Nonlinear radial consolidation of vertical drains under a general time-variable loading

作者：Lu, Mengmeng^*; Wang, Shanyong; Sloan, Scott W.; Indraratna, Buddhima; Xie, Kanghe

来源：International Journal for Numerical and Analytical Methods in Geomechanics, 2015, 39(1): 51-62.

DOI：10.1002/nag.2295

• consolidation
• nonlinearity
• vertical drain
• multistage loading
• preloading-unloading-reloading

By incorporating the nonlinear variation of a soil's compressibility and permeability during the process of consolidation, an analytical solution for the radial consolidation of vertical drains has been developed for a general time-variable loading. The general solution was verified for the cases of instantaneous loading and ramp loading. Detailed solutions were further derived for two special loading schemes: multistage loading and preloading-unloading-reloading. The nonlinear consolidation behavior of a vertical drain subjected to these two types of loading schemes was then investigated by a parametric study. The results show that the loading rate, the ratio of the compressibility index to the permeability index (C-c/C-k), and the initial stress state have a significant influence on the consolidation rate. A smaller value of C-c/C-k, a larger initial stress, or a fast loading rate always leads to a rapid consolidation rate. During the unloading period, a negative excess pore water pressure may occur, and a slower unloading rate may reduce this negative value.

• 出版日期2015-1
• 单位浙江大学; 中国矿业大学（北京）