CONSOLIDATION THEORY FOR PREFABRICATED VERTICAL DRAIN WITH LINEAR PRELOADING

Consolidation calculations for prefabricated vertical drains(PVds) are approximately equivalent to sand well model at home and abroad. PVds are equivalent to the flat oval cylinder in this paper. Consolidation solution for PVD foundation is derived with linear load according to equal strain assumption with confocal elliptical coordinate. The correctness of present theory is verified by ADINA finite element calculation and the existing results. The present theory is closer to Long & Covo model "d_w=0.5b+0.7δ" in two-dimensional consolidation theory. The "shape effect" of flat rectangular cross is better than circular cross-section. Equivalent model for PVds in "Code for design of sea dike project(GB/T 51015-2014)" and "Technical Specification for Vacuum preloading Technique to Improve Soft Soils(JTS147-2-2009)" overestimates the capacity of PVds while considering well resistance. In addition, the longer of linear loading time, the slower rate of consolidation rate, and significant difference with the plummeted loading conditions.