The Stanford University Museum of Art (MOA), now known as Cantor Center for Visual Arts, was designed by architects Percy and Hamilton and constructed in 1891. The MOA was the first major public building to utilize the then state of the art twisted steel ...

Prepared By: Quinn Peck
Occupancy: Unknown
Year Built: 1891
Height: ft
Number of stories: 2
Stories below ground: 1
Size: 130000 gsf
Original Code: None
Modification: Unknown
Year Modified: 1898-1899,
Code of Modification: None
Lateral Load System: Other
Other Load System: Interior and exterior unreinforced concrete walls.
Vertical Load System: Other
Other Vertical Load System: Unreinforced concrete load bearing walls, cast-in-place reinforced concrete beam and slab floor system.
Foundation : Other
Other Foundation : Flared basement column and walls.
Country: United States
State: California
City: Palo Alto
Street: 328 Lomita Drive, Stanford, CA 94305
Latitude: 37.433
Longitude: -122.1705


 

Stanford Museum of Art

Earthquake Information

 

 

Earthquake Date 10/17/1989
Moment Magnitude 6.9
Epicentral Distance 51
Local Intensity VII MMI
Site Description The soil at the site of the MOA is sand and gravel with a capacity between 6,000 and 9,000 psf. (Elsesser et al., 1991)
PGA Lateral None (g)
PGA Vertical None (g)
SaT
Ground motion recording stations USGS Station No. 752 (Menlo Park VA Hospital, Bldg 37)
Distance to station 4
Station Latitude 37.468
Station Longitude -112.157
Ground Motion Summary The October 17, 1898 Loma Prieta earthquake occured along the San Andreas fault near the summit of Loma Prieta Mountain at a depth of approximately 18 kilometers. Geodetic and seismic network data suggest right-lateral strike-slip and reverse movement on a northwest-striking plane dipping 70 degrees to the southwest. The rupture zone had an area of roughly 300 square kilometers. The earthquake and subsequent aftershocks filled a spatial gap in observed seismicity over the previous 20 years.

 

Damage Information

 

 

Performance summary

As in the 1906 earthquake, the Loma Prieta caused extensive damage in the Stanford Museum of Art. It was closed to the public immediately after the earthquake and remained unoccupied ten years, until it was reopened as the Iris & B. Gerald Cantor Center for Visual Arts.

Damage state description

The Loma Prieta earthquake caused major cracking throughout the unreinforced concrete walls in the main wing and severe cracking in the second floor slab of the side galleries and the vaulted ceiling over the main lobby. A number of concrete walls were cracked in a stepped pattern that mirrored the location of the construction joints and voids within the walls. Cracking was also observed around many window and door openings. The rotundas were also extensively damaged, with severe cracking in the unreinforced masonry walls. Large segments of these walls displaced from the second floor slab by up to two inches. The damage to the walls and separation from the slab left the rotundas with negligible lateral resistant and minimal gravity support.

Summary of causes of damage

1. The overall lack of reinforcing throughout the museum resulted in significant cracking, especially around wall openings and diaphragm transition zones. 2. The thick, stiff unreinforced concrete walls had a tendency to rock, leading to cracking along the construction joints. 3. The minor amount of reinforcing in the diaphragms were unable to adequately transfer the seismic forces in to the walls, resulting in diaphragm separation at various locations throughout the museum.

Observed Design and Construction Characteristics

 

Construction Quality

MaterialsNotesContribution to Damage
Concrete
Reinforcing steel Rather than the common deformed bars used today, the MOA utilized twisted square bars.

ExecutionNotesContribution to Damage
Conveyance/placement of concrete
Rebar Much of the structure was completely unreinforced, with steel only present in the floor slabs and above door jambs.
Field variance with design documents
OtherNotesContribution to Damage
Other Factors Construction Quality

Configuration

Plan IrregularitiesNotesContribution to Damage
Torsion
Perimeter boundary
Diaphragm
Out-of-plane offsets in lateral resisting system
Non-orthogonal systems

Vertical IrregularitiesNotesContribution to Damage
Soft story
Weak story
Geometric variablility of lateral resisting system
In-plane discontinuity of lateral resisting system
Mass distribution
Setback
Change in stiffness

OtherNotesContribution to Damage
Other Factors Configuration

Lateral Load Resisting System‐General

StrengthNotesContribution to Damage
Overall lack of strength

StiffnessNotesContribution to Damage
Extreme Flexibility

Load PathNotesContribution to Damage
Collectors/Struts
Anchorage of nonstructural elements
Out-of-plane capacity of walls
Diaphragm chords
Diaphragm openings

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-General

Lateral Load Resisting System‐Frames

ColumnsNotesContribution to Damage
Shear strength
Flexural strength
Axial load ratio
Vertical load columns drift capacity
Interference of frame action by infill

BeamsNotesContribution to Damage
Strength relative to columns
Shear controlled behavior
Continuity of longitudinal reinforcing
Loss of vertical capacity
Interference of frame action by infill beams

JointsNotesContribution to Damage
Interior
Exterior
Corner

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-Frames

Lateral Load Resisting System‐Shear Walls

ShearNotesContribution to Damage
Diagonal tension/compression
Sliding Shear
Flexure/shear

FlexureNotesContribution to Damage
Compression zone buckling capacity
Discontinuity of wall
Boundary reinforcing fracture/buckling
Boundary Reinforcing at openings

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting System-Shear Walls

Lateral Load Resisting System‐Infills

InfillsNotesContribution to Damage
Unreinforced
Interference with frame action
Out of plane
Attachment to framing

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting Systems-Infills

Lateral Load Resisting System‐Other

FoundationsNotesContribution to Damage
Liquefaction
Pounding
Surface Rupture

OtherNotesContribution to Damage
Pile/Pier tension capacity

MiscellaneousNotesContribution to Damage
Spread footing capacity
Other Factors Lateral Load Resisting Systems-Other-Foundations

OtherNotesContribution to Damage
Other Factors Lateral Load Resisting Systems-Other-Misc

Repair and Retrofit Information

 

 

Type of Retrofit or Repair

Improved Performance

Other Retrofit or Repair

Performance Level

Unknown

Hazard Level

Unknown

Retrofit or Repair Code

Unknown

Other Retrofit or Repair Code

Lateral Analysis

Unknown

Other Lateral Analysis

Design Strategy

The Stanford Museum of Art was retrofitted based on the observed damage patterns in both the Loma Prieta earthquake and the 1906 earthquake. The designers realized that the structure's unique structural system had a tendency to rock in discrete blocks when lateral forces were applied. In a large earthquake, the broad unreinforced concrete shear walls were expected to crack and settle into a stable rocking motion. Rather than attempting to retrofit the structure to dissipate seismic energy through inelastic deformation, the building's natural rocking motion was harnessed as the method of energy dissipation.

Retrofit Summary

The designers installed shear walls and braced frames in strategic locations that allowed the building's natural rocking behavior to dissipate seismic energy while reducing the overall damage to the structure. Collectors and chords were added throughout the building to ensure that diaphragm forces could be adequately transferred to these new lateral force-resisting elements without causing significant damage. New steel trusses were also installed in the roof diaphragm of the main gallery wings.

References

 

http://nisee.berkeley.edu/elibrary/Text/200803133
Elsesser, E., Naaseh, S., Walters, M., Sattary, V., and Whittaker, A., 2001. Repair of five historic buildings damaged by the Loma Prieta earthquake, The Seismic Retrofit of Historic Buildings Conference, San Francisco, CA


http://eqs.eeri.org/resource/1/easpef/v6/iS1/p25_s1?isAuthorized=no
Borcherdt, R. D. and Donovan, N. C., 1990. Ground Motion,Earthquake Spectra,6, Supplement, 2580.


http://db.concretecoalition.org/static/data/3-additional-ground-motion/USA004_Ground_Motion_1.jpeg
United States Geological Survey (USGS), 2009.CISN Rapid Instrumental Intensity Map for Loma Prieta Earthquake,http://earthquake.usgs.gov/earthquakes/shakemap/nc/shake/LomaPrieta/ (20 July 2012).


http://db.concretecoalition.org/static/data/6-references/USA004_Reference_4.pdf
Plafker, G., and J. Galloway, 1989. Lessons learned from the Loma Prieta, California earthquake of October 17, 1989. USGS Circular 1045, 48 pp.


http://eqs.eeri.org/resource/1/easpef/v6/iS1/p7_s1?isAuthorized=no
Borcherdt, R. D. and Donovan, N. C., 1990. Geosciences,Earthquake Spectra,6, Supplement, 724.


Poland, Chris, 2006. "Restraint, Respect, and Rehabilitate: A Tale of Three Seismic Projects at Stanford."Stanford University. Stanford, California. 17 January 2006.