JOB BB0113 SHELL LAKE STR. & APPRS. (S) MARCH 10, 2015 LETTING QUESTIONS PREVIOUSLY ASKED UNDER JOB BB0106. There are notes in the plans regarding driving the test pile without the use of a follower. The test pile are the same length as the production pile and given the fact all piling must first be driven without dewatering the cofferdam we are left wondering how this can take place? A long pile is used for test piles to eliminate the need for a follower in accordance with Subsection 805.07(f) of the Standard Specifications. This requirement is to be met, otherwise the results of the Wave Equation Analysis Method B could be skewed or adversely affected by the energy-dampening effects of the follower. As stated in the Standard Specification, the test piles will be used to establish the required pile penetration for production piles. With the approval of the Engineer, a follower may be used on the production piles to keep the hammer out of the water. The Geogrid for Pavement Reinforcement shown in the plans is typically used with untreated Aggregate Base. On this project it is shown directly under the Cement Stabilized Crushed Stone Base Course. Is this the correct application of the geogrid product? This is the correct application of the geogrid product. What is the intent with the Public Notification System (PNS) as far as changing messages? The intent of the PNS is to broadcast messages about traffic in and near the work zone in greater detail that what can be displayed on a portable message board. The messages for the PNS are to be changed by the Contractor or their vendor operating the AWIS system. Page 1 of 10
Does the Department want to interface with them as you have in the past via web browser? Interface by the Department personnel will primarily be via the idrivearkansas.com website to ensure the data push is operating. However, a separate website is necessary to allow for PTZ access to the cameras for Department personnel similar to previous deployments of portable cameras. Does the Department want the AWIS software to change the messages automatically? PNS Messages are to be changed manually by the Contractor or the vendor; information such as travel time or length of delay messages may be displayed automatically by the AWIS software but must be monitored by ensure accurate and timely information is being displayed. Section 5 of the AWIS portion, subsection C: What is the Department s intent in regards to the quantity of HAR Alert beacon signs per HAR device, 1-to-1? The intent of the HAR beacon alert sign is for one to be near the end of the broadcast range of each individual HAR transmitter so a beacon to transmitter radio of 2:1 ratio is recommended as a minimum. Is it the Department s intent to have actual streaming video to idrivearkansas.com? No. Screen captures refreshed at least once every 60 seconds are sufficient for the data push to the idrivearkansas.com website. Regarding integration of the information from the AWIS to idrivearkansas.com, who will be modifying the idrivearkansas.com site to accept the information push? Page 2 of 10
Will these development costs be taken on by the department or will these costs be considered subsidiary to the AWIS mobilization pay item? Modifications to the idrivearkansas.com website to accept the data push will be the responsibility of the Department. Regarding page 3 of 9 of the AWIS portion, section 2, under CDN it is mentioned: allow for separate controllable/configurable steams for the public and operators. Are you referring to having a separate stream that allows for PTZ/configuration of the camera for agency operators and a separate stream that just has video to the public? Yes, a separate stream must be provided for Department or other designated agency such as law enforcement allowing for PTZ access via a separate website. My question pertains to the 16, 18 and 24 steel shell piling and the 16 and 18 steel pipe test pile. I see that both are A252-2 steel but I could not find in the plans what the wall thicknesses are for the various sizes. What are the wall thicknesses? The wall thickness is shown as 0.5 on Standard Drawing 55021 which is included in the plan sheets. Removal of existing bridge structures section 205 states Debris from bridge removal shall not enter the waterway unless approved as temporary fill or permanent.. if material or debris resulting from the Contractor s operations does enter the waterway, the Engineer will make a determination based on the applicable permits whether or not the material may remain. Will small pieces of concrete be allowed in the water as a result of breaking lines in the concrete deck for removal operations? Also, most bents to be removed are in the water and we would anticipate some material will fall in the water. Is this acceptable? Small pieces of concrete as described above could be left in place. Larger pieces should be removed. As stated in Section 205, the Resident Engineer will make the final determination. Page 3 of 10
Section 205 states Unless otherwise designated on the plans or directed by the Engineer, substructure units shall be removed to a minimum depth of 2 below subgrade or final ground surface and to a greater extent if necessary to avoid interference with new construction work. Obstructions shall be removed from the established waterway. This does not clearly define the depth or parameters for removal of substructure bents in the water. Will the existing footings/bents be required to be removed below the mud line? Please explain to what extent the footings/bents will be required to be removed. Will blasting be allowed for removal of substructure bents? Will the requirements be different for each of the three bridge sites? If so, please explain. Existing footings/bents are required to be removed down to 2 below the mud line. The new bridge is positioned to avoid interference with existing piling. Therefore, we do not expect any conflict between the existing and new structures. If all permits and permissions have been acquired, blasting will be allowed. All four corners of the bridge at Shell Lake are designated as Environmentally Sensitive Areas. Will the contractor be allowed to place temporary rip rap fill for construction access across these areas? Will the contractor be allowed to drive temporary pile bents or use barges in these areas? The areas shown in the shown figure have been cleared for use. This would include temporary pile bents and barges if the contractor prefers. Any activities outside of those areas are prohibited. A temporary work plan should be submitted to the Engineer for approval. Page 4 of 10
Will the test piles in the cofferdams be used to set a specific depth and length of the production piles or will they be used to set the blow count and stoke for the hammer used? For example, the contractor drives the test pile gets bearing at a length of 40 from tip of pile to cut off, will the AHTD set the permanent production pile lengths at 40 or will the production piles be measured to the nearest tenth of an inch for the actual driven length upon achieving bearing on each individual pile? Test piles will be driven by Method B (Wave Equation Analysis) and will be used to determine the length of production piles. The test piles would be driven without a follower, driven to the plan capacity and driven to the plan tip elevation or lower. Production pile will not be established to the nearest tenth. Page 5 of 10
Will the contractor be allowed to have material deliveries at the bridge sites during daytime hours without a lane closure? If not, will the contractor be allowed to build a temporary acceleration/deceleration lane for construction materials deliveries for daytime hours? Deliveries can be made during the day. However, as stated in the Maintenance of Traffic Special Provision, the contractor is responsible for safe ingress and egress of construction traffic. Once production pile lengths have been established from test piles, will production pile cut offs or build ups be paid for? No. Layout General Notes clearly state Piles and test piles will be measured and paid for as the actual linear feet of accepted piles left in place. There will be no payment for cut-off or build-up of the piles. QUESTIONS FOR LETTING OF MARCH 10, 2015. Job BB0115 is a combination job of BB0113 and BB0114. Please verify the quantities for the AWIS system for Jobs BB0113 and BB0114. The quantities are correct. The quantities for Jobs BB0113 and BB0114 are provided due to the possibility of two separate Contractors for each project. In Job BB0115, the two areas are in close proximity; therefore the quantity shown is sufficient for Job BB0115. The Base and Surfacing-Maintenance of Traffic quantity box on Plan Sheet 52 shows a quantity of 1,377.56 square yards of Cement Stabilized Crushed Stone Base Course (6 Comp d. Depth) and ACHM Surface Course (3/8 ) from Sta. 5123+80.00 to 5129+25.00. The quantity for Temporary Portland Cement Concrete Pavement is 6,030 square yards. Why are there differences in these quantities? Page 6 of 10
The quantity for Temporary Portland Cement Concrete Pavement (10 Uniform Thickness) will be revised. An addendum has been issued. The top typical section on Plan Sheet 8 is showing longitudinal joints 3 from center line, 18 from center line, and 24 form center line. Can the joints be at different intervals as long as we have the same amount of joints? Please note that the longitudinal joints at 3 and 18 from the center line are at the ramp lane edges. The longitudinal joint at 24 from the center line is where the paved shoulder ends. There will be no change in the plans. In regards to the reconstruction of the Shell Lake Bridge (BR #06939), improvements will be made to the Hwy 149 & I-40 Interchange. These improvements are estimated to take approximately 2-3 months to complete. The current Sequence of Construction for BB0113 & BB0115 requires these improvements to be made in Stage 4a, after the reconstruction of BR #06939 is complete. The relative scope of the structure work for BR #06939 (BB0113) & BR #06940 (BB0114) is similar. It is fair to assume these would finish in the same time frame. However, since BB0113 & BB0115 require the Hwy 149 & I40 Interchange improvements, it would reasonable to assume the respective contracts would allow more C days. Would the Department consider adding an additional 40 working days to complete Jobs BB0113 & BB0115, or allow the Stage 4A work at Hwy 149 to be completed prior to the current sequence of construction? The Hwy. 149 Interchange-Ramp Reconstruction Section of the Maintenance of Traffic Special Provision states, Prior to completion of the I-40 main lane Shell Lake Bridge No. 06939, the temporary embankments and pavement shown in the plans for ramp maintenance of traffic may be constructed during the lane closures permitted for other I-40 work within the project. and Construction of the permanent interchange ramps will have no hourly restrictions with the approval of the Engineer. No additional days will be added. Due to the maximum allowable time to complete and lane closure restrictions the respective projects will require sustained day and night work. It is typical for a business to have its Page 7 of 10
week restart on Sunday. This would be considered the start of a Monday Shift. On recent projects the Department has stated working day assessment will be based upon midnight (See Section 101 of the Standard Specifications for the definition of a Calendar Day). Work is not allowable prior to 12am Monday since Sunday is not an allowable working day. Any work past Midnight Friday- will result in assessment of a Saturday. The project Special Provisions for Jobs BB0113, BB0114, and BB0115 imply portions of Sunday work is allowable and a typical shift would begin in the PM. EX: AHTD BB0115 MOT SP- A normal schedule for a night shift meeting these conditions would be: Timeframes for Working Day assessment appear to be adaptable to a specific project. Page 8 of 10
Per the Standard Definition of a Calendar Day, all days respective to the Projects have been identified by the Maintenance of Traffic SP, therefore the standard definition of Calendar Day used for Working Day assessment has been modified. This allows for a daily schedule relative to the project restrictions such as the one above. The schedule shall be agreed upon by the Contractor and Engineer prior to starting work. Would the Department consider a request to allow Working Days to be assessed relative to the project specific requirements? Working days will be assessed according to the Standard Specifications and the Special Provision Assessment of Working Days-Saturdays. The plans detail dimensions for the Neat lines of Seal. It also states that The inside face of the cofferdam shall be at or outside the seal concrete dimensions shown. The plan quantity for seal concrete and structural excavation shall be based on the dimension shown. Is it permissible to construct a larger cofferdam to allow 2 footings to be constructed inside the larger cofferdam? The Seal Concrete would be enlarged to fill the entire area inside the cofferdam. The plan quantity for seal concrete, plan quantity for structural excavation, and plan quantity for cofferdam would be paid based on the dimension and quantities shown in the plans. It is permissible for the two seal footings in each stage of construction to be poured as one. Upon award of Contract, the Contractor shall formally make this request. However, due to the complexity of seismic design, a design review would have to be performed by the Design Consultant. At minimum, this review would include the following: depth of seal footing, footing design, number of piling, length of piling, etc. This review could possibly warrant revised plan drawings. The Contractor will be responsible for the Design Consultants review fee, and if necessary, all cost associated with preparation of revised plan drawings. Payment for all items, except piling, will be made on the basis of plan quantities. In the event that an additional number of piles or additional piling length is required, the Contractor will also assume these costs. The pay item listed in the Pavement Reinforcement System Special Provision is Geogrid for Pavement Reinforcement. Does this include fabric and geogrid? Page 9 of 10
The fabric is subsidiary to the pay item Geogrid for Pavement Reinforcement. After award of the Contract, a change order will be implemented to revise the language in the Special Provision. Page 10 of 10