-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
1/81
Forell / Elsesser Engineers, Inc.
100th Anniversary
Earthquake ConferenceCommemorating the
1906 San Francisco Earthquake
Implementation of Base IsolationImplementation of Base Isolationin Retrofit Applicationsin Retrofit Applications
Presented bySimin Naaseh, SE, PrincipalMason Walters, SE, Principal
Forell/Elsesser Engineers, Inc.April 17th, 2006
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
2/81
Forell / Elsesser Engineers, Inc.
Impetus for Base Isolation of
Existing Buildings
Enhanced seismic protectionEnhanced seismic protection
Reduced extent ofReduced extent ofsuperstructure retrofitsuperstructure retrofit
Protection of historic fabricProtection of historic fabric
Protection of valuable contentsProtection of valuable contents
Cost advantageCost advantage
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
3/81
Forell / Elsesser Engineers, Inc.
Technical Issues Unique to
Base Isolation Retrofit
Isolation system is designedIsolation system is designedto meet certain thresholdsto meet certain thresholds
Limited existing structureLimited existing structure
capacitycapacity
Unique dynamic response ofUnique dynamic response ofthe structurethe structure
Limits on floor accelerationLimits on floor acceleration
Limits on moat dimensionLimits on moat dimension
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
4/81
Forell / Elsesser Engineers, Inc.
Base Isolation Retrofit
Planning and Design Challenges
Accommodating the isolatorAccommodating the isolatorspacespace
Accommodating the moatAccommodating the moat
Retrofitting the buildingRetrofitting the buildingappendages to accommodateappendages to accommodatefree movementfree movement
Retrofitting stairs and elevatorsRetrofitting stairs and elevatorsto accommodate largeto accommodate largedisplacementsdisplacements
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
5/81
Forell / Elsesser Engineers, Inc.
Base Isolation Retrofit
Construction Challenges
Minimize building vulnerabilityMinimize building vulnerabilityduring constructionduring construction
Minimize impact on brittleMinimize impact on brittle
elementselements
Isolator installation sequenceIsolator installation sequence
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
6/81
Forell / Elsesser Engineers, Inc.
Seismic Retrofit of San Francisco City Hall
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
7/81
Forell / Elsesser Engineers, Inc.
Historic Rotunda
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
8/81
Forell / Elsesser Engineers, Inc.
Major Earthquake Response Issues
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
9/81
Forell / Elsesser Engineers, Inc.
Fixed Base Response - Shear Walls
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
10/81
Forell / Elsesser Engineers, Inc.
Major Earthquake Response Issues
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
11/81
Forell / Elsesser Engineers, Inc.
Fixed Base Response
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
12/81
Forell / Elsesser Engineers, Inc.
Base Isolated Response
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
13/81
Forell / Elsesser Engineers, Inc.
Sequence of Construction
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
14/81
Forell / Elsesser Engineers, Inc.
New Foundation
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
15/81
Forell / Elsesser Engineers, Inc.
New Foundation
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
16/81
Forell / Elsesser Engineers, Inc.
New Foundation
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
17/81
Forell / Elsesser Engineers, Inc.
Column Jacking
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
18/81
Forell / Elsesser Engineers, Inc.
Column Cutting
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
19/81
Forell / Elsesser Engineers, Inc.
Installation of Base Isolators
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
20/81
Forell / Elsesser Engineers, Inc.
Perimeter Shoring
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
21/81
Forell / Elsesser Engineers, Inc.
Perimeter Side Beams
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
22/81
Forell / Elsesser Engineers, Inc.
Perimeter Side Beams
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
23/81
Forell / Elsesser Engineers, Inc.
Installed Isolators at Perimeter
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
24/81
Forell / Elsesser Engineers, Inc.
New Ground Floor
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
25/81
Forell / Elsesser Engineers, Inc.
New Shear Walls
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
26/81
Forell / Elsesser Engineers, Inc.
Berkeley Civic Center
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
27/81
Forell / Elsesser Engineers, Inc.
C
Isolators at Basement
Section Looking West
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
28/81
Forell / Elsesser Engineers, Inc.
C
Basement Wall / Jacking Pier
Construction Sequence
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
29/81
Forell / Elsesser Engineers, Inc.
C
Column Jacking / Isolator Installation
Construction Sequence
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
30/81
Forell / Elsesser Engineers, Inc.
Existing Condition
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
31/81
Forell / Elsesser Engineers, Inc.
Install Foundation Reinforcing
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
32/81
Forell / Elsesser Engineers, Inc.
New Foundation Built
I t ll F k f J ki Pi
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
33/81
Forell / Elsesser Engineers, Inc.
Install Formwork for Jacking Piers
Around Existing Columns
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
34/81
Forell / Elsesser Engineers, Inc.
Jacking Pier Construction
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
35/81
Forell / Elsesser Engineers, Inc.
Jacking Pier Built
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
36/81
Forell / Elsesser Engineers, Inc.
Temporary Jacks Installed
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
37/81
Forell / Elsesser Engineers, Inc.
Existing Column Cut
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
38/81
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
39/81
Forell / Elsesser Engineers, Inc.
Isolator Installed
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
40/81
Forell / Elsesser Engineers, Inc.
Isolator Installed
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
41/81
Forell / Elsesser Engineers, Inc.
Isolator Locking Plates Installed
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
42/81
Forell / Elsesser Engineers, Inc.
Steel Bracing Installed
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
43/81
Forell / Elsesser Engineers, Inc.
Locking Plates Removed
I l I ll d
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
44/81
Forell / Elsesser Engineers, Inc.
Isolators Installed
Base Isolation Response at
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
45/81
Forell / Elsesser Engineers, Inc.
Base Isolation Response at
Perimeter Wall
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
46/81
Forell / Elsesser Engineers, Inc.
Design an Construction
Problems and Solutions
Construction Problems and Solutions
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
47/81
Forell / Elsesser Engineers, Inc.
Construction Problems and Solutions
Sequence of operationsSequence of operations
Symmetry and balanceSymmetry and balance
Cutting and jackingCutting and jacking
PreloadingPreloading
Temporary lateral strengthTemporary lateral strength
Structure Types
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
48/81
Forell / Elsesser Engineers, Inc.
Structure Types
UnreinforcedUnreinforced masonry bearing wallmasonry bearing wall
Steel / masonry infillSteel / masonry infill
Reinforced concreteReinforced concrete
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
49/81
Forell / Elsesser Engineers, Inc.
Example:Unreinforced Masonry
Bearing Wall Building
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
50/81
Bearing Wall Sequence
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
51/81
Forell / Elsesser Engineers, Inc.
Bearing Wall Sequence
Bearing Wall Sequence
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
52/81
Forell / Elsesser Engineers, Inc.
Bearing Wall Sequence
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
53/81
Forell / Elsesser Engineers, Inc.
Isolator Installedat Perimeter
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
54/81
Forell / Elsesser Engineers, Inc.
Example:Steel Framed Building
with Masonry Infill
Oakland City Hall
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
55/81
Forell / Elsesser Engineers, Inc.
Oakland City Hall
Identification of Existing
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
56/81
Forell / Elsesser Engineers, Inc.
g
Building Properties
Archaic materials and infill systemsArchaic materials and infill systems
Structures Modal frequenciesStructures Modal frequencies
Forced/Ambient Vibration TestsForced/Ambient Vibration Tests
Historic DataHistoric Data
OldOld AccelerogramsAccelerograms
Masonry infill exampleMasonry infill example
Identification of Existing
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
57/81
Forell / Elsesser Engineers, Inc.
g
Building Properties
Tests of Existing MasonryTests of Existing Masonry
InIn--situ cyclic testssitu cyclic tests
Obtain shear stressObtain shear stress--strain relation, Gstrain relation, G
Obtain diagonal cracking strain,Obtain diagonal cracking strain, ggcrcr
Use G for elastic modeling of structureUse G for elastic modeling of structure
UseUse ggcrcr to determine the limits ofto determine the limits ofacceptable interacceptable inter--story driftstory drift
In-Situ Masonry Test
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
58/81
Forell / Elsesser Engineers, Inc.
In Situ Masonry Test
Stress Versus Deflection
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
59/81
Forell / Elsesser Engineers, Inc.
Stress Versus Deflection
Local Wall Model
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
60/81
Forell / Elsesser Engineers, Inc.
Local Wall Model
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
61/81
Forell / Elsesser Engineers, Inc.
ETABS Model
(Non-Linear ANSR)
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
62/81
Forell / Elsesser Engineers, Inc.
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
63/81
Forell / Elsesser Engineers, Inc.
Jacking of Existing Column
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
64/81
Forell / Elsesser Engineers, Inc.
g g
Column Cutting
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
65/81
Forell / Elsesser Engineers, Inc.
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
66/81
Forell / Elsesser Engineers, Inc.
Example:Reinforced Concrete
Frame Buildings
Pasadena City Hall
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
67/81
Forell / Elsesser Engineers, Inc.
Building Section
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
68/81
Forell / Elsesser Engineers, Inc.
Showing Load Transfer
8
3
(E) Column
7
2
59
6
1(E) Footing
(to be Removed)
1
(E) Wall
(E) Basement
Grade
1 Shoring
2 Foundation
3
4
5
6
7
8
9
(E) Wall
Moat Cover
4
Grade Beam & S.O.G. Friction Pendulum Isolator PT Threadbar(Clamping Reinforcing)
Concrete Pedestal
Temporary Shoring
PT Conc. Transfer Girder
Concrete Slab
Installation of Isolators
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
69/81
Forell / Elsesser Engineers, Inc.
Utah State Capital Building
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
70/81
Forell / Elsesser Engineers, Inc.
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
71/81
Forell / Elsesser Engineers, Inc.
OverallBasement
Plan
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
72/81
Forell / Elsesser Engineers, Inc.
Big Idea
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
73/81
Forell / Elsesser Engineers, Inc.
Rotunda base must be isolated withRotunda base must be isolated withremainder of buildingremainder of building
Main problemMain problem getting isolators beneathgetting isolators beneathrotunda footingrotunda footing
Below and Above approaches studiedBelow and Above approaches studied
Above approach safer to build, requiresAbove approach safer to build, requiresless excavationless excavation
Big Idea
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
74/81
Forell / Elsesser Engineers, Inc.
Existing concrete has relatively goodExisting concrete has relatively goodquality, strengthquality, strength
Maintain footingMaintain footing make it work as part ofmake it work as part ofnew transfer girdernew transfer girder
CompositeComposite
Allow new transfer structure to span toAllow new transfer structure to span toisolators on new foundations (fig)isolators on new foundations (fig)
New foundation can be built ahead ofNew foundation can be built ahead oftransfertransfer outside existing footingoutside existing footing
Existing Footing
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
75/81
Forell / Elsesser Engineers, Inc.
How to Achieve Composite Action and
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
76/81
Transfer Load?
Stress Girders
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
77/81
Forell / Elsesser Engineers, Inc.
How to Achieve Composite Action and
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
78/81
Forell / Elsesser Engineers, Inc.
Locate andMark PT Ducts
on Flange
Transfer Load?
Rotunda Footing
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
79/81
Forell / Elsesser Engineers, Inc.
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
80/81
Forell / Elsesser Engineers, Inc.
100th Anniversary
-
8/14/2019 100th Anniversary Earthquake Conference Commemorating the 1906
81/81
Forell / Elsesser Engineers, Inc.
Earthquake ConferenceCommemorating the
1906 San Francisco Earthquake
Implementation of Base IsolationImplementation of Base Isolation
in Retrofit Applicationsin Retrofit Applications
Presented bySimin Naaseh, SE, PrincipalMason Walters, SE, Principal
Forell/Elsesser Engineers, Inc.
April 17th
, 2006