Geotechnical properties of sawdust used in induced trenches

Abstract

Induced trenches are a common aspect of highway construction in areas of high fills over pipes. Many different materials have been used for the compressible material in the induced trench, but there is lack of data proposing which material possesses the optimum characteristics. The purpose of this senior report is to determine the geotechnical properties of fine sawdust and compare the results to other data on highly compressible materials and granular soils. The geotechnical properties of fine sawdust were determined using compression, direct shear, and creep. Samples were placed loose in each case and three compacted samples underwent direct shear tests. These tests enabled the determination of the internal angle of friction for both loose and compacted samples, the percent compression during loading, and the secondary rate of consolidation. The geotechnical properties of fine sawdust are compared to those of other documented compressible materials and it was determined that sawdust is more compressible but at the same time has higher shear strength and low creep rate.