Investigation of Construction Techniques for Tactical Bridge Approach Roads Across Soft Ground.

The objective of this study was to investigate and test the feasibility of various new techiques for constructing bridge approach roads across soft ground. A test section containing seven test items was constructed on a soft clay subgrade which had an average strength of 0.9 CBR. Accelerated traffic tests were conducted using various loads on a 5-ton military dump truck. Traffic was recorded in terms of coverages of equivalent 18-kip single-axle, dual-wheel load operations. A major finding of this investigation was the potential use of sand-confinement systems for base courses over soft subgrades. Both a large-volume confinement system and a small-volume system outperformed the crushed stone control item by a substantial margin.