Lucas Pettinati Rafael Monzon Andreas Dinopoulos architect structural engineer construction manager Berkeley Georgia Tech Strathclyde, UK

Luciana Barrosoowner

• The Project• Project Requirements• Owner Requirements• Architectural Context• Site Context• Alternatives• Preferred Alternative• A-E-C Solutions• A-E-C Interactions• Lessons Learned

Today’s Outline

• Year 2010• Lake Tahoe area• Rebuild 3-story educational building

• Ridge University Engineering School

The Project

• Maintain existing footprints• 36’ height limitation• $5,500,000 budget• One year duration

Project Requirements

• Showpiece building• “Safe” structure within site context• On budget / on time

Owner Requirements

Architectural Context

• South Lake Tahoe• Building style based on

University of California Berkeley Art Museum and I.M. Pei’s NCAR Building

Architectural Desires

• Large curtain wall• Unobstructed seating in

auditorium and lecture rooms• Heavy vs. light

• Boundary conditions• Geological features• Local weather conditions• Local working week

Site Context

Alternative 1: Architecture

• Pre-existing structural layout• Privacy increases on vertical and inward motion• Use of internal light wells to unite spaces• Large spaces within to be used for interaction

Alternative 1: Engineering and Construction

•Explored structural systems:•Concrete•Steel•Concrete+Steel

•Preferred Structural System:•Concrete+Steel

•Construction Cost: $5,800,000

Alternative 2: Architecture

• Programmatic in nature• Separation of function by level• Individuality• Large spaces within to be used for interaction

Alternative 2: Engineering and Construction

•Explored structural systems:•Concrete•Steel

•Preferred Structural System:•Steel

•Construction Cost: $5,400,000

Alternative 3: Architecture

• Programmatic in nature• Separation of function by level• Individuality• Periphery vs. core• Large spaces within to be used for interaction

Alternative 3: Engineering and Construction

•Explored structural systems:•Concrete•Steel

•Preferred Structural System:•Concrete

•Construction Cost: $6,000,000

Alternative 4: Architecture

• Auditorium as indoor/outdoor space• 8º shift • Cantilevers hold offices • Glass curtain• Slope roof

Alternative 4: Engineering and Construction

•Explored structural systems:•Concrete•Steel•Concrete+Steel

•Preferred Structural System:•Concrete+Steel

•Construction Cost: $5,700,000

Preferred Solution: Alternative 4

Architectural Elements• Glass curtain walls• Cantilevered offices• Dual purpose auditorium• Open space light well at

lobby• Dynamic spaces that allow

for options

Structural Elements• Challenging cantilever

system• Sound lateral load resisting

system• Structure nicely integrated

into architecture

Owner’s preference

Construction Elements• Tight time scheduling• Challenging cost cut-down

Architecture Final Iteration

Overview

• Based on Alternative 4• Faculty offices along periphery• Student offices in an open environment• Auditorium follows ground

1st Floor: Circulation

1st Floor: Egress

1st Floor: Lecture Rooms

1st Floor: Lecture Rooms

• The following QuickTime VR movie is representative of the layout and feeling of the lecture rooms within the structure

1st Floor: Small Classroom

2nd Floor: Circulation

2nd Floor: Egress

2nd Floor: Instructional Facilities

2nd Floor: Seminar Rooms

2nd Floor: Student Offices

3rd Floor: Circulation

3rd Floor: Egress

3rd Floor: Faculty Offices

3rd Floor: Faculty Offices

• The following QuickTime VR movie is representative of the layout and feeling of the dean’s office within the structure

3rd Floor: Faculty Lounge

3rd Floor: Secretaries

Architecture Performance

Grand Total Actual Program DifferenceUseable Space 23400 30000Underground Storage/Machines 3000Open Space 1200Total 27600 30000 8.00%

• Planned space is 8% smaller than the program requirements • Total area: 27,600 square feet

• All areas handicap accessible per ADA regulations• At least 2 means of egress on every floor• Centralized plumbing runs• HVAC and Electrical distribution imbedded in walls

Architecture Performance

• Room affinities maintained from initial program• Some room functions combined into larger yet customizable units

•Seminar Rooms•Small Classrooms•Secretaries

• Security increases with levels• 1st Floor: Public• 2nd Floor: Semi-private• 3rd Floor: Private

• No internal stairwell

Engineering Final Iteration

Structural System Description

Classroom + Office Building:•Concrete lateral load resisting system•Concrete plate slab•Steel cantilever system

Auditorium:•Steel braced frames•Truss roof system

Moderate to high seismicity (Zone 3) Heavy snow loads

Live Loads 40psf (Classrooms) 50psf (Offices) 100psf (Storage & Hallways) Snow Load = 125psf

Dead Loads 100psf (Slab + Beams) 25psf (Floor + Partitions) 10psf (Installations)

Structural Considerations

12x18 Concrete Ring Beam

Steel Cantilever Elements

12” Shear Walls 16x16 Concrete Columns

4” Composite Slab

8” Concrete Plate Slab

Third Floor Slab& Roof Slab Second Floor Slab

Classroom & OfficeBuilding

UBC Code Seismic Reduction Factor, Rw = 12 Seismic Zone Factor, Z = 0.3 Peak Ground Acceleration , Ao = 0.3 Importance Factor, I = 1.0 Site Coefficient, S = 1.2

Building Weight = 4807 K Design Base Shear = 255 K

(in both directions)

Analysis Parameters

Analysis Results

Vibration Modes

Mode 1:T = 0.23 sec

Mode 2:T = 0.21 sec

Max Disp = 1.70” (0.4% of total height)

Limit Drift Ratio = 0.03/Rw = 0.0025Max Drift Ratio Obtained < 0.0008

DriftsWest Side Frame

Axial Force Diagram

Moment Diagram

Shear Force Diagram

M+ max = 38.47 K-ft

A max = 197.5 KV max = 23.95 K

M- max = 82.04 K-ft

M, V & Axial ForceDiagramsWest Side Frame

Wall Stresses

ShearStresses

VerticalStresses

Max Vertical Stress0.73 Ksi << F’c

Max Shear Stress0.27 Ksi << F’v

ITERATION16x16 ColumnAs required = min = 1.0% = 2.6sqin

PRELIMINARY SIZE18x18 Column:As req= min = 1.0% = 3.2sqin

Column Sizing Iteration

ITERATION12x18 Beam:As max req = 1.02sqin (0.60%)

PRELIMINARY SIZE12x20 Beam:As max req = 0.71sqin (0.35%)

Beam Sizing Iteration

Auditorium Iteration

Roof Truss SystemBraced FramesColumns

Secondary Roof Elements

Construction Final Iteration

• Mechanical excavator• Bulldozer• Dump Trucks• Tower crane• Concrete mixers

Machinery

4D Model loading…

Cost Breakdown

3%

4%

3%

12%

11%

13%2%

40%

3% 9%

Demolition

Foundations

Substructure

Superstructure

Exterior

Interior

Conveying

M&E

Special Construction

Fees

$5,350,000

$5,400,000

$5,450,000

$5,500,000

$5,550,000

$5,600,000

$5,650,000

$5,700,000

Building Cost Budget Preliminary Cost

Cost Comparison

•Insulation

•R-30 Batt for roof

•R-19 Batt for walls

•Carpets for added insulation

•Glazing

•Double pane glazing to retain heat

•Conveying

•Pneumatic vs. hydraulic elevator

Life Cycle Considerations

A-E-C Interactions

Architecturalproposal

Engineeringrationale

Solution

A-E Interaction: Cantilever System, Part 1

Preliminary Engineering Proposal

Final Solution

ArchitecturalRequirements

+ Mentor Feedback

A-E Interaction: Cantilever System, Part 2

Can we afford to lower the Auditorium?

Problem: Cost increase of earthworks by 17%

Solution: Use a site that naturally slopes and create a building that follows it.

A-C Interaction: Auditorium

Preliminary Engineering Proposal

Final Solution

Construction Requirements+ Mentor Feedback

E-C Interaction: From Frame System to Flat Slab

E-C Interaction:

•Not dependable of weather

•Minimum erection time

•More expensive

•Transportation problems

•Last moment alterations possible

•Productivity rate can be fast

•Labor intensive

Pre-cast vr Cast in-situ

Lessons Learned

• Applying theory into practice• Iteration, iteration, iteration…• Negotiation is key• When technology doesn’t work it’s

not the end of the world.• Adapt technology to suit your

needs and conditions

Lessons Learned

• Distance is not a barrier• No one is ever “always right”• Ideas often come from outside

your discipline• Mentor feedback is crucial• Trust your teammates

Lessons Learned

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