Revit HMSG RFI Questions Bundle 6_AE Responses 274-282.pdf

RFI # Drawing/Spec Category Question Response by Response

333302-23RF-0010010 Revitalization of the Hirshhorn Museum Sculpture Garden

REQUEST FOR INFORMATION

The Material Schedule on sheet A801 indicates that C3 Structural Concrete is to be color "beige" which is the same indication for the Architectural Concrete types C1 and C2.

Please confirm that color matching of the structural concrete to the architectural concrete is not required. Please also confirm that the color components required in the architectural concrete (C1, C2) i.e., white portland cement and color admixtures (per 033300.2.3.D and g.8) are not required for C3 Structural Concrete.

A/E

Regarding beige on A801, reference response to RFI 272.

033000 2.2.C includes both gray and white Portland cement. Where structural concrete is not required to meet color requirements, it may use gray Portland cement. As indicated in 033000 2.7.H, some elements of structural concrete classes C and D are also architectural and required to meet the color and other requirements of specfication section 033300. These elements are indicated graphically throughout the drawing set. Concrete class E for structural site concrete has similar requirements as noted in 033000 2.7.E.

Specification section 032000.2.1.D Concrete Reinforcing seems to indicate that all reinforcing steel is to be galvanized reinforcing bars (zinc coated). Since not all of the concrete is subject to F3 exposure conditions (i.e., concrete exposed to freezing-and-thawing cycles with continual exposure to water and exposure to deicing chemicals), can standard reinforcing steel (not galvanized) be used at non-exposed (F0) conditions? This would include footings and mat footings as indicated in 033000.2.7.A, B. Please advise.

A/E Provide galvanized reinforcing as required.

The notes regarding the Support of Excavation system utilizing an H pile system (i.e. E6/S401) require a cantilevered design.

The notes indicate that tiebacks are not to be used at the west, north or south sides of the site. Given that the typical vertical limitations of this type of system (+/- 12'-15' high) conflict with the need for as much as a 23' deep system (at the north), can tiebacks be permitted at the north and south sides? The notes and details also indicate temporary rakers to be used to supplement the cantilevered system, but, in many cases, the rakers would penetrate exposed architectural concrete walls, which would not result in the desired final finish. Please advise.

A/E

Refer to response of previous RFI #87. Where possible, rakers located through the heel of the perimeter wall footing are preferable.

Where rakers must penetrate the perimeter concrete wall, the visible penetration must be at least 18 inches below finish grade on the public side of the wall. The walls typically have at least 4'-6" from top of footing to finish grade so placing rakers in this depth is feasible and do not require penetrating architectural walls in their exposed portion. At the north wall, even more height between top of footing to finish grade is available as the footing steps down for the overlook cistern. Coordination of the raker locations with finish construction elements, both structural, civil, and other disciplines is required. Waterproofing at wall penetrations is required.

Specification section 329100 3.2A references sheet L-200SP for excavation and removal but it was not issued. Please provide L-

200SP.

A/E This should reference sheet L101 rather than L200SP. There is no L200SP.

Keynote 03-6.30 on S-261 details a single 20” ⌀ auger cast pile with no load specified. Please provide compression, tension, and lateral design loads for this element. Additionally, is it acceptable to substitute multiple 12” ⌀ piles for this element?

A/E Loads for this pile were given in previous RFI #47 response and added to the addendum drawings. While we are not opposed to multiple smaller piles, the pad being supported is only 5 feet square and we do not believe that with the the minimum code required edge offset plus minimum placement tolerance that even a 3 pile group would fit.

Drawings do not detail the piles having any embedment into the piles/grade beams. IBC Code 2018 Section 1810.3.11 Pile Caps states (…tops of vertical deep foundation elements shall be embedded not less than 3 inches into pile caps…) Specification Section 316316 indicates the CFA Pile Contactor shall bear sole responsibility for the design and installation of CFA piles, including pile cap connection. Please confirm that the existing slab/grade beam depths are sufficient to resist the punching shear of the pile if the pile is embedded into the foundation element.

A/E The pile may be embedded 3". The grade beams and slabs are sufficient to resist punching shear.

Keynotes 03-2.21 and 03-2.22 indicates locations of 12” ⌀ columns. Please confirm that these are locations of auger cast piles.

A/E Yes, these notes refer to auger cast piles.

Detail J2 on S-402 details a 6’ unbonded depth and a 13’ bonded pile length. What is the design intent of the unbonded length and is a bond break required between the pile and soil? If a bond break is required, please provide details on how it should be achieved.

A/E The unbonded length is due to the thick layer of uncompacted planting soil under many of the garden slabs. A specific bond break is not required.

RFI # Drawing/Spec Category Question Response by Response

333302-23RF-0010010 Revitalization of the Hirshhorn Museum Sculpture Garden

REQUEST FOR INFORMATION

In order to identify the stone materials that will be used in this project, we need photographs of the architect's samples. Please provide pictures of the following materials: Millennium Granite, Antique Asian Pink, and Kyoto Machiya Granite.

A/E All three stone materials referenced in the question are on site at the Sculpture Garden. We believe you are referring to the "Antique Asian Plank" pavers rather than "Antique Asian Pink." Refer to extant paver and seat wall mock-ups at the Sculpture Garden to illustrate material characteristics. Refer to specification article 2.2A 3a. Additional site visits can be arranged if necessary.