MGE was the prime consultant to provide construction management services for the project that consisted of replacing a 32-foot-long timber bridge superstructure, concrete abutment foundations, flared wingwalls and timber guard railing, along with construction of new roadway approaches on the existing alignment. During construction, and traffic w
as detoured downstream to a temporary bridge. This inconvenience to the public (though minor) required good communication between the County, the Construction Management Team, and the Contractor. Keeping the public and other interested parties informed as to construction progress and anticipated activities on a continual basis went a long way in earning their understanding and acceptance of the inconvenience at hand.
Construction of the new structure: The previous timber stringer bridge superstructure, and reinforced concrete abutment foundations were completely removed so the new single-span, cast-in-place reinforced concrete slab bridge with concrete diaphragm abutments could be constructed. The new abutments are supported by cast-in-drilled-hole concrete piles. The new bridge is 45 feet long and 25 feet wide. The total roadway approach reconstruction is approximately 260 feet long and consists of asphalt, and aggregate base. The profile was raised approximately 1.5 feet which required the reconfiguration of five driveways and construction of a modular block retaining wall. The project also involved installation of fencing, guard railing, ¼-ton rock slope protection and erosion control to protect the new fill slopes.
During construction, several challenges occurred. An active bird nest was discovered before bridge demolition. The Pacific Slope Flycatcher nest took 10 working days to fledge. The day the birds were determined to be fledged, a small bat colony was discovered. Both of these events involved the contractor supplied biologist recommendations reviewed by CDFW with subsequent recommendations by CDFW. During these events, the project was affected by wild fires in Lake County, delaying the project another 5 working days. MGE and the County propose to accelerate the project schedule with a Contract Change Order to ensure all in-water work in Robinson Creek was completed on or before October 15th. This CCO had the County participating in compensation for overtime hours to complete the in-water work based on a time-impact analysis to determine the number of days that were fair to the contractor for compensation. Items considered during construction included:
- Traffic control and detours
- Environmental, Cultural monitoring
- Conformance to regulatory agency permit requirements
- Constricted area for construction activities
- Timely construction staking verification
- Driveway conforms
- Clearing & grubbing
- Earthwork to construct the widening
- Constructing concrete barrier &metal beam guard rail
- Placing aggregate base and hot mix asphalt concrete paving and dikes
- Shoulder backing
- Thermoplastic pavement striping
- Delineator guide markings and signs
- Temporary water pollution control
- Potential temporary water diversion