塑料排水板处理超软土地基的数值模拟分析  

Numerical Simulation Analysis of Plastic Drainage Plate to Treat Super-soft Ground

作　　者：董超强 苗雨[1] 钱志创 

机构地区：[1]华中科技大学土木工程与力学学院,湖北武汉430074

出　　处：《土木工程与管理学报》2018年第1期110-116,共7页Journal of Civil Engineering and Management

基　　金：国家自然科学基金(51378234)

摘　　要：在含水量高、压缩性高及承载力低的超软土地区,运用塑料排水板堆载预压法进行软基处理可加速地基的排水固结。本文针对霞浦县滩涂地区某超软土地基工程,在PLAXIS二维有限元软件中将塑料排水板分别用排水线和Chai的二维等效方法进行简化并做了相应的数值模拟分析。通过分析两种简化模型计算结果,并与现场实测数据进行对比,得出如下结论:(1)路基地表沉降、深层沉降、坡脚处深层水平位移及超静孔压与实测数据较吻合,偏差在允许范围内;(2)对比两种简化模型,说明等效渗透系数方法计算结果可靠,故Chai的二维等效方法可以推广到其他进行塑料排水板堆载预压法的有限元分析中,弥补该类有限元软件进行塑料排水板简化分析的局限性;(3)通过用PLAXIS软件进行数值模拟分析,发现该法降低了传统竖井地基固结理论计算的复杂性,具有一定的适用性,可用于指导同类工程设计与施工。Using the method of prefabricated vertical drains with preloading for soft foundation treatment can accelerate the drainage consolidation of the ground in super-soft soil area with high water content,high compressibility and low bearing capacity. In this paper,aiming at the example of a super-soft soil foundation engineering in Xiapu tidal flat,the plastic drainage plate was simplified by the drainage line and Chai's two-dimensional equivalent method respectively,and the corresponding numerical simulation analysis was carried out in PLAXIS 2 D finite element software. By analyzing the calculation results of the two simplified models of plastic drainage plate compared with the measured data,the following conclusions can be drawn:(1) the surface settlement,deep settlement,deep horizontal displacement and excess pore water pressure of the subgrade were in agreement with the measured data,and the deviation was within the allowable range.(2) the calculation result of the equivalent permeability coefficient method was reliable by comparing the two simplified models,so Chai's two-dimensional equivalent method can be extended to other finite element analysis of prefabricated vertical drains with preloading method,making up for the limitation of simplified analysis of plastic drainage plate by using the similar finite element software.(3) By using PLAXIS software,it is found that the method reduces the calculation complexity of the traditional consolidation theory for prefabricated vertical drain and has certain applicability,which can be used to guide the similar engineering design and construction.

关 键 词：塑料排水板 超软土地基 等效渗透系数 超静孔压 数值模拟 

分 类 号：TU447[建筑科学—岩土工程]