Experimental, Numerical, and Field Evaluation of a Reinforced Foundation Pad on Soft Clay
摘要
The improvement of bearing capacity of soft clay overlain by a sand foundation pad reinforced by geosynthetics is examined using a small-scale physical model, a three-dimensional finite element model, and a full-scale test. Combined assessment of short- and long-term performance of a reinforced sand pad underlain by soft clay is presented. The short-term performance of a high-density polyethylene geosynthetic-reinforced foundation pad was assessed using a small-scale model. Then, the results of the small-scale physical model were used to validate the numerical parameters of a three-dimensional finite element model. The finite element model is used to evaluate the long-term performance of the reinforced foundation pad overlain by a single spread footing or a four-footing group. It is shown that If decreases by 8.0%-18.4% at a consolidation degree of 90% compared to the undrained condition. It is also shown that the interaction between four-symmetrical footings resulted in a reduction in If compared to the case of a single spread footing when the distance between the footings normalized by the footing width was less than 8.0. A three-month full-scale test is used to examine the performance of a sand pad reinforced by four layers of polypropylene biaxial geogrid underlain by soft clay interlayered with silty sand. The reinforced sand pad was capable of bearing a stress equal to 156 kPa at a settlement of 4.5–4.7 cm at the end of the test period at 82% consolidation degree, and after the exposure of the geogrid to installation damage and creep.