考虑渗流时水泥土墙支护结构计算与分析

发布时间：2018-07-26 07:50

【摘要】：目前水泥土墙的设计仍是参照传统的重力式挡墙的模式来进行计算,采用静水压力,不考虑渗流作用的影响。但在地下水位较高的地区对基坑进行开挖时,都需对基坑进行降水,悬挂式止水帷幕使得坑内外存在水头差,土体中将会产生渗流的作用,且大量的基坑工程实例表明,渗流对基坑支护结构的水土压力分布及稳定性的影响非常显著,但目前有关考虑渗流对基坑工程性状的研究并不多见。本文采用有限元软件ABAQUS对稳定渗流下的水泥土墙进行模拟,初步研究了稳定渗流对水泥土墙水土压力及稳定的影响,主要研究内容如下:1.在简单介绍饱和稳定渗流的有限元控制方程及定解条件的基础上,分析了作用在水泥土墙前后的水压力变化规律,并与静水压力进行了对比,从水压力方面证明了考虑稳定渗流的必要性。2.应用有限元软件ABAQUS对水泥土墙支护结构中稳定渗流的情况进行模拟,分析结果表明:稳定渗流下水泥土墙中的土压力无论是坑内还是坑外都要大于不考虑渗流情况下的土压力,但是对于水压力,由于渗流力的作用,水泥土墙内的水压力小于静水压力,而水泥土墙外水压力则大于静水压力。在此基础上,研究了稳定渗流对水泥土墙的抗倾覆和抗水平滑移稳定安全系数的影响,其结果表明:稳定渗流下对水泥土墙的稳定性是不利的,按不考虑渗流的情况下进行设计是偏于不安全的。
[Abstract]:At present, the design of cement-soil wall is still based on the traditional gravity retaining wall. The static water pressure is adopted and the influence of seepage is not considered. However, when excavation of foundation pit is carried out in areas with high groundwater level, it is necessary to degrade the foundation pit. The suspended water sealing curtain makes the water head difference inside and outside the pit, and seepage will occur in the soil, and a large number of examples of foundation pit engineering show that, The influence of seepage on soil and water pressure distribution and stability of foundation pit support structure is very significant, but there are few researches on foundation pit engineering characteristics considering seepage at present. In this paper, the finite element software ABAQUS is used to simulate the cement-soil wall under steady seepage, and the influence of steady seepage on the pressure and stability of soil and water wall is preliminarily studied. The main research contents are as follows: 1. On the basis of a brief introduction of the finite element control equation and the definite solution conditions of saturated steady seepage, the variation of water pressure before and after the action of cement earth wall is analyzed and compared with that of hydrostatic pressure. From the aspect of water pressure, the necessity of considering steady seepage flow is proved. The finite element software ABAQUS is used to simulate the steady seepage in the cement-soil wall supporting structure. The results show that the earth pressure in the cement-soil wall under steady seepage is greater than that in the pit or outside the pit without considering the seepage. However, for the water pressure, the water pressure in the cement soil wall is smaller than that in the static water pressure because of the seepage force, and the water pressure outside the cement soil wall is greater than the hydrostatic pressure. On this basis, the influence of steady seepage on the stability of cement soil wall is studied. The results show that the stability of cement soil wall is unfavorable to the stability of cement soil wall under steady seepage. It is not safe to design without considering seepage.
【学位授予单位】：河北工程大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU476

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