ADMINISTRATION - Dan Schluender, City Engineer
Title
AUTHORIZE CHANGE ORDER NO. 1 IN THE AMOUNT OF $287,270.64 FOR THE 132ND LANE AND TAYLOR STREET AREA RECONSTRUCTIONS, IMPROVEMENT PROJECT NO. 19-18
Background
Soil borings taken prior to design generally indicated the presence of 3 to 4 inches of aggregate base material under the existing bituminous pavement on the streets in the 132nd Lane and Taylor Street Area Reconstruction project. Based on this geotechnical information it was determined that this would allow for reclaiming the existing pavement into gravel, removing the excess reclaimed gravel needed to install 3-1/2 inches of bituminous pavement and there would still be a 4 inch aggregate base under the new pavement, which is the City standard for this type of project. The plans were designed and the project was bid in this manner.
During excavations to replace water main valves and adding storm sewer catch basins, it was observed that the aggregate base was not of uniform thickness along any of the roads on the project as depicted in the borings. Most areas had approximately 2 inches of aggregate base. Due to the shortage of gravel in most areas it was determined that it would be problematic to create the standard 4 inch aggregate base layer under the bituminous pavement unless the reclaimed gravel was stripped off of the road and approximately 3 inches of the sandy subgrade removed before replacing all of the reclaimed gravel. This operation required the contractor to spend extra time in equipment and labor to create the necessary 4 inches minimum of aggregate base to meet the City’s standard typical road section.
Change Order No. 1 reflects the actual time and materials necessary to accomplish the changes in scope of work as described above.
Recommendation
By motion, approve Change Order No. 1 in the amount of $287,270.64, amend the total contract budget to $1,986,050.17, and authorize the Director of Public Works to sign said Change Order No. 1.