CONTRACTOR'S INQUIRY RESPONSES
 
 

April 10, 2001
 
 

CONTRACT NO. 04-0435C4
San Francisco-Oakland Bay Bridge
WestBound Approach - Archeology and Retrofit





The responses to contractors' inquiries, unless incorporated into a formal addenda to the contract, are not a part of the contract and are provided for the contractor's convenience only. In some instances, the question and answer may represent a summary of the matters discussed rather than a word-for-word recitation. The responses may be considered along with all other information furnished to prospective bidders for the purpose of bidding on the project. The availability or use of information provided in the responses to contractors' inquiries is not to be construed in any way as a waiver of the provisions of section 2-1.03 of the Standard Specifications or any other provision of the contract, the plans, Standard Specifications or Special Provisions, nor to excuse the contractor from full compliance with those contract requirements. Bidders are cautioned that subsequent responses or contract addenda may affect or vary a response previously given, and any such subsequent response or addenda should be taken into consideration when submitting a bid for the project. Inquiries submitted within seventy-two (72 ) hours of the bid opening date might not be addressed.

The Caltrans District 4 Office is located at 111 Grand Avenue, Oakland, CA 94612. The mailing address is P.O. Box 23660, Oakland, CA 94623-0660. The Toll Bridge Program Duty Senior telephone number is (510) 286-5549, the email address for Contractor's inquiries is Duty_Senior_Tollbridge_District04@dot.ca.gov, and the fax number is (510) 286-4563. All inquiries must include the contract number.
 
 

1. Where can I get specification and plans for this Contract?
For the official paper versions of the bidders and non-bidder packages, write to the California Department of Transportation, Plans and Bid Documents, Room 0200, P.O. Box 942874, Sacramento, CA 94272-0001, telephone (916) 654-4490 or fax (916) 654-7028. Office hours are 7:30 a.m. to 4:15 p.m. When ordering bidder or non-bidder packages it is important that you include a telephone and fax number, P.O. Box and street address so that you can receive addenda.

2. On page 42 of the specifications, a maximum price of $152,000.00 is listed for bridge removal LOC A & B. This work is covered by bid items 31 & 32, is it the intent that each bid item has a maximum price of $152,000.00 or that the total of these two bid items equals $152,000.00?
Please refer to addendum 2.

3. On page 122, of the specifications it states that backfill of the top 2 feet of the archeological excavations is included in the price for roadway excavation. On page 126 of the specifications it states that the backfill of the top 2 feet of these excavations will be paid as roadway backfill. Which of these is correct? If the latter is correct then a new bid item must be added to cover this work.
Please refer to addendum 2.

4. The chart on sheet 100/166 of the plans calls out a cover of 1.5' over the existing footing for bent L-102. Field observations show the AC pavement raised up 3" above the adjacent paving over this footing indication a cover less than 1.5'. Due to the location of the existing building, our access from 4th Street will be cut off when we excavate for this footing. Is access available from 5th Street?
Access will be available from the entrance on Harrison between 4th and 5th Streets.

5. Detail "A" on sheet 131/166 of the plans shows the removal of the top of column flare for all the columns at the Transbay Transit ramps. What reinforcing steel is located in this cap and how is it to be treated? How is this work to be paid for?
The entire flared column portion below the bottom soffit shall be removed. This item of work is described as the removal of the annular column protector as described in the third paragraph in Section 10 - 1.30 Bridge Removal (Portion) of the special provisions and is paid for as Bridge Removal Portion Location A. Please refer to the as-built drawings for the location of any reinforcing steel.

6. The traffic handling plan shown on sheet 58/166 of the plans does not accommodate traffic in and out of the parking garage when construction the slab for the west turnaround, is this the intent?
The intent of the plans is that partial access into the indoor parking garage shall be maintained at all times. Due to the staging, however, not all entrances will be available.

7. With regards to the west turn around slab area, the existing slab is PCCP, how thick is this slab and is it reinforced? How is the removal of this concrete slab paid for?
It is unclear as to what the bidder means by "the existing PCCP Slab" (the upper deck slab that is being cored with a 3 1/2" diameter hole for the shear pin or the top of the existing grade beam). This question needs further clarification to answer.

8. With regards to the west turn around slab area, the drawings call for a new slab 2'-6" thick that is placed to match the existing grade. The chart shown on sheet 130/166 of the plans shows the cover over the existing grade beams to be less than 2'-6" in most cases. Does this mean that we are to remove all or in some cases part of these grade beams? Are these grade beams reinforced, please provide more details. How is this work to be paid for?
The existing grade beams and cover shall be removed to a depth of 2'-6" plus 3" to allow for construction of the new mat slab and a 3" AC overlay. Depending on the depth of cover it may mean that a large portion of the existing grade beam will be removed. It is expected that the grade beams are reinforced, please refer the bidder to the as-built drawings for expected reinforcing details. The removal of the grade beams shall be paid for as bridge removal portion location A and the limits of removal are shown in the limits of removal detail on sheet 131. The removal of the AC and soil above the existing grade beam is to be paid for as structure excavation bridge.

9. With regards to the east turn around slab area, what is the structural section of the existing slab? How is this removal paid for?
It is unclear as to what the bidder means by "existing slab". This question needs further clarification to answer.

10. With regards to the east turn around slab area, what is our access from Beale Street for this work? Can we use the driveway at the north side of the work? Do we keep the parking lot in operation during construction?
The Contractor will have access from Beale Street. The parking lot shall be closed to the public during construction work in this area.

11. With regards to the work at west turnaround columns, the existing roof overhang is supported on columns N-114 (conc seat) Q-115 (conc seat) and R-116 (angle support). What provisions are there to support roof during construction and permanently?
Please refer to addendum 2.

12. With regards to the work at west turnaround columns, should the detail for "removal of catenary grillage" apply to column N-114 and how is roof attached to this concrete?
The remove column bracket detail applies to column 114N and 115Q.  The roof will be temporarily supported and reattached during the column casing installation.  The roof will be reattached to the corbels as shown in column 114-N and column 115-Q details on sheet 133 of 166.  Please refer to addendum  2 for detail showing the existing roof.

13. With regards to the work at west turnaround columns, what is the status of the 8" c.i. line that is suspended across the column caps at columns U-114, S-114 and R-114? Can this line be shut down during the removal of these column caps & for how long?
The line cannot be shut down during construction. However, runoff may be rerouted.

14. With regards to the work at east turnaround ramp (remove bus shelters), what happens to the two existing fire lines? Do we remove the existing raised concrete pad? The description of work provided in the specifications (pg 119) appears to be written for an on grade installation; not one that is on a deck slab. How are we to leave the remaining slab after we remove the supports?
Please refer to addendum 2.

15. With regards to the work at east turnaround ramp, how is the concrete work shown on sheets 161 - 165 paid for?
Please refer to addendum 4.

16. Regarding column casings; please confirm if note 5 on sheet 132 of 166 pertains to all of the column casings on sheet 130 of 166 with the exception of columns #114N and 115Q. I have only located the thickness for casings at 114N and 115Q.
Please refer to addendum 2.

17. Please advise on how to arrange a site inspection of the inside of the Transbay Terminal?
A site tour will be conducted on February 23, 2001 at 10:00am. To reserve a space on the site tour contact the Toll Bridge Duty senior by fax or e-mail. The Toll Bridge Duty Senior fax number is (510) 286-4563 and the e-mail address is duty_senior_tollbridge_district04@dot.ca.gov.

The following is the site tour itinerary:

10:00am Meet at the Toll Bridge Field Office parking lot at 280 Beale Street, San Francisco, CA.

10:15am Begin tour of Transbay Terminal.

All tour attendees are require to have a hard hat and an orange, strong yellow-green or fluorescent colored warning vest. Caltrans will not provide these items.

18. Question # 7 that was submitted earlier concerned the existing concrete slab in the parking area that is bounded by columns N-114 - U-120 (pln sht 134/166). What is the structural section of this slab and is it reinforced? How is this paid for?
The concrete slab varies from 4" to 8" thick with minor reinforcement at some locations. See as-builts for complete details. The as-builts for the structural section in this area are available for review at the Toll Bridge Duty Senior's Office, located at 111 Grand Avenue, Oakland, CA 94612, phone number (510) 286-5549, e-mail: duty_senior_tollbridge_district04@dot.ca.gov. Requests to review the as-builts must be made with the duty senior at least 24 hours in advance. Excavation of the structural section is paid for under item 34 (Structural Excavation (Type H)).

19. Question #9 that was submitted earlier concerned the structural section of the existing asphalt parking lots located at Transbay Terminal that are to be removed. How thick is a.c.?
Please see Sheet X-1 of the project plans.

20. Are the as built drawings referred to in the answer to question #5 available for review at the Duty Senior's office in Oakland?
Yes. The as-builts are available for review at the Toll Bridge Duty Senior's Office, located at 111 Grand Avenue, Oakland, CA 94612, phone number (510) 286-5549, e-mail: duty_senior_tollbridge_district04@dot.ca.gov. Requests to review the as-builts must be made with the duty senior at least 24 hours in advance.

21. The job specifications state that the "sand bag barrier" will be included in cost of Bid Item #11 "Temporary silt fence at chain link fence," but there is a Bid item #14 with this description. Where is sand bag barrier paid for?
Please refer to addendum 2.

22. How is non hazardous structure excavation paid for?
All structure excavation on the contract is paid for under Structure Excavation (Type H).

23. How is 4" concrete curb shown on detail "B" on plan sheet 131/166 paid for and is this curb placed at all columns?
Please refer to addendum 4.

24. May we view the "Site Investigation Report" mentioned in the Special Provisions?
The "Site Investigation Report" (16 volumes plus the asbestos survey) is available for contractors to view at Department of Transportation, Toll Bridge Duty Seniorís Desk, 111 Grand Avenue, Oakland, California, (510) 286-5549, e-mail: duty_senior_tollbridge_district04@dot.ca.gov. Requests to review the reports must be made with the duty senior at least 24 hours in advance.

25. Do you have any listings or resources to provide for DVBE subcontractors in your area?
For information regarding DVBE contractors, please refer to the plans and specifications.

26. Sheet 135-136 of 166 shows slabs for the transbay terminal. Sections H-H, I-I, F-F, and E-E (Sheets 138 of 166) indicates 3" AC. Sheet 71 of 166 has table for AC indicating 399 ton and 411 ton for the west and east loops. Sheet 7-8 of 166 indicates the limits of 3" AC. The quantity and limits shown would indicate the whole area to be paved. But sections A-A, B-B, C-C, D-D, and G-G show no AC. Please clarify.
Please refer to addendum 4.

27. Sheet 137-138 of 166 sections A-A through I-I shows slabs cross sections. Some sections indicate AC, some with no AC and no PCC collars are shown either. Sheet 131 of 166, detail B, show PCC collars around columns. Does AC get placed up to columns in some locations and not other? Please clarify when and where collars are needed.
Please refer to addendum 4.

28. Sheet 98 of 166, detail B, indicates butt welding of square to round bar reinforcing. The notes indicate "mechanical butt splices may be used in lieu of butt welds." Square to round HRC couplers have been approved for use on other Caltrans projects. Are square to round HRC couplers approved for use at these locations?
HRC-XT 560 and HRC 509/571 are on the list of prequalified steel reinforcing couplers these are approved for use of 1" square to #8 & #9 round bars.

29. Sheet 132 of 166 indicates the use of polyethylene for steel casings both in the details and notes section. The detail for the class P/F column indicates that the "limits of the polyethylene to be shown on the plans". No limits are shown so is it to be assumed that no polyethylene will be required for column casings?
Please refer to addendum 2.

30. Sheet 132 of 166 indicates in the notes that casings for columns 4'-4" diameter or less must be a minimum 1/4" thick. If 1/4" casings are used the weights per item 56 do not work out. If 3/8" casings are used the weights per item 56 match. Is it the State of California's intent that all the column casings for transbay terminal to be 3/8"?
Please refer to addendum 2 and addendum 4.

31. Sheet 29 of 166 show details for the curb and gutter to be placed at Natoma St. and parking areas. No reinforcing is shown in these details. Are these items placed with no reinforcing or dowel connections?
Yes.

32. Reference project plan sheet 163 of 166 "Reinforced Concrete Enclosure Details." Plan 1 entitled "Stair and New Concrete Wall Plan," depicts a door and what appears to be louvers that are incorporated into the new work. Are the door and louvers new? Are they existing and to be salvaged and reused? What are the specifications if they are new? Please review and clarify.
Please refer to addendum 4.

33. Reference special provisions section 10-1.54 "Bridge Deck Drainage System," and project plan sheets 110 and 111 of 166 "'Deck Drain Details 1 and 2." In special provision section 10-1.54, paragraph 9 states that "all new, and existing drains disturbed by the retrofit work, are to be cleaned and painted in accordance with clean and paint of the special provisions. On project plan sheet 110 note 2 states, "Piping shall be 6" GSP (Galvanized Steel Pipe)" and note 3 states, "To weld GSP the galvanizing shall be removed where welded and respray with galvanizing paint": these same notes appear on sheet I 11. Is the drain-pipe galvanized or is it painted? Please review and clarify.
Please refer to addendum 2.

34. Reference project plan sheet 134 of 166 "Mat Slab Details NO 1" The dimension at column line 114 (top of plan) of the "West Turnaround" is shown as 4'-9 3/4". Should it be 14'-9 3/4"? Please review and clarify.
The dimension is correct as drawn.

35. Reference project plan sheet 100 and 112 of 166 "Bent Details L98-L103 and Pipe Pile Details." The table on sheet 112, titled "Pile Elevations for Impact Hammer and Vibratory Hammer (FT)," gives the bottom of existing bent footing L102 as elevation +10.5: see column titled "Bottom of Existing Footing Elev." With additional information from the table on sheet 100, "Bent Dimensional Data Table," the elevation of the existing grade is + 14.5: add "X" (existing footing depth) + "G" (soil cover) + the bottom of existing footing elevation. Knowing that the bottom of bent Ll02 is at elevation +10.5 and the depth of the new footing is 4.5 ft then the top of the new footing is at elevation +15 or 6" above finished grade. Is this correct? Since this area is a parking lot please provide new contour grading. Please review and clarify.
The elevations are correct as shown on the plans.  The footing retrofit may be finished above grade.

36. Reference project plan sheet 133 of 166 "Columns Details No. 4." The detail "Downdrain Tape Bracket Tabs" implies downdrains on the exterior of the existing columns at the Transbay Transit Terminal. Do these downdrains need to be removed, reworked and reinstalled? If so how will this work be paid for? Please review and clarify.
Bid according to the plans and specifications.

37. Specification 5-1.21, Construction paragraph, states that no seismic retrofit construction is permitted within the ASA until the investigations are complete. Is the ASA work shown in block 11 to be the last investigative area?, or can the ASA work be performed in more than one block at a time?
Block 11 is not the last investigative area. ASA work may be performed in more than one block at a time with the approval of the Engineer. Please refer to section 5.1.21-"Area of Study and Assessment" and section 10.1.01 -"Order of Work" for further clarification.

38. Please clarify the note on SC-1 which states, "Contractor may only access one stage at a time during construction operation in the area encompassing Stages 1 and 2."
The intent of the note is to have at least one of the two parking lots in Blocks 9 and Block 10 available to the public at all times.

39. Where is the AC and ballast removals and patching at the West Loop of the Trans Bay Terminal paid for?
The removal of the AC and ballast is paid for in the Core concrete (3 1/2") and bond rod.  Please refer to addendum 2.

40. Where the removal of the existing grade beams is performed for the new mat slab as shown on sheet 131 of 166, what is to be done with the existing rebar that is exposed during removal operations?
The existing reinforcing steel may be removed flush with the face of the concrete removal.  The remaining reinforcing steel will be covered by the new mat slab.

41. In reference to plan sheet 94, "Index to Plans," the last structural steel note states, "Grillage assemblies to be considered as fracture critical primary members for inspection purposes." Please define "grillage assemblies."
There are no grillage assemblies on this project.

42. The plans give the top of existing grade beam elevations but does not give new grade elevations.   We request the new grade elevations so we can determine the exact limits that the top of the existing grade beams need to be removed to accommodate the new mat slab.
There are no "new grade beam elevations."   The existing grade beams shall be chipped down where needed to make room for the new mat slab depth.

43. The "Typical Section" of a curb and overhang removal shown on Page 123 of 166 is not accurate.  There are several different types of existing overhang.  Could you please detail the different types showing the extent of removal required?
Please refer to addendum 4.

44. See sheets 137 & 138 0f 166.  Are the # 5 hoops @ 12" welded hoops or should  they be shown thus?..(croquis) Please clarify.
Please refer to addendum 4.

45. I am writing to request a meeting with you at the job site.
A site tour will be conducted on March 29, 2001 at 9:30am. To reserve a space on the site tour contact the Toll Bridge Duty senior by fax or e-mail. The Toll Bridge Duty Senior fax number is (510) 286-4563 and the e-mail address is duty_senior_tollbridge_district04@dot.ca.gov.

The following is the site tour itinerary:

9:30 AM Meet at the Toll Bridge Field Office parking lot at 280 Beale Street, San Francisco, CA.

9:40 AM Begin tour of Transbay Terminal.

All tour attendees are require to have a hard hat and an orange, strong yellow-green or fluorescent colored warning vest. Caltrans will not provide these items.

All the persons must sign the Release Responsibility Form before he or she may go on the visit site.

46. Related to "Site Investigation Report - West Approach Project, Transbay Terminal Loop, San Francisco, California June 1999", and "Addendum Site Investigation Report - West Approach Project, Bayshore Retrofit Portion, Westbound and 4th Street On-Ramp, San Francisco Oakland Bay Bridge, San Francisco, California, August 1999."  In the Tables detailing analytical results for lead I understand that the first set of figures depicts total lead, the second set of figures, if any, depicts STLC results, and the third set of figures, if any, depicts TCLP results.† This is how I read them.† Am I correct?
Yes, the first set of numbers is the total lead.  The second set of numbers, presented in parenthesis, depicts the STLC results.  The third set of numbers, presented in brackets, depicts the TCLP results.

47. Per the job walk on 3/29/01, the mechanical contractor subcontractor noticed a couple of discrepancies. First, in the scope of work we are to relocate (E) AC-2 in the east turnaround shown on sheet 152 of 166. The (E) AC-2 is not present and in its place is currently plywood. There is another (E) AC unit not shown on plans. Please clarify. Also does this scope of work include the demo of (E) exhaust fan, not shown on plans, with duct work running from the building towards the underground parking lot for the approximate length of 2 bays. Please clarify.
The Contractor should bid work as provided on the plans and bid documents.

48. On the plan sheets 152/166 (E) AC2 is shown to be relocated.  This unit is not present (there is a sheet of plywood where unit was shown.)
The Contractor should bid work as provided on the plans and bid documents.

49 On the plan sheets 152/166, the unnumbered existing AC unit shown to be is not there.
The Contractor should bid work as provided on the plans and bid documents.

50. The plans are unclear as to the status of exist exhaust fan  and its ductwork running from the building to the underground parking.  Is this equipment to be removed?
The garage duct and equipment to be removed and to remain is shown on sheets M-2 and M-9.

51. Sheet 137, # 5 hoops @ perimeter of slab.  Are they mechanical or welded spliced?  Or just lapped stirrups.
Please refer to addendum 4.