Buildings, Vol. 16, Pages 2738: Experimental and Discrete Element Study on the Bearing Behavior of Fully Penetrating Geosynthetic-Encased Stone Columns

Buildings, Vol. 16, Pages 2738: Experimental and Discrete Element Study on the Bearing Behavior of Fully Penetrating Geosynthetic-Encased Stone Columns

Buildings doi: 10.3390/buildings16142738

Authors:
Feng Liu
Jiancai Zhu
Haibo Hu
Shile Zhou
Xinyu Xie
Panpan Guo

Geosynthetic-encased stone columns (GESCs) utilize geosynthetics to form a geosynthetic sleeve over a certain length of the stone column, thereby increasing lateral confinement and extending the engineering applications of conventional stone columns in ground improvement. In this paper, a series of laboratory model tests and discrete element numerical simulations were conducted to investigate the bearing behavior, load transfer mechanism, and deformation patterns of fully penetrating GESCs. The lateral confinement provided by the geogrid can increase the bearing capacity of fully penetrating GESCs, and the bearing capacity increases with increasing reinforcement depth. Compared with the ordinary stone column, the fully penetrating GESC with full-length encasement exhibits an approximately 1.5-fold increase in bearing capacity. The geogrid effectively restricts the movement of gravel particles; within the reinforced zone, the column deformation is relatively uniform, and bulging deformation occurs in the unreinforced section. Reinforced zone leads to a 10% decrease in the bulging ratio compared with the unreinforced section. The longer the encasement length, the more effectively the column transfers the upper load downward. When the reinforcement depth exceeds 75% of the column length, the improvement in bearing capacity of the fully penetrating GESC becomes less pronounced. Considering the encasement efficiency and engineering economy, it is recommended that the encasement length be 75% of the column length.