Consolidation theory for prefabricated vertical drain assuming elliptic cross section and nonlinear well resistance
HUANG Chaoxuan1，DENG Yuebao2，HU Guojie3
(1. Zhejiang Design Institute of Water Conservancy and Hydroelectric Power，Hangzhou，Zhejiang 310002，China；2. Institute of Geotechnical Engineering，Ningbo University，Ningbo，Zhejiang 315211，China；3. Cold and Arid Regions Environmental and Engineer Research Institute，Chinese Academy of Sciences，Lanzhou，Gansu 730000，China)
Abstract：The consolidation process for foundations with prefabricated vertical drain(PVD) of plate shape is normally analysed with the assumption of the vertical drain to be circular in cross section with equivalent area. Such simplification leads to the discrepancy between the assumed and actual shapes. In this paper，the cross section of PVD was assumed as an elliptic shape which is close to the plate shape. The basic equations of consolidation for the vertical drain under the elliptic cylindrical coordinate system were presented and the degree of consolidation was then obtained. Comparisons between the new and traditional solutions were conducted and discussed. The traditional methods were found to overestimate the drainage effects of PVD. The drainage coefficient of permeability decreases linearly with depth and exponentially with time. The larger well resistance leads to the slower consolidation and even to serious clogging of the drainage board.
2017, Vol. 36 
