Improvement of Load-Settlement Behaviour of Strip Footings Using Geogrid-Reinforced Granular Trench under Cyclic Loading

Increasing bearing capacity of shallow foundations has always been one of the issues which geotechnical engineers have dealt with for weak soils. One of the various ways of improving these types of soils is to use granular trench that is the plane strain form of stone columns. This experimental investigation was conducted by using a practical model on a strip foundation overlying on a geogrid-reinforced and unreinforced granular trench embedded with sand under combination of static and cyclic loading with over 10000 cycles loading and unloading.In this study, the effect of placement depth and number of layers for geo-grid materials, and also their optimum values under cyclic loading has been determined. The influence of different amplitude of cyclic loading on footing having various number of layers were tested. The results demonstrate that regardless of reinforcing conditions, with the increasing number of loading cycles, settlement increases as well. If geo-grid layers are used in granular trench, by adding the number of layers, settlement and optimum distance between layers would decrease. For low intensity of the amplitude of cyclic loading, reinforcing is not quite effective.

کلیدواژه ها:

Practical model ، Strip foundation ، Granular trench ، Static and cyclic loading