非饱和土理论在膨胀土边坡稳定性分析中的应用研究

发布时间：2018-03-12 12:12

本文选题：非饱和土　切入点：膨胀土　出处：《天津大学》2013年硕士论文　论文类型：学位论文

【摘要】：南水北调中线工程总干渠途经大面积的膨胀土地区，渠道边坡的稳定直接关系到工程效益、工程调水的高保证率的实现以及工程投资效益。膨胀土以其独特的工程性质，成为工程界的难题，尤其是表现在边坡稳定性分析上。膨胀土的裂隙性和胀缩性是边坡失稳的主要因素，而降雨入渗是诱发因素。本文根据这一本质性要点，分析了膨胀土边坡失稳的机理，为在膨胀土地区渠道的工程地质勘察、设计和施工工作提供了方向和技术支撑。本文的主要工作如下： 1.通过查阅大量相关的文献，归纳总结非饱和土理论的发展过程和现状，以及在实际工程应用。系统地学习了非饱和土性状、本构关系和抗剪强度理论，并充分了解了非饱和土边坡的稳定分析方法。 2.搜集了大量膨胀土边坡失稳的案例，归纳整理出膨胀土边坡失稳的浅层性、平缓性、伴随着持续降雨、长期性和方向性等特征。 3.结合参加膨胀土地区渠道工程地质勘察经历和相关的勘察成果，分析了膨胀土的矿物化学成分、土粒结构方式、土-水作用方式，，并归纳膨胀土裂隙产生的原因和胀缩循环过程，以及雨水入渗后影响和水压力作用。 4.结合非饱和土理论，对膨胀土区渠道工程地质勘察所得物理力学性质进行分析和修正，使试验参数尽可能地反映出工程实际情况，以谋求计算分析成果能符合实际情况。 5.运用Geo-slope/w模块，使用Morgenstern-price法、Ordinary法、Bishop法和Janbu简化法，分膨胀土在初始没有产生裂隙时、胀缩循环产生裂隙后以及雨水从裂隙入渗3种工况，分别模拟了边坡的稳定性、滑动面位置以及滑动特征。文章进而分析了这四种算法的特点和安全性，也模拟出膨胀土的裂隙是其边坡稳定性控制因素。其中工况雨水从裂隙入渗模拟的结果完全符合膨胀土边坡失稳的特征。
[Abstract]:In the middle route of South-to-North Water transfer Project, the main trunk canal passes through a large area of expansive soil area. The stability of channel slope is directly related to the engineering benefit, the realization of high guarantee rate of engineering water transfer and the benefit of project investment. The expansive soil has its unique engineering properties. It has become a difficult problem in engineering field, especially in the analysis of slope stability. The fissures and dilatancy of expansive soil are the main factors of slope instability, while rainfall infiltration is the inducing factor. The mechanism of instability of expansive soil slope is analyzed, which provides direction and technical support for engineering geological investigation, design and construction of channel in expansive soil area. The main work of this paper is as follows:. 1. By consulting a large number of relevant documents, the development process and present situation of unsaturated soil theory and its application in practical engineering are summarized. The properties, constitutive relations and shear strength theory of unsaturated soil are systematically studied. And fully understand the unsaturated soil slope stability analysis method. 2. A large number of cases of expansive soil slope instability are collected, and the characteristics of the slope instability are summarized, such as shallowness, smoothness, continuous rainfall, long-term and directivity, and so on. 3. Based on the experience of canal engineering geological survey in expansive soil area and the related survey results, the mineral chemical composition, soil particle structure, soil-water interaction mode of expansive soil are analyzed. The causes of fissures in expansive soil, the process of expansion and shrinkage cycle, the influence of Rain Water after infiltration and the action of water pressure are also summarized. 4. Combined with unsaturated soil theory, the physical and mechanical properties of channel engineering geological survey in expansive soil area are analyzed and revised, so that the test parameters can reflect the actual engineering situation as much as possible, so that the calculation and analysis results can accord with the actual situation. 5. By using Geo-slope/w module, Morgenstern-price ordinary method and Janbu simplification method, the stability of slope is simulated under three working conditions: expansion and shrinkage cycle and Rain Water infiltration from the crack, when the expansion soil does not produce the crack at the beginning. The characteristics and security of the four algorithms are analyzed. It is also simulated that the fissures of expansive soil are the controlling factors of slope stability, and the simulation results of Rain Water's infiltration from fissures fully accord with the characteristics of instability of expansive soil slopes.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU443

【参考文献】