Effect of Bagasse and Filter Cake on load support capacity of a silty clay loam soil under different water contents using plate sinkage test

Bagasse and filter cake are by-products of sugar factories which are full of nutritional ingredients and organic matters. Mechanical characteristics of the soil are considered very important in order to determine the allowable stress for preventing soil compaction. One of the important indices is pre-compaction stress which can be used as a criterion for load support capacity of the soil. In this research, the soil samples with wet bulk density 1.5 g cm-3 were prepared; then a plate sinkage test (PST) was used to determine the soil pre-compaction stress (σpc). The effects of two types of sugarcane residues with two different rates (1 and 2%) at two water contents (WCs) of 0.9PL and 1.1PL (plastic limit) on soil σpc were studied. Results showed that σpc was significantly decreased by adding residues to the soil and also increasing WC. By adding residues to the soil at WC of 0.9PL, the load support capacity of the soil was decreased by 22.6%. In the residue-added treatments as compared to control, the σpc was decreased by more than 32% when the WC increased from 0.9PL to 1.1PL. When the WC increased from 0.9PL to 1.1PL, in the filter cake-treated soil, the susceptibility to compaction was increased. Consequently, by adding residues to the soil and changing the water condition from moist to wet, the resistance of the soil to compression was remarkably reduced.