Numerical analysis of encased granular pile with vertical hollow steel pipe

Stone column/granular pile (GP) system has been utilized for supportive adaptable structures built on soft ground. However, in the instance of soft soil, granular piles experience excessive settlement due to inadequate lateral resistance presented by the soft soil in contradiction of bulging. Bulging might be minimized by fortifying the GPs either by encasing them with geosynthetic or by placing geosynthetic disks inside the GPs at an even interval. In the current study, vertical hollow steel pipe is used as an alternative to the above for confinement and increasing the overall stiffness. The encasement effect of vertical hollow steel pipe in granular piles on the load–displacement response is analyzed by a numerical method. The principle target of this investigation is to predict and quantify the effectiveness of the encasement of vertical hollow steel pipe in a single floating granular pile. This investigation focuses on the load–displacement response for different lengths of encasement of hollow pipe and the length to diameter ( L / D ) ratio of GP. The results show that the load–displacement response of encased GPs improved for the better with the increasing length of encased hollow steel pipe.