Experimental Study of the Bearing Capacity of Stiff Clay Overlying Sand with and without Geotextile Inclusion

The objective of this study is to investigate the potential benefits of using reinforcement inclusion to improve the bearing capacity of stiff clay over very loose to medium dense sand. Model load tests were performed on two layered systems, namely stiff clay over very loose, loose, medium dense sand with and without geotextile inclusion between the two layers and on stiff clay only. The load-settlement curves were plotted from the experimental test results, and the ultimate bearing capacity was obtained using Log – Log (L-L), Tangent (TIM), 0.1B and Hyperbolic (HYP) methods. Theoretical approaches were used to compute the ultimate bearing capacities of the tests without and with reinforcement. The test results have shown an increase in the ultimate bearing capacities due to increase in the relative densities of the bottom sand layer. The bearing capacity increased significantly with the inclusion of geotextile layer. The bearing capacity ratio (BCR) for the case of very loose sand as bottom layer was the highest compared to loose and medium dense cases. Load - settlement curve of the pure clay test plots above or is identical to the load - settlement curve of stiff clay overlying medium dense sand with geotextile layer. The maximum benefit for the geotextile inclusion was gained at large strain when the sand was very loose. The analytical methods were generally in good agreement with the experimental model test results obtained by the 0.1B method.