UCOP SEISMIC PERFORMANCE LEVEL...Kroeber Hall. The canopy structure does not support any cladding as...
Transcript of UCOP SEISMIC PERFORMANCE LEVEL...Kroeber Hall. The canopy structure does not support any cladding as...
Evaluator: XXX Evaluator: EGM/BL
Date: 05/11/2019
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07-15-19
ASCE 41-17 Tier 1 Seismic Evaluation
Building Name: Kroeber Hall Canopy
CAAN ID: 1486
Auxiliary Building ID: 1486.1
Address: Core Campus, Berkeley, 94720
Site location coordinates: Latitude 37.8699 o Longitudinal -122.2553 o
Plan East elevation (looking northwest)
UCOP SEISMIC PERFORMANCE LEVEL (OR “RATING”) BASED ON TIER 1 EVALUATION FINDINGS: V
BUILDING DATA
ASCE 41-17 Model Building Type (Governing Building Type bolded for Seismic Risk Model when multiple
types exist):
a. Longitudinal Direction: C1: Concrete Moment Frames
b. Transverse Direction: C1: Concrete Moment Frames
Square Footage: 1,885 (calculated)
Building Length: 116’-0” in N-S direction
Building Width: 14’-6” in E-W direction
Building Height: 11’-6” to Roof
Story Height: 11’-6”
Number of stories above grade: 1
Number of basement stories below grade: 0
Year of Original Construction and Code Year: Construction was completed in 1959. The drawings are dated
1957 (1955 UBC assumed).
Year of Later Constuction and Code Year: No retrofits, additions, or alterations
COST RANGE TO RETROFIT (if applicable): Medium: $50-$200 per square foot
Building Name: Kroeber Hall Canopy Evaluator: EGM/BL
CAAN ID: 1486.1 Date: 05/11/2019
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BUILDING DESCRIPTION
General
The Kroeber Hall Canopy is a one-story reinforced concrete canopy structure. It is located at the south
entrance of Kroeber Hall between Kroeber Hall and Boalt Hall. The canopy is rectangular in plan measuring
14’-6” in the east-west direction by 116’-0”in the north-south direction. The typical bay is 14’-6” square,
and the canopy is one bay wide by eight bays long. It contains cruciform-shaped columns that support a
pitched roof slab and gently arched concrete beams. It was constructed in 1959 at the same time as
Kroeber Hall. The canopy structure does not support any cladding as the finish surface of the members
are painted concrete.
Structural System
The Kroeber Hall Canopy is constructed from a 4 ½” thick two-way reinforced concrete slab that spans
14’-6” in each direction to reinforced concrete beams. The slab is sloped in each direction with a high
point located at the center of each bay. It is reinforced with #4 bars spaced at 18” o.c. in each direction
and on each face. Along the north elevation, a ¾” separation gap occurs between the canopy slab and the
exterior wall of Kroeber Hall. This gap occurs inside a recessed pocket located within the wall of Kroeber
Hall and is not visible from the exterior. It is unknown if a similar gap occurs along the west elevation of
the canopy as this detail is missing from the available drawings.
The beams are located around the canopy perimeter in the longitudinal direction and are spaced at 14’-6”
o.c. in the transverse direction. The top of the beam is flat, while the bottom is arched with a 36’-0” radius.
They are 10” wide and are 18” deep at the face of the column and 8 ½” deep at mid-span. They contain
2-#6 flat longitudinal bars at the top and 3-#7 curved longitudinal bars at the bottom. The shear ties
consist of two legs of open #4 ties spaced at approximately 9” o.c. The top of the beam is depressed
slightly from the top of the slab, possibly for drainage.
The canopy columns are constructed from reinforced concrete and are spaced at 14’-6” in both directions.
They have a cruciform shape with a 20” x 20” dimension from outside face to outside face. Each leg of the
cross is 10” wide x 5” deep and protrudes from a 10”x 10” square segment of concrete. They are reinforced
with 8-#6 longitudinal bars and four legs of #3 ties spaced at 8” o.c. The typical column details show the
column shear reinforcing stops at the underside of the beams. Likewise, the typical beam details show the
beam shear reinforcing stops at the face of the column. Since no alternate details are provided for the
canopy, it is assumed that the typical details were followed during construction. As such, it is possible that
the canopy beam-column joint does not contain any shear reinforcing. The columns are 11’-6” tall above
grade and extend 4’-6” below grade. The drawings indicate that the column shape may transition from a
cruciform to a square below grade. The slab-on-grade is 5” thick and is reinforced with a single layer of #4
bars spaced at 18” o.c. in each direction.
The columns are supported by a grade beams in both directions. The grade beams are 2’-6” wide x 1’-9”
deep. They contain 5-#11 longitudinal bars at the top and 2-#11 longitudinal bars at the bottom. The shear
reinforcing consists of 2 legs of #5 open ties spaced a 6” o.c. near at the face of the column and at 16” o.c.
at the mid-span. The ties are open at the bottom of the grade beam.
Building Name: Kroeber Hall Canopy Evaluator: EGM/BL
CAAN ID: 1486.1 Date: 05/11/2019
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The gravity beam and column assembly of the canopy also serves as the lateral force-resisting system by
creating a concrete moment frame in both directions. Some fixity at the base of the columns is afforded
by the grade beams which connect the column in a grid pattern.
Building Condition: Good
Date of Site Visit: 04/08/2019, Emma Meehan and Bret Lizundia, Rutherford + Chekene
Limitations of walk-through: None
SITE INFORMATION
Site Class (A-F): C Basis: Site Specific Zone Map of campus by Geomatrix
Site Specific Ground Motion Study? Yes, 2015 Update to the Site-Specific Seismic Hazard Analyses and
Development of Seismic Design Ground Motions
BSE-1N Spectral Accelerations: Basis: 2015 Update to the Site-Specific Seismic Hazard Analyses and
Development of Seismic Design Ground Motions, Table 5 for 36 ft – 75 ft Soil based on depth of rock
readings from Site Specific Zone Map of campus by Geomatrix
SDS: 2.40g SD1: 0.72g
BSE-2E Spectral Accelerations: Basis: 2015 Update to the Site-Specific Seismic Hazard Analyses and
Development of Seismic Design Ground Motions, Table 6 for 36 ft - 75 ft Soil based on depth of rock
readings from Site Specific Zone Map of campus by Geomatrix
SXS: 3.15g SX1: 1.05g
Level of Seismicity: High
Performance Level: Collapse Prevention Structural Performance
Geologic Hazards:
Fault Rupture: No Basis: CGS website http://maps.conservation.ca.gov/cgs/informationwarehouse/
Liquefaction: No Basis: CGS website http://maps.conservation.ca.gov/cgs/informationwarehouse/
Landslide: No Basis: CGS website http://maps.conservation.ca.gov/cgs/informationwarehouse/
PREVIOUS RATINGS SUMMARY
Good - 1997 Preliminary Seismic Evaluation (SAFER), Degenkolb Engineers
DOCUMENTATION
Architectural Drawings: Social Science and Arts Building University of California, Berkeley,
California, Gardner A. Dailey, F.A.I.A. and Associates – Architects, May 14, 1957, Sheets A1 to A38.
Structural Drawings: Social Science and Arts Building University of California, Berkeley, California,
H.J.Brunnier Structural Engineer, May 14, 1957, Sheets S3 to S35.
Seismic Evaluations: 1997 Preliminary Seismic Evaluation (SAFER), Degenkolb Engineers
Geotechnical Reports: None
Other Documents: None
Building Name: Kroeber Hall Canopy Evaluator: EGM/BL
CAAN ID: 1486.1 Date: 05/11/2019
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CONSTRUCTION DATA
LATERAL-FORCE-RESISTING SYSTEM
Longitudinal Transverse
ASCE 41-17 Building Type: C1: conc. moment frames C1: conc. moment frames
Diaphragms: 4.5” thick RC slab 4.5” thick RC slab
Vertical Elements: Concrete columns Concrete columns
Connections: Beam stirrups are not
closed. Beam bottom
reinforcement is bent at
ends to contribute for
positive moment at support
boundaries.
Beam stirrups are not
closed. Beam bottom
reinforcement is bent at
ends to contribute for
positive moment at support
boundaries.
Details: S5.24 for connections S5.24 for connections
Estimated Fundamental Period, T (sec): 0.16 sec 0.16 sec
BSE-2E Spectral Acceleration, Sa: 3.15g 3.15g
Modification Factor, C: 1.3
(C1: Table 4-7 in ASCE 41-17)
1.3
(C1: Table 4-7 in ASCE 41-17)
Building Weight, W (kips): 201 kips 201 kips
Seismic Base Shear, V (kips): 822 kips 822 kips
System Modification Factor, Ms: 2.0 for shear stress
2.5 for axial stress
2.0 for shear stress
2.5 for axial stress
Gravity Load Structural System: 4 ½” thick concrete two-way slab that spans to concrete beams and
columns
Exterior Transverse Walls: None – canopy of open on all
4 sides
Opening(s)? Not Applicable
Exterior Longitudinal Walls: None – canopy of open on all
4 sides
Opening(s)? Not Applicable
Roof Materials/Framing: 4 ½” thick concrete two-way slab that spans to concrete beams and
columns. Architectural drawings indicate a layer of dex-o-tex”
epoxy coating applied to roof surface.
Intermediate Floors/Framing: No intermediate floors are present.
Ground Floor: 5” reinforced concrete slab-on-grade over compacted fill
Columns: Reinforced cruciform concrete
columns
Foundation: 21” deep
foundation beam
General Condition of Structure: Good
Evidence of Settling?: No
Special Features & Comments:
Building Name: Kroeber Hall Canopy Evaluator: EGM/BL
CAAN ID: 1486.1 Date: 05/11/2019
Page 5
Significant Structural Deficiencies, Potentially Affecting Seismic Performance Level Designation:
� Lateral System Stress Check (wall shear, column shear or flexure, or brace axial as applicable)
☐ Load Path
� Adjacent Buildings
☐ Weak Story
☐ Soft Story
☐ Geometry (vertical irregularities)
☐ Torsion
☐ Mass – Vertical Irregularity
☐ Cripple Walls
☐ Wood Sills (bolting)
☐ Diaphragm Continuity
☐ Openings at Shear Walls (concrete or masonry)
☐ Liquefaction
☐ Slope Failure
☐ Surface Fault Rupture
☐ Masonry or Concrete Wall Anchorage at Flexible Diaphragm
☐ URM wall height to thickness ratio
☐ URM Parapets or Cornices
☐ URM Chimney
☐ Heavy Partitions Braced by Ceilings
☐ Appendages
OVERALL SEISMIC DEFICIENCIES & EXPECTED SEISMIC PERFORMANCE
The Kroeber Hall Canopy is a one-story reinforced concrete structure that utilizes concrete moment
frames as the lateral force-resisting system in both directions. The beams and columns are flexure
controlled and the flexural capacity of the column is larger than the flexural capacity of the beam by at
least 20%. However, the Tier 1 assessment indicates potential deficiencies including inadequate seismic
separation, inadequate column shear capacity, and a lack of beam-column reinforcing.
The Tier 1 calculations indicate that the separation between the canopy and Kroeber Hall may be
inadequate. The canopy was built close to the exterior walls of Kroeber Hall, and the two structures may
pound against each other during a seismic event. The roof of the canopy is located at the midspan of the
exterior wall and may impose out-of-plane loading on these walls.
The Tier 1 assessment also indicates that the canopy columns do not have adequate shear capacity in the
transverse direction for the loads imposed by the BSE-2E level earthquake. The calculated column shear
is 143 psi which exceeds the limit of 110 psi. This indicates that yielding of the canopy is likely. Although
the Tier 1 quick checks indicate that the likely plastic mechanism for the canopy may be flexural hinges in
the beams, Tier 1 quick checks do not explicitly examine the capacity of the beam-column joint. The
canopy does not appear to contain joint shear reinforcing, and the joint may fail prior to the formation of
beam hinges. This is a brittle failure mode and may limit the ability of the canopy to deform inelastically.
Building Name: Kroeber Hall Canopy Evaluator: EGM/BL
CAAN ID: 1486.1 Date: 05/11/2019
Page 6
Seismic Performance Level Rating
A Seismic Performance Level rating of Level V is assigned to the Kroeber Hall Canopy based on the Tier 1
evaluation, including review of the details and analytical results, because of the deficiencies identified
above, including the undersized seismic separation between the canopy and Kroeber Hall and potentially
unreinforced beam-column joints.
Recommended Next Step
A Tier 2 evaluation can be completed to compute the drift of the canopy and assess if the provided ¾”
gap is adequate and if capacity of the beam-column joint is sufficient if it is assumed that no joint
reinforcing is present. A field investigation may be completed to verify the presence of the existing ¾”
seismic separation on the north and west elevations. In addition, destructive investigation can be
completed from the top of the canopy to assess the presence of beam-column joint reinforcing.
Seismic Retrofit Concept Sketches/Description (only if above-listed rating is V or greater):
• Saw cut existing slab at the interface of the canopy and the wall of Kroeber Hall in order to enlarge
a seismic separation gap
• Alternatively, add a damper the roof of the canopy.
Appendices
A. Additional Images
B. ASCE 41-17 Tier 1 Checklists (Structural)
C. UCOP Seismic Safety Policy Falling Hazards Assessment Summary
D. Quick Check Calculations
APPENDIX A
Additional Images
Building Name: Kroeber Hall Canopy Evaluator: EMG/BL
CAAN ID: 1486.1 Date: 5/11/19
Page 2
Plan
Canopy structural roof plan
Building Name: Kroeber Hall Canopy Evaluator: EMG/BL
CAAN ID: 1486.1 Date: 5/11/19
Page 3
East elevation (looking northwest)
South elevation of Kroeber Hall (canopy to the right)
Building Name: Kroeber Hall Canopy Evaluator: EMG/BL
CAAN ID: 1486.1 Date: 5/11/19
Page 4
Articulated concrete roof framing (looking south)
Extension of canopy slab to Kroeber Hall exterior wall on canopy west
elevation
Building Name: Kroeber Hall Canopy Evaluator: EMG/BL
CAAN ID: 1486.1 Date: 5/11/19
Page 5
Extension of canopy slab to Kroebar Hall exterior wall at north elevation
of canopy
APPENDIX B
ASCE 41-17 Tier 1 Checklists (Structural)
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 1 of 3
ASCE 41-17
Collapse Prevention Basic Configuration Checklist
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
LOW SEISMICITY
BUILDING SYSTEMS - GENERAL
Description
C NC N/A U
LOAD PATH: The structure contains a complete, well-defined load path, including structural elements and connections, that
serves to transfer the inertial forces associated with the mass of all elements of the building to the foundation. (Commentary:
Sec. A.2.1.1. Tier 2: Sec. 5.4.1.1)
Comments:
C NC N/A U
Op
Op
Op
ADJACENT BUILDINGS: The clear distance between the building being evaluated and any adjacent building is greater than
0.25% of the height of the shorter building in low seismicity, 0.5% in moderate seismicity, and 1.5% in high seismicity.
(Commentary: Sec. A.2.1.2. Tier 2: Sec. 5.4.1.2)
Comments: Per Det. 2/S3, Kroeber Hall has a ¾” recess where the structure meets with the Kroeber Hall
canopy. Based upon a 11.6 ft height from the slab-on-grade to the canopy roof, a 2” gap is required.
C NC N/A U
MEZZANINES: Interior mezzanine levels are braced independently from the main structure or are anchored to the seismic-
force-resisting elements of the main structure. (Commentary: Sec. A.2.1.3. Tier 2: Sec. 5.4.1.3)
Comments: No mezzanines occur
BUILDING SYSTEMS - BUILDING CONFIGURATION
Description
C NC N/A U
WEAK STORY: The sum of the shear strengths of the seismic-force-resisting system in any story in each direction is not
less than 80% of the strength in the adjacent story above. (Commentary: Sec. A2.2.2. Tier 2: Sec. 5.4.2.1)
Comments: The canopy is one-story structure.
C NC N/A U
SOFT STORY: The stiffness of the seismic-force-resisting system in any story is not less than 70% of the seismic-force-
resisting system stiffness in an adjacent story above or less than 80% of the average seismic-force-resisting system stiffness
of the three stories above. (Commentary: Sec. A.2.2.3. Tier 2: Sec. 5.4.2.2)
Comments: The canopy is one-story structure.
C NC N/A U
VERTICAL IRREGULARITIES: All vertical elements in the seismic-force-resisting system are continuous to the foundation.
(Commentary: Sec. A.2.2.4. Tier 2: Sec. 5.4.2.3)
Comments: All columns are continuous to the foundation.
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 2 of 3
ASCE 41-17
Collapse Prevention Basic Configuration Checklist
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
C NC N/A U
GEOMETRY: There are no changes in the net horizontal dimension of the seismic-force-resisting system of more than 30%
in a story relative to adjacent stories, excluding one-story penthouses and mezzanines. (Commentary: Sec. A.2.2.5. Tier 2:
Sec. 5.4.2.4)
Comments: The structure is rectangular.
C NC N/A U
MASS: There is no change in effective mass of more than 50% from one story to the next. Light roofs, penthouses, and
mezzanines need not be considered. (Commentary: Sec. A.2.2.6. Tier 2: Sec. 5.4.2.5)
Comments: The canopy is one-story structure.
C NC N/A U
TORSION: The estimated distance between the story center of mass and the story center of rigidity is less than 20% of
the building width in either plan dimension. (Commentary: Sec. A.2.2.7. Tier 2: Sec. 5.4.2.6)
Comments: The lateral system is symmetrical.
MODERATE SEISMICITY (COMPLETE THE FOLLOWING ITEMS IN ADDITION TO THE ITEMS FOR LOW SEISMICITY)
GEOLOGIC SITE HAZARD
Description
C NC N/A U
LIQUEFACTION: Liquefaction-susceptible, saturated, loose granular soils that could jeopardize the building’s seismic
performance do not exist in the foundation soils at depths within 50 ft (15.2m) under the building. (Commentary: Sec. A.6.1.1.
Tier 2: 5.4.3.1)
Comments: Per CGS website http://maps.conservation.ca.gov/cgs/informationwarehouse/
C NC N/A U
SLOPE FAILURE: The building site is located away from potential earthquake-induced slope failures or rockfalls so that it is unaffected by such failures or is capable of accommodating any predicted movements without failure. (Commentary: Sec. A.6.1.2. Tier 2: 5.4.3.1)
Comments: Per CGS website http://maps.conservation.ca.gov/cgs/informationwarehouse/
C NC N/A U
SURFACE FAULT RUPTURE: Surface fault rupture and surface displacement at the building site are not anticipated.
(Commentary: Sec. A.6.1.3. Tier 2: 5.4.3.1)
Comments: Per CGS website http://maps.conservation.ca.gov/cgs/informationwarehouse/
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 3 of 3
ASCE 41-17
Collapse Prevention Basic Configuration Checklist
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
HIGH SEISMICITY (COMPLETE THE FOLLOWING ITEMS IN ADDITION TO THE ITEMS FOR MODERATE SEISMICITY)
FOUNDATION CONFIGURATION
Description
C NC N/A U
OVERTURNING: The ratio of the least horizontal dimension of the seismic-force-resisting system at the foundation level to the building height (base/height) is greater than 0.6Sa. (Commentary: Sec. A.6.2.1. Tier 2: Sec. 5.4.3.3)
Comments: In transverse direction B=14.5 ft, H=11.5 ft, B/H = 1.26 Sa = 3.15g for UCB at BSE-2E
0.6 x Sa = 1.89 B/H < 0.6 Sa
C NC N/A U
TIES BETWEEN FOUNDATION ELEMENTS: The foundation has ties adequate to resist seismic forces where footings, piles, and piers are not restrained by beams, slabs, or soils classified as Site Class A, B, or C. (Commentary: Sec. A.6.2.2. Tier 2: Sec. 5.4.3.4)
Comments: Soil Site Class C
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 1 of 4
ASCE 41-17
Collapse Prevention Structural Checklist For Building Type C1
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
Low Seismicity
Seismic-Force-Resisting System
Description
C NC N/A U
REDUNDANCY: The number of lines of moment frames in each principal direction is greater than or equal to 2. (Commentary: Sec. A.3.1.1.1. Tier 2: Sec. 5.5.1.1) Comments: 2 moment frames occur in longitudinal direction and 9 moment frames in transverse direction.
C NC N/A U
COLUMN AXIAL STRESS CHECK: The axial stress caused by unfactored gravity loads in columns subjected to overturning forces because of seismic demands is less than 0.20f’c. Alternatively, the axial stress caused by overturning forces alone, calculated using the Quick Check procedure of Section 4.4.3.6, is less than 0.30f’c. (Commentary: Sec. A.3.1.4.2. Tier 2: Sec. 5.5.2.1.3) Comments: Per ASCE 41-17 an assumed compressive strength of f’c = 3 ksi is used. The axial stress due to overturning forces is 0.06 ksi in the transverse direction, and 0.29 ksi in the longitudinal direction. These values are less than 0.3f’c = 0.9 ksi.
Connections
Description
C NC N/A U
CONCRETE COLUMNS: All concrete columns are doweled into the foundation with a minimum of four bars. (Commentary: Sec. A.5.3.2. Tier 2: Sec. 5.7.3.1)
Comments: Typical column details show foundation dowels that match the column bars. No alternate details are noted at the canopy columns, so it is assumed that the typical detail was followed.
Moderate Seismicity (Complete The Following Items In Addition To The Items For Low Seismicity)
Seismic-Force-Resisting System
Description
C NC N/A U
REDUNDANCY: The number of bays of moment frames in each line is greater than or equal to 2. (Commentary: Sec. A.3.1.1.1. Tier 2: Sec. 5.5.1.1) Comments: There are one-bay frames in the transverse direction and eight-bay frames in the longitudinal direction.
C NC N/A U
INTERFERING WALLS: All concrete and masonry infill walls placed in moment frames are isolated from structural elements. (Commentary: Sec. A.3.1.2.1. Tier 2: Sec. 5.5.2.1.1) Comments: No concrete and masonry infill walls occur.
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 2 of 4
ASCE 41-17
Collapse Prevention Structural Checklist For Building Type C1
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
C NC N/A U
COLUMN SHEAR STRESS CHECK: The shear stress in the concrete columns, calculated using the Quick Check procedure of Section 4.4.3.2, is less than the greater of 100 lb/in.2 (0.69 MPa) or 2√f’c. (Commentary: Sec. A.3.1.4.1. Tier 2: Sec. 5.5.2.1.4) Comments: Per ASCE 41-17 an assumed compressive strength of f’c = 3 ksi is used. The column shear stress is 0.14 ksi in the transverse direction, and 0.08 ksi in the longitudinal direction. These values are greater than 2√f'c = 0.11 ksi.
C NC N/A U
FLAT SLAB FRAMES: The seismic-force-resisting system is not a frame consisting of columns and a flat slab or plate without beams. (Commentary: Sec. A.3.1.4.3. Tier 2: Sec. 5.5.2.3.1) Comments: The moment frames are comprised of concrete beams and columns.
High Seismicity (Complete The Following Items In Addition To The Items For Low And Moderate Seismicity)
Seismic-Force-Resisting System
Description
C NC N/A U
PRESTRESSED FRAME ELEMENTS: The seismic-force-resisting frames do not include any prestressed or post-tensioned elements where the average prestress exceeds the lesser of 700 lb/in.2 (4.83 MPa) or f’c/6 at potential hinge locations. The average prestress is calculated in accordance with the Quick Check procedure of Section 4.4.3.8. (Commentary: Sec. A.3.1.4.4. Tier 2: Sec. 5.5.2.3.2) Comments: No prestressed frame elements occur.
C NC N/A U
CAPTIVE COLUMNS: There are no columns at a level with height/depth ratios less than 50% of the nominal height/depth ratio of the typical columns at that level. (Commentary: Sec. A.3.1.4.5. Tier 2: Sec. 5.5.2.3.3) Comments: All the concrete columns extend from the slab-on-grade to the canopy roof.
C NC N/A U
NO SHEAR FAILURES: The shear capacity of frame members is able to develop the moment capacity at the ends of the members. (Commentary: Sec. A.3.1.4.6. Tier 2: Sec. 5.5.2.3.4) Comments: Columns and beams are able to develop their moment capacity before shear failure occurs. For this check, moment capacity is calculated using expected material properties and the shear capacity is calculated using lower bound properties.
C NC N/A U
STRONG COLUMN—WEAK BEAM: The sum of the moment capacity of the columns is 20% greater than that of the beams at frame joints. (Commentary: Sec. A.3.1.4.7. Tier 2: Sec. 5.5.2.1.5) Comments: Using expected column and beam capacity: In longitudinal direction: Mcol > 1.2*(2*Mbeams) 131.2 k-ft > 1.2*(2*44.2 k-ft) = 106.08 k-ft, OK In transverse direction: Mcol > 1.2*Mbeams
131.2 k-ft > 1.2*(44.2 k-ft) = 53.04 k-ft, OK
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 3 of 4
ASCE 41-17
Collapse Prevention Structural Checklist For Building Type C1
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
C NC N/A U
BEAM BARS: At least two longitudinal top and two longitudinal bottom bars extend continuously throughout the length of each frame beam. At least 25% of the longitudinal bars provided at the joints for either positive or negative moment are continuous throughout the length of the members. (Commentary: A.3.1.4.8. Tier 2: Sec. 5.5.2.3.5) Comments: Two #6 bars are continuous at the top. Two #7 bars are embedded the beam-column joint at the bottom due to the geometry of the arched beam.
C NC N/A U
COLUMN-BAR SPLICES: All column-bar lap splice lengths are greater than 35db and are enclosed by ties spaced at or less than 8db. Alternatively, column bars are spliced with mechanical couplers with a capacity of at least 1.25 times the nominal yield strength of the spliced bar. (Commentary: Sec. A.3.1.4.9. Tier 2: Sec. 5.5.2.3.6) Comments: Details for the canopy columns are not explicitly shown so typical exterior column details are assumed for this check. Column bar splice length is 32db, which is less than 35db. Bar splices are enclosed by 4 ties spaced at 4” o.c. and then remaining ties are spaced at 8” o.c. The closely spaced ties do not extend ovre the entire splice length and the 8” ties spacing exceeds 8db which is 6” for #6 longitudinal bars.
C NC N/A U
BEAM-BAR SPLICES: The lap splices or mechanical couplers for longitudinal beam reinforcing are not located within lb/4 of the joints and are not located in the vicinity of potential plastic hinge locations. (Commentary: Sec. A.3.1.4.10. Tier 2: Sec. 5.5.2.3.6) Comments: Lap splices in top reinforcement occur at frame midspan.
C NC N/A U
COLUMN-TIE SPACING: Frame columns have ties spaced at or less than d/4 throughout their length and at or less than 8db at all potential plastic hinge locations. (Commentary: Sec. A.3.1.4.11. Tier 2: Sec. 5.5.2.3.7) Comments: Tie spacing is at 8” o.c. where plastic hinges are not expected to occur. This spacing is more than d/4 = 20”/4 = 5” at center. The tie spacing is at 4” o.c. for a length of 16” from the column ends, which is less than 8db = 8*0.44in = 3.52in.
C NC N/A U
STIRRUP SPACING: All beams have stirrups spaced at or less than d/2 throughout their length. At potential plastic hinge locations, stirrups are spaced at or less than the minimum of 8db or d/4. (Commentary: Sec. A.3.1.4.12. Tier 2: Sec. 5.5.2.3.7) Comments: Beams contains #4 ties at approximately 9” o.c. Considering the cross section at center: d/2 = 8.5/2 = 4.25”. NG Considering plastic hinge location: d/4 = 18”/4 = 3.91”. NG
C NC N/A U
JOINT TRANSVERSE REINFORCING: Beam–column joints have ties spaced at or less than 8db. (Commentary: Sec. A.3.1.4.13. Tier 2: Sec. 5.5.2.3.8) Comments: Per typical exterior columns details in S-11, no ties or stirrups occur in the joints.
UC Campus: Berkeley Date: 5/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: RUTHERFORD + CHEKENE
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley, 94720 Page: 4 of 4
ASCE 41-17
Collapse Prevention Structural Checklist For Building Type C1
Note: C = Compliant NC = Noncompliant N/A = Not Applicable U = Unknown
C NC N/A U
DEFLECTION COMPATIBILITY: Secondary components have the shear capacity to develop the flexural strength of the components. (Commentary: Sec. A.3.1.6.2. Tier 2: Sec. 5.5.2.5.2) Comments: All columns are part of the moment-frame system and are considered as primary elements.
C NC N/A U
FLAT SLABS: Flat slabs or plates not part of the seismic-force-resisting system have continuous bottom steel through the column joints. (Commentary: Sec. A.3.1.6.3. Tier 2: Sec. 5.5.2.5.3) Comments: Flat slab is supported by beams around its perimeter. The straight slab bottom bars are embedded into the beams.
Diaphragms
Description
C NC N/A U
DIAPHRAGM CONTINUITY: The diaphragms are not composed of split-level floors and do not have expansion joints. (Commentary: Sec. A.4.1.1. Tier 2: Sec. 5.6.1.1)
Comments:
Connections
Description
C NC N/A U
UPLIFT AT PILE CAPS: Pile caps have top reinforcement, and piles are anchored to the pile caps. (Commentary: Sec. A.5.3.8. Tier 2: Sec. 5.7.3.5)
Comments: Kroeber Hall canopy has grade beams.
APPENDIX C
UCOP Seismic Safety Policy Falling Hazards Assessment
Summary
UC Campus: Berkeley Date: 05/11/2019
Building CAAN: 1486.1 Auxiliary CAAN:
By Firm: Rutherford+Chekene
Building Name: Kroeber Hall Canopy Initials: EGM Checked: BL
Building Address: Core Campus, Berkeley 94720 Page: 1 of 1
UCOP SEISMIC SAFETY POLICY
Falling Hazard Assessment Summary
Note: P= Present, N/A = Not Applicable
Description
P N/A
Heavy ceilings, features or ornamentation above large lecture halls, auditoriums, lobbies, or other areas where large numbers of people congregate (50 ppl or more)
Comments:
P N/A
Heavy masonry or stone veneer above exit ways or public access areas
Comments:
P N/A
Unbraced masonry parapets, cornices, or other ornamentation above exit ways or public access areas
Comments:
P N/A
Unrestrained hazardous material storage
Comments:
P N/A
Masonry chimneys
Comments:
P N/A
Unrestrained natural gas-fueled equipment such as water heaters, boilers, emergency generators, etc.
Comments:
P N/A
Other:
Comments:
P N/A
Other:
Comments:
P N/A
Other:
Comments:
Falling Hazards Risk: Low
APPENDIX D
Quick Check Calculations
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Flat Load Tables
Seismic Weight Dead Load
CANOPY ROOF psf psf Remarks
Roofing + Waterproofing 0 0
Slab 64 64 4.5" sloped slab over RC beams
Girders / Joists 22 22 Concrete curved beams
Lighting, gutters, and misc. 2 2
Columns 18 0 Concrete cruciform columns
Total 106 88
1- No roofing material is present. The concrete is painted.
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Story Weight
Floor Area (ft2)
1Floor Weight (psf)
Floor LevelsCANOPY ROOF CANOPY ROOF
Total Seismic Weight
(kips)
Roof 1,885 106 201
Total Weight = 201
Notes:
1 - Canopy is a one-story structure. The seismic base is set to the slab-on-grade.
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Period
Ct= 0.018
hn (ft)= 11.50
B= 0.9
T= 0.16 sec
Notes:
1- The period calculated per ASCE 41-17 Equation 4-4.
3- The building height is taken from slab-on-grade to the roof.
2- Ct and B are for "moment-resisting frame systems of reinforced concrete" per ASCE 41-
17 Section 4.4.2.4.
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Site Parameters
Period Sa
0 1.26
0.07 3.15
0.33 3.15
0.58 1.800
0.83 1.260
1.00 1.050
1.25 0.840
1.50 0.700
1.75 0.600
2.00 0.525
2.25 0.467
2.50 0.420
2.75 0.382
3.00 0.350
3.25 0.323
SXS = 3.15 g
SX1 = 1.050 g
To = 0.07 s
Ts = 0.33 s
Sa = 3.150 g
T= 0.16 s
Notes:
2- At this site, rock is located between 36 to 75 ft below grade.
1- Site Specific spectral accelerations based upon soil type and rock profile are provided in report "2015 Update to the Site-Specific Seismic Hazard
Analyses and Development of Seismic Design Ground Motions, UC Berkeley, 15 July 2015 by URS Corporation. Procedure as specified in ASCE 7-16,
Section 21.4 is used to develop Design Response Spectrum shown above.
0
0.5
1
1.5
2
2.5
3
3.5
0 0.5 1 1.5 2 2.5 3 3.5
Sp
ect
ral A
cce
lera
tio
n (
g)
Period (sec)
BSE-2E Response Spectrum
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Seismic Force Distribution
Sa= 3.15
W= 201 kips
C= 1.3
Per ASCE 41-17
Table 4-7
V= 822 kips
k= 1.00
Floor Levels Story Height Total Height, H Weight, W W x Hk
coeff Fx Story Shear, V
(ft) (ft) (kips) (kips) (kips)
Roof 11.50 11.50 201 2,308 1.00 822 822
Grade
2,308 1 822
Notes:
1- Base of building is assumed to be at the slab-on-grade.
2- Modification Factor, C, per ASCE 41-17, Table 4-7
Per ASCE 41-17 Section 4.4.2.2, K = 1.0 for periods less than
0.5 sec and K = 2.0 for T >2.5 sec. It varies linearly in
between 0.5 sec and 2.5 sec period.
RUTHERFORD + CHEKENE TIER 1 EVALUATION
BEAMS AND COLUMNS SHEAR-CONTROLLED CHECK Calculations to estimate shear failure in beams and columns per Tier 1 Checklist for Building Type C1.
Check consists of verifying that shear capacity of frame members is able to develop the moment capacity at the ends of the members.
A typical cruciform column, a longitudinal beam, and a transverse beam were used for this analysis.
Material properties
- Concrete f'c 3 ksi Based upon Table 4-2 (ASCE 41) and building vintage
- Steel rebar fy 40 ksi Based upon Table 4-3 (ASCE 41) and building vintage
Other parameters
- Flexural ductility knl 0.7
- Normal weight λ 1.0
b (in) h (in) AG (in2) D (in) AS (in
2) D (in) AV (in
2) d' (in) dc (in) hb (in) L (ft) Ln (in) s/d acol Ln/2dc MU/VUd 6f
0.5/(M/Vd) NUG (k)
1x (ft) y (ft) Atrib (ft
2) (1+N/6Af
0.5)
0.5VS (k) VC (k) Vcol (k)
2MP=0 (k-ft)
3M (k-ft)
3 2M/L (k) Vp/Vcol
#Column C-10-1F-20X20-8#6 Column C-10 1 20 20 300 8 #6 0.75 3.5 4.0 #3 8 0.375 0.44 1.875 17.75 18.0 11.5 120.0 0.45 1.0 3.4 3.4 0.10 12 14.5 7.3 105.1 1.1 39.2 24.7 44.7 123.8 133.0 26.6 Flexure 0.59
#Beam ARB1-1F-10X12.5-# Beam ARB1 1 10 12.5 125 2.7 2.0 #4 9.5 0.4 0.25 1.9 10.60 20.0 16.2 174.0 0.90 0.4 8.2 4.0 0.08 0 14.5 7.3 105.1 1.0 4.7 8.2 9.0 44.2 44.2 6.1 Flexure 0.68
Beam ARB3 1 10 12.5 125 2.7 2.0 #4 9.1 0.4 0.25 1.9 10.60 20.0 14.5 154.0 0.86 0.6 7.3 4.0 0.08 0 14.5 7.3 105.1 1.0 6.6 8.2 10.4 44.2 44.2 6.9 Flexure 0.66
Notes:
1- Based on 1.1DL+0.275LL, which leads to higher axial load as compared to 0.9DL.
2 - Shear capacity of beams and column is based on ASCE 41-17 Eq 10-3 using nominal material strengths with φ =1.0
acol = 1.0 for s/d <= 0.75, 0.0 for s/d >=1.0
4 - Transverse reinforcement spacing assuming typical exterior column conditions.
5 - Plastic moment capacity of the column is based upon expected flexural strength using 1.5 f'c and 1.25 fy.
6 - Column cross-section
3 - The beams are arched with a deep cross-section at the beam ends and a shallow cross-section mid-span. The plastic
moment demand is computed at the beam ends and the shear capacity is computed based on the shallow cross-section
midspan.
spColumn
Model
Location
(Column or
Beam Type)
LevelSIZE LONGITUDINAL SHEAR/FLEX.
CONTROLn-# n-#-s (in)
DIMENSION CONFINEMENT FLEX. YIELD AXIAL SHEAR FLEXURETRANVERSE
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Per Section 4.4.3.6 in ASCE 41-17
nf = 9 nf = 2
V = 822 kips V = 822 kips
hn = 11.5 ft hn = 11.5 ft
L = 14.5 ft L = 14.5
Ms = 2.5 Ms = 2.5
Acol = 300.0 in2
(typical column) Acol = 300.0 ft2
(typical column)
pot = 0.06 ksi pot = 0.29 ksi
f'c = 3 ksi f'c = 3 ksi
Assumed per ASCE 41-17 Table 4-2 Assumed per ASCE 41-17 Table 4-2
0.3f'c = 0.9 ksi 0.3f'c = 0.9 ksi
Check is OK Check is OK
Column Axial Stress Check Caused by
Overturning Under 41-17 BSE-2E Site Specific
Capacity Capacity
X-direction (transverse) Y-direction (longitudinal)
Demand Demand
RUTHERFORD + CHEKENE TIER 1 EVALUATION
Per Section 4.4.3.2 in ASCE 41-17
nc = 18 nc = 18
nf = 9 nf = 2
Ac = 5758.0 in2
Ac = 5758.0 in2
V = 822 kips V = 822 kips
Ms = 2 Ms = 2
vavg
= 0.143 ksi vavg
= 0.080 ksi
f'c = 3 ksi f'c = 3 ksi
Assumed per ASCE 41-17 Table 4-2 Assumed per ASCE 41-17 Table 4-2
max of: 2x√f'c = 0.110 ksi max of: 2x√f'c = 0.110 ksi
0.1 ksi 0.1 ksi
Check is NG Check is OK
Capacity Capacity
Average Columns Shear Stress Check under
ASCE 41-17 BSE-2E Site Specific Spectra
X-direction (transverse) Y-direction (longitudinal)
Demand Demand