Title
Consider and take action on the award of a construction contract to David Wight Construction Co. Ltd in the amount of $121,393 for the Driveway and Parking Improvements for the Line Repair Facility, and authorization of a Work Change Directive budget of $12,139 (Deputy City Manager)
Background:
Approval of this item will award the construction contract to David Wight Construction Co. Ltd for construction of a concrete paving system for the Driveway and Parking Improvements for the Line Repair Facility.
The purpose of this project is to replace approximately 1,480 square yards of the existing crushed limestone driveway and parking area with a permanent and durable pavement material. At the City Council Meeting held on April 8, 2014, City Council voted to postpone the Award of Bid and requested staff to obtain a Geotechnical Engineering Report to evaluate the concrete and asphalt pavement system to determine the proper design for the Driveway and Parking Improvements.
Included in this Agenda Item package, is the Geotechnical Engineering Report for the Paving Improvements at the Line Repair Facility, prepared by Terracon Consultants, Inc. Terracon's report recommends a concrete pavement system with a minimum 7-inch reinforced concrete, underlain by a minimum 6-inch lime or cement treated subgrade. Section 4.3 of the report further states: "Based on the subsurface soil conditions observed at this site and our experience with similar soil conditions and existing drainage conditions, we recommend a concrete pavement system be considered for this project."
Terracon's report also states: "The asphalt concrete pavement system, if planned, should consist of a minimum 3-inch asphaltic concrete surface course underlain by a minimum 10-inch cement treated base course with a minimum 6-inch lime or cement treated subgrade."
City Staff bid this project with a Base Bid for the construction of the driveway and parking using 7-inch reinforced concrete pavement with 6-inches of cement stabilized sand subgrade material. An Alternate Bid was provided for the construction of the driveway and parking using 2-inch asphalt pavement with 6-inches of cement stabilized limestone base material and 6-inches of cement stabilized sand subgrade material. Based on Terracon's report, if the asphalt pavement system was to be considered as an equivalent to the concrete pavement system, the asphalt and base material thicknesses should have been more substantial than what was bid.
For this application, asphalt pavement is not recommended. Asphalt pavement is a flexible base pavement with a low service life when exposed to high volume of heavy construction vehicles and equipment, including stopping and starting and wheel turning movements. Asphalt pavement is also susceptible to deteriorating effects from flowing or ponding water. The new pavement will be mildly sloped to allow for sheet flow type drainage, but any deformation of the flexible base pavement will allow for water to pond and penetrate the base material, causing potholing and premature failure. The Line Repair Building has roof drains along the side that will flow across the driveway and parking. In addition, this area is used for the wash-down of equipment, tools, and utility materials.
Reinforced concrete pavement is a low permeable and durable pavement that will provide a long service life with minimal maintenance. Concrete can endure the effects of flowing or ponding water without deteriorating.
Attached is the bid tabulation which includes the results of the Base Bid for the concrete pavement system, as recommended by Terracon, along with the Alternate Bid for the asphalt pavement system, substandard to the Terracon recommendation. David Wight Construction Co. Ltd submitted the lowest bid for the concrete pavement system in the amount of $121,393, and; Teamwork Construction Services, Inc. submitted the lowest bid for asphalt pavement system in the amount of $88,826.
Staff is recommending the award of the bid to David Wight Construction Co. Ltd for the concrete pavement system in the amount of $121,393, along with the approval of a Work Change Directive budget not to exceed $12,139.30 (10 percent of bid amount) that will allow staff to approve minor field changes to expedite decisions and avoid possible construction delays and/or damage claims by the contractor. Funds for this project were budgeted in the FY 2014 Line Repair Department's operating budget.
Bids for this project were received on March 18, 2014 and were to remain subject to acceptance for 90 days. Since the Staff was requested to obtain a Geotechnical Engineering Report, the 90 days bid acceptance period has expired. David Wight Construction Company has indicated they are willing to honor their original bid price, if the City is willing to wait 5 to 6 weeks before issuing a Notice to Proceed.
This project is anticipated to take 30 calendar days from the notice to proceed.
Attachments:
1) Data Sheet
2) Geotechnical Engineering Report
3) Aerial Plan
4) Design Drawing
5) Bid Tab
6) Photos
CONTRACT ORIGINATION:
FUNDING
{ } NOT APPLICABLE
{X} Funds are available in the amount of $133,532.30 from Line Repair's Contractual Services operating
budget, account 020-3321-695-5349
{ } Requires Budget Amendment to transfer from Account #________ to Account #_______