B08_Attachment_9_RFI_Responses_0005.pdf

Solicitation 140P8525R0009 SAFR – Replace Retaining Wall

1) On page S02 note 7, there is reference to the identification symbol refencing see 16/S04, with note 7 stating new driven H piles be installed. The existing conditions appear that the dirt is up against the existing building. How close to the existing structure are the H piles supposed to be placed? Also please provide the proper spacing for the piles and a detail showing this location. It appears to be only 8’ wide or less. The detail shows 3 H beams ranging in lengths. The elevation on 16/S04 shows all the information necessary for the piles. The spacing might be just slightly more than 8ft. The location for these piles is as close as possible to the neighboring building while remaining on the project’s property.

2) In reference to the lower wall sections, on sheet G02 note 5 and S02 note 15, the existing wood lagging and wall is to be abandoned in place. Note 6 new H piles 21.5 ft tall are to be driven next to the existing 4x6 lagging. However, the existing 4x6 posts are not straight and in some places the lagging has been bulged out. In those locations how is this to be accomplished? Is there leeway given to get as close as possible or does it need to be snug against the existing posts?

Please confirm we are to not install lagging in between the new H piles. Detail 4/S04 allows leeway because the block between the pile and the existing 4x6 is not specified.

3) Once this new H Piles are driven and attached to the existing post, was consideration given during the design stage that the concrete retaining wall will need to be formed and poured in place? Detail 1/S04 does not seem to account for any type of form boards to be used. Please provide a detail takes this condition into account, or please provide details on how this is to be constructed as it could affect the space shown of 6’2 3/4” between the bocce ball court and the FOW. Detail 1/S04 clearly shows the new concrete wall being cast directly against the existing wall. Forming of the rest of the wall is means and methods and is to be performed by the contractor to achieve the intended design.

4) Please clarify the TOW elevation for the concrete wall, which currently shows 31.00’, and top of H Pile 29.00’ Both the 31.00’ and the 29.00’ are correct. No clarification is necessary.

5) The overhang structure might affect the install of the H Piles. Has the engineer verified there is enough room necessary for the equip to fit and to properly drive the piles without damaging the structure or the existing bocce ball courts? Because the type of equipment to be used is means and methods, it is up to the contractor to choose the correct equipment to avoid any adjacent structure.

6) Please provide appendices listed in “Attachment 1 – Specifications” – Appendix A Geotechnical Report, Appendix B Misc. Maps, Appendix C Title I/II Reports. The geotechnical report is attached.

7) Are we able to use Subcontractor’s past performance? Subcontractor past performance will only be considered if it correlates to the work the subcontractor will be performing on this requirement.

8) Note 9 on sheet 5 of 10 states structural backfill per Geotech Report? Has there been a Geotech report done for this project? If so, please provide. A copy of the report is attached.

9) Are we to assume the shed that is to be demolished is clean and does not contain lead or asbestos? No readily visible asbestos. Current understanding is that it was placed in 1984, so likely no lead paint is present.

10) Has the soil been tested for contamination? If not, shall we assume the soil is clean? Do we need to include analytical testing in our pricing? Typically, any soil materials that are to be off hauled will need analytical testing to confirm clean prior to haul-off and disposal. Geological boring tests were conducted by the AE in 2022, two borings. Have requested report. A copy of the geotech report is attached.

11) Please specify the type of emulsion to be used for the binder in the DG. The specifications on this are not clear and we have run into issues with some of these products where it does not bind correctly. Provide emulsion product data and sample of DG for review prior to use per specifications.

12) Please verify if the building to be demolished has concrete footings. There temporary structure on site does not qualify as a “building” per code and regulation. It is a non-occupiable temporary shed structure placed by the club that was meant to be temporary. There are no permanent in-ground footings, it is placed on wood sleepers.

Image of shed sitting on grade on wood sleepers. (NPS)

13) We were wondering when you plan to post the sign in sheet for the site visit that took place on June 10th. Posted with amendment 0002.

14) For Factor 4, Past Performance, Section L, p. 38 of 45, do we need to do past performance questionnaires, or do we just provide project information and a customer contact person, with contact information, and NPS contacts the customers as you see fit? Section M, p. 42 of 45, mentions evaluation based in part on "survey responses," but we do not see a questionnaire form.

No Past Performance Questionnaires will be provided. Information requested on pages 38 and 45 should be provided to allow for an assessment of your companies past performance to be made.

If we already have a questionnaire completed by our customer for a previous bid, can we submit that as our questionnaire? If questionnaires are provided to substantiate past performance, ensure they are relevant to the current project.

15) Please let me know if the City of San Francisco or National Park Service will be requiring permits? The work site is solely under the jurisdiction of the National Park Service. No permit process is required at this time.

16) Would the inspection be done by the City of San Francisco or National Park Service? National Park Service; inspections as are called for in the specifications.

17) Can the H beams be drilled in lieu of vibration or using pile driving method? Alternate installations are acceptable but would require engineering at the contactors expense, and would then require review by SEOR for approval.

18) Can NPS determine the size of the (10) trees to be removed? The sizes of the trees are indicated on drawing G02.

19) Can NPS determine the structural make-up of the shed to be removed? ? The shed is light framed wood construction, uninsulated. AE may supply additional information as needed to complete the conveyance of the task identified in the drawings.

20) Can NPS determine the type and depth of the shed foundation to be removed? It is a non-occupiable ad hoc shed structure that was meant to be temporary. There are no permanent in-ground footings, it is placed on wood sleepers.

21) Provide an overview of potential staging areas. Due to the large amounts of material being removed from the site, staging location is critical in determining scheduling? Staging area is identified on the plans on Van Ness Avenue. Additional staging can be made available as needed at Van Ness (parking and street areas) and/or at the lower level through negotiation with the park.

Space at the lower level is limited. If staging affects vehicle and pedestrian traffic flow, the contractor shall coordinate and provide a detour route and related signage to maintain access to the northern part of Van Ness Avenue.