On the Apparatus and Measuring Method of Silt Impermeability
粉土抗渗强度测定设备和方法研究

Silt is a kind of complex and transition soil between sand and clay whose engineering property is different from them. According to the limit equilibrium analysis of silt sample, a new apparatus was developed for effectively measuring silt critical hydraulic gradient under seepage failure in laboratory test. The changing water level device and the transparent vessel insure the accuracy and dependability of impermeability intensity measuring. Parallel connection multi-containers were used so more samples could be tested simultaneously.Test results of Qiantang River silt in Hangzhou show that the critical hydraulic gradient of the silt differs from that of sandy soil. It also shows that the impermeability of undisturbed soil sample with horizontal bedding is greater then that of the compaction sample, and that impervious layer of geotextile can considerably improve the impermeability of silt. The result provides more understanding of the prevention of silt seepage failure, and may used as an important reference for engineering.