HomeMy WebLinkAboutFile Documents.200 S Aspen St.0007.2017 (2).ACBK Structural Plan Review
April 4, 2017
Responses Attached in Letter from KL&A
Review/Report is based on structural Construction Documents prepared by KL & A, Inc. dated
11/09/2016 (Permit Drawings) and architectural drawings prepared by Forum PHI, dated
1/26/2017 and received via electronic transfer on 03/22/2017. Structural drawings are stamped
and signed by the engineer of record.
Project Name: 200 S. Aspen
Project Location: 200 South Aspen Street, Aspen, CO 81611
Review based on International Building Code (IBC) Edition: 2009
Building Construction Type: Building structure consists of a three level steel framed
building with a basement level. Foundation system is concrete foundation walls and footings.
Lateral system steel moment frames and concrete shear walls.
Building Department Jurisdiction: Aspen Building Department
Risk Category: IV (IBC 2015 Table 1604.5)
Basic Wind Speed: 115 mph (ultimate)
Exposure: B
Seismic Site Class: C
Importance Factor: le = 1.0
Snow Load: 75 psf uniform
Ground Snow Load: 75 psf
Importance Factor: Is = 1.0
Frost Depth: 3'-6"
Structural Review Comments:
1. Sheet S-001 Structural Design Criteria: The allowable soil bearing capacity indicated on
the drawings is 6000 psf throughout. The soils report prepared by HP Geotech
recommends a design bearing capacity of 3000 psf for footing widths less than 4'-0".
Please clarify that footings less than 4'-0" in width have been designed for the
recommended 3000 psf.
City of Aspen
Received
7/10/17
Building Department
Page 12
2. Sheets S-102, S-103 and S-104 Framing Plans: Please provide details that indicate how
the large lateral drag forces (plan note 6) will be transferred into the elevator walls.
3. Sheet S-201 Wall Elevations: It appears based on the high lateral loads shown on the
plans that additional corner reinforcement will be required to anchor the shear walls to
the foundation. Please indicate what reinforcement is required to resist these high
overturning forces.
4. Sheet S-102 Park Level Framing Plan: It appears the concrete car lift walls will provide
substantial resistance to lateral loads in the north-south direction due to their size and
length. However, no lateral loads have been noted on the plan. Please provide
calculations and details that indicate that these walls were not considered and designed
to resist lateral loads.
5. Sheet S-200 Moment Frame Elevations: Please provide completed details for the base
connections for the moment frames.
6. Sheet S-500 Foundation Details: No footing schedule was found on drawings as
indicated on the drawing plan notes. Please provide.
7. Sheet S-500 Foundation Details: Footing reinforcement is not complete. Please provide.
8. Sheet S-500 Foundation Details: Bearing pressures for eccentric footings appear to be
quite high. Please provide calculations that indicate the allowable bearing pressures
have not been exceeded.
Plan Review by:
Dan C. Donegon, P.E.
HCDA Engineering, Inc.
(719) 633-7784
ddonegon@hcdaengineering.com
Final Report Review and Local Contact:
Thomas R. Thompson, CBO and ICC Certified Plans Examiner
Sunrise Engineering
4261 Garrison Street
Wheat Ridge, Co. 80033-3023
Cell (303) 328-1546
Home (303) 422-7808 E-mail thompson@sunrise-eng.com
City of Aspen
Received
7/10/17
Building Department
,i441 KL&A, Inc.
Structural Engineers and Builders
KL&A, Inc.
1875 Lawrence Street, Suite 700
Denver, Colorado 80202
Telephone: (303) 575-9510
June 30,2017
Responses for: Structural Plan Review
Issued: April 4, 2017
Reviewer: Dan C. Donegon, PE
Project Name: 200 S Aspen
Project Address: 200 South Aspen Street
Aspen, CO 81611
KL&A Project Number: L0115
1) Sheet 5-001 Structural Design Criteria: The allowable soil bearing capacity indicated on
the drawings is 6000 psf throughout. The soils report prepared by HP Geotech
recommends a design bearing capacity of 3000 psf for footing widths less than 4'-0".
Please clarify that footings less than 4'-0" in width have been designed for the
recommended 3000 psf.
Response: All footings less than 4'-0" in width have been designed for a reduced
bearing capacity of 3000 psf. These footings occur primarily at the building entrance on
the main level along grid 1. Sheet S-001 has been modified to address the reduced
bearing capacity. See the supplemental calculation package for additional information.
2) Sheets S-102, S-103 and S-104 Framing Plans: Please provide details that indicate how
the large lateral drag forces(plan note 6) will be transferred into the elevator walls.
Response: Drag loading from wind, seismic and soil forces is being transmitted to
the concrete cores through bearing of the composite floor slab onto the ends of the wall
and shear transfer along the length of the wall. Shear from the diaphragms is transmitted
through headed studs and embeds in the face of the wall (see details 1/S-510 and 9/S-
510). At the main level drag connections were used due to high loading (see details 5,
6/S-511 and 12/S-510). See the supplemental calculation package for additional
information.
3) Sheet S-201 Wall Elevations:It appears based on the high lateral loads shown on the plans
that additional corner reinforcement will be required to anchor the shear walls to the
foundation. Please indicate what reinforcement is required to resist these high
overturning forces.
Response: Dowels will be provided into all foundation elements to match the
vertical reinforcing in the wall. These dowels will develop the forces from the walls into
the foundation. Corner reinforcement will be provided per detail 7/S-004 at all wall
intersections. Additional corner reinforcement is not required. See detail 9/S-501 for
City of Aspenitional information.
Received
7/10/17 Page 1 of 3
Building Department
11 KL&A, Inc.
.ram Structural Engineers and Builders
4) Sheet S-102 Park Level Framing Plan: It appears the concrete car lift walls will provide
substantial resistance to lateral loads in the north-south direction due to their size and
length. However, no lateral loads have been noted on the plan. Please provide
calculations and details that indicate that these walls were not considered and designed
to resist lateral loads.
Response: The vehicle lift walls were included in the lateral analysis shown in the
original calculation package. Drag loading has been added to the revised framing plans.
Where loading could not be transferred along the length of the wall, drag connections
were provided. See detail 12/S-510 and the supplemental calculation package for
additional information.
5) Sheet S-200 Moment Frame Elevations: Please provide completed details for the base
connections for the moment frames.
Response: The moment frame base plate has been included in the base plate
schedule (BP5). See the supplemental calculation package for additional information.
6) Sheet S-500 Foundation Details: No footing schedule was found on drawings as indicated
on the drawing plan notes. Please provide.
Response: Footing schedule is provided on sheet S-600. Plan notes have been
updated to reference this sheet.
7) Sheet 5-500 Foundation Details: Footing reinforcement is not complete. Please provide.
Response: See response to comment 6 above. All footing and reinforcing
information is included on sheet S-100,S-101 and in the footing schedule on sheet S-600.
8) Sheet S-500 Foundation Details: Bearing pressures for eccentric footings appear to be
quite high. Please provide calculations that indicate the allowable bearing pressures have
not been exceeded.
Response: Eccentric footing calculations were included in the original calculation
package (pages 30-44, bearing pressures shown on page 39). The maximum bearing
pressure for the eccentric footings was approximately 6000psf. The geotechnical report
allows for a 1/3 increase in bearing at eccentrically loaded foundation, therefore the
maximum bearing pressure is less than the allowable bearing pressure of 8000psf. The
stiffness/ fixity of the wall at the foundation was utilized to help distribute loading into
the footing and make the bearing more uniform.
City of Aspen
Received
7/10/17 Page 2 of 3
Building Department
f ii KL&A, Inc.
r Structural Engineers and Builders
Please let us know if you need any additional information or have any additional questions.
Sincerely,
Jeffrey L Myers, PE /,..'�p,0 I Lice-
Principal Engineer ,•oO PE �L�tijy.•c1�
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City of Aspen
Received
7/10/17 Page 3 of 3
Building Department