action. For example, only beams that are continuous (or within a small offset)can be assigned the same beam line number. If the engineer tries to assign or delete abeam line number that will result in this rule being violated, the program will issue awarning and not perform the selected action.When assigning or removing beams from a beam line the program can automaticallyassign end releases or fixity to the selected gravity, concrete beams. To have the programautomatically assign beam fixities the 'Automatically Assign Beam Fixities' checkbox mustbe selected. Select between 'Fix all beams' and 'Release All Beams' to have the program Fixor Release, respectively, the ends of the subsequently selected gravity, concrete beams.Fixed beams will be considered continuous in the analysis. Pinned beams will beconsidered released for bending at each end but will remain fixed for torsion.



Add new beam line : By selecting this option and clicking Single or Fence the dialog boxwill close and the cursor will change to the target or fence cursor respectively. Select themember/s to which a new beam line number will be assigned. Note that the beam linenumber that is assigned is automatically determined to be the next available beam linenumber for that story. To assign the next higher beam line number, right click the mouse(to redisplay the Assign Beam Line Number Manual window) and choose the mode (Singleor Fence) in which to assign the next beam line numbers. The beam line number to beassigned is automatically incremented each time the window is displayed.Note the order in which members are assigned to a beam line is important. The beamsmust be selected in a continuous row so none of the beam line rules are violated.Add beams to beam line number : To add additional beams to an existing beam lineselect this option and choose an existing beam line number from the drop down list. Byclicking Single or Fence the dialog box will close and the cursor will change to the targetor fence cursor respectively. Select the member/s to which a new beam line number willbe assigned. Note that the beams assigned the selected beam line number must becontinuous with an existing beam of the same beam line number.Remove from beam line : To remove one or more beams from a beam line, select thisoption. Click Single or Fence to close the dialog box and be presented with a target orfence cursor. Select the member/s to be removed from a beam line. Beams can only beremoved from the ends of a beam line to prevent the creation of a discontinuous beamline. Only beams specifically selected will be removed from beam lines.Remove all beams in beam line : Select this option to remove the beam line number fromall the beams in any beam line that is selected. Click Single or Fence to close the windowand be presented with a target or fence cursor. Select the beam/s with beam line numbersto remove from the model. The beam line number will be removed from all beams thathave the same beam line number as the selected beam.

2.7 Process

2.7.1 Analyze

The Process - Analyze command invokes the generation of finite element models for each story, thecalculation of loads, and the analysis and computation of column and beam design forces. For each storythe process is broken into three phases, namely: preprocessing, analysis and post-processing. Duringthe pre and post-processing of each story, a status log will be displayed. Intermittently another progressdialog will appear which indicates that the actual finite element analysis is being performed.Once all stories are analyzed (successfully or unsuccessfully) the user can scroll through the progresslog for a summary of each story's analysis. In case of models which have hanging columns the storyanalysis data will be present repeatedly. The repetitions are performed only on the levels which areaffected by hanging column forces. The repetitions are equal to the number of times the iteration isperformed to achieve the convergence in hanging column forces. Select Close to hide the log dialog box.Following an analysis the menu commands under the Process-Results menu will be available.

RAM Concrete Gravity AnalysisProcess


To stop the analysis before it is completed, press the Cancel button on the status log dialog.

2.7.2 Results - FE Model Information

Following an analysis the user can select Process > Results > FE Model Info to display the finiteelement model that is created for each story of the analysis. Refer to the Technical Notes Chapter forinformation regarding the Finite Element model created for each story.Each story in the structure is analyzed independently. The user can use this dialog box to view themodel that was analyzed on each story. If the analysis reported an error, it will report a membernumber, node number or a coordinate. The user can use this dialog box to view the story that was beinganalyzed when the error occurred, so that the location of the error might be observed and action takento correct the problem.Note that the display options selected here are only visible on the screen while this dialog box isdisplayed. The dialog box can be moved and the screen printed or manipulated (zoom etc) while thiswindow is displayed.Click Apply to have the selected options display on the screen.Story Select the Story for which to display the Finite Element Model that was analyzed. When the

Apply button is clicked, only the members that were part of the analysis of this story will bedisplayed.

FENodes

The physical model created in the RAM Modeler is automatically converted to create a finiteelement model for the analysis. At each location that a member is intersected by any othermembers it is given a node. By selecting this option all the nodes for the selected story's FEModel will be displayed. Note that there may be many nodes displayed interior to slabdecks and walls. These nodes represent the locations at which the slab deck and wall hasbeen meshed. A size slider is provided to change the size of the nodes during the display ofthe finite element model.NodeNumbers

Select this option to display the node numbers assigned for the analysis.Many of the error messages that may be issued during the analysis referto the nodes by number.

NodeRestraints

After a successful analysis of a story the node restraints can be displayedby selecting the option to Show Restraints. This will display one of thefollowing two symbols at the restrained nodes.

When the longitudinal axis is horizontal, this symbol indicates that thenode is restrained against translation in the direction of the longitudinalaxis and restrained for bending in the same direction (about a horizontal



axis perpendicular to the longitudinal axis). When the axis is vertical, thesymbol indicates restrained against translation in the direction of thelongitudinal axis and restrained for bending in the direction around thisaxis (preventing twisting of columns around their own axis).

The longitudinal axis of the restraint illustrated above is alwayshorizontal and indicates that the node is restrained against translation inthe direction of the longitudinal axis. This restraint is typically applied tothe support nodes of walls at the levels above and below the story beinganalyzed.In general a vertical support is provided to each column and wall directlyunder the story being analyzed. This node is also restrained for torsionaround the vertical axis (columns cannot twist). In addition, translationaland rotational restraints are provided to the column stack (above andbelow the story) where they are braced. Refer to the Criteria-Bracing Section 2.5.6 and Model Boundary Conditions in the Technical NotesChapter for information on how column bracing is determined.

Mesh Select this option to display the finite element mesh of the selected story. A quadrilateralelement mesh is automatically generated using the criteria specified in the mesh controls.The mesh is always generated for the story at which there are any two way slab-decks. Theslab deck mesh is not generated for stories which have only one way slab deck. A slab-deckmay have one or more openings defined in the layout. The meshing procedure considerscolumns as point constraints, beams and walls (above and below) as line constraints andhence always a conformal mesh is generated.



BeamFixity

Select this option to display the fixities that are assigned to each physical member for theanalysis. The fixities assigned may differ from those observed using the View-Memberswindow as they are modified according to the following:Gravity beams in general are all considered released (pinned) about the major and minoraxis at each end, but fixed for torsion. Gravity concrete and other beam fixity can bemodified in this module or the RAM Modeler. Frame beams all utilize the fixity they wereassigned by the user in the RAM Modeler or RAM Frame. If instability occurs at nodes offrame members their fixity may need to be modified in the RAM Modeler or RAM Frame.The display convention for beam fixity is 0 = released and X = fixed. The order the fixitiesare displayed in the following figure:

ColumnFixity

Select this option to display the fixities that are assigned to each physical column for theanalysis. The fixities assigned may differ from those observed using the View-Memberswindow as they are modified according to the following:Gravity columns are assumed continuous above and below the story being analyzed.However, the gravity (non-concrete) columns above the story are assumed pinned(released) at the level of the story being analyzed. Concrete gravity columns are continuousthrough the story being analyzed. The user can choose to release the base of gravitycolumns where they frame into the foundation (refer to the Criteria-Analysis Section 2.5.2).Frame columns all utilize the fixity they were assigned by the user in RAM Modeler or RAMFrame.



The display convention for column fixity is 0 = released and X = fixed. The order the fixitiesare displayed in the following figure:

2.7.3 Results - Vertical Reactions

Following a successful analysis of one or more stories the user can select Process > Results > VerticalReactions to display the Vertical Reactions of each story's analysis. These results can be used toindependently verify the results of the analysis for each story's analysis. Note that reaction forces ateach story are reversed and applied as loads to the supporting story for the next stories. Only significantreactions (larger than some small magnitude) are shown for each load case. Reactions are scaledrelative to each other but the scaling is not exact.The display options selected here are only visible on the screen while this dialog box is displayed. Thedialog box can be moved and the screen printed and model manipulated (zoom etc) while this windowis displayed.Click Apply to have the current selections displayed on the screenStory Select the Story for which to display the reactions from the analysis. When a story is selected,

all of the analyzed load cases for that story will be available for selection in the Load Casedrop-down. When the user clicks Apply, only the members that were part of the analysis ofthis story will be displayed

LoadCase

Select the load case for which to view reactions. Refer to the Analysis Criteria (see Section2.5.2) for more information on how load cases are generated. Click Apply to have the loadcase reactions displayed on the screen. The beams or surface load polygons (in the two-waydeck region) that are loaded in the selected load case are highlighted. If no beams arehighlighted then the selected load case is one in which the columns are loaded (loads fromstory above or user applied column point loads).Load Cases are labeled according to their type (Dead Load = DL, Live Load Reducible = LLred,Live Load Unreducible and Partition = LLunred, Live Load Storage = LLstor, and live load roof= LLroof). Where there are multiple load cases of one type, (LLred1, LLred2 etc) theyrepresent all the different load cases in which loads of that particular type (live loadreducible) was applied.



2.7.4 Results - Member Forces

Following a successful analysis of one or more stories the user can select Process > Results > MemberForces to display the Member Forces and Beam/Column force diagram from each story's analysis.These results can be used to independently verify the results of the analysis and duplicate the calculatedbeam and column design forces. Forces and diagrams are only displayed on members that havesignificant forces for the selected load case. Click Apply to have the current selections displayed on thescreen.The display options selected here are only visible on the screen while this dialog box is displayed. Thedialog box can be moved and the screen printed and model manipulated (zoom etc) while this windowis displayed.Click Apply to have the current selections displayed on the screen.Story Select the Story for which to display member forces from the analysis. When a story is

selected all the analyzed load cases for that story will be available for selection in theLoad Case drop-down. When the user selects Apply, only the members of the structurethat were part of the analysis of this story will be displayed

Load Case Select the load case for which to display member forces. Refer to the Analysis Criteria(see Section 2.5.2) for more information on how load cases are generated. Click Applyto have the member forces displayed on the screen for the current load case. Thebeams that are loaded in the selected load case are highlighted. If no beams arehighlighted then the selected load case is one in which only the columns are loaded(loads from story above or user applied column point loads).Load Cases are labeled according to their type (Dead Load = DL, Live Load Reducible =LLred, Live Load Unreducible and Partition = LLunred, Live Load Storage = LLstor, andlive load roof = LLroof). Where there are multiple load cases of one type, (LLred1,LLred2 etc) they represent all the different load cases in which loads of that particulartype (live load reducible) was applied.

Beam Forces Select this option to display beam forces on the screen for the currently selected storyand load case. Forces are displayed along the length of the beam according to the SignConvention (see Section 3.4.2). Beams will always be oriented from the lower to thehigher numbered node (Node I is the lower node number on the beam span). Allforces are displayed at the face of the beams (i.e. not at center-line) except for beamscontinuous over girders in which case a knife-edge support is assumed for the beams.Select the Show At Quarter Points option to display the forces at beam ends, and threepoints along the span. The distance to quarter and mid-span force is calculated basedon the centerline span length. Select the type of force (Moment, Shear, or Torsion) todisplay. Click Apply to have the selection displayed on the screen. Note that forces willonly be displayed on beams that have significant force (above some small limit) for theselected load case and story.Beam forces for live load cases display the unreduced live load forces. These forces arereduced according to the members Live Load Reduction Factor (see Section 3.3.9)when determining a beams design forces. The Beam Line Force Envelope Report (see Section 5.7) is based on the reduced live load forces.



A Note onBeamDeflections:

The computation of beam gravity deflections is performed during the analysis. Deadand Live Load deflections are calculated at 20 stations along beams with associatedbeam. No deflection data is computed or available for non-beam line beams. Theselection of skip-loading and live load reduction in the Analysis - Criteria menu has asignificant effect on the computed deflections as described in the technical section. Noadditional user input is necessary. The deflection values are not available from thescreen only from the Reports Menu.

ColumnForces

Select this option to display column forces on the screen for the currently selectedstory and load case. Forces are displayed at each end of the column in accordance withthe Sign Convention (see Section 3.4.2). Columns are oriented from top to bottom(upper node to the lower node). All forces are displayed at the face of the columnswhere they are continuous. Select the type of force (Moment, Shear or Torsion) todisplay. Click Apply to have the selection displayed on the screen. Note that forces willonly be displayed on columns that have significant (above some small limit) force forthe selected load case and story.Column forces for live load cases display the unreduced live load forces. These forcesare reduced according to the member's Live Load Reduction Factor (see Section 3.3.9)when determining a column's design forces. The Column Forces report (see Section5.9) is based on the reduced live load forces.

Wall Forces Select this option to display column forces on the screen for the currently selectedstory and load case. From this dialog, select the wall force (Shear, Moment or Axial) todisplay for the currently selected story and load case. Walls are meshed prior toanalysis but the wall forces reported are the cumulative resultant of all the finiteelements in the physical wall. This is true even for wall with openings that existthrough the entire height or width of a physical wall, essentially breaking it into twoor more physical walls. All live load forces are unreduced.Reported forces for wall members include axial force, major axis shear and major axisbending moment (overturning moment). The figure below shows the positivedirection of wall member forces.

Show ForceDiagram

Select this option to display force diagram on the screen for the currently selectedstory, load case and members. Forces are displayed only for beams and columns alongtheir length according to the sign convention (see Section 3.4.2).



Scale Factor Scale factor value is used to scale the member force diagram on the screen. The scalefactor number is only used for representation. One may also specify a negative valueof scale factor to show the diagram on the tension face of beams and columns.

2.7.5 Results - Displacements

Following a successful analysis of one or more stories, the user can select Process > Results >Displacements to display the global displaced shape and displacement contours from each story'sanalysis. Click Apply to have the current selections displayed on the screen.The display options selected here are only visible on the screen while this dialog box is displayed. Thedialog box can be moved and the screen printed and model manipulated (zoom etc) while this windowis displayed.Story Select the Story for which to display the displaced shape from the analysis. When a

story is selected all the analyzed load cases for that story will be available forselection in the Load Case drop-down. When the user selects Apply, only themeshed elements of the structure that were part of the analysis of this story willbe displayed.

Load Case Select the load case for which to display the nodal displacements. The load case inthe drop down menu are the applied loads in the modeler and does not containany skip loading cases. Click Apply to have the nodal displacements displayed onthe screen for the current load case. Load Cases are labeled according to their type(Dead Load = DL, Live Load Reducible = LLred, Live Load Unreducible andPartition = LLunred, Live Load Storage = LLstor, and live load roof = LLroof).

ShowDisplacementContour

Select this option to see the global displacement contours on the meshed elements(two-way floor slab elements). A color palette shown at the bottom showsdifferent colors used in the displacement contour display (see description belowfor more info).

Show DisplacedShape

Select this option to view the displaced shape of the story.

Animate Select this option to animate the displaced shape of the story.Show Mesh Select this option to view the finite element mesh.Scale Factor This scale factor is provided to scale the displacements in the generated view.TransparencySlider

This transparency slider is provided to control the transparency of thedisplacement contours.

Color PaletteLegend

A color palette shows the range of colors associated with showing deflectioncontours of different magnitudes on the screen (see Show DisplacementContours above). The palette is centered on zero deflection (dark green) withnegative (downward) displacement values extending to color red and upward,positive values to dark blue. The maximum displacement value for the selectedstory and load type is indicated on the ends of the slider in the unit indicated inthe dialog title (mm or in). The engineer can also adjust the range of colorsassociated with the deflection values by clicking and dragging the slider (smalltriangle) located at each end of the color palette. As the slider is dragged the



displacement value will show on the slider. Using this control an engineer canestablish a displacement limit, drag the triangle slider to that limit, and theprogram will color all elements with displacement larger than the limit in theextreme color (red or blue).

2.8 Reports

2.8.1 Report Destination

The first four options under the Reports menu are used to control the destination of the selected report.A check mark is placed beside the current selection. This selection is relevant to the current model inRAM Concrete Analysis only. To change the report destination on a global level, use the Tools ReportStyles command located in RAM Manager.

2.8.2 Reports

Various reports are available in the Gravity Analysis mode. These reports are used to gain informationabout the model and its analysis. For more information about the individual reports, see Chapter 5.Various reports are available in the Gravity Analysis mode. These reports are used to gain informationabout the model and its analysis. For more information about the individual reports, see Chapter 5.Some of the reports can be generated on a member-by-member basis using a single or fence action. Togenerate a specific report for a single member select the Specific Report-Single command (whereavailable on the menu), and click on a member. To generate reports a specific report for multiplemembers select the Specific Report-Fence command and fence the members.

2.9 View

2.9.1 Gravity Loads

The View-Gravity Loads command is used to display the member gravity loads that are automaticallycalculated by the program. This is only presented for loads applied on one way decks. (Refer to the RAMManager for more information about member self weight). Select View-Gravity Loads to display theView-Gravity loads dialog box.

RAM Concrete Gravity AnalysisReports


Select one of the load types shown in the dialog box and click Apply to have the selected gravity loadsdisplayed on the screen. Note that only those load types defined in the RAM Modeler are displayed inthis list. If a load type is defined in the RAM Modeler but not assigned to the model, selecting that loadtype will not display any member loads. It may be preferable to be in low resolution (see View-Resolution menu command in the 3D Viewer manual) or in elevation view when observing appliedloads on large structures.

2.9.2 Beam Lines

The View-Beam Lines command is used to display the beam lines on a selected story. Select the dialogbox displayed below appears when the command is invoked. See Assigning Beam Lines (Section 2.6.3)for more information on beam line numbers. Select options from the dialog box and click Apply todisplay the selected options on the screen. Close will hide the dialog box, select View-Reset Model toremove the beam line numbers and highlighted members that are displayed on the screen.Story From the story list, select the story for which to display beam line numbers. When

selected, the list of beam line numbers will be updated to show all the beam linenumbers currently assigned on the selected story.

Select BeamLine Numbers

Select one or more beam line numbers from the list of beam line numbers.Depending on the selection, the beams with the selected beam line numbers will behighlighted and/or numbered, when Apply is selected. By clicking Select All(Unselect All), all the beam line numbers in the list will be selected (unselected).

Show BeamLine Numbers

Select this option to display the beam line number on each beam that is assigned abeam line number equal to the numbers selected in the list.

Highlight BeamLines

Select this option to highlighted each beam that is assigned a beam line numberequal to the numbers selected in the list.

2.9.3 Beam Line Numbers (only on the toolbar)

Select this toolbar button to toggle all the beam line numbers, on all beams in the structure, on and off.Refer to the analysis toolbar description (see Section 2.3.2) for the location of this toolbar button.

RAM Concrete Gravity AnalysisView


2.9.4 Model Colors / Design Colors toggle

Image Description

A 'Model Colors' / 'Design Colors' toggle button and associated menu items havebeen added to the RAM Concrete modules. Both the RAM Concrete Column andRAM Concrete Beam modules change the display colors of the members to reflecttheir current design status. Clicking the 'Change to Model Colors' button, orselecting 'Colors - Model Colors' from the 'View' menu will switch display colorsback to the default colors assigned for each type. This can make it easier toidentify the specific type of member by its color.

While the Model Colors/Design Colors button appears on the toolbar, it will not change the color ofthe members. This is because no design results are available in analysis mode.

Image Description

After clicking the 'Change to Model Colors' button, the button graphic will toggleto the 'Change to Design Colors' button. Clicking this button or selecting 'Colors -Design Colors' from the 'View' menu will toggle the color display back to 'design'colors.

The graphic displayed on the button reflects the current model display colors, which are the opposite ofthe mode that will be toggled to by clicking the button.

2.10 Exiting RAM Concrete AnalysisThe Mode menu or drop-down combo box on the toolbar can be used to exit the Concrete GravityAnalysis mode and navigate to another RAM Concrete mode.The File Close command is used to exit RAM Concrete. Issuing File Close will return the user to theRAM Manager.

RAM Concrete Gravity AnalysisExiting RAM Concrete Analysis


Technical Notes 3Within the RAM Concrete Gravity Analysis mode the beam and column gravity forces are generated.There are several steps to the computation of gravity design forces from the original building model.First the full structural model is broken into multiple finite element models, one for each story in thestructure. Each finite element model is then loaded with the appropriate gravity loads in specific loadcases, and analyzed. Following the analysis, beam and column forces are computed and combined perthe code to produce the most accurate gravity design forces. Also during the analysis the beam localdeflections are calculated along with associated member forces necessary for checking the short andlong-term deflection.The gravity member forces are used in load combinations in the Concrete Beam and Concrete Columnmodes to produce the final design forces. The deflection information is used in the RAM Concrete Beamprogram to calculate the appropriate dead, live, long term and net deflection magnitudes and performthe deflection checks. This technical section describes the details and assumptions made by the programin generating these beam and column gravity forces and deflections.

3.1 Concrete Design CodeThe analysis and computation of design forces in the RAM Concrete Gravity Analysis mode are based onthe requirements of the following concrete codes:ACI 318 99/02 "Building Code Requirements for Structural Concrete" (ACI 318-99 & ACI 318-02) andCommentary, 2002, American Concrete Institute, Farmington Hills, MIThis code is hereafter referred to as ACI318-02 or simply ACI.BS 8110-1:1997 "Structural use of concrete - Part 1: Code of practice for design and construction",Incorporating Amendments 1, 2 & 3.This code is hereafter referred to as BS8110.CP 65-1:1996 "Code of practice for structural use of concrete - Part 1: Design and construction"This code is hereafter referred to as CP 65. When not explicitly mentioned in a section of this documenta reference to BS8110 will apply to CP 65.AS 3600-2001 "Concrete Structures". This code is hereafter referred to as AS 3600.GB 50010 is the concrete design code for China.


3.2 Analytical ModelThe program performs an elastic finite element analysis as stipulated by ACI Section 8.3.1 for a singlestory at a time as permitted by ACI Section 8.9.1 and BS8110 3.2.1. This section of the manual describesthe generation and details of the analytical model used in analysis of each story.

3.2.1 Geometry

A finite element model for each story is generated from a subset of the members in the full model. Thefinite element model of a single story is thus comprised of: All the slab decks defined as two way, Slab decks from one way region but only if they occur with two way slab deck within a slab edge

loop, All the beams on the story, All the walls in the model that are located within one story above or below the current story, All the columns up to the levels at which they are braced above and below the current story.Note that RAM Concrete Gravity Analysis does not currently consider braces in the gravity finiteelement model that is created for any story. The presence of braces is considered in RAM Frame, andhence their affect is considered when determining forces on concrete members due to lateral loads. Thegravity forces calculated in this mode are combined with the lateral forces in each of the Concrete Beamand Concrete Column Design Modes.

3.2.2 Model Boundary Conditions

As indicated above, the finite element model for each story extends approximately one story above andbelow the current level. For walls this is always true and the program will provide a translationalrestraint at the top and bottom of the walls above and below the current story respectively.For columns, the program provides restraints for each axis where it is braced at the story above orbelow the story being analyzed. To determine the levels at which a column is braced above or below aparticular story the program uses the criteria specified by t

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Ram Concrete Analysis

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