Field tests on top-shaped concrete block cushion-reinforced soft soil foundation drained with sand bag well

The soft soil foundation drained by the conventional sand bag wells requires slow loading, which occupies more construction period and is not conducive to post-construction settlement control. In order to accelerate the loading rate of the drainage foundation of sand bag wells, field tests on the top-shaped concrete blocks-reinforced drainage foundation of sand bag wells are conducted. The research shows that the top-shaped concrete blocks can improve the overall stability of the foundation, and keep the foundation stable under the condition that the rapid loading causes the value of the pore pressure coefficient $\overline{B}$ of soft soil to be greater than 1. The top-shaped concrete blocks reduce the high-compressibility soil in the shallow part of the foundation. The compression of the layer relatively increases the compression of the undrained soil layer under the soft soil layer, inhibits the development of lateral deformation of the soft soil, and reduces the rate of post-construction settlement. The top-shaped concrete block layer reduces the pore pressure in the compression layer, and the peak value accelerates the consolidation process of soft soil. The top-shaped concrete blocks have greater rigidity than the sand cushions, resulting in a significant change in the type of additional stress distribution generated by the upper load in the foundation, leading to that the comprehensive behavior of the drainage sandbag ground is strengthened.