Abstract
The results of a series of preliminary studies that were conducted to develop a penetration device to be used in the assessment of the in situ condition of backfill materials behind the conduit wall of soil-steel structures and in other buried conduits are described.In particular, the methodologies associated with the design of an impact cone device and the results of a series of preliminary tests conducted on dense sand and loose granular soils are discussed. This paper appears in transportation research record no. 1315, Culverts and pipelines: design, monitoring, evaluation, and repair 1991.