20190403-SEAoSC Spruce Goose · google spruce goose pn sc repair location diagrams 5865 south...
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Transforming a historic hanger into a modern office complex Maximum length Delamination BRBFs for Building 14 BUILDING 14 BUILDING 16 BUILDING 15 Tie Horizontal Roof Truss BRBF in Longitudinal Direction BRBF in Longitudinal Direction Retrofit to repair delamination of existing arches Mechanical Core BRBF Spruce Goose Playa Vista, CA Structural Engineer: Arup Client: Google Architect: ZGF Contractor: Matt Construction We have transformed the aircraft hangars originally used by Howard Hughes for the construction of the Hercules 4 amphibious timber airplane (also known as the ‘Spruce Goose’) into modern office accommodations. The two large hangars and two smaller saddle buildings located in Playa Vista Los Angeles, CA—which stretch to a length of 740ft and a height of 75ft—were built during the Second World War and are a registered national historic building. Arup worked in collaboration with the architecture firm, ZGF, to rehabilitate and seismically upgrade the existing timber building and to create four new levels of office and film production spaces within the hangars. SEAOSC/SEAOC 2019 Excellence in Structural Engineering Awards The retrofit scheme of the existing building is summarized with the above cross section through the Hangars B14, B15, and B16. Four buckling restrained braced frame (BRBF) cores are located in the center of the spine of Building 15. As the spine build up is a designated historical part of the building, there were constraints at existing foundations due to the alignment of the structure with existing gridlines. This left only eleven 20-ft wide bays for the BRB frames. The roof diaphragm was strengthened with a horizontal steel roof truss, connecting to the BRB cores to meet current building standard seismic requirements. Multi-tier braced frames (MTBF) at the exterior east and west walls of B15 were added for additional lateral stability and work together with the BRB cores in the longitudinal direction. The isometric view (left) shows the layout of all BRBFs used in the seismic retrofit and new building seismic force resisting system. To limit and control the deformation capability requirements of the large hangars in the transverse direction, steel tie rods were added at approximately 60-ft on center. The tie rods reduced bending stresses in the glue laminated arches when the building moves away from the BRB cores and were introduced at selected arches at an elevation 53’-6” above ground. Buildings 14 and 16 are smaller side buildings and were retrofitted similarly with BRB frames along the perimeter in the longitudinal direction and at intermittent locations in the transverse direction. Digital tools were used to develop visualization templates of the analysis and design results, facilitating and accelerating the design process and permit process. Analysis results from an ETABs model of the entire existing structure were post-processed to create a stress distribution envelope of the glue laminated arches over the 38 gridlines. The final representation was one cross section, allowing for direct verification of all stresses below the capacity limit. The conceptual connection of the tie-rods to the glue laminated wood arches is shown on the left, as compared to the detail as constructed in field on the right. The pre-tensioned tie rods are a critical part of the retrofit as they significantly reduce transverse building dress and subsequently, stresses in the glue laminated arches. R E G I STERED PROFESSIONAL ENG IN E E R STATE OF CALIFORNIA S IM O N R E E S ISSUED FOR CONSTRUCTION S6.00 GOOGLE SPRUCE GOOSE GLULAM REPAIR DELAMINATION DEFINITION GUIDELINES Core & Shell #1 Permit 5 DELAMINATION ON ONE SIDE ONLY - DEPTH <1/2" AT WEB OR <1 1/2" AT FLANGE 6 DELAMINATION ON BOTH SIDES - SUM OF DEPTH <1/2" AT WEB OR <1 1/2" AT FLANGE 4 GLULAM REPAIR GENERAL GUIDELINES R E G I STERED PROFESSIONAL ENG IN E E R STATE OF CALIFORNIA S IM O N R E E S ISSUED FOR CONSTRUCTION S6.25 GOOGLE SPRUCE GOOSE REPAIR LOCATION DIAGRAMS Core & Shell #1 Permit 1 WCadj – 2OR MORE DELAMINATION ADJACENT TO EACH OTHER ANYWHERE IN THE WEB 2 WC – WEB OF WIDE FLANGE SECTION 3 WOF - INTERSECTION OF OUTER FLANGE AND WEB 7 WIF - INTERSECTION OF INNER FLANGE AND WEB (WIF) 8 IFIF - INNER FACE OF INNER FLANGE 9 IFOF - INNER FACE OF OUTER FLANGE 13 OFOF1 - OUTER FACE OF OUTER FLANGE (SCREWED FROM OUTER FLANGE) 14 OFOF2 - OUTER FACE OF OUTER FLANGE (SCREWED FROM INNER FLANGE) LEVEL 1 17' - 0" LEVEL 2 33' - 0" LEVEL 3 46' - 6" LEVEL 4 60' - 0" ROOF 73' - 0" EA EB EC ED EE EF EG EH EI EJ EK EL EM EN EO EP EQ A B C D E G H I J K PENTHOUSE 80' - 2 1/2" S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.23 6 S6.22 5 S4.64 9 S4.64 15 1" = 10'-0" S6.07 2 GLULAM REPAIR - GL E14 The existing structure consists of glue laminated wood arches considered as new technology at the time they were glued on-site in 1943. 17,000 fully- threaded screws were used to retrofit the original glue laminated arches showing signs of small to heavy delamination. Fully-threaded screws were chosen due to installation and cost efficiency, and resulted in the first time these screws were used in Los Angeles. Arup specified a condition assessment that was performed by an external timber assessment consultant. An overview of each of the delaminations per arch in elevation was used to create construction documents including retrofit details and schedules that corresponded to various delamination classifications. This allowed the contractor to measure the depth of each delamination in-field and determine the applicable retrofit detail. Due to this lightweight solution, additional costs for a gravity retrofit that would have otherwise been triggered was avoided. The erection of the 55-ft and approximately 11-ft wide multi-tier braced frames (MTBFs) required close coordination with the steel contractor. MTBFs were located directly in front of the existing sheathed shear walls to minimize visual impact that would take away from the historical nature of the building. Adjustments to anchor bolts and foundations were included in the structural design to allow for erection in a tight space due to adjacency to the existing building structure. MTBFs were not part of any building code at the time of design and Arup worked with the Los Angeles Department of Building and Safety to design and permit this frame assembly. Maximum depth
Transcript of 20190403-SEAoSC Spruce Goose · google spruce goose pn sc repair location diagrams 5865 south...
Transforming a historic hanger into a modern offi ce complex
Maximum length
Delamination
BRBFs for Building 14
BUILDING 14 BUILDING 16BUILDING 15
TieHorizontal Roof Truss
BRBF inLongitudinal Direction
BRBF inLongitudinal Direction
Retro� t to repair delamination ofexisting arches
Mechanical CoreBRBF
Spruce GoosePlaya Vista, CA
Structural Engineer: ArupClient: GoogleArchitect: ZGFContractor: Matt Construction
We have transformed the aircraft hangars originally used by Howard Hughes for the construction of the Hercules 4 amphibious timber airplane (also known as the ‘Spruce Goose’) into modern offi ce accommodations. The two large hangars and two smaller saddle buildings located in Playa Vista Los Angeles, CA—which stretch to a length of 740ft and a height of 75ft—were built during the Second World War and are a registered national historic building.Arup worked in collaboration with the architecture fi rm, ZGF, to rehabilitate and seismically upgrade the existing timber building and to create four new levels of offi ce and fi lm production spaces within the hangars.
SEAOSC/SEAOC 2019 Excellence in Structural Engineering Awards
The retrofi t scheme of the existing building is summarized with the above cross section through the Hangars B14, B15, and B16. Four buckling restrained braced frame (BRBF) cores are located in the center of the spine of Building 15. As the spine build up is a designated historical part of the building, there were constraints at existing foundations due to the alignment of the structure with existing gridlines. This left only eleven 20-ft wide bays for the BRB frames. The roof diaphragm was strengthened with a horizontal steel roof truss, connecting to the BRB cores to meet current building standard seismic requirements. Multi-tier braced frames (MTBF) at the exterior east and west walls of B15 were added for additional lateral stability and work together with the BRB cores in the longitudinal direction.
The isometric view (left) shows the layout of all BRBFs used in the seismic retrofi t and new building seismic force resisting system. To limit and control the deformation capability requirements of the large hangars in the transverse direction, steel tie rods were added at approximately 60-ft on center. The tie rods reduced bending stresses in the glue laminated arches when the building moves away from the BRB cores and were introduced at selected arches at an elevation 53’-6” above ground. Buildings 14 and 16 are smaller side buildings and were retrofi tted similarly with BRB frames along the perimeter in the longitudinal direction and at intermittent locations in the transverse direction.
Digital tools were used to develop visualization templates of the analysis and design results, facilitating and accelerating the design process and permit process. Analysis results from an ETABs model of the entire existing structure were post-processed to create a stress distribution envelope of the glue laminated arches over the 38 gridlines. The fi nal representation was one cross section, allowing for direct verifi cation of all stresses below the capacity limit.
The conceptual connection of the tie-rods to the glue laminated wood arches is shown on the left, as compared to the detail as constructed in fi eld on the right. The pre-tensioned tie rods are a critical part of the retrofi t as they signifi cantly reduce transverse building dress and subsequently, stresses in the glue laminated arches.
1/2" MAX
1 1/2" MAX
NO LENGTH LIMIT
NO LENGTH LIMIT
NO LENGTH LIMIT
NO LENGTH LIMIT
La
Lb
6"6"
12" T
ALL Z
ONE
ON O
PPOS
ITE
SIDE
OF
WEB
La + Lb <1/2" MAX
Ld
Lc
ON OPPOSITESIDE OF FLANGE
Lc + Ld <1 1/2" MAX
WITHIN ANY 48"
WITHIN ANY 48"
>1/2" UP TO FULL DEPTH
1 1/2" UP TO FULL DEPTH
12" MAX
12" MAX
WITHIN ANY 48"
WITHIN ANY 48"
>1/2" UP TO FULL DEPTH
1 1/2" UP TO FULL DEPTH
L2
L2
L1
L1 L1 + L2 < 12" MAX
GENERAL GLULAM REPAIR GUIDELINES FOR BUILDING 15 (GL E1-E38/A-K)
1. GLULAM REPAIR DETAILS IN THE S6 SERIES DEFINE 5 REGIONS FOR THE GLULAM ARCHES (SEE DETAIL 4/S6.23). EACH REGION IS RELATED TO TYPICAL REPAIR DETAILSSHOWN IN THE DRAWING SET.
2. ALL DELAMINATIONS SHALL BE REPAIRED PER THE TYPICAL DETAILS BASED ON REGION AND LOCATION OF DELAMINATION EXCEPT FOR THE FOLLWING CONDITIONS.THE CONTRACTOR SHALL ESTABLISH IN FIELD IF A DELAMINATION REQUIRES REPAIR OR NOT BASED ON THE FOLLOWING GUIDELINES IN CONNECTION WITH DETAILS 5,6, 11, 12 ON SHEET S6.00. CONTACT SEOR FOR CLARIFICATION IF FIELD CONDITION CANNOT BE CATEGORIZED ACCORIDNG TO THE PRE-DEFINED DELAMINATIONSTYPES IN THIS DOCUMENT.
2.1. DELAMINATIONS IN THE WEB OF THE GLULAM ARCHES
2.1.1. NO REPAIR REQUIRED FOR DELAMINATIONS LESS THAN 0.5” IN DEPTH ON ONE SIDE OF THE WEB (MEASURED ACROSS THE THICKNESS OF THE GLULAM ARCH), SEEDETAIL 5/S6.00.
2.1.2. NO REPAIR REQUIRED FOR DELAMINATIONS SIMILAR TO 2.1.1 WHERE THE 0.5” DEPTH CAN CONSIST OF EITHER 0.5” ON ONE SIDE ONLY OR THE SUM OF TWODELAMINATIONS ON BOTH SIDES OF THE WEB, SEE DETAIL 6/S6.00.
2.1.3. NO REPAIR REQUIRED FOR DELAMINATIONS MORE THAN 0.5” IN DEPTH BUT LESS THAN 12” IN LENGTH ALONG THE GLULAM ARCH WITHIN ANY 48”, SEE DETAIL 11/S6.00.
2.2. DELAMINATIONS IN THE FLANGE OF THE GLULAM ARCHES
2.2.1. NO REPAIR REQUIRED FOR DELAMINATIONS LESS THAN 1.5” IN DEPTH ON ONE SIDE OF THE FLANGE (MEASURED ACROSS THE THICKNESS OF THE GLULAM ARCH), SEEDETAIL 5/S6.00.
2.2.2. NO REPAIR REQUIRED FOR DELAMINATIONS SIMILAR TO 2.2.1 WHERE THE 1.5” DEPTH CAN CONSIST OF EITHER 0.5” ON ONE SIDE ONLY OR THE SUM OF TWODELAMINATIONS ON BOTH SIDES OF THE WEB, SEE DETAIL 6/S6.00.
2.2.3. NO REPAIR REQUIRED FOR DELAMINATIONS MORE THAN 1.5” IN DEPTH BUT LESS THAN 12” IN LENGTH ALONG THE GLULAM ARCH WITHIN ANY 48”, SEE DETAIL 11/S6.00.
3. WITH REFERENCE TO THE MEMO "COMMENTS ON DELAMINATIONS IDENTIFIED IN THE REPORT ON WOOD CONDITION ASSESSMENT, CARGO BUILDING COMPLEX, PLAYAVISTA" FROM RON ANTHONY ASSOCIATES DATED MARCH 19, 2017 THE DEPTH OF THE DELAMINATION SHALL BE MEASURED BY THE CONTRACTOR USING A 0.025 INCHGAUGE, FOR EXAMPLE A SPARK PLUG GAP INDICATOR.
4. THE STRUCTURAL REPAIR DETAILS AND LOCATIONS OF GLULAM DELAMINATIONS SHOWN IN THE ARUP STRUCTURAL DRAWINGS ARE TAKEN FROM THE WOODASSESSMENT REPORT BY RON ANTHONY ASSOCIATES FROM MAY 6TH 2016. ARUP HAS RELIED ON THE ACCURACY OF THE INFORMATION IN THIS EXPERT REPORT FORESTABLISHING THESE REPAIR GUIDELINES AND DESIGNING STRUCTURAL REPAIR DETAILS.
REG I
S TERE
D PROFESS I ONA L ENG INEER
S T A T E O F C A L I F O RN I A
S I MON REESS4897
Exp.
S T R U C T U R A
L
9/30/2018
515 South Flower StreetSuite 3700Los Angeles, CA 90071T 213 617 1901F 213 617 0047www.zgf.com
Drawing No.
Date:
Job No:
Checked By:
Drawn By:
Drawing Title
Revisions
Consultants
CIVIL, STRUCTURAL, MEP,ACOUSTICS, LIGHTINGARUP12777 West Jefferson Blvd., Bldg. DLos Angeles, CA 90066T 310-578-4400
Stamp
Key Plan
LANDSCAPE ARCHITECTTOM LEADER STUDIO1015 Camelia StreetBerkeley, CA 94710T 510-524-3363
ISSUED FOR CONSTRUCTION
11/2
0/20
17 1
0:16
:26
AM
4.10.2017
239941
S6.00
GOOGLE SPRUCEGOOSE
PN
SC
GLULAM REPAIRDELAMINATIONDEFINITIONGUIDELINES
5865 South Campus Center DriveLos Angeles, CA, 90094
Core & Shell #1Permit
1 1/2" = 1'-0"S6.005 DELAMINATION ON ONE SIDE ONLY - DEPTH <1/2" AT WEB OR <1 1/2" AT FLANGE
1 1/2" = 1'-0"S6.006 DELAMINATION ON BOTH SIDES - SUM OF DEPTH <1/2" AT WEB OR <1 1/2" AT FLANGE
1 1/2" = 1'-0"S6.0011 ONE DELAMINATION ON ONE SIDE - DEPTH >1/2" AT WEB OR >1 1/2" AT FLANGE
1 1/2" = 1'-0"S6.0012 MORE THAN ONE DELAMINATION ON ONE SIDE - DEPTH >1/2" AT WEB OR >1 1/2" AT
FLANGE
12" = 1'-0"S6.004 GLULAM REPAIR GENERAL GUIDELINES
Rev Date Description
31 04.10.2017 Revision #3 – Core & Shell
WCadj -2 OR MORE DELAMINATIONADJACET TO EACH OTHERANYWHERE IN THE WEB
0
WC -DELAMINATION ANYWHEREIN THE WEB0
WOF -DELAMINATION ATINTERSECTION BETWEENOUTER FLANGE AND WEB
WIF -DELAMINATION AT INTERSECTIONBETWEEN INNER FLANGE AND WEB
IFIF -INNER FACE OF INNER FLANGE
IFOF -INNER FACE OF OUTER FLANGE
OFOF1 -OUTER FACE OF OUTERFLANGE
SCREW DIRECTION -SCREWED FROM OUTER FLANGE
OFOF2 -OUTER FACE OF OUTER FLANGE
SCREW DIRECTION -SCREWED FROM INNER FLANGE
REG I
S TERE
D PROFESS I ONA L ENG INEER
S T A T E O F C A L I F O RN I A
S I MON REESS4897
Exp.
S T R U C T U R A
L
9/30/2018
515 South Flower StreetSuite 3700Los Angeles, CA 90071T 213 617 1901F 213 617 0047www.zgf.com
Drawing No.
Date:
Job No:
Checked By:
Drawn By:
Drawing Title
Revisions
Consultants
CIVIL, STRUCTURAL, MEP,ACOUSTICS, LIGHTINGARUP12777 West Jefferson Blvd., Bldg. DLos Angeles, CA 90066T 310-578-4400
Stamp
Key Plan
LANDSCAPE ARCHITECTTOM LEADER STUDIO1015 Camelia StreetBerkeley, CA 94710T 510-524-3363
ISSUED FOR CONSTRUCTION
11/2
0/20
17 1
0:19
:15
AM
4.10.2017
239941
S6.25
GOOGLE SPRUCEGOOSE
PN
SC
REPAIR LOCATIONDIAGRAMS
5865 South Campus Center DriveLos Angeles, CA, 90094
Core & Shell #1Permit
1" = 1'-0"S6.251 WCadj – 2OR MORE DELAMINATION ADJACENT TO EACH OTHER
ANYWHERE IN THE WEB
1" = 1'-0"S6.252 WC – WEB OF WIDE FLANGE SECTION
1" = 1'-0"S6.253 WOF - INTERSECTION OF OUTER FLANGE AND WEB
1" = 1'-0"S6.257 WIF - INTERSECTION OF INNER FLANGE AND WEB (WIF)
1" = 1'-0"S6.258 IFIF - INNER FACE OF INNER FLANGE
1" = 1'-0"S6.259 IFOF - INNER FACE OF OUTER FLANGE
1" = 1'-0"S6.2513 OFOF1 - OUTER FACE OF OUTER FLANGE (SCREWED FROM OUTER
FLANGE)
1" = 1'-0"S6.2514 OFOF2 - OUTER FACE OF OUTER FLANGE (SCREWED FROM INNER
FLANGE)
Rev Date Description
31 04.10.2017 Revision #3 – Core & Shell
LEVEL 117' - 0"
LEVEL 233' - 0"
LEVEL 346' - 6"
LEVEL 460' - 0"
ROOF73' - 0"
EA EB EC ED EE EF EG EH EI EJ EK EL EM EN EO EP EQA B C D E G H I J K
PENTHOUSE80' - 2 1/2"
S6.236
S6.2312
S6.236
S6.245
S6.236
S6.236
S6.236
S6.225
S6.226
S4.649
S4.6415
LEVEL 117' - 0"
LEVEL 233' - 0"
LEVEL 346' - 6"
LEVEL 460' - 0"
ROOF73' - 0"
EA EB EC ED EE EF EG EH EI EJ EK EL EM EN EO EP EQA B C D E G H I J K
PENTHOUSE80' - 2 1/2"
S6.236
S6.236
S6.236
S6.236
S6.236
S6.236
S6.236
S6.236
S6.236
S6.236
S6.225
S4.649
S4.6415
NOTES:
1. REPLACE ALL TERMITE AFFECTED ROOF AND WALL SHEATHING.2. BOARD SIZE, GRADE AND NAILING TO MATCH EXISTING CONDITION. MINIMUM REQUIRED PER AS BUILT DRAWINGS FOR ROOF: 2x6 DFL STRUCTURAL NO 1 WITH 3x16d NAILS AT ENDS OF BOARDS AND 2x16d NAILS AT INTERMEDIATE CONNECTIONS.MINIMUM REQUIRED PER AS BUILT DRAWINGS FOR WALLS: 1x6 DFL STRUCTURAL NO 1 TONGUE AND GROOVE WITH 3x8d NAILS AT ENDS OF BOARDS AND 2x8d NAILS AT INTERMEDIATE CONNECTIONS.3. EXTENT OF BOTH TERMITE DAMAGE AND DECAY SHOWN ON EXISTING ROOF PLAN AND GLULAM REPAIR SECTIONS IS PER THE WOOD CONDITION ASSESSMENT REPORT BY ANTHONY & ASSOCIATES, INC, DATED MAY 6, 2016.
REG I
S TERE
D PROFESS I ONA L ENG INEER
S T A T E O F C A L I F O RN I A
S I MON REESS4897
Exp.
S T R U C T U R A
L
9/30/2018
515 South Flower StreetSuite 3700Los Angeles, CA 90071T 213 617 1901F 213 617 0047www.zgf.com
Drawing No.
Date:
Job No:
Checked By:
Drawn By:
Drawing Title
Revisions
Consultants
CIVIL, STRUCTURAL, MEP,ACOUSTICS, LIGHTINGARUP12777 West Jefferson Blvd., Bldg. DLos Angeles, CA 90066T 310-578-4400
Stamp
Key Plan
LANDSCAPE ARCHITECTTOM LEADER STUDIO1015 Camelia StreetBerkeley, CA 94710T 510-524-3363
ISSUED FOR CONSTRUCTION
11/2
0/20
17 1
0:17
:16
AM
12.07.2016
239941
S6.07
GOOGLE SPRUCEGOOSE
JS
SC
GLULAM REPAIRSECTIONS SHEET 7
5865 South Campus Center DriveLos Angeles, CA, 90094
Core & Shell #1Permit
1" = 10'-0"S6.071 GLULAM REPAIR - GL E13
1" = 10'-0"S6.072 GLULAM REPAIR - GL E14
Rev Date Description
10 12.07.2016 Addendum #1 - Core &Shell
28 03.8.2017 Addendum #1 Rev. 1 - Core& Shell Permit
31 04.10.2017 Revision #3 – Core & Shell
The existing structure consists of glue laminated wood arches considered as new technology at the time they were glued on-site in 1943. 17,000 fully-threaded screws were used to retrofi t the original glue laminated arches showing signs of small to heavy delamination. Fully-threaded screws were chosen due to installation and cost effi ciency, and resulted in the fi rst time these screws were used in Los Angeles. Arup specifi ed a condition assessment that was performed by an external timber assessment consultant. An overview of each of the delaminations per arch in elevation was used to create construction documents including retrofi t details and schedules that corresponded to various delamination classifi cations. This allowed the contractor to measure the depth of each delamination in-fi eld and determine the applicable retrofi t detail. Due to this lightweight solution, additional costs for a gravity retrofi t that would have otherwise been triggered was avoided.
The erection of the 55-ft and approximately 11-ft wide multi-tier braced frames (MTBFs) required close coordination with the steel contractor. MTBFs were located directly in front of the existing sheathed shear walls to minimize visual impact that would take away from the historical nature of the building. Adjustments to anchor bolts and foundations were included in the structural design to allow for erection in a tight space due to adjacency to the existing building structure. MTBFs were not part of any building code at the time of design and Arup worked with the Los Angeles Department of Building and Safety to design and permit this frame assembly.
Maximum depth
