INTEGRATED SOLUTION SYSTEM FOR BRIDGE AND CIVIL ENGINEERING
Project Application
All Frame Girder as Plate All Plate
Cross Frame Substructure Modeling with Soil Substructure
Staged Seuencing - Pour Sequence
midas Civil I Bridging your Innovations to Realities
!
I
Moving Load
Daniel MariscalSenior Structural Engineer
URS
Corporation
Tampa, FL
In 2006, I was tasked to evaluate several structural analysis software
packages, and to select the best alternative for our office. Following several
weeks of trials, I selected Midas Civil, and after several years of usage, I am
very pleased with my choice.
Coming from using non-graphical interfaced structural analysis programs, the
selection of Midas Civil was an easy choice. The graphical interface was
powerful, intuitive, and very easy to use. The menu structure and the
maneuverability of the program were simple to learn and fast to get use to.
The capabilities and scope of the program have proven thru the years to be
everything a structural engineer needs by its side to provide an efficient and
effective structural design. The output results are handled via the graphi- cal
interface or spreadsheets. Either way, output is detailed and easy to obtain.
Output and results are handled with a powerful graphical interface where
deformations, forces and stresses are viewed on any direction or thru a cross
section cut. The program can be described with one word: amazing.
Excellent customer technical support is as important as the software itself,
and Midas has provided thru the years excellent support. The support
personal are knowledgeable not only of the software itself, but of
engineering in general. Support answers to my technical questions have
been prompt, honest and always courteous.
Frank BlakemoreDesign Manager
US 69 Bridge Replacement D/B
Project Garver USA
Kansas City, MO
Garver first started using MIDAS a couple of years ago and we have been
impressed with its capabilities. So when our team was shortlisted for the US
69 Bridge project, we naturally chose MIDAS to develop a global model of
the bridge that would provide us reliable results. Now that we are in the final
design phase, we have further developed the MIDAS model and are using it
extensively in our design process.
Our engineers that have been developing the model have been very
pleased with its functionality and ability to create large models efficiently.
The ease of inputting and updating our cross-sections, where properties are
reliably calculated, has been benefi- cial in our iterative process for final
design. Also, the ability to import input data and export results quickly
allowed us to easily adapt our pre- and post-analysis tools to MIDAS.
The technical support has been great throughout our learning curve. Whenever
we have modeling questions, the support team has been very reliable in
getting back to us and generating solutions to any of our modeling issues.
The on-line tutorials and webinars have been very helpful whenever we
introduce younger engineers to MIDAS, and have gotten them up to speed
much quicker than we expected.
Output and results are handled with
a powerful graph-ical interface
where deforma-tions, forces and
stresses are viewed on any
direction or thru a cross section cut.
The ease ofinputting and updating our
cross-sections, where proper-
ties are reliably calculated, has been beneficialin our iterative
process for finaldesign.
Travis ButzBridge Engineer
Burgess and Niple, Inc.
Columbus, OH
I have been using Midas Civil for over six years, and I have found it to be a
powerful and flexible tool for bridge analysis and design. The program
has a user-friendly interface that allows new users to become
productive very quickly. It also has a wide range of analysis capabilities,
allowing users to perform complex tasks such as construction stage
analysis, buckling analysis, and analysis of time-dependent concrete
behavior.
My experience with Midas technical support has been outstanding. My
questions are always answered promptly, and numerous online tutorials
and demonstrations are available to help users take full advantage of the
software. Midas Civil is a great option for engineers looking for user-
friendly, highly functional structural analysis software.
Past Projects Using midas Civil:
- Rich Street Bridge, Columbus, Ohio
- Market Street Bridge, Steubenville, Ohio
- New River Gorge Bridge, Fayetteville, West Virginia
- LUC-75-0577, Toledo, Ohio
- Post-Tensioned Concrete Arch Design
- Steel Suspension Bridge Rehabilitation
- Steel Arch Bridge Rehabilitation
- Curved Steel Girder Design
Ken LeeSenior Bridge Engineer
Jacobs
Engineering
Denver, CO
I first used Midas Civil while working on the Ohio River DB project last
year, and am pleased to address that it provided a set of advanced and
practical solutions that has unique features among any other bridge
software.
The first distinguishing features were its user-friendly interface and
text editor that can handle a complex structural modeling easily.
Especially text editor can be interacted intuitively to graphic interface.
Defining composition section is also my favorable aspect of the
Midas Civil. With the feature composition sections can be defined
in an elaborate way for steel and concrete girder composite
bridges. Another notable feature I recognized during a recent
project is Midas includes multiple solution techniques to solve a
nonlinear static or dynamic problem.
It is for these reasons that Midas Civil will benefit to bridge engineers
to meet their satisfaction.
Daniel MariscalSenior Structural Engineer
URS
Corporation
Tampa, FL
In 2006, I was tasked to evaluate several structural analysis software
packages, and to select the best alternative for our office. Following several
weeks of trials, I selected Midas Civil, and after several years of usage, I am
very pleased with my choice.
Coming from using non-graphical interfaced structural analysis programs, the
selection of Midas Civil was an easy choice. The graphical interface was
powerful, intuitive, and very easy to use. The menu structure and the
maneuverability of the program were simple to learn and fast to get use to.
The capabilities and scope of the program have proven thru the years to be
everything a structural engineer needs by its side to provide an efficient and
effective structural design. The output results are handled via the graphi- cal
interface or spreadsheets. Either way, output is detailed and easy to obtain.
Output and results are handled with a powerful graphical interface where
deformations, forces and stresses are viewed on any direction or thru a cross
section cut. The program can be described with one word: amazing.
Excellent customer technical support is as important as the software itself,
and Midas has provided thru the years excellent support. The support
personal are knowledgeable not only of the software itself, but of
engineering in general. Support answers to my technical questions have
been prompt, honest and always courteous.
Frank BlakemoreDesign Manager
US 69 Bridge Replacement D/B
Project Garver USA
Kansas City, MO
Garver first started using MIDAS a couple of years ago and we have been
impressed with its capabilities. So when our team was shortlisted for the US
69 Bridge project, we naturally chose MIDAS to develop a global model of
the bridge that would provide us reliable results. Now that we are in the final
design phase, we have further developed the MIDAS model and are using it
extensively in our design process.
Our engineers that have been developing the model have been very
pleased with its functionality and ability to create large models efficiently.
The ease of inputting and updating our cross-sections, where properties are
reliably calculated, has been benefi- cial in our iterative process for final
design. Also, the ability to import input data and export results quickly
allowed us to easily adapt our pre- and post-analysis tools to MIDAS.
The technical support has been great throughout our learning curve. Whenever
we have modeling questions, the support team has been very reliable in
getting back to us and generating solutions to any of our modeling issues.
The on-line tutorials and webinars have been very helpful whenever we
introduce younger engineers to MIDAS, and have gotten them up to speed
much quicker than we expected.
Output and results are handled with
a powerful graph-ical interface
where deforma-tions, forces and
stresses are viewed on any
direction or thru a cross section cut.
The ease ofinputting and updating our
cross-sections, where proper-
ties are reliably calculated, has been beneficialin our iterative
process for finaldesign.
Travis ButzBridge Engineer
Burgess and Niple, Inc.
Columbus, OH
I have been using Midas Civil for over six years, and I have found it to be a
powerful and flexible tool for bridge analysis and design. The program
has a user-friendly interface that allows new users to become
productive very quickly. It also has a wide range of analysis capabilities,
allowing users to perform complex tasks such as construction stage
analysis, buckling analysis, and analysis of time-dependent concrete
behavior.
My experience with Midas technical support has been outstanding. My
questions are always answered promptly, and numerous online tutorials
and demonstrations are available to help users take full advantage of the
software. Midas Civil is a great option for engineers looking for user-
friendly, highly functional structural analysis software.
Past Projects Using midas Civil:
- Rich Street Bridge, Columbus, Ohio
- Market Street Bridge, Steubenville, Ohio
- New River Gorge Bridge, Fayetteville, West Virginia
- LUC-75-0577, Toledo, Ohio
- Post-Tensioned Concrete Arch Design
- Steel Suspension Bridge Rehabilitation
- Steel Arch Bridge Rehabilitation
- Curved Steel Girder Design
Ken LeeSenior Bridge Engineer
Jacobs
Engineering
Denver, CO
I first used Midas Civil while working on the Ohio River DB project last
year, and am pleased to address that it provided a set of advanced and
practical solutions that has unique features among any other bridge
software.
The first distinguishing features were its user-friendly interface and
text editor that can handle a complex structural modeling easily.
Especially text editor can be interacted intuitively to graphic interface.
Defining composition section is also my favorable aspect of the
Midas Civil. With the feature composition sections can be defined
in an elaborate way for steel and concrete girder composite
bridges. Another notable feature I recognized during a recent
project is Midas includes multiple solution techniques to solve a
nonlinear static or dynamic problem.
It is for these reasons that Midas Civil will benefit to bridge engineers
to meet their satisfaction.
Pankaj Shrestha
Structural Engineer
GM2 Associates, Inc. Glastonbury, CT
"I believe in MIDAS" In our firm we not only design advanced structures but also we do complex structural
analysis. In our previous experiences with other processes, we found modeling irregular structures to be very difficult and likewise, analyzing those structures was extremely time consuming; not at all fast and efficient. Upon finding out about MIDAS. We were able to model structures very easily and the powerful processer actually allowed us to run through our results far more and beyond our previous software.
Along with the software itself, I'm always impressed with the support team. They answered my queries on a timely manner and even sent me feedback and suggestions to improve my model. I believe in MIDAS and I know that they will continue to service even more to the engineering community.
I have already used MIDAS for two different projects already; one is for the 1-95 over
Housatonic River, a curved steel tip girder bridge for load rating.
Behrooz Adnani Senior Project Engineer
Close Jensen & Miller
Wethersfield, CT
"Recommed use of this
software for all types of bridge
and complex structures" We were investigating for a finite element analysis and rating software to utilize for analyzing steel box girder superstructure bridges and complex multi-span truss bridges. We found out CTDOT is now utilizing MIDAS for rating/design of bridge type structures that AASHTOWare is not able to analyze. We purchased MIDAS software for rating and analyzing an old multi-span complex truss bridge with piers supported on concrete cap and piles.
The ease of graphic interface to model the structure has been extremely helpful and time saver. Of course, we are at an initial learning curve phase of utilizing the software however, the online technical support and technical staff have been extremely helpful and punctual in making our experience easier. We would recommend use of this software for all types of bridge and complex structures.
We are currently utilizing MIDAS on CTDOT Project 158-212, bridge 1349, route 136 over Saugatuck river in Westport CT.
We were able to model structures
very easily and the powerful
processor actually allowed us to run
through our results
The ease of graphic
interface to model the
structure has been extremely
helpful and time saver
Concrete Girder Design
Report
Concrete Bridge Design Report(Sample)
1. Design Condition
Design Code Element AASHTO-LRFD2012 26
• Section Properties
- Gross section
H (in.) B (in.)
czp (in.) czm (in.) czps (in.) czms (in.) A
g (in.2)
ly (in.4)
s, (in. 3)
Sb (in. 3)
s,s (in. 3)
sbs (in.3)
• Materials
- Concrete
Girder Slab
Before
106.30 334.65
37.85 68.45
9.905.E+03 1.118.E+07 2.955.E+05 1.634.E+05
f C
(ksi) 5.000 5.000
Node(I/J) I
After
118.11 334.65
25.37 80.93 37.18 25.37
1.386.E+04 1.664.E+07 4.409.E+05 1.382.E+05 4.475.E+05 6.559.E+05
Ee
(ksi)
Section Composite
- Transformed sectionBefore
H (in.) 106.30 B (in.) 334.65
czp (in.) 37.77 czm (in.) 68.53 czps (in.) czms (in.) A
g (in.2) 1.049.E+04 ly (in.4) 1.266.E+07
s, (in.3) 3.350.E+05 Sb (in.3) 1.847.E+05 s,s (in.3)
sbs (in.3)
f,=0.20\ir'c
(ksi) 4074.3 0.447 4074.3 0.447
* 131 is 0.85 in lower fc 4ksi, the others are 0.85-0.05(fc-4.0) 2':0.65
- Prestressing steel Information
No. Tendon Name Bond dp
Aps Strength (ksi)
Type (in.) (in.2) f
py fpu
1 S_B2L Bond 96.457 8.169 232.060 275.572 2 S_B1L Bond 88.583 8.169 232.060 275.572 3 S_B4L Bond 112.205 8.169 232.060 275.572 4 S_B3L Bond 104.331 8.169 232.060 275.572 * d
P is Distance from extreme compression fiber to centroid of prestressing tendon.
- Longitudinal non prestressed steel reinforcement Information.Girder Slab Bottom for Flexure Top for Flexure
Es fy Es fy ds As ds As (ksi) (ksi) (ksi) (ksi) (in.) (in.2) (in.) (in.2)
29000.0 60.001 29000.0 1 60.00 114.17 10.16 3.94 53.34 * ds or d's is Distance from extreme compression fiber to centroid of non prestressing reinforcement.
- Tranverse non prestressed steel reinforcement Information.
After
118.11 334.65
25.82 80.48 37.63 25.82
1.445.E+04 1.818.E+07 4.901.E+05 1.573.E+05 4.421.E+05 6.443.E+05
131
0.800 0.800
EP
(ksi) 29007.539 29007.539 29007.539 29007.539
Torsion A1
(in.2)
18.00
Shear Torsion Es f
y a Av
I A,
I (ksi) (ksi) (deg.) s s, (in.2
) (in.) (in.2) (in.)
* α is angle between longitudinal and stirrup.
■ Sectional forces/stresses due to effective prestress
* ep is Distance from centroid of section to centroid of tendon
2.Flexure design for a section■ Moment Direction : Positive- Method of Calculation : Code- The maximum Strength Limit Load Combination :- The maximum factored moment (Mu) :
1) Depth of neutral axis to compression face (c). (see. 5.7.3.1)
4 S_B3L 0.396 268.668 2194.873 214499.1663 S_B4L 0.396 269.153 2198.830 232199.5542 S_B1L 0.396 267.441 2184.847 179112.326
Apsfps(dp-c)
1 S_B2L 0.396 268.105 2190.269 196803.044
609.600 65574.617 1873.795 4996.142
No.Axial force in tendons(Bond) by Code
Tendon Name k fps Tps=Apsfps
Axial force in reinforcement steels tensile zone compressive zone
Ts=Asfs ΣAsfs(ds-c) Cs=A'sf's ΣA'sf's(c-d's)
6.603 5.283 1767.821 2.641 7513.239 29767.442
586268.632 (kips-in.)
Axial force in concrete (compressive zone)c a=β1c Ac ac Cc=0.85f'cAc Cc(c-ac)
81156.610Σ 0.541 4857.116 305294.184
cLCB1
4 S_B3L Bond -66.698 0.059 1216.774
61843.8583 S_B4L Bond -74.572 0.041 1241.750 92600.041
69693.676
No. Tendon Name
2 S_B1L Bond -50.950 0.241 1213.8111 S_B2L Bond -58.824 0.200 1184.780
BondType
ep
(in.)Apsfe(z-dir)
(kips)Apsfe(x-dir)
(kips)
5.906
Apsfe(x-dir)ep
(kips-in.)
29000.0 60.000 90.000 2.400 5.906 0.600
* fps = fpu(1-k c/dp) k = 2(1.04-fpy /fpu)
2) Flexural resistance▪ Nominal resistance(Mn). (see. 5.7.3.2)
Mn = ΣAsfs(ds-c)+ΣApsfps(dp-c)+Cc(c-ac)+ΣA'sf's(c-d's) =
▪ Resistance factor(Φ).dt = (in.)εt = 0.003(dt/c-1) = : Net tensile strain in the extreme tension steel
∴ Φ = : Tension Controlled Range, 0.005 ≤εt
▪ Factored resistance(M r = ΦMn)Mr = ≥ Mu =
3) Minimum reinforcement▪ Judgement (see. 5.7.3.3.2)
Mr = ≥ 1.33Mu =
∴ No check.
■ Moment Direction : Negative - Method of Calculation : Code - The maximum Strength Limit Load Combination : - The maximum factored moment (Mu) :
1) Depth of neutral axis to compression face (c). (see. 5.7.3.1)
* fps = fpu(1-k c/dp) k = 2(1.04-fpy /fpu)Σ 2366.747 22295.343
4 S_B3L 0.396 92.408 754.924 -7066.8223 S_B4L 0.396 -151.810 -1240.201 21374.8392 S_B1L 0.396 190.095 1552.974 9918.948
Apsfps(dp-c)
1 S_B2L 0.396 159.013 1299.049 -1931.623
3200.400 291341.162 609.600 11706.453
No.Axial force in tendons(Bond) by Code
Tendon Name k fps Tps=Apsfps
Axial force in reinforcement steels tensile zone compressive zone
Ts=Asfs ΣAsfs(ds-c) Cs=A'sf's ΣA'sf's(c-d's)
23.140 18.512 1166.135 9.256 4956.074 68811.606
cLCB60.000 (kips-in.)
Axial force in concrete (compressive zone)c a=β1c Ac ac Cc=0.85f'cAc Cc(c-ac)
922952.290 (kips-in.) 586268.63 (kips-in.) OK
922952.290 (kips-in.) 779737.28 (kips-in.)
1.00092
922952.29 (kips-in.)
114.1730.0489
1.00
Tps
6.603 7513.239 1873.795 609.600 8768.819
Σ 8768.819 822614.089
c (in.)Compression Force (kips.) Tensile Force (kips.) Tolerance
(C/T)Cc Cs Ts
2) Flexural resistance▪ Nominal resistance(Mn). (see. 5.7.3.2)
Mn = ΣAsfs(ds-c)+ΣApsfps(dp-c)+Cc(c-ac)+ΣA'sf's(c-d's) =
▪ Resistance factor(Φ).dt = (in.)εt = 0.003(dt/c-1) = : Net tensile strain in the extreme tension steel
∴ Φ = : Tension Controlled Range, 0.005 ≤εt
▪ Factored resistance(M r = ΦMn)Mr = ≥ Mu =
3) Minimum reinforcement▪ Judgement (see. 5.7.3.3.2)
Mr = ≥ 1.33Mu =
∴ No check.
3.Shear design for a section■ Maximum Shear- Section type : Segmental-Solid- The Strength Limit Load Combination : cLCB1- The factored Shear force : Vu =- Factored moment : Mu =- Factored axial force : Nu =- Resistance factor for shear : Φ =- Component of prestressing force
in direction of the shear force : Vp = ΣAps·fe(z-dir) = (kips.)1) Effective depth
bv = (in.) : Effective web width
0.9de , 0.72h ] : Effective depth for shearApsfps+Asfs
Apsfps+Asfs
dv = Max [Mn ,
0.90
0.14
62.99
de =Apsfpsdp+Asfsds = 101.309 (in.) : Effective depth for Bending
47.76 (kips.)578397.37 (kips-in.)
0.00 (kips.)
394154.564 (kips-in.) 0.00 (kips-in.) OK
394154.564 (kips-in.) 0.00 (kips-in.)
0.99974
394154.56 (kips-in.)
114.1730.0118
1.00
Tps
23.140 4956.074 609.600 3200.400 2366.747
c (in.)Compression Force (kips.) Tensile Force (kips.) Tolerance
(C/T)Cc Cs Ts
= , , ]=
2) Maximum spacing for transverse reinforcement (s max)▪ Shear stress on concrete (v u).
(Eq. 5.8.2.9-1)
▪ Maximum spacing for transverse reinforcement (s max)vu = < 0.125·f'c =
∴ = Min[0.8dv, 24.0(in.)] = (Eq. 5.8.2.7-1)
∴ = ≤
3) Minimum required transverse reinforcement (A v,min)
(Eq. 5.8.2.5-1)
∴ = (in.2) ≥ * Defining "OK" or "NG" will be checked inchecking Shear resistance by transverse reinforcement
4) Longitudinal Strain(εs)
∴ εs =where, = Max [ Mu , |Vu-Vp|dv ] = , ]
== =
5) Component of shear resisted by tensile stresses in concrete (V c)▪ Factor indicating diagonally cracked concrete to transmit tension (β).
(Eq. 5.8.3.4.2-1)
▪ Nominal shear resistance provide by concreteVc = 0.0316β √f'c bvdv = (Eq. 5.8.3.3-3)
6) Component of shear resisted by transverse reinforcement (V s)
Av ≥ Av,min(1+750εs)
2102.564 (kips.)
β =4.8
= 4.800 ∵
578397.373 (kips-in.)fpo 0.7fpu 192.900 (ksi.)
0.0 ≤ εs≤ 0.006 (Eq. 5.8.3.4.2-4)EsAs+EpAps
0.0000|Mu| Max [ 578397.373 4686.722
εs =(|Mu|/dv + 0.5Nu + |Vu-Vp|-Apsfpo) = -0.0003 ,
0.438 (in.2)fyAv 2.400 Av,min
s 5.906 (in.) smax OK
Av,min = 0.0316 √f'cbvs =
0.009 (ksi) 0.625 (ksi)smax 24.000 (in.)
vu =| Vu - ΦVp |
= 0.009 (ksi.)Φbvdv
Max [ 98.412 91.178 85.03998.412 (in.)
▪ Area of transverse reinforcement required (See 5.8.2.4)
Vu < 0.5Φ(Vc+Vp) ∴ No shear reinforcing
▪ Component of shear resisted by transverse reinforcement (V s)
(Eq. 5.8.3.3-4)where, θ = = (Eq. 5.8.3.4.2-3)
α = (deg.)
7) Shear resistance.▪ Nominal shear strength (Eq. 5.8.3.3.-1)
Vc +Vs +Vp = ≤
∴ Vn = =
▪ Factored shear resistance (V r).
∴ Vr = = ≥ Vu =
■ Minimum Shear- Section type : Segmental-Solid- The Strength Limit Load Combination : cLCB2- The factored Shear force : Vu =- Factored moment : Mu =- Factored axial force : Nu =- Resistance factor for shear : Φ =- Component of prestressing force
in direction of the shear force : Vp = ΣAps·fe(z-dir) = (kips.) 1) Effective depth
bv = (in.) : Effective web width
= , , ]=
Max [ 98.412 91.178 85.03998.412 (in.)
0.9de , 0.72h ] : Effective depth for shearApsfps+Asfs
Apsfps+Asfs
dv = Max [Mn ,
0.90
0.14
62.99
de =Apsfpsdp+Asfsds = 101.309 (in.) : Effective depth for Bending
OK
-443.83 (kips.)398010.09 (kips-in.)
0.00 (kips.)
7749.144 (kips.)Vc+Vs+Vp 6431.854 (kips.)
ΦVn 5788.668 (kips.) 47.764 (kips.)
29+3500εs 29.000 (deg.)90.000
6431.854 (kips.) 0.25·f'cbvdv + Vp =
Vs =Av·fy·dv(cotθ+cotα)sinα
= 4329.150 (kips.)s
0.5Φ(Vc+Vp) Φ(Vc+Vp) Vu
946.22 kips 1892.43 kips 47.76 kips
2) Maximum spacing for transverse reinforcement (s max)▪ Shear stress on concrete (v u).
(Eq. 5.8.2.9-1)
▪ Maximum spacing for transverse reinforcement (s max)vu = < 0.125·f'c =
∴ = Min[0.8dv, 24.0(in.)] = (Eq. 5.8.2.7-1)
∴ = ≤
3) Minimum required transverse reinforcement (A v,min)
(Eq. 5.8.2.5-1)
∴ = (in.2) ≥ * Defining "OK" or "NG" will be checked inchecking Shear resistance by transverse reinforcement
4) Longitudinal Strain(εs)
∴ εs =where, = Max [ Mu , |Vu-Vp|dv ] = , ]
== =
5) Component of shear resisted by tensile stresses in concrete (V c)▪ Factor indicating diagonally cracked concrete to transmit tension (β).
(Eq. 5.8.3.4.2-1)
▪ Nominal shear resistance provide by concreteVc = 0.0316β √f'c bvdv = (Eq. 5.8.3.3-3)
6) Component of shear resisted by transverse reinforcement (V s)▪ Area of transverse reinforcement required (See 5.8.2.4)
0.5Φ(Vc+Vp) Φ(Vc+Vp) Vu
946.22 kips 1892.43 kips 443.83 kips
Av ≥ Av,min(1+750εs)
2102.564 (kips.)
β =4.8
= 4.800 ∵
398010.092 (kips-in.)fpo 0.7fpu 192.900 (ksi.)
0.0 ≤ εs≤ 0.006 (Eq. 5.8.3.4.2-4)EsAs+EpAps
0.0000|Mu| Max [ 398010.092 43692.231
εs =(|Mu|/dv + 0.5Nu + |Vu-Vp|-Apsfpo) = -0.0015 ,
0.438 (in.2)fyAv 2.400 Av,min
s 5.906 (in.) smax OK
Av,min = 0.0316 √f'cbvs =
0.080 (ksi) 0.625 (ksi)smax 24.000 (in.)
vu =| Vu - ΦVp |
= 0.080 (ksi.)Φbvdv
Vu < 0.5Φ(Vc+Vp) ∴ No shear reinforcing
▪ Component of shear resisted by transverse reinforcement (V s)
(Eq. 5.8.3.3-4)where, θ = = (Eq. 5.8.3.4.2-3)
α = (deg.)
7) Shear resistance.▪ Nominal shear strength (Eq. 5.8.3.3.-1)
Vc +Vs +Vp = ≤
∴ Vn = =
▪ Factored shear resistance (V r).
∴ Vr = = ≥ Vu =
4.Torsional design for a section■ Case of Vmax.
- Section type : Segmental-Solid- The Strength Limit Load Combination : cLCB1- The factored Torsional moment : Tu =- The factored Shear force : Vu =- Factored moment : Mu =- Factored axial force : Nu =- Resistance factor for shear : Φ =- Component of prestressing force
in direction of the shear force : Vp = ΣAps·fe(z-dir) = (kips.)
1) NotationAo = Area enclosed by the shear flow path,
including any area of holes therein=
ph = Perimeter of the centerline of theclosed tranverse torsion reinforcement.
=Acp = Total area enclosed by outside
Perimeter of the concrete section.=
pc = The length of the outside perimeter ofconcrete section.
=
2) Checking Torsional Effects▪ Torsional cracking moment (T cr).
(Eq. 5.8.2.1-4)
where,= Acp
2/pc 121930.93 (in.3)
fpc)(1/2) = 64974.02 (kips-in.)
pc 0.125√f'cTcr = 0.125·√f'c
Acp2
( 1+
299.213 (in.)
13857.028 (in.2)
1240.157 (in.)
0.00 (kips.)0.90
0.14
5642.011 (in.2)
OK
16674.88 (kips-in.)47.76 (kips.)
578397.37 (kips-in.)
7749.144 (kips.)Vc+Vs+Vp 6431.854 (kips.)
ΦVn 5788.668 (kips.) -443.831 (kips.)
29+3500εs 29.000 (deg.)90.000
6431.854 (kips.) 0.25·f'cbvdv + Vp =
Vs =Av·fy·dv(cotθ+cotα)sinα
= 4329.150 (kips.)s
fpc = Compressive stress in concrete due to effective prestress only.
Tu = > = (Eq. 5.8.2.1-3)∴ Tu > 0.25Tcr, Consider Torsional Effects.
▪ Check torsional moment (Eq. 5.8.3.6.2-1)
where,θ = = (Eq. 5.8.3.4.2-3)
=
▪ Required longitudinal reinforcementIn solid section, (Eq. 5.8.3.6.3-1)ΣAps·fps+ΣAs·fy =
■ Case of Vmin.
- Section type : Segmental-Solid- The Strength Limit Load Combination : cLCB2- The factored Torsional moment : Tu =- The factored Shear force : Vu =- Factored moment : Mu =- Factored axial force : Nu =- Resistance factor for shear : Φ =- Component of prestressing force
in direction of the shear force : Vp = ΣAps·fe(z-dir) = (kips.)
1) Checking Torsional Effects▪ Torsional cracking moment (T cr).
(Eq. 5.8.2.1-4)
where,=
fpc = Compressive stress in concrete due to effective prestress only.
=ΣAps·fe(x-dir) 0.35
= 64974.02 (kips-in.)
(ksi)Ag Iy
0.125√f'c
Acp2/pc 121930.93 (in.3)
0.90
+ΣAps·fe(x-dir)·ep·yjoint =
0.14
Tcr = 0.125·√f'cAcp
2
( 1+fpc
)(1/2)
pc
-443.83 (kips.)398010.09 (kips-in.)
0.00 (kips.)
∴ ΣAps·fps+ΣAs·fy < NG
-16674.88 (kips-in.)
Apsfps+Asfy
9378.419 (kips.)
= 10360.64 (kips.)
0.9de , = 98.412
, 0.0 ≤ εs≤ 0.006
(in.) (See. 5.8.2.9)
(Eq. 5.8.3.4.2-4)EsAs+EpAps
0.00000
dv = Max [Mn , 0.72h ]
29+3500εs 29.000 (deg.)
εs =(|Mu|/dv + 0.5Nu + |Vu-Vp|-Apsfpo) = -0.0003
=Φ·2·Ao·At·fy·cotθ
= 111686.18 (kips-in.) OKst
Tu = 16674.88 (kips-in.) ≤ ΦTn
= 0.35 (ksi)Ag Iy
16674.882 (kips-in.) 0.25ΦTcr 14619.15 (kips-in.)
=ΣAps·fe(x-dir) +
ΣAps·fe(x-dir)·ep·yjoint
2 20.5 0.45
cot 0.52
u u u h up s
v o
M N V p TV V
d A
2 20.5 0.45
cot 0.52
u u u h up s
v o
M N V p TV V
d A
Tu = > = (Eq. 5.8.2.1-3)∴ Tu > 0.25Tcr, Consider Torsional Effects.
▪ Check torsional moment (Eq. 5.8.3.6.2-1)
where,θ = = (Eq. 5.8.3.4.2-3)
=
▪ Required longitudinal reinforcementIn solid section, (Eq. 5.8.3.6.3-1)ΣAps·fps+ΣAs·fy =
■ Case of Tmax.
- Section type : Segmental-Solid- The Strength Limit Load Combination : cLCB2- The factored Torsional moment : Tu =- The factored Shear force : Vu =- Factored moment : Mu =- Factored axial force : Nu =- Resistance factor for shear : Φ =- Component of prestressing force
in direction of the shear force : Vp = ΣAps·fe(z-dir) = (kips.)
1) Checking Torsional Effects▪ Torsional cracking moment (T cr).
(Eq. 5.8.2.1-4)
where,=
fpc = Compressive stress in concrete due to effective prestress only.
Tu = > = (Eq. 5.8.2.1-3)∴ Tu > 0.25Tcr, Consider Torsional Effects.
▪ Check torsional moment (Eq. 5.8.3.6.2-1)
-16674.882 (kips-in.) 0.25ΦTcr 14619.15 (kips-in.)
=ΣAps·fe(x-dir) 0.35
= 64974.02 (kips-in.)
(ksi)Ag Iy
0.125√f'c
Acp2/pc 121930.93 (in.3)
0.90
+ΣAps·fe(x-dir)·ep·yjoint =
0.14
Tcr = 0.125·√f'cAcp
2
( 1+fpc
)(1/2)
pc
-355.70 (kips.)406684.84 (kips-in.)
0.00 (kips.)
∴ ΣAps·fps+ΣAs·fy ≥ OK
-16674.88 (kips-in.)
Apsfps+Asfy
9378.419 (kips.)
= 7535.03 (kips.)
0.9de , = 98.412
, 0.0 ≤ εs≤ 0.006
(in.) (See. 5.8.2.9)
(Eq. 5.8.3.4.2-4)EsAs+EpAps
0.00000
dv = Max [Mn , 0.72h ]
29+3500εs 29.000 (deg.)
εs =(|Mu|/dv + 0.5Nu + |Vu-Vp|-Apsfpo) = -0.0015
=Φ·2·Ao·At·fy·cotθ
= 111686.18 (kips-in.) OKst
Tu = -16674.88 (kips-in.) ≤ ΦTn
-16674.882 (kips-in.) 0.25ΦTcr 14619.15 (kips-in.)
2 20.5 0.45
cot 0.52
u u u h up s
v o
M N V p TV V
d A
2 20.5 0.45
cot 0.52
u u u h up s
v o
M N V p TV V
d A
where,θ = = (Eq. 5.8.3.4.2-3)
=
▪ Required longitudinal reinforcementIn solid section, (Eq. 5.8.3.6.3-1)ΣAps·fps+ΣAs·fy =
5.Crack check■ Bottom- The maximum Service Limit Load Combination : cLCB23- The maximum spacing of steel reinforcement in layer closet to the tension face(s max) (Eq. 5.7.3.4-1)
where,
dc = (in.)γe = : Exposure factorfss = (ksi.) : Tensile stress in bar at the service limit state
1.003.165
(in.) OK
= 1.049
(in.) ≥
1 +dc
202.921
0.7(h-dc)
3.937
∴ ΣAps·fps+ΣAs·fy ≥
βs·fss
βs =
OK
smax =700·γe - 2dc = suse = 7.874
Apsfps+Asfy
9378.419 (kips.)
= 7808.19 (kips.)
0.9de , = 98.412
, 0.0 ≤ εs≤ 0.006
(in.) (See. 5.8.2.9)
(Eq. 5.8.3.4.2-4)EsAs+EpAps
0.00000
dv = Max [Mn , 0.72h ]
29+3500εs 29.000 (deg.)
εs =(|Mu|/dv + 0.5Nu + |Vu-Vp|-Apsfpo) = -0.0015
=Φ·2·Ao·At·fy·cotθ
= 111686.18 (kips-in.) OKst
Tu = -16674.88 (kips-in.) ≤ ΦTn
2 20.5 0.45
cot 0.52
u u u h up s
v o
M N V p TV V
d A
2 20.5 0.45
cot 0.52
u u u h up s
v o
M N V p TV V
d A
Steel Girder Design Report
I. Design Condition (Positive Flexure)
1. Section Properties
1) Slab Properties
Bs = in
ts = in
th = in
fc' = ksi
Ec = ksi
Ar = in2
Fyr = ksi
2) Girder Properties
[Section]
bfc = in bft = in
tfc = in tft = in
D = in tw = in
[Design Strength]
Fyc = ksi (Compression Flange Yield Strength)
Fyw = ksi (Web Yield Strength)
Fyt = ksi (Tension Flange Yield Strength)
Es = ksi (Elastic Modulus of Steel)
3) Transverse Stiffener Properties
2. Elastic Section Properties
1) Steel Section
2) Short-term Composite Section
STop(n) (in3) 16087.410 SBot(n) (in) 4689.372
dTop(n) (in) 16.702 dBot(n) (in) 57.298
A(n) (in2) 255.949 Iy(n) (in
4) 268691.653 Iz(n) (in4) 121599.508
STop (in3) 3563.908 SBot (in3) 3830.890
dTop (in) 38.336 dBot (in) 35.664
- 90.000
A (in2) 133.812 Iy (in4) 136625.408 Iz (in
4) 2882.695
Web 1Side 36.000 5.000 1.500 -
4.500
3865.202
15.800
60.000
18.000 20.000
Fy (ksi) H (in) B (in) tw(in) tf(in) d0 (in)
50.000
50.000
50.000
29000.000
Position Type
Web A709-50W 0.563 50.000 70.000 less than 2 in.
Element 541Position I
Moment Type Beam
Tension Flange A709-50W 2.500 50.000 70.000
fy (ksi) fu (ksi) Note
Compression Flange A709-50W 2.500 50.000 70.000
2.500 2.500
69.000 0.563
Position Material Thick (in)
108.000
9.000
5.000
Steel composite Bridge Design Report(Sample)
3) Long-term Composite Section(Es/Ec=3n)
II. Strength Limit State - Flexural Resistance
1. Flexure
■ Positive moment
1) Design Forces and Stresses
Positive load combination does not exist. Skip this check.
III. Design Condition (Negative Flexure)
1. Section Properties
1) Slab Properties
Bs = in
ts = in
th = in
fck = ksi
Ec = ksi
Ar = in2
Fyr = ksi
2) Girder Properties
[Section]
bfc = in bft = in
tfc = in tft = in
D = in tw = in
[Design Strength]
Fyc = ksi (Compression Flange Yield Strength)
Fyw = ksi (Web Yield Strength)
Fyt = ksi (Tension Flange Yield Strength)
Es = ksi (Elastic Modulus of Steel)
3) Transverse Stiffener Properties
2. Elastic Section Properties
1) Steel Section
- 90.000
A (in2) 133.812 Iy (in4) 136625.408 Iz (in
4) 2882.695
Web 1Side 36.000 5.000 1.500 -
Fy (ksi) H (in) B (in) tw(in) tf(in) d0 (in)
50.000
50.000
50.000
29000.000
Position Type
Web A709-50W 0.563 50.000 70.000 less than 2 in.
Tension Flange A709-50W 2.500 50.000 70.000
fy (ksi) fu (ksi) Note
Compression Flange A709-50W 2.500 50.000 70.000
2.500 2.500
69.000 0.563
Position Material Thick (in)
108.000
9.000
5.000
4.500
3865.202
15.800
60.000
20.000 18.000
STop(3n) (in3) 7242.680 SBot(3n)(in
3) 4348.148
dTop(3n) (in) 27.760 dBot(3n) (in) 46.240
A(3n) (in2) 174.525 Iy(3n) (in
4) 201057.767 Iz(3n) (in4) 42454.966
2) Short-term Composite Section
3) Long-term Composite Section(Es/Ec=3n)
4) Short-term Composite Section(Long. Reinforcement)
5) Long-term Composite Section(Long. Reinforcement/3)
IV. Strength Limit State - Flexural Resistance
1. Flexure
■ Negative moment
1) Design Forces and Stresses
Loadcombination Name :
Loadcombination Type :
2) Cross-section Proportions
① Web Proportions (AASHTO LRFD Bridge, 2012, 6.10.2.1)
D
tw
② Flange Proportions (AASHTO LRFD Bridge, 2012, 6.10.2.2)
bf
2tw
bf = ≥ =
= 4.000 ≤ 12 ...... OK
18.000 D/6 11.500 ...... OK
-27.218
= 122.667 ≤ 150 ...... OK
StressesTop 16.292 4.618 6.047 26.958
Bot -15.157 -4.725 -7.337
-332.958 -218.967
Component fc,t (ksi)
Steel (MD1) Long-term (MD2) Short-term Sum
Forces ( - ) -58063.925 -18627.322 -30216.698 -106907.944
scLCB1
MY-MIN
ComponentMu (kips·in) Vu
(kips)T
(kips·in)Steel (MD1) Long-term (MD2) Short-term Sum
STop(R3) (in3) 4033.488 SBot(R3)(in
3) 3942.619
dTop(R3) (in) 36.578 dBot(R3) (in) 37.422
A(R3) (in2) 139.079 Iy(R3) (in
4) 147538.813 Iz(R3) (in4) 7285.160
STop(R) (in3) 4996.615 SBot(R) (in) 4118.349
dTop(R) (in) 33.435 dBot(R) (in) 40.565
A(R) (in2) 149.612 Iy(R) (in
4) 167061.266 Iz(R) (in4) 16090.704
STop(n) (in3) 7242.680 SBot(n) (in3) 4348.148
dTop(n) (in) 27.760 dBot(n) (in) 46.240
A(n) (in2) 174.525 Iy(n) (in
4) 201057.767 Iz(n) (in4) 42454.966
STop(n) (in3) 16087.410 SBot(n) (in3) 4689.372
dTop(n) (in) 16.702 dBot(n) (in) 57.298
A(n) (in2) 255.949 Iy(n) (in
4) 268691.653 Iz(n) (in4) 121599.508
STop (in3) 3563.908 SBot (in3) 3830.890
dTop (in) 38.336 dBot (in) 35.664
tf = ≥ =
Iyc
Iyt
③ Minimum Negative Flexure Concrete Deck Reinforcement (AASHTO LRFD Bridge, 2012, 6.10.1.7)
Ars = ≥ = in2
in which :
Adeck = in2
3) Flexural Strength Limit State in negative flexure
▪ Section Classification (AASHTO LRFD Bridge, 2012 6.10.6.3)
= ≤ ksi
Iyc
Iyt
Es
Fyc
in which :
Iyc = in4
Iyt = in4
Dc = in∴ Compact or Noncompact section.
▪ Hybrid Factor, Rh (AASHTO LRFD Bridge, 2012, 6.10.1.10.1)
in which :
ρ = =
β = =
Dn = in (larger of distance from elastic NA to inside flange face)
Fn = ksi (yield stress corresponding to Afn)
Afn = in2 (flange area on the side of NA corresponding to Dn)
▪ Plastic Moment(Mp) (AASHTO LRFD Bridge, 2012, D6.1)
① Plastic Forces
- Plastic Forces
Prt = = kips
Prb = = kips
Pt = = kips
Pw = = kips
Pc = = kips
- Distance from the plastic neutral axis
2 · H · tw · Fyw 1940.625
bfc · tfc · Fyc 2500.001
50.000
Fyr Art 474.000
Fyr Arb 474.000
bft · tft · Fyt 2249.996
min( Fyw /Fn , 1.0 ) 1.000
2Dn·tw / Afn 0.856
38.065
50.000
Rh =12 + β(3ρ-ρ3)
= 1.00012+2β
137.274 ...... OKtw
1666.674
1214.998
34.678
2 Dc= 123.300 ≤ 5.7 √ =
1062.000
min ( Fyc, Fyt ) 50.000 70.0 ...... OK
= 1.37 ≥ 0.3 ...... OK
10.0 ...... OK
15.800 0.01Adeck 10.620 ...... OK
in4
12
0.1 ≤ = 1.372 ≤
12
Iyt =tft · bft
3
= 1214.998
2.500 1.1tw 0.619 ...... OK
Iyc =tfc · bfc
3
= 1666.674 in4
drt = in (distance from the PNA to the centerline of the top layer of reinforcement)
drb = in (distance from the PNA to the centerline of the bottom layer of reinforcement)
dt = in (distance from the plastic neutral axis to midthickness of the tension flange)
dw = in (distance from the plastic neutral axis to middepth of the web)
dc = in (distance from the plastic neutral axis to midthickness of the compression flange)
② Plastic Moment
- Check the case of the plastic neutral axis
= kips ≥ Pt + Prb + Prt = kips∴
PNA In Web
- Distance of the plastic neutral axis
D
2
- Plastic Moment
Pw
2D
▪ Yield Moment(My) (AASHTO LRFD Bridge, 2012, D6.2.2)
① Yield Moment of Top Flange
MD1
STop
MAD = kips·in
MyTop = MD1 + MD2 + MAD = kips·in
② Yield Moment of Bottom Flange
MD1
SBot
MAD = kips·in
MyBot = MD1 + MD2 + MAD = kips·in∴My = min ( MyTop, MyBot ) = kips·in
in which :
S : noncomposite section modulus (in3)Sn : long-term composite section modulus with longitudinal reinforcements (in3)MD1 : moment of noncomposite section (kips·in)
MAD : additional yield moment of short-term composite section (kips·in)
##########
##########
##########
ksiSBot(R) SBot(R) 3.831E+03 3.943E+03 4.118E+03
+-1.863E+04
+MAD
= 50.000
##########
##########
Fy = +MD2
+MAD
=-5.806E+04
50.000 ksiSTop(R) STop(R) 3.564E+03 4.033E+03 4.997E+03
-5.806E+04+
-1.863E+04+
MAD=
= ########## kips·in
Fy = +MD2
+MAD
=
Mp = · [ Y2 + (D - Y)2 ] + [ Prt · drt+ Prb · drb+ Pt · dt +Pc · dc]
...... OK
Y = · (Pc - Pt - Prt -Prb
+ 1 ) = 22.091 inPw
23.341
12.409
48.159
Pc + Pw 4440.626 3197.996
32.755
32.571
▪ Web Load-Shedding Factor, Rb (AASHTO LRFD Bridge, 2012, 6.10.1.10.2)
2 Dc Es
tw fyc
in which :
fyc = ksi (specified minimum yield strength of a compression flange)
Rb =
▪ Limiting Unbraced Length, Lp (AASHTO LRFD Bridge, 2012, 6.10.8.2.3)
E
Fyc
in which :
rt = effective radius of gyration for lateral torsional buckling
1
3
▪ Moment Gradient Modifer, Cb (AASHTO LRFD Bridge, 2012, 6.10.8.2.3)
Calculation of Stress (C6.4.10)
f0 = ksi
f2 = ksi
fmid = ksi
f1 = f0 ) = ksi
For fmid/f2 > 1.0
Cb =
▪ Second-order elastic compression-flange Lateral bending stress (AASHTO LRFD Bridge, 2012, 6.10.1.6)
i. Because of discretely braced flange
Mu
Sl
ii. check Lb
Lb = in
Lb ≤ Lb'
fl = fl1 = ksi
fl = ≤ = ksi
▪ Web Plastification Factor, Rpc and Rpt (AASHTO LRFD Bridge, 2012, A6.2)
E
Fyc Dcp
Dc
in which :
)2
Rh · My
λpw(Dcp) = = 86.313 ≤ λrw (
( 0.54Mp
-
6.452
6.452 0.6Fyf 30.000 ...... OK
√
) = 185.690
0.09
, 220.563 ) = 212.736 infbu/Fyc Mu/Myc
, 1.2Lp√Cb·Rb
) = min( 212.736
120.000
Lb' = min( 1.2Lp√Cb·Rb
-1075.338= 6.452 ksi
tft(bft)2/6 166.667
1.000
fl = =Muz
=
bfc·tfc
-13.705
11.302
-13.705
max( 2fmid-f2 , -13.705
=
bfc
= 5.431 in√ 12( 1 +
Dc·tw)
= 137.274
50.000
1.000
Lp = 1.0 rt √ = 130.800 in
= 123.300 ≤ λrw = 5.7 √
Rh =
E
Fyc
Dcp = in
Dc = in∴=
Dc
Dcp
∴=
Mp Mp
Myc Myc
∴Rpc =
Mp Mp
Myt Myt
∴Rpt =
▪ Flexural Resistance in Continuously Braced Tension Flange (AASHTO LRFD Bridge, 2012, A6.1.4)
Mu = ≤ =
in which :
Фf =
▪ Local Buckling Resistance base on Discretely Braced Compression Flange (AASHTO LRFD Bridge, 2012, A6.3.2)
E
Fyc
λf ≤ λpf Therefore, compact flange
= =
▪ Limiting Unbraced Length, Lp (AASHTO LRFD Bridge, 2012, 6.10.8.2.3)
E
Fyc
in which :
rt = effective radius of gyration for lateral torsional buckling
1
3
▪ Lateral-Torsional Buckling Resistance based on Discretely Braced Compression Flange (AASHTO LRFD Bridge, 2012, A6.3.3)
bfc·tfc
=
bfc
= 5.431 in√ 12( 1 +
Dc·tw)
kips·in
Lp = 1.0 rt √ = 130.800 in
λpf = 0.38 √ = 9.152
Mnc(FLB) Rpc · Myc ##########
...... OK
1.000
λf =bfc
= 4.0002 tfc
0.871Mp λrw - λpw(Dc)
0.871
########## Фf · Rpt · Myt ########## kips·in
λw - λpw(Dc)) ] = 0.871 ≤ =
1.145Mp λrw - λpw(Dc)
1.028
Rpt = [ 1- ( 1-Rh · Myt
) (
λw - λpw(Dc)) ] = 1.028 ≤ =Rpc = [ 1- ( 1-
Rh · Myc) (
≤ λrw
λpw(Dc) 63.808
λw =2 Dc
= 123.300tw
> λpw(Dcp) Therefore, Compact Web Sectiontw
λpw(Dc) = λpw(Dcp) ( ) = 63.808
46.909
34.678
λpw(Dcp) 86.313
2 Dcp= 166.787
1.000
λrw = 5.7 √ = 137.274
Lb ≤ Lp Therefore, compact unbraced length
= =
Mnc = = ksi
▪ Flexural Resistance based on Discretely Braced Compression Flange (AASHTO LRFD Bridge, 2012, A6.1.1)
1
3
in which :
Sxc = = in3
Фf =
V. Strength Limit State - Shear Resistance
1. Shear
■ Max
1) Design Forces and Stresses
Loadcombination Name :
Loadcombination Type :
2) Shear Resistance (AASHTO LRFD Bridge, 2012, 6.10.9)
▪ Ratio of the shear-buckling resistance to the shear yield strength, C (AASHTO LRFD Bridge, 2012, 6.10.9.3.2)
▪ Web Classification
:
:
Transverse Spacing = in < D = in
So, this web is considered
shear-buckling coefficient of stiffened Webs
d0
D
D E·k
tw Fyw
therefore,
E·k
D Fyw
tw
▪ Nominal Resistance of Stiffened interior Webs (AASHTO LRFD Bridge, 2012, 6.10.9.3.2)
Vp = = kips
therefore,
0.58Fyw · D · tw 1125.563
2D · tw= 0.817 ≤ 2.500
( bfc · tfc + bft · tft )
C =1.57
· ( ) = 0.480
( )2
= 122.667 > 1.40 √ = 95.000
stiffened web
k = 5 +
5
= 7.939( )2
Transverse Stiffener Exist
90.0 3 207.0
Forces -169.047 -62.076 -143.335 -374.457
Longitudinal Stiffener Not Exist
1.000
scLCB1
FZ-MIN
ComponentVu (kips)
Steel Long-term Short-term Sum
= ########## kips·in...... OK
Myc / Fyc 4222.094
Mu + fl · Sxc = ########## ≤ Фf · Mnc
Mnc(LTB) Rpc · Myc ########## kips·in
min( Mnc(FLB) , Mnc(LTB) ) ##########
d0
D
Vu = ≤ = kips
in which :
Фv =
3) Transverse Stiffeners (AASHTO LRFD Bridge, 2012, 6.10.11)
① Projecting Width (AASHTO LRFD Bridge, 2012, 6.10.11.1)
bt = in ≥ = in
= in ≥ bt = in < = in
in which :
D = in (height of steel section)
tp = in (thickness of stiffener)
bf = in (width of flange)
② Moment of Inertia and Radius of Gyration (AASHTO LRFD Bridge, 2012, 6.10.11.1.3)
It = = in4
J = max (Jcal, 0.5) =
It1 = = in4 (yielding of stiffener)
Fyw
E
in which :
ρt = =
Vu ≤ Therefore,
It = in4 ≥ = in4
VI. Service Limit State
■ Positive/Negative moment
1) Design Forces and Stresses
There is no service load combination. Skip this check.
■ Negative moment
▪ Concrete Deck Effectiveness Check
fr, modulus of rupture = ksi
Service II factored longitudinal tensile stress in deck = ksi∴
Concrete deck is effective in tension
1) Design Forces and Stresses
Loadcombination Name :
Loadcombination Type :
scLCB5
MY-MIN
ComponentMs (kips·in) / fc,t (ksi)
62.500 min( It1, It2 ) 6.140 ...... OK
0.509
0.497
Fys ) = 36.000 ksi(bt/tp)2
ΦvVcr
62.182 in4
40
max(Fyw / Fcrs , 1.0) 1.389
Fcrs = min (0.31E
,
(d0/D)2
0.500
b · tw3 · J 6.140
It2 =D4 · ρt
1.3
( )1.5 =
69.000
1.500
20.000
tp · bt3 / 3 62.500
Jcal =2.5
- 2.0 = -0.531
16.0 tp 24.000 5.000 bf / 4 5.000 ...... NG
...... OK
1.000
5.000 2.0 + D / 30.0 4.300 ...... OK
850.316 kips√ 1+( )2
-374.457 Фv · Vn 850.316
Vn = Vp[ C +
0.87(1-C)
] =
▪ check stress of the concrete deck
Compact composite section in positive flexure utilized in shored construction
fdeck = ≤ fc' = ksi
in which :
( ) · ( )
( ) · ( )
n = =
fc' = ksi
2) Permanent deformation (AASHTO LRFD Bridge, 2012, 6.10.4.2)
▪ This section is not a compact section in positive flexure, skip top and bottom flange stress check.
▪ Nominal Bend-buckling Resistance for webs (AASHTO LRFD Bridge, 2012, 6.10.4.2.2)∴Fcrw = ksi
in which :
Dc = in
k = =
fc = ksi ≤ Fcrw = ksi
in which :
fc = compression-flange stress at the section under consideration due to the Service II loads.
VII. Constructibility
1. Flexure
■ Negative moment
1) Design Forces and Stresses
Construction Stage :
Step :
2) Check slenderness of web (AASHTO LRFD Bridge, 2012, 6.10.6.2.3-1)
Es
Fyc
in which :
Dc = in
137.274 ...... Compact or noncompact Webtw
33.164
2 · Dc= 117.917 ≤ 5.7 √ =
Force (-) -69676.710
Stress(fbu)
Top 19.551
Bot -18.188
...... OK
Stage3-1
2
ComponentMu (kips·in) / fc,t (ksi)
Steel Section Only
50.000
38.270
9 / ( DC / D )2 29.257
-19.913 50.000
ksi ≤ min ( Rh·Fyc, Fyw/0.7 ) = 50.000 ksi
Es / Ec 7.503
4.500
Fcrw =0.9 E · k
= 50.748( D / tw )2
28.202= 0.497 ksi
I · n ########## 7.503
-19.913
0.497 0.24 1.080 ...... OK
fdeck =M · y
=-35494.159
StressesTop 13.034 1.801 1.395 16.231
Bot -12.125 -3.001 -4.787
Forces ( + ) -46451.140 -13047.469 -22446.690 -81945.298
ComponentSteel Long-term Short-term Sum
3) Discretely Braced Flanges in Compression (AASHTO LRFD Bridge, 2012, 6.10.3.2.1)
▪ Web Load-Shedding Factor, Rb (AASHTO LRFD Bridge, 2012, 6.10.1.10.2)
In constructibility (AASHTO LRFD Bridge, 2012, 6.10.3.2.1)
Rb =
▪ Limiting Unbraced Length, Lp (AASHTO LRFD Bridge, 2012, 6.10.8.2.3)
E
Fyc
in which :
rt = effective radius of gyration for lateral torsional buckling
1
3
▪ Moment Gradient Modifer, Cb (AASHTO LRFD Bridge, 2012, 6.10.8.2.3)
Calculation of Stress (C6.4.10)
f0 = ksi
f2 = ksi
fmid = ksi
f1 = f0 ) = ksi
For fmid/f2 > 1.0
Cb =
▪ Second-order elastic compression-flange Lateral bending stress (AASHTO LRFD Bridge, 2012, 6.10.1.6)
i. Because of discretely braced flange
Mu
Sl
ii. check Lb
Lb = in
Lb ≤ Lb'
fl = fl1 = ksi
fl = ≤ = ksi
① Check flange nominal yielding
= ≤ = kips
in which :
Φf =
Rh =
② Check flexural resistance
= ≤ = ksi
in which :
...... OK
1.000
1.000
fbu + fl/3 18.665 Φf · Fnc 50.000
1.430
1.430 0.6Fyf 30.000 ...... OK
fbu + fl 19.618 Φf · Rh · Fyc 50.000 ...... OK
, 273.923 ) = 260.899 infbu/Fyc Mu/Myc
, 1.2Lp√Cb·Rb
) = min( 260.899
120.000
Lb' = min( 1.2Lp√Cb·Rb
-238.252= 1.430 ksi
tft(bft)2/6 166.667
1.000
fl = =Muz
=
)bfc·tfc
-19.551
16.164
-19.551
max( 2fmid-f2 , -19.551
in
=
bfc
= 5.445 in√ 12( 1 +
Dc·tw
1.000
Lp = 1.0 rt √ = 131.130
Φf =
Fnc = ksi
▪ Local Buckling Resistance based on Discretely Braced Compression Flange (AASHTO LRFD Bridge, 2012, 6.10.8.2.2)
λf = =
λpf = =
▪ Web Load-Shedding Factor, Rb (AASHTO LRFD Bridge, 2012, 6.10.1.10.2)
In constructibility (AASHTO LRFD Bridge, 2012, 6.10.3.2.1)
Rb =
λf ≤ λpf Therefore,
= = ksi
in which :
Rb =
Rh =
▪ Limiting Unbraced Length, Lp (AASHTO LRFD Bridge, 2012, 6.10.8.2.3)
E
Fyc
in which :
rt = effective radius of gyration for lateral torsional buckling
1
3
▪ Lateral-Torsional Buckling Resistance based on Discretely Braced Compression Flange (AASHTO LRFD Bridge, 2012, 6.10.8.2.2)
Lb ≤ Lp Therefore, compact unbraced length
= = ksi
in which :
Rb =
Rh =
Fnc = = ksi
③ Check web bend buckling
For sections with compact or noncompact webs, shall not be checked.
4) Discretely Braced Flanges in Tension (AASHTO LRFD Bridge, 2012, 6.10.3.2.2)
▪ Flange Lateral bending Stress (AASHTO LRFD Bridge, 2012, 6.10.1.6)
Because of discretely braced tension flange.
Mu
Sl
fl = ≤ = ksi ...... OK
= 1.765 ksitft(bft)
2/6 135.000
1.765 0.6Fyf 30.000
min( Fnc(FLB), Fnc(LTB) ) 50.000
fl = =Muz
=-238.252
bfc·tfc
Fnc(LTB) Rb · Rh · Fyc 50.000
1.000
1.000
=
bfc
= 5.445 in√ 12( 1 +
Dc·tw)
Lp = 1.0 rt √ = 131.130 in
1.000
Fnc(FLB) Rb · Rh · Fyc 50.000
1.000
1.000
1.000
50.000
bfc / 2tfc 4.000
0.38√(E/Fyc) 9.152
① Check flange nominal yielding
= ≤ = kips
in which :
Φf =
Rh =
2. Concrete Deck
1) Check longitudinal stresses in concrete deck (AASHTO LRFD Bridge, 2012, 6.10.1.7)
fdeck = > = ksi
in which :
( ) · ( )
( ) · ( )
n = =
fr = = ksi
fc' = ksi
3. Shear
■ Max
1) Design Forces
Construction Stage :
Step :
2) Shear requirement for webs (AASHTO LRFD Bridge, 2012, 6.10.3.3)
▪ Ratio of the shear-buckling resistance to the shear yield strength, C (AASHTO LRFD Bridge, 2012, 6.10.9.3.2)
shear-buckling coefficient of stiffened Webs
d0
D
D E·k
tw Fyw
therefore,
E·k
D Fyw
tw
▪ Nominal Resistance of Unstiffened interior Webs or End pannel
Vp = = kips
Vn = Vcr = = kips
in which :
C = ratio of the shear-buckling resistance to the shear yield strength
=
Vu = ≤ = = kipsФv · Vn 540.759 ...... OK
0.58Fyw · D · tw 1125.563
C · Vp 540.759
0.480
-202.856 φv · Vcr
C =1.57
· ( ) = 0.480
( )2
= 122.667 > 1.40 √ = 95.000
k = 5 +
5
= 7.939( )2
2
ComponentVu (kips)
Steel Section Only
Force -202.856
Es / Ec 7.503
0.24 √ fc' 0.509
4.500
Stage3-1
= 0.975 ksiI · n 2.687E+05 7.503
fdeck =M · y
=-6.968E+04 28.202
1.000
1.000
0.975 0.9 · fr 0.458 ...... NG
fbu + fl 21.315 Φf · Rh · Fyt 50.000 ...... OK
in which :
Фv =
VIII. Fatigue Limit State
■ Fatigue moment
1) Design Forces and Stresses
Loadcombination Name :
Loadcombination Name :
2) Load-Induced Fatigue (AASHTO LRFD Bridge, 2012, 6.6.1.2)
■ Top Flange
The stress from unfactored DL = ksi ( - : Compression)
The stress from fatige LCB = ksi
Check Load-Induced Fatigue. [The stress from unfactored DL is the tensile stress.]
(ADTT)SL( = ) > Constant-Amplitude Fatigue Thresholds from Table 6.6.1.2.5-3 ( = )
=> Check for fatigue I
For Fatigue I, according to Table 6.6.1.2.5-3 Constant-Amplitude Fatigue Thresholds
ksi∴
ksi
= ksi < ksi (warping stress = ksi)
■ Bottom Flange
The stress from unfactored DL = ksi ( - : Compression)
The stress from fatige LCB = ksi
-14.114
0.000
γ(Δf) 1.369 (ΔF)n = 12.000 0.000 ...... OK
10000.00 745.00
(ΔF)TH = 12.000
(ΔF)n = (ΔF)TH = 12.000
0.000
No Category (ADTT)SL Number of stress (n)
1 C' 10000.000 1.000
scLCB8
ComponentVu
(kips)
Shear Force -301.542
13.823
0.000 0.000
Bot(Comp.) - -11.275 -2.838 -5.282 -5.282
Bot(Tens.) - 0.000 0.000 0.122
1.369
Top(Comp.) - 0.000 0.000 0.000 0.000Stresses
Top(Tens.) - 12.184 1.639 1.369
Bot(Tens.) - 0.000 0.000
Short-term Sum
Forces
Top(Tens.) - -46451.140 -13047.469 -25900.027 -25900.027
Top(Comp.)
1.000
scLCB8
Component LCBMu (kips·in) / fc,t (ksi)
Steel Long-term
0.122
Bot(Comp.) - -46451.140 -13047.469 -25900.027 -25900.027
- 0.000 0.000 0.122 0.122
Skip this check. [ (The compressive stress from unfactored DL) > (The tensile stress from fatige LCB)]
3) Special Fatigue Requirement for Webs with transverse stiffeners (AASHTO LRFD Bridge, 2012, 6.10.5.3)
▪ Ratio of the shear-buckling resistance to the shear yield strength, C (AASHTO LRFD Bridge, 2012, 6.10.9.3.2)
shear-buckling coefficient of stiffened Webs
d0
D
D E·k
tw Fyw
therefore,
E·k
D Fyw
tw
Vu = ≤ Vcr = =
in which :
Vu = shear in the web due to the unfactored permanent load plus the factored fatigue load(Fatigue I)
C = 0.480
-301.542 kips 0.58 C · Fyw · D · tw 540.759 kips ...... OK
C =1.57
· ( ) = 0.480
( )2
= 122.667 > 1.40 √ = 95.000
k = 5 +
5
= 7.939( )2