Task 1.4: Add aggregate to the road surface on the bridge; install impervious membrane.


Replenish the aggregate on the road surface so that the tops of the arch stones are covered and the road surface is at its original level.


South approachDeep rills have formed in the roadbed.



The road surface material has washed away to the extent that there are a number of places where the tops of the arch stones are exposed. Lines can be seen on the balusters showing where the stone was covered with aggregate and protected from weathering. This task would also be a good opportunity to remove the remnants of a bituminous wearing surface that failed. Further, at this time an impervious membrane could be installed beneath the aggregate to protect the arch stones from further deterioration caused by water infiltration. A waterproof membrane such as used to line sanitary landfills could be used to carry water off the bridge, and underground lateral drains could be installed at each end of the membrane to carry water to the sides.

Accomplished by:

This task would most likely be carried out by the County road and bridge crew. No estimate have been done as to the cost of a membrane nor the amount of aggregate that would be needed to bring the road surface up to the proper level.

Return to Phase 1 Summary.