CONTRACT NO. 04-0436V4


CONTRACTOR'S INQUIRY RESPONSES NO. 1

MAY 11,1998

BID SUMMARY RESULTS
MORRISON KNUDSEN TRAYLOR BROS $ 102,436,598.00, AWARDED ON NOV 13, 1997
TUTOR SALIBA KOCH DUTRA JV $ 113,497,508.00
FCI CONSTRUCTION INTERBETON JV $ 138,497,508.00


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CALTRANS TOLL BRIDGE RETROFIT PROGRAM ADDRESS

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 Retrofit Duty Senior telephone number is (510) 286-5549, and the fax number for Contractor's inquiries submittals is (510) 286-4563.

WOULD CONTRACT PLAN ELECTRONIC FILES BE AVAILABLE TO CONTRACTOR?

Contract plan electronic files will not be available to Contractors.

COASTWISE TRADE DETERMINATION FOR QUALIFIED BARGES

A non-coastwise qualified barge may be used as a moored stationary work platform within the territorial waters of the United States without violating the coastwise laws, provided that it transport neither passengers nor merchandise while under tow between coastwise points." Contractors have to get all the appropriate permits from the US Coast Guard.

DOES THE WORKER'S COMPENSATION INSURANCE FOR THIS PROJECT FALL UNDER THE JURISDICTION OF THE UNITED STATES LONGSHORE AND HARBOR WORKER ACT/OR THE JONES ACT?

The Jones Act (46 U.S.C & 13 et seq.) applies to seamen and shipping and does not relate to construction workers on the bridge. The Longshore and Harbor Workers' Compensation Act (33 U.S.C. & 901 et seq.) applies to employees engaged in maritime employment. A federal court decision of the Fourth Circuit Court of Appeals has held that a construction worker employment in building a bridge over navigable water, designed to benefit both traffic and navigation, is engaged in maritime employment under the Longshore and Harbor Workers' Compensation Act. (LeMelle v. B.F. Diamond Const. Co.)(1982) 674 Fed2.d 296). Under California law (Lab. Code & 3700), every employer is responsible for being insured against liability to pay workers' compensation. That responsibility is incorporated into the Department of Transportation's (Department) construction contracts under the provisions of the Standard Specifications Section 7-1.01(A)(6) that requires the construction contractor to certify compliance with Labor Code Section 3700.

PREBID MEETING, BID OPENING, AND PREAWARD MEETING DATES FOR CONTRACT 04-0436V4

Prebid meeting date has been moved from August 13, 1997, to September 3, 1997. THIS PREBID MEETING HAS BEEN CANCELED. Bid Opening date has been rescheduled from October 7, 1997 to November 4, 1997. The Pre award meeting date has been rescheduled from October 9, 1997 to November 6, 1997.

DOES CALTRANS HAVE FISHING PIER PLANS AND DESIGN CRITERIA DATA, AND IS THIS AVAILABLE?

As built plans are available at the District Toll Bridge Retrofit Duty Senior's office. No design criteria data is available.

REFER TO SPECIAL PROVISION SECTION 10-1.17 "EARTHWORK," MAY THE CONTRACTOR SUBSTITUTE THE "GPS SURVEY SYSTEM" FOR THE SHORT TO MEDIUM RANGE "EPS," SPECIFIED UNDER "CONTROL AND MONITORING SURVEYS"?

Yes, the "EPS Survey System" could be used as a substitute to the "GPS System."

REFERENCE PLAN SHEET S-1 SIGN DETAILS & QUANTITIES. DOES THE CHANGEABLE MESSAGE SIGN PANEL GET PAID FOR WITH ITEMS 61 & 62 AND IS THE QUANTITY INCLUDED?

No, the sign panel will be provided by a future construction contract. This contract will only provide the sign structure.

IS THE RIGHT-OF-WAY AREA AT THE WEST END OF THE BRIDGE AVAILABLE FOR LAYDOWN AND STAGING OF CONSTRUCTION ACTIVITIES

No State right of way is available at the west end area.

CAN THE HIGHRISE BRIDGE BE REDUCED FROM A THREE LANE IN EACH DIRECTION TO A TWO LANE IN EACH DIRECTION?

No, the third lane is used for truck lane. A closure of that lane will create considerably traffic delays.

WILL THE CONTRACTOR BE ALLOWED TO USE THE EXISTING UTILITIES UNDERNEATH THE BRIDGE SUCH AS WATER, ELECTRIC, AND AIR LINES?

Please refer to Section 5-1.26, "Utilities," of the Contract Special Provisions.

DOES THE CONTRACTOR HAVE TO BACKFILL THE EXCAVATED AREAS AROUND THE PIER FOUNDATIONS?

No backfill is required

CAN THE NEW TOWER PLATES BE TACK WELDED TO THE EXISTING STEEL PRIOR TO BOLTING? IF SO, CAN THE TACK WELDS REMAIN AFTER BOLTING IS COMPLETE?

The design calls for bolting the plates in place. I don't see anything that precludes tack welding these plates but since tack welds are not required by the plans or special provisions, these welds must be included in the working drawings and approved by the Engineer. Tack welds must be ground and painted.

IS THE EXISTING PAINT COATING "LEAD BASED"? IF SO, PLEASE ADVISE HOW THE STATE EXPECTS THE REMOVAL AND DISPOSAL TO BE HANDLED?

Read Section 10-1.16 "Existing Highway Facilities," starting on page 56 of the special provisions.

DOES THE EXISTING PAINT ON THE OUTSIDE FACE OF THE COLUMNS NEED TO BE REMOVED PRIOR TO THE INSTALLATION OF THE NEW TOWER PLATE? WHAT ARE THE CLEANING REQUIREMENTS?

No, see "Fabrication" on page 106 of the special provisions which refers you to cleaning and painting structural steel. Section 10-1.38 "Clean and Paint Structural Steel" on page 115 of the specials says to just clean the existing surface of High strength bolted connections.

DOES THE EXISTING PAINT ON THE INSIDE FACE OF THE COLUMNS, WHERE THE NEW STEEL AND BOLTS ARE TO BE INSTALLED, HAVE TO BE REMOVED PRIOR TO INSTALLATION OF SAID STEEL AND BOLTS? WHAT ARE THE CLEANING REQUIREMENTS FOR THE EXISTING STEEL PRIOR TO INSTALLATION OF THE NEW PLATES?

No, see previous inquiry for the outside face of the columns.

PLEASE REFER TO CONTRACT DRAWING SHEET 129, NOTES 6 AND 11 AND THE ELEVATION SHOWN ON THE SAID DRAWING. NOTE 6 AND 11 CALLS FOR SPLICE DETAIL ON THE TRANSVERSE FACE AND THE "SEE NOTE" IS POINTING TO THE LONGITUDINAL FACE. WHICH IS CORRECT?

These notes send you to other sheets (131 and 147 ) which show the details that are called out on page 129. Longitudinal Elevations show the transverse face & detail and vice versa.

PLEASE REFER TO CONTRACT DRAWING SHEETS 129 & 131. ON SHEET 129 THE LONGITUDINAL ELEVATIONS SHOW THE SINGLE TOWER PLATE. HOWEVER, ON SHEET 131, THE COLUMN BASE DETAIL SHOWS THIS PLATE ON THE TRANSVERSE. WHICH IS CORRECT?

Transverse Elevations show the Longitudinal face & detail and vice versa.

PLEASE REFER TO CONTRACT DRAWING, SHEET 152. WHAT PART OR PARTS OF THE EXISTING PLATFORMS AND LADDER ARE TO BE RECONSTRUCTED?

The ladders are removed for plate installation and then reinstalled. See Section 1.16E " Reconstruct Ladders," starting on page 60 of the special provisions.

PLEASE REFER TO CONTRACT DRAWING SHEETS 150, 172, AND 173. WHAT ARE THE SOFFIT AND DECK ACCESS HOLES USED FOR?

Openings are for access of materials for retrofitting the inside of the steel box.

REFER CONTRACT DRAWING SHEET 158, THE DRAWING CALLS FOR THE REMOVAL OF THE BOTTOM SHEAR LOCK. IS THE NEW LOCK INSTALLED IN THE SAME LOCATION AND WHERE CAN AS-BUILT DRAWINGS SHOWING THE EXISTING LOCK BE LOCATED AND VIEWED.

The old shear locks are on the inside of the box, new are on the outside. See Section 10-1.16 "Existing Highway Facilities" of the special provisions for as-built availability.

REFERENCE SHEET 95 OF 308 - SECTION B-B. IS THE 1" NEOPRENE PAD SUPPOSED TO BE CAST (EMBEDDED) WITH THE PRECAST GIRDER FRAME, THEREBY MAKING THE BOTTOM OF THE NEOPRENE PAD FLUSH WITH THE BOTTOM OF THE GIRDER FRAME, OR IS IT TO BE GLUED TO THE BOTTOM OF THE PRECAST GIRDER PRIOR TO SETTING THE FRAME IN POSITION AND PLACING THE PILE CONCRETE FILL? IF IT IS TO BE GLUED TO THE PRECAST FRAME PLEASE PROVIDE SPECIFICATION DATA FOR THE ADHESIVE. THE SPECIAL PROVISIONS REFER TO STANDARD SPECIFICATION 51-1.14 WHERE SECTION 51-1.145 ADDRESSES ADHESION OF NEOPRENE PADS. IS THIS SPECIFICATION SECTION APPROPRIATE FOR THIS APPLICATION?

The neoprene pad may be glued in place in accordance with 51-1.145 of the Standard Specifications.

WHAT IS THE MINIMUM CONCRETE FILL STRENGTH NECESSARY FOR THE "CISS" PILE TO ASSUME FULL DEAD LOAD OF THE PRECAST CONCRETE FRAMES?

Section 10 -1.01, "Order of work," Paragraph 6, item 5 requires 3 day minimum cure time

UNDER WHICH BID ITEM IS THE "CISS" PILE CONCRETE PLUG AND CONCRETE FILL INCLUDED?

Filing materials for cast-in-place concrete piles, are included in the price for furnishing cast-in-place concrete piles. Furnishing the filling materials is included in furnishing the pile and placing the filling materials is included in drive pile. See Standard Specifications 49-6.02 paragraph 4 and 7

DURING A SITE INVESTIGATION, WE OBSERVED A SAND BAR BETWEEN PIERS 6 AND 7 THAT IS NOT INDICATED BY THE CONTOURS ON SHEET 67 OF 308. PLEASE PROVIDE THE LOCATION AND THE ELEVATION OF THE SAND BAR.

See addendum No. 7

AS-BUILT PILE DRIVING INFO AND LENGTHS?

For all available as-built information, contact the Toll Bridge Retrofit Duty Senior at District 4 Office or the Transportation Laboratory as mentioned on page 72 of the special provisions.

AS-BUILT TOWER STIFFENER CONFIGURATIONS AND CELLS?

See Section10-1.16 "Existing Highway Facilities," on page 56 of the special provisions.

AS-BUILT SPANDREL REBAR AND FOOTING REBAR?

See Section10-1.16 "Existing Highway Facilities," on page 56 of the special provisions.

WHAT IS THE LOAD CAPACITY OF THE EXITING FISHING PIER?

Unknown.

IS JETTING ALLOWED FOR CISS PILING AS WELL AS FOR CIDH PILES (PER PAGE 83, "DRIVING STEEL SHELLS")?

Jetting will be allowed for both CISS and CIDH piles. See restrictions in the second paragraph on the second column on page 79 of the special provisions.

WILL IT BE ACCEPTABLE TO PUMP COFFERDAM WATER BACK TO THE BAY WHEN DEWATERING THE CELLS?

Please refer to page 38, paragraph 2 of subsection "Pile Dewater," of the special provisions.

THE COMPLEXITY AND NATURE OF THE FOUNDATION WORK WILL REQUIRE SIGNIFICANT AREAS OF CONSTRUCTION/ACCESS DREDGING ADJACENT TO THE PIER. WILL THIS BE ALLOWED FOR IN THE PERMITS AND SPECIFICATIONS?

Please refer to page 65, paragraph 4 of subsection "Dredging," of the special provisions.

REFERENCE THE TABLE OF UNSOUND CONCRETE REMOVAL, SHEET 76. LOWER SPANDREL AT PIERS' 12 THRU 27 ARE 12' HIGH, AND 6' WIDE (EXCEPT 18 & amp;21), AND 26' LONG. THE TOTAL SURFACE AREA IS 936 SF. SEVERAL QUANTITIES SHOWN IN THE TABLE ARE GREATER THAN THE SURFACE AREA OF THE EXISTING SPANDREL. ARE THESE QUANTITIES CORRECT AND DOES THIS MEAN WE ARE TO REMOVE THE ENTIRE SURFACE AT TO 4" OR MORE DEPTH?

Only three (3) spandrels are over the total surface and by a total of only a few hundred square feet which is not significant for the bidding of this item. Actual areas for removal will be determined in the field at construction time and the numbers given are approximate only.

PLAN SHEET 144 OF 308 SHOWS A DETAIL CALLED "SPANDREL SOFFIT SPLICE DETAIL" FOR PIERS 19 AND 20. THERE IS NO SIMILAR DETAIL FOR PIER 2 THROUGH 18 AND PIERS 21 THROUGH 27. DOES THIS MEAN THAT THE SPANDREL SOFFIT SPLICES FOR THOSE PIERS DO NOT GET RETROFITTED?

For piers 12-27 see note 3 on page 132 and 137, and note 4 on 143. Piers 2 thru 11 are concrete spandrels and are being retroffited differently.

PLAN SHEET 129 OF 308 SHOWS THE LENGTH OF THE VARIOUS TOWER STRENGTHENING PLATES. HOWEVER, THERE IS NO DIFFERENTIATION MADE BETWEEN THE INSIDE OF THE TRANSFER FACE AND THE OUTSIDE OF THE TRANSFER FACE. ALSO, THERE IS NO DETAIL OF BOLT SPACING OR THE ACTUAL CONNECTION WHERE THE PLATES ON THE INSIDE TRANSFER FACE MEET THE SOFFIT OF THE SPANDREL BEAM. PLEASE VERIFY.

See Addendum No. 6.

PLAN SHEET 128 OF 308 SHOWS A TABLE OF APPROXIMATE QUANTITIES OF CLEAN AND PAINT STRUCTURAL STEEL FOR THE PIERS. THE QUANTITIES GIVEN SEEM TO INDICATE THAT THE FAYING SURFACE BETWEEN THE EXISTING PIER LEG AND THE NEW PLATES DOES NOT GET CLEANED OR PAINTED. PLEASE CONFIRM.

The contact surface of the existing pier leg does get painted. Section 10-1.38 "Clean and Paint Structural Steel," of the special provisions, (page 115), provides instruction on cleaning the faying surface.

PLEASE PROVIDE THE COLUMN DIAMETER FOR THE COLUMNS ABOVE THE BELL FOUNDATIONS.

This information should be available on the "As Built" Plans. Our information indicates 18' diameter.

DETAILS ON PLAN SHEET 103 OF 308 INDICATE THAT THE CONTRACTOR IS TO LOCATE THE EXISTING #11 REBAR IN THE DIAPHRAGM AND THEN CORE DRILL 5 INCH DIAMETER HOLES TO MISS THE #11 REBAR. SECTION B-B INDICATES THREE ROWS OF #11 REBAR ABOVE AND THREE ROWS OF #11 REBAR BELOW THE 7'- 4" HS ZONE. IS THERE ANY REBAR WITHIN THE HS BAR ZONE?, IF SO, WHAT IS THE PROCEDURE IF A HS BAR CORE HOLE INTERFERES WITH A #11 REBAR.

The two layers of longitudinal #11 bars, top and bottom are not to be disturbed. There are #6 longitudinal bars between these and they can be cut and removed, if encountered.

NOTE 2 ON SHEET 120 OF 308 STATES THAT "APPROPRIATE INJECTION NOZZLES TO BE PROVIDED ON CASING, BUT REMOVED AND GROUND FLUSH FOLLOWING COMPLETION OF GROUTING OPERATION". DOES "GROUND FLUSH" MEAN PLUG WELDED AND GROUND FLUSH OR DRY PACKED AND GROUND FLUSH?

Usual practice is to dry pack and grind flush, but the Engineer will make the proper determination in the field.

IS THERE A MAXIMUM ALLOWABLE GROUT LIFT HEIGHT WHEN GROUTING THE ELLIPTICAL COLUMN CASINGS? IF SO, DOES THE HEIGHT VARY WITH COLUMN CASING THICKNESS?

See Section 10-1.35 "Column Casing" on page 111 of the special provisions: The Contractor shall limit the height of each lift of grout to minimize undulations and displacements of the surface of the shell during grouting. Undulations in the shell surface, including undulations from fabrication and erection, shall not exceed 1/4 inch per foot nor shall the total displacement from plan location exceed 2 inches at any point. At the Contractors option, a bracing system or other means may be employed to restrain the casing within the specified tolerances. Except where shown on the plans, restraints shall not pass through the columns. The grout shall harden prior to placing the next lift of grout, unless a bracing system is used.

NOTE 13 ON PLAN SHEET 129 OF 308 STATES THAT WELDS THAT INTERFERE WITH NEW CONSTRUCTION (EXTERIOR REINFORCEMENT PLATES ) ARE TO BE GROUND SMOOTH, CLEANED AND PAINTED. THE NOTE ALSO REFERS TO TABLE 2 ON SHEET 128 OF 308 FOR APPROXIMATE AREA OF CLEAN AND PAINT STRUCTURAL STEEL. WHAT IS THE QUANTITY AND SIZE OF WELDS TO BE GROUND SMOOTH, CLEANED AND PAINTED.

The amount of bead protruding on the outside face of the existing columns is not known. For information they should be field verified.

WHAT WELDING INSPECTION AND TESTING WILL BE REQUIRED ON THE 1" AND 1 1/4" THICK COLUMN CASINGS? WILL THE COLUMN CASINGS WELDS HAVE TO BE GROUND SMOOTH?

Caltrans standards will be followed

FOR THE COFFER DAMS REQUIRED FOR THE RETROFIT AT RECTANGULAR FOUNDATIONS:

A) CAN ADDITIONAL TEMPORARY CONSTRUCTION LOADS (HORIZONTAL OR VERTICAL) BE PLACED ON THE EXISTING FOOTINGS TO FACILITATE PLACEMENT OF THE COFFER DAM?

A) Yes. However, the contractor must provide working drawings and engineering calculations showing that the foundation will not be damaged or over stressed. Approval of your plan will come from the Engineer.

B) CAN A TREMIE SEAL FOR THE COFFER DAM COME IN CONTACT WITH THE EXISTING STRUCTURE AND/OR SEAL COURSE?

B) Yes. It would be difficult to form a seal if it did not come in contact with the existing structure.

PLEASE REFER TO THE PRELIMINARY SEISMIC GEOLOGIC, AND FOUNDATION INFORMATION (PGR):

A) PROVIDE ANY INFORMATION AVAILABLE ON THE ROCK BACKFILL OF THE ORIGINAL EXCAVATION FOR THE BELL PIERS 14 TO 29.

A) We do not have this information.

B) WAS THERE ANY EXCAVATION AND BACKFILL OUTSIDE THE ORIGINAL COFFERDAM LIMITS FOR THE RECTANGULAR FOUNDATIONS?

B) We do not have this information.

WAS THE DETOUR TRESTLE INSTALLED FOR THE ORIGINAL CONSTRUCTION COMPLETELY REMOVED FROM PIERS 30 TO 38, INCLUDING PILLING?

We do not have this information.

SPECIFICATION 10 - 1.19 PILING STATES THAT CONCRETE SHALL BE PLACED IN A DRY OR DEWATERED HOLE OR MAY BE PLACED UNDER SLURRY. THE TOPS OF THE "CISS" AND "CIDH" PILES ARE UNDERWATER WHEN PLACING THE TOP 15'-0" OF FILL CONCRETE WHICH EMBEDS THE FOUNDATION FRAME CONNECTION. THIS PRECLUDES THE PLACEMENT OF CONCRETE IN THE DRY OR UNDER SLURRY. PLEASE SPECIFY A CONCRETE PLACEMENT METHOD THAT IS COMPATIBLE WITH THESE CONDITIONS.

Water may be used as a slurry when the hole is cased. See "Water" on page 83 of the special provisions which reads: "At the option of the Contractor water may be used as slurry when casing is used for the entire length of the drilled hole'. The portion of the holes that are drilled into bedrock at piers 2 & 3 may be temporarily cased to meet the requirements for casing "the entire length of the drilled hole".

BORINGS AND OTHER GEOLOGICAL DATA PROVIDED DO NOT COVER THE AREA BETWEEN PIERS 2 AND 14. THIS INFORMATION IS NECESSARY TO SHOW THE ELEVATION OF THE ROCK THAT MUST BE PENETRATED PER THE CONTRACT AS WELL AS THE TYPE, CONDITION AND HARDNESS OF THE ROCK. CAN YOU PROVIDE A SECTION SHOWING BEDROCK CONTOURS?

The foundation recommendations included in the "material information handout" has a graph (Appendix A, generalized Soil Profile along San Mateo - Hayward Bridge) and a table (Table 1) which should give you clues to the bedrock elevation. For pile driving records and other information, contact the Toll Bridge Retrofit Duty Senior at District 4 Office or the Transportation Laboratory as mentioned on page 72 of the special provisions.

DOES CALTRANS HAVE CONE PENETROMETER TEST (CPT) DATA AVAILABLE FROM THE GEOTECHNICAL WORK PREPARED FOR THE SEISMIC RETROFIT OF THE BRIDGE?

For all available as-built information, contact the Toll Bridge Retrofit Duty Senior at District 4 Office or the Transportation Laboratory as mentioned on page 72 of the special provisions.

DOES CALTRANS HAVE SOIL SHEAR STRENGTH DATA FOR THE UPPER LEVEL MUDS AT ALL PIERS UNDER THIS CONTRACT? IF AVAILABLE, DOES DATA DIFFERENTIATE "OLD" AND "NEW" BAY MUDS?

For all available as-built information, contact the Toll Bridge Retrofit Duty Senior at District 4 Office or the Transportation Laboratory as mentioned on page 72 of the special provisions

PILE CAPACITY REQUIREMENTS ARE NOT INDICATED IN THE CONTRACT DOCUMENTS. THIS INFORMATION IS NECESSARY IN ORDER TO ANALYZE CONSTRUCTION METHODOLOGY AND RISK EVALUATIONS RELATIVE TO THE PROJECT. DOES CALTRANS HAVE THIS DATA AND IS IT AVAILABLE.

Piles are designed based on lateral load only. There should be enough information provided for the Contractor to estimate this.

FOR THE STRUCTURAL STEEL, DOES, THE 300 AIR LINE MILES ONLY APPLY TO THE WELDED PORTIONS OF THE STRUCTURAL STEEL?

This is my interpretation of the special provisions. Also, this requirement applies to check samples.

IS THE CONTRACTOR ALLOWED TO UTILIZE THE EXISTING MAINTENANCE TRAVELER RAILS TO SUPPORT A CONTRACTOR FURNISHED TRAVELER TO FACILITATE CONSTRUCTION ACTIVITIES? IF THIS IS ALLOWED WHAT IS THE SIZE AND CAPACITY OF THIS RAIL?

See Section 5-1.125 "Areas for Contractor's Use", on page 24 and 10-1.06 "Cooperation", on page 48. With these restrictions in mind, the Contractor may use the existing railings. The Contractor will have to provide working drawings and calculations showing that the Contractor's operation will not damage or over stress the existing rails. The Crane is not available to the Contractor.

PLEASE INDICATE THE ASSUMED DESIGN CAPACITIES FOR THE CIDH AND CISS PILING.

There is no required design capacity for the piles. The controlling loads are lateral. Piles need only be driven to specified tip elevation as specified in the 17th paragraph of Section 10-1.19 "Piling" on page 73. The Contractor should be able to determine the forces need to drive piles to tip from the geology information provided.

WILL THERE BE ANY SPECIAL REQUIREMENTS FOR SPLICING LONGITUDINAL REINFORCEMENT OF THE PRECAST PRESTRESSED CONCRETE FOUNDATION FRAME

Mechanical fasteners are required at the splice between the two halves of the foundation frame. Normal splice requirements prevail for the construction of the frames themselves.

REFERENCE SPECIAL PROVISIONS SECTION 10-1.17 EARTHWORK, SHEET 101 AND 104 OF 308, SHEET 103 OF 308. WE DO NOT FIND ANY REQUIREMENTS IN THE SPECIFICATIONS OR DRAWINGS FOR BACK FILL. ARE WE TO ASSUME THAT THE CONTRACT DOES NOT REQUIRE BACK FILL AT THE RECTANGULAR OR BELL PIER FOUNDATIONS? THE PAY LIMIT FOR THE BELL PIER FOUNDATIONS DO NOT PROVIDE SUFFICIENT WORK ROOM TO INSTALL THE BOLTS BELOW THE DIAPHRAGM. IS THE ADDITIONAL EXCAVATION REQUIRED FOR THE BOLT INSTALLATION TO BE INCIDENTAL TO THE STEEL CASING AT BELL FOUNDATIONS INSTALLATION? WILL THE UNDERCUT AT THE BELL FOUNDATION DIAPHRAGM FOR BOLT INSTALLATION REQUIRE BACK FILL?

No backfill is required. It appears that there is sufficient room to install the bolts under the diaphragm although it will be difficult work. The Contractor may excavate further to improve access but the limits for payment are as shown on the plans and these additional item costs must be included in the quantity shown on the Engineers Estimate.

REGARDING EXCAVATION AND DREDGING OF MATERIAL IN THE BAY, WHAT IS THE NATURAL ANGLE OF REPOSE FOR THIS MATERIAL? HAS THIS NATURAL ANGLE OF REPOSE BEEN CONSIDERED IN CALCULATING THE QUANTITIES FOR DISPOSAL?

2.5:1 is the angle of repose assumed by the Consultant. If the Contractor chooses, or because of safety is required, to lay back the slope or shore the excavation, the limits for payment are as shown on the plans and these additional item costs must be included in the quantity shown on the Engineers Estimate.

REFERENCE SPECIAL PROVISIONS SECTION 10-1.136 COLUMN CASINGS (BELL FOUNDATION RETROFIT) . THIS SECTION MAKES REFERENCE TO CENTERING EARS AT THE EXISTING BELL FOUNDATIONS THAT WILL REQUIRE REMOVAL UNDER THIS CONTRACT. REVIEW OF THE AS-BUILT DRAWINGS, IN PARTICULAR THE BELL SETTING GUIDE DETAIL ON SHEET 25, THE GUIDES SHOWN ARE INTERNAL TO THE BELL FOUNDATION PRECAST UNIT. REVISION 1 INDICATES THAT THE AS-BUILT OF THIS POSITIONING DEVICE WAS "USED ON PIERS 14 THROUGH 17 INCLUSIVE ONLY."

These guides are internal to the existing bell foundations and should not be of concern for removal. As-built shop plans for pier 18-20 and 27-29 should have location for the positioning devices. The removals are required to eliminate interference with new bell casings. Seals for grouting the casings are the Contractor's responsibility subject to the Engineer's approval.

PLEASE PROVIDE DETAILS FOR THE POSITIONING DEVICES USED ON PIERS 18, AND 20 THROUGH 27, 28 AND 29. ALSO PROVIDE DETAILS ON WHAT REMOVAL IS REQUIRED TO BE COMPLETED UNDER THIS CONTRACT. THIS SECTION MANDATES SPECIFIC REQUIREMENTS FOR THE GROUTING OF THE BELL CASINGS. IT MUST BE COMPLETED BY TRENIE METHODS WITHOUT SPILLAGE OF GROUT INTO THE WATER DURING GROUT PLACING OPERATIONS. NO DETAILS HAVE BEEN PROVIDED BY THE ENGINEER AS TO HOW TO SEAL THE BOTTOM OR TOP OF THE CASING FOR THE GROUTING PROCESS, IS IT THE CONTRACTORS RESPONSIBILITY TO DESIGN THESE SEALS.

Seals are contractor's responsibility, subject to engineer's approval.

REFERENCE THE SPECIAL PROVISION SEAL COURSE CONCRETE LIMITS THE AMOUNT OF NEW TRENIE ALLOWED TO BE LEFT IN PLACE TO BE 3 FT OUTSIDE THE EXISTING PILE CAP. DUE TO SHEETPILE SHAPES AND THE ACCURACY OF AS-BUILTS DIMENSIONS SHOWN FOR THE EXISTING SEAL, THIS IS EXTREMELY LIMITING, AND WOULD REQUIRE REMOVAL OF NEW TREMIE SEALS EVEN IF NEW SHEETS WERE DRIVEN 1 FT FROM THE EXISTING SEAL. PLEASE CLARIFY.

The weight of the new tremie must be kept to a minimum in order to prevent overloading of the existing piles. Additional mass to the foundation is a prime seismic problem and must be limited by the limits given.

REFERENCE DRAWING 120 OF 308, DETAIL "A" AND DETAIL "B". THE 1" MINIMUM CLEARANCE AT THE CHAMFERED CORNER IS NOT SUFFICIENT TO ALLOW A FLOW OF GROUT AT THE CORNERS. OUR NAPA PROJECT REQUIRES A MINIMUM OF 3" OF CLEARANCE WHICH IS BARELY ENOUGH TO ALLOW THE FLOW OF GROUT. PLEASE CONSIDER INCREASING THE CLEARANCE. ALSO ARE INTERNAL OR EXTERNAL SUPPORTS ALLOWED AT THE COLUMN CASING TO ASSIST IN HOLDING THE ELLIPTICAL SHAPE OF THE CASING DURING PLACEMENT OF GROUT?

Changing the size of the clearance, and thus the size of the column, would require re-analysis of the entire structure for its effect on the earthquake response. The 1" clear is standard for grout filling and has proven adequate though not necessarily easy. Additional injection nozzles may be necessary. Bracing is allowed (see the first paragraph of the second column on page 112).

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