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

Today’s Outline The Project Project Requirements Owner Requirements Architectural Context Site Context Alternatives Preferred Alternative A-E-C Solutions A-E-C Interactions Lessons Learned

The Project Year 2010 Lake Tahoe area Rebuild 3-story educational building Ridge University Engineering School

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

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

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

Site Context Boundary conditions Geological features Local weather conditions Climate Zone 16 Local working week

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: 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: 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: Construction Cost: $5,600,000

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: Construction Cost: $5,700,000

Preferred Solution: Alternative 4 Owner’s preference 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 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 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

Structural Considerations 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)

Classroom & Office Building Third Floor Slab & Roof Slab Second Floor Slab 12x18 Concrete Ring Beam 12” Shear Walls 16x16 Concrete Columns 8” Concrete Plate Slab 4” Composite Slab Steel Cantilever Elements

Analysis Parameters Analysis Results 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 Analysis Results Building Weight = 4807 K Design Base Shear = 255 K (in both directions)

Vibration Modes Mode 1: T = 0.23 sec Mode 2: T = 0.21 sec

Drifts West Side Frame Max Disp = 1.70” (0.4% of total height) Limit Drift Ratio = 0.03/Rw = 0.0025 Max Drift Ratio Obtained < 0.0008

M, V & Axial Force Diagrams West Side Frame Moment Diagram M, V & Axial Force Diagrams West Side Frame M- max = 82.04 K-ft M+ max = 38.47 K-ft Shear Force Diagram Axial Force Diagram V max = 23.95 K A max = 197.5 K

Wall Stresses Vertical Stresses Shear Stresses Max Vertical Stress 0.73 Ksi << F’c Max Shear Stress 0.27 Ksi << F’v

Column Sizing Iteration PRELIMINARY SIZE 18x18 Column: As req= min = 1.0% = 3.2sqin ITERATION 16x16 Column As required = min = 1.0% = 2.6sqin

Beam Sizing Iteration PRELIMINARY SIZE 12x20 Beam: As max req = 0.71sqin (0.35%) ITERATION 12x18 Beam: As max req = 1.02sqin (0.60%)

Auditorium Iteration Columns Braced Frames Roof Truss System Secondary Roof Elements

Construction Final Iteration

Machinery Mechanical excavator Bulldozer Dump Trucks Tower crane Concrete mixers

4D Model loading…

Cost Breakdown

Cost Comparison

Life Cycle Considerations 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

A-E-C Interactions

A-E Interaction: Cantilever System, Part 1 Architectural proposal Engineering rationale Solution

Preliminary Engineering A-E Interaction: Cantilever System, Part 2 Architectural Requirements + Mentor Feedback Preliminary Engineering Proposal Final Solution

A-C Interaction: Auditorium 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.

Preliminary Engineering E-C Interaction: From Frame System to Flat Slab Construction Requirements + Mentor Feedback Preliminary Engineering Proposal Final Solution

Pre-cast vs Cast in-situ E-C Interaction: Pre-cast vs Cast in-situ Not dependent on weather Minimum erection time More expensive Transportation problems Last moment alterations possible Productivity rate can be fast Labor intensive

Lessons Learned

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

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