多级挡土墙土压力传递效应与沉降规律研究

发布时间：2018-09-10 13:13

【摘要】：随着国民经济和经济建设的发展,挡土墙的应用高度从最初的几米发展到几十米,甚至最高可达到六七十米,多级挡土墙就是在这种情况下产生许多应用。目前国内外专业刊物对加筋及台阶式加筋挡土墙的实际现场试验有研究成果,对多级重力式挡墙试验内容介绍很少,尤其是多级重力式挡土墙的土压力、变形、沉降及稳定性方面的研究就更少；现场试验中因为天气和地势等方面的原因,测试人员不能在现场操作,就不能及时、有效的识别路基沉降或土体中应力发生的突变,对这问题论文采用虚拟仪器的应用,在室内可以实现监测过程的连续化和自动化。论文针对在湖北段某高速公路的实际多级挡土墙工程情况,采用现场原型试验、室内试验、理论分析、数值模拟相结合的手段对该多级挡土墙进行土压力及变形的研究,取得以下主要成果： (1)通过对比分析土压力理论,得出多级挡土墙的土压力计算公式,优化级挡土墙结构尺寸设计； (2)用现场实测的试验数据,分析每个工况下每级挡墙墙后土压力的变化规律,归纳土压力的变化分成三个阶段；即在开始施工一定阶段为快速增长阶段,之后一段时间为稳定阶段,；在墙背施工一定高度后土压力为缓慢增长阶段； (3)分析得出多级挡土墙墙后土压力作用点的位置会随第一级、第二级及多级挡土墙施工高度增加不断上移,合力也是相应增大变化,得到土压力合力作用点位置在0.4H～0.5H之间,对多级挡土墙稳定分析有很重要作用； (4)对现场实测多级挡土墙的整体土压力数据表现为锯齿型分布结果进行分析,得出锯齿型分布结果与挡土墙之间的台阶宽度有很大关系：通过采集多级挡土墙的级与级应力变化值,与有限元模拟受力过程变化分析值相结合,得出上下级挡土墙合理布置宽度； (5)针对在特殊气候和工程条件下人员无法采集现场试验数据的问题,论文运用LABVIEW软件编制了实时监测系统,应用LABVIEW程序的计算机软件,对原始信号进行分析处理并对处理后的数据进行显示存储,实现了多级挡土墙的实时监测。
[Abstract]:With the development of national economy and economic construction, the application height of retaining wall has developed from the initial several meters to several tens meters, even the highest can reach 60 to 70 meters. At present, professional journals at home and abroad have made research achievements on the actual field tests of reinforced and stepped reinforced retaining walls, and have seldom introduced the contents of multistage gravity retaining walls, especially the earth pressure and deformation of multistage gravity retaining walls. There is less research on settlement and stability; in field tests, because of the weather and topography, it is impossible for the tester to identify the subgrade settlement or the sudden change of stress in the soil in a timely and effective manner if the tester cannot operate on the spot. The application of virtual instrument to this problem can realize the continuity and automation of monitoring process indoors. In this paper, according to the actual multi-stage retaining wall engineering situation of a highway in Hubei section, the field prototype test, laboratory test, theoretical analysis and numerical simulation are used to study the earth pressure and deformation of the multi-stage retaining wall. The main achievements are as follows: (1) through the comparison and analysis of earth pressure theory, the calculation formula of earth pressure of multistage retaining wall is obtained, and the structural dimension design of multi-stage retaining wall is optimized; (2) the field measured test data are used. This paper analyzes the variation law of earth pressure behind each stage of retaining wall under each working condition, and concludes that the change of earth pressure is divided into three stages, that is, at a certain stage of construction, it is a rapid growth stage, and then it is a stable stage for a period of time. At a certain height on the back of the wall, the earth pressure increases slowly. (3) it is concluded that the position of the earth pressure at the back of the multistage retaining wall will move upward with the increase of the construction height of the first stage, the second stage and the multistage retaining wall. The resultant force also increases correspondingly, and the position of the earth pressure acting point is between 0.4H~0.5H, which plays an important role in the stability analysis of multistage retaining wall. (4) analyzing the overall earth pressure data of multistage retaining wall measured in the field as sawtooth distribution. It is concluded that the sawtooth distribution results have a great relationship with the step width of the retaining wall. By collecting the stress variation values of the multi-stage retaining wall and combining with the finite element simulation analysis value of the stress process, the results show that the distribution of the sawtooth type is related to the step width of the retaining wall. The reasonable layout width of upper and lower retaining wall is obtained. (5) aiming at the problem that people can not collect field test data under special weather and engineering conditions, the paper uses LABVIEW software to compile a real-time monitoring system. By using the computer software of LABVIEW program, the original signal is analyzed and processed, and the processed data is displayed and stored. The real-time monitoring of multistage retaining wall is realized.
【学位授予单位】：武汉理工大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU476.4

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