非单一平面滑移破坏模式下挡土墙的地震非线性土压力探讨

发布时间：2018-01-02 12:17

本文关键词：非单一平面滑移破坏模式下挡土墙的地震非线性土压力探讨　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：挡土墙是一种防止土体坍塌的土工构筑物,被广泛地应用于水利和水电工程、港口工程、建筑工程、公路工程和铁路工程等工程领域。随着我国经济实力的快速增长,全国各地基础设施的建设脚步不断向前,尤其是中西部许多地区的现有交通建设已不能满足经济发展的需求,这一形势也对基础设施建设中大量使用的挡土墙工程提出了新的挑战。在挡土墙的抗震设计中,地震土压力的计算起到非常关键的作用。西方有学者早在17世纪就已经着手研究土压力,但是,关于挡土墙地震土压力这方面的研究却进展缓慢,研究成果也仅仅停留在理论阶段,应用于工程实践还存在诸多缺陷和不足。但在近几十年,国内外许多专家学者针对这一问题做了许多的理论和工程应用方面的研究工作,提出了很多理论和方法,为挡土墙的抗震设计和施工提供了有效的依据。然而,由于地震的破坏力巨大和诸多不确定因素,挡土墙的地震土压力研究仍然是学术界与工程界共同关注的热点问题。现行的应用最为广泛的地震土压力理论是M-O方法,计算挡土墙地震土压力时假设破坏面是一个平面,然而现实中的破坏面基本上为不规则曲面,两者差别明显;其它不足之处,如不能应用于粘性填土、不考虑填土对地震的放大效应、计算所得地震土压力呈线性分布等。本文考虑到挡土墙施工质量受限于天气、地形和工期等的影响,墙背填土并非均匀。假定挡土墙墙背填土为2层性质各异、干燥的无粘性土,地震条件下滑移破裂面为更接近实际情况的非单一平面;基于水平层分析法,建立地震条件下确定挡土墙土压力分布的微分方程。通过求解模型,得到地震作用下挡土墙土压力的非线性分布解析解;分析了地震系数、填土内摩擦角对地震土压力分布、地震土压力合力及其作用点的影响。结果表明,上层填土范围内挡土墙土压力与单一平面滑移破坏基本一致,呈非线性变化;而下层填土范围内的挡土墙土压力随深度变化近似线性关系。从而知,上层填土范围内的挡土墙土压力问题是分析的主要部分。通过本文研究,提高了复杂条件下计算挡土墙地震土压力的精确性,对以后的设计,施工以及成本控制有一定的指导意义。
[Abstract]:A retaining wall is to prevent the collapse of soil structures, is widely used in water conservancy and Hydropower Engineering, port engineering, construction engineering, road engineering and railway engineering. With the rapid growth of China's economic strength, the construction steps of infrastructure across the country continue to move forward, especially the existing traffic construction many of the Midwest have been unable to meet the needs of economic development, the situation of the infrastructure construction in the large-scale use of retaining wall engineering has brought new challenges. In the seismic design of retaining wall, seismic earth pressure calculation plays a very important role. Some western scholars have started to study early in seventeenth Century earth pressure, however, research on seismic earth pressure of retaining walls in this area are slow, research only stays at the theoretical stage, applied to the engineering practice there are still many defects and deficiencies. But in recent years, many domestic and foreign experts and scholars on this issue to do research work in theory and engineering application in many aspects, put forward many theories and methods, and provides an effective reference for seismic design and construction of the retaining wall. However, due to the force of the earthquake and a great many uncertain factors, research seismic earth pressure of retaining wall is still a hot issue of common concern of academia and engineering. The current application of the seismic earth pressure theory widely used is the M-O method, calculation of seismic earth pressure on retaining wall when assuming the failure surface is a plane, but the failure surface in reality basically for irregular surface, the difference between the two obviously; other deficiencies, such as can not be applied to the soil, without considering the effect of amplification of seismic soil on the linear distribution of seismic earth pressure calculation considering the retaining wall. The construction quality is limited On the influence of terrain and weather, time limit, the wall backfill is not uniform. It is assumed that the retaining wall backfill into 2 layers of different nature, cohesionless soil drying conditions, seismic slip rupture surface is closer to the actual situation of the non single plane; horizontal layer analysis method based on the establishment of earthquake conditions determine the gear differential equation earth pressure distribution. By solving the model, nonlinear analysis of the distribution of earth pressure on retaining wall under earthquake solution; analysis of seismic coefficient, internal friction angle of seismic earth pressure distribution, influence of seismic earth pressure resultant and its point. The results show that the upper filling range of retaining wall and single plane slip failure is consistent, is nonlinear; while the lower filling range of earth pressure of retaining wall with depth approximate linear relationship. To know the upper soil retaining wall soil pressure is within the scope of the problem The main part of the analysis is to improve the accuracy of calculating the seismic earth pressure of retaining wall under complex conditions through this study, which is of guiding significance for future design, construction and cost control.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU476.4

【参考文献】