Contractor Inquiry Responses, California Toll Bridge Seismic Retrofit



OCTOBER 1, 1998

42) Fuse Device - Fuse Force. Plan sheet 288 of 489, design criteria #8 states the "Ffuse is 1100 kips per truss chord". Since there are four (4) dampers per truss chord, we would like confirmation that the Fuse force is equally distributed between all four (4) dampers. Is the fuse force 275 kips per damper?

The fuse force of 1100 kips shall be equally distributed between all four dampers. The fuse force shall be 275 kips per damper.

43) Damper Stroke. Plan sheet 317 of 489, design criteria #5 states that "Total Stroke = 84 inches (+/- 37 inches)". Is the stroke +/- 37 inches or +/- 42 inches.

See future new combined contract for Richmond-San Rafael Bridge.

44) In the 5th paragraph of Special Provisions Section 10-1.55 "Clean Concrete" defines high pressure water blast cleaning as a maximum 1,000 psi pressure. This pressure is not adequate for underwater cleaning. In the Richmond-San Rafael Outreach Briefing, a cleaning pressure of 10,000 psi was noted as an effective way to clean the concrete surfaces of marine growth and fowling. Should the Special Provisions be changed to a 10,000 psi pressure?

See future new combined contract for Richmond-San Rafael Bridge.

45) In order to install the 66" piling at bents 31-37 on the northern side of the bridge, a portion of the upper deck will be required to be removed and replaced. Please provide details to address this issue.

The overhead clearance restrictions for CIDH piles 33-L thru 37-L have been reviewed and no conflicts were found to prohibit the installation of the pile reinforcing. The details shown on the plans indicate areas of the CIDH piles where splices are not allowed and a required splice at the construction joint. Neither the plans nor specifications disallow the use of lap splices or butt splices outside these areas in order to place the reinforcing under low overhead conditions.

46) Sheets 243-245 (of 663) of the Contract Plans indicate that there are four interior diaphragm walls and two end diaphragm walls per precast girder section. Sheets 263 and 264 (of 663) show six interior diaphragm walls and two end diaphragm walls. Please Clarify this ambiguity.

Four interior diaphragm walls are for monolithic option and six interior diaphragm walls are for segmental option.

47) The plans and Specifications indicate that the bent caps must be precast. Can the bent caps be cast-in-place?

Bent cap shells are precast and main bent cap is cast in place. Refer to plan sheets 231-234 of 663.

48) Section 10-1.26 of the Special Provisions lists several references that are available for our review. Where can we obtain these references?

All reports refer in the special provisions are available at the Caltrans District 4 Office located at 111 Grand Avenue, Oakland, CA 94612. The Toll Bridge Duty Senior telephone number is (510) 286-5549.

49) In regards to sections 5-1.23 of the Special Provisions titled "Overhead", we would like you to respond to the following hypothetical scenarios:

a) The Specifications state that "for progress payment purposes, the number of working days to be paid for time related overhead in each monthly estimate will be the number of working days specified above to be measured for payment that the Contractor performed work on the current controlling operation or operations as Specified in Section 8-1.06, "Time of Completion" of the Standard Specifications does not apply to this Contract. Does Section 8-1.06 apply for section 5-1.23 or not? If it does not apply, will money for time related overhead be withheld if we do not work on Saturdays, Sundays, and holidays?

If the Contractor doesn't work on Sundays, Saturdays, and holidays on a current controlling operation, the Contractor will not be paid for "Overhead" for that specific day.

b) If the Contract is successfully completed ahead of schedule, will the Contractor receive the total amount (700 days) for the time related overhead bid item or will the amount be reduced to reflect the actual number of working days required to complete the contract?

If the contract is successfully completed ahead of schedule, the Contractor will receive the total bid item amount of "Overhead".

50) Section 10-1.28 Earthwork of the special provisions states "Surplus excavated material and those materials classified as "Materials With Aerially Deposited Lead" and "Contaminated and Hazardous Material" shall become the property of the Contractor and shall be disposed of outside the highway right of way in accordance with the provisions in Section 7-1.13 of the Standard Specifications."
Is Caltrans still the generator of the contaminated and/or hazardous materials?
If so, we request an addendum be issued that states Caltrans is the generator.

Caltrans as the owner of the "Surplus excavated material" is the generator. The Resident Engineer (RE) will be responsible for signing all shipping manifests.

51) My question regarding this project is about Item #16, Portable Changeable Message Signs. Pages 110 and 111 of the Special Provisions outline requirements for the communication system for the changeable message signs with which I have no problem with, except for the last sentence of the second to last paragraph of section 10-1.20. It states that all modems in the system shall use MNP-10 protocol. The system that we currently use, uses MNP-3 protocol. All of our modems are internal in standard cellular phones supplied by Motorola. My question is if Item #16 requires furnishing the complete control system, can we use MNP-3 protocol as long as the whole system is the same?, our system works very well with it. No where in the specification does it state that the control system must be compatable with another system that uses MNP-10 protocol so why MNP-10?

The portable changeable signs shall be operated with complete remote control equipment from location(s) near the job site as designated by the Engineer. All the modems in the entire changeable message sign system shall use MNP-10 protocol and be tested before being used in the field.

52) Ref. Incidental Harrassment Document form Nat'l Marine Fisheries letter 12/16/97 page 3, Item 5d (also referred to in Special Prov 5-1.29) regarding no pile installation allowed between 9pm and 7am with noise restriction of 86 db. What activities does "installing Piles" include? (Setting pile, sinking pile, driving pile, drilling, cleanout, setting rebar, concreting, etc.) There are essentially no effective lane closures allowed during the daytime to allow piledriving. We feel the referenced restrictions on pile installation are extremely restrictive and unacceptable. Please modify the documents to allow night time pile installation and driving.

The Incidental Harassment Authorization from the National Marine Fisheries Service will be revised to be in conformance with the special provisions Section 5-1.25, "Sound Control Requirements", which allows any activity to be performed between the hours of 9:00 p.m. and 7:00 a.m. that does not exceed 86 dbA at a distance of 50 feet.

53) Section 10-1.28 of the Special Provisions states that "sealed cofferdams" shall be used at Piers 62 through 77. Please clarify whether a sealed cofferdam refers to sealing the sides of the excavation only, or the sides and bottom of the excavation area.

Cofferdams shall be sealed in such a way as to meet the requirements of the special provisions.

54) Section 10-1.05 further states that "the maximum seepage rate of the sealed excavation...shall not exceed five gallons per square yard of the excavation area per eight hour period." There are a number of piers at the East Foundation that require foundation retrofit work at elevations that are within the range of tidal water, but are not specified to get a seal course slab. These piers cannot be kept dry without a seal course slab and within the seepage limits as specified above. An exception to the maximum seepage rate is required for these piers or seal course slabs should be specified. Also, if a seal course slab is added to these piers, please note that the seal slab must extend under the existing footing.

The work shall be done in accordance with the special provisions.

55) Specification Section 5-1.44 callsout that "Excavated operations outside structural excavation pay limits will be the Contractor's expense." We assume the State would be the "Generator" of this material. Please clarify.

Caltrans as the owner of the "Surplus excavated material" is the generator. The Resident Engineer (RE) will be responsible for signing all shipping manifests.

56) Specification Section 10-1.28B indicates that Type Y material will be disposed of at an approved landfill. What approval is required-State, EPA, Caltrans, etc.?

An approved landfill is one that allows disposal of the material in question.

57) The existing upper and lower deck trestle sections have been painted on the bottom and sides of the deck, girders and bent caps. Has this paint been tested for lead? If so, can we get copies of tests? Significantly higher demolition and disposal costs will be incurred if the concrete has lead paint on it.

The paint used on the trestle section of the bridge is not lead based.

58) Is the Contractor to prevent debris from entering the bay water when performing underwater concrete pier cleaning and underwater core drilling? In reviewing the project permits this is not addressed and we are assuming that no containment is necessary.

There are not requirements for containing debris resulting from underwater pier cleaning and underwater core drilling. However, the Contractor is required to describe the intended procedures for this work in the SWPPP.

59) Specification Section 10-1.28 "Earthwork below elevation 4.6 NVGD for purposes of constructing temporary site access, installing temporary platforms or work trestles will not be allowed." Permit 1-97, "The permittee is strictly prohibited from using solid fill in the Bay for construction access and work platforms purposes..." If solid fill platforms are not allowed, if underpiled work trestles are not allowed, if water depth does not allow floating plant to access the works. Please advise how Contractor is assumed to execute retrofit works on above piers?

The intent of the special provision Section 10-1.28, "Earthwork", and the BCDC permit is to not allow solid fill material (e.g. silt, sand, clay, gravel, rock) to be placed, or activities to place such material, below elevation 4.6 NGVD. Pile supported work platforms are not considered solid fill material and therefore are acceptable as stated in the BCDC permit.

60) Incidental Harrasment Authorization Permit from the National Marine Fisheries Service, states that between 9:00 P.M. and 7:00 A.M., no piles may be installed on the Bay Bridge and construction noise may not exceed 86 dBA at 50 ft.. Contract 04-043824 and 04-043844, special provision 5-1.25, "Sound Requirements," The noise level between 9:00 P.M. and 7:00 A.M., shall not exceed 86 dBA at 50 ft.. The subject of driving piles during the night is not mentioned in the contract documents. Please clarify.

The Incidental Harrasment Authorization Permit from the National Marine Fisheries Service will be revised to be in conformance with the special provisions, "Sound Control Requirements," which allows any activity to be performed between the hours of 9:00 p.m. and 7:00 a.m. that does not exceed 86 dBA at a distance of 50 feet.


61)Reference plan sheet 165 of 663. Does General Note 11 apply to any of the underwater surfaces in contact with the steel casing or precast pile cap grout or tremie concrete?

The underwater steel casing and precast pile cap are not included in this contract.

62)Reference plan sheet 327 of 663 and Section 10-1.41, "Precast Concrete Panel," of the special provisions. There is no specification to torque or tension the HS rods. Are the HS rods supposed to be torqued or tensioned? If so, to what specification?

There is no requirement of torque nor tension on these HS rods.

63)Reference plan sheet 325 of 663. The 2" diameter horizontal formed holes are not indicated to be grouted. Can the 2" diameter formed holes be filled with grout when the jacket annulus and the diaphragm cored holes are grouted?

Grout is to be used to fill the 2" diameter horizontal formed holes. Grouting procedures are specified in Section 10-1.41, "Precast Concrete Panel," of the special provisions.

Caltrans Toll Bridge Program always welcome any comments or suggestions.
Author:Yader A. Bermudez