厦门地区花岗岩残积土降雨滑坡模拟试验及土体破坏细观演变规律研究

发布时间：2018-06-12 23:03

本文选题：花岗岩残积土 + 力学特性　；参考：《厦门大学》2014年硕士论文

【摘要】：我国东南沿海经济开放区主要分布在花岗岩风化壳上,该区域残积土厚度较大,其中在闽粤沿海地区一般为20-35m。福建省地处东南沿海,位于亚热带东南季风气候区,中低山和丘陵占全省面积的80%,气候湿热,台风暴雨频繁,降雨集中,岩土渗流强度大,丘陵山地风化与侵蚀作用强烈,导致花岗岩残积土广泛覆盖,其中50%分布在闽东南丘陵、沿海平原等地,其中厦门地区最厚达50-7m。因此,花岗岩残积土在东南部省份普遍存在,工程中所遇的山地、丘陵、剥蚀准平原上都分布着残积土,是大部分工程建设的地基基础和地质环境重要介质。福建省正在实施海峡西岸经济区发展战略,填海造地、高速公路和铁路、海港码头、福州地铁、厦门地铁等岩土工程空前繁荣。因此,东南沿海地区残积土安全稳定性、工程力学特性和降雨引发滑坡等地质灾害规律等研究是福建省实现新一轮跨越式发展中面临的重要而紧迫的研究课题,对预防控制重大岩土工程事故和滑坡等严重地质灾害具有重大的理论和现实意义。论文以福建省自然科学基金项目“强降雨条件下松散岩土体发生滑坡、泥石流地质灾害的相态演变机理研究”为依托,以厦门地区分布广泛的花岗岩残积土为代表性土样,通过室内试验,降雨滑坡模拟试验、岩土细观检测分析、岩土细观成像分析与数字处理等研究技术手段,主要开展以下研究工作： 1.通过查阅国内外文献,总结分析了岩土含水率对岩土体力学性质的关系及其作用机理,为制定该试验研究方案提供基本依据和参考。 2.采集厦门地区花岗岩残积土为代表性土样,配制成5种不同含水率的试样,通过直剪试验,测试试样含水率与内部粘聚力、内摩擦角的相互关系,从而揭示含水率对残积土力学性能的影响规律。 3.以土体边坡坡度、降雨强度为控制变量,设计了16种降雨滑坡模拟试验方案。在不同降雨强度条件下对不同角度的土体边坡模型进行了降雨滑坡模拟试验,并对试验结果进行统计对比分析,从宏观角度对土体失稳破坏的规律进行探讨,并在此基础上,总结目前土体失稳破坏的原型试验及调查结果,验证模型试验结果的合理性； 4、采用岩土细观变化图像采集和分析系统,采集大量细观变化图像和照片,通过图像处理技术,结合计算机语言编写图像处理程序,进行计算和处理,获得土体颗粒团的细观运动数据信息和运动轨迹,经过统计对比分析,从细观角度揭示降雨滑坡土体失稳破坏的细观演变规律,揭示土体失稳宏观破坏形式与细观运动演变的之间的关系。
[Abstract]:The open area of southeast coastal economy of China mainly distributes on the weathering crust of granite, and the thickness of residual soil in this area is relatively large, which is 20-35 m in the coastal area of Fujian and Guangdong. Fujian Province is located in the southeast coast, located in the subtropical southeast monsoon climate area. The middle and low mountains and hills account for 80 percent of the province's area. The climate is humid and hot, the typhoon rainstorm is frequent, the rainfall is concentrated, the seepage intensity of rock and soil is large, and the weathering and erosion of hilly areas are strong. As a result, granite residual soil is widely covered, 50% of which are distributed in hilly areas of southeast Fujian and coastal plains, among which the thickest is 50-7 m in Xiamen area. Therefore, granite residual soil is widely found in southeast provinces. The mountainous, hilly and denuded quasi plain, which are encountered in the engineering, are all distributed in the residual soil, which is an important medium for the foundation and geological environment of most projects. Fujian Province is implementing the development strategy of the economic zone on the west side of the strait, reclamation, highway and railway, port wharf, Fuzhou subway, Xiamen subway and other geotechnical engineering prosperity unprecedented. Therefore, the research on the safety and stability of residual soil, engineering mechanical properties and landslide induced by rainfall in southeast coastal area is an important and urgent research topic in Fujian province to realize a new round of leapfrog development. It is of great theoretical and practical significance to prevent and control serious geological disasters such as major geotechnical accidents and landslides. Based on the project of Fujian Natural Science Foundation, "study on the mechanism of phase evolution of landslide in loose rock mass and geological hazard of debris flow under heavy rainfall", the paper takes granite residual soil widely distributed in Xiamen area as representative soil sample. Through laboratory test, rainfall landslide simulation test, geotechnical mesoscopic detection and analysis, geotechnical mesoscopic imaging analysis and digital processing, the main research work is as follows: 1. By consulting the literature at home and abroad, this paper summarizes and analyzes the relationship between soil moisture content and the physical properties of rock and soil and its mechanism of action, which provides the basic basis and reference for the formulation of the experimental research scheme. 2. The granite residual soil in Xiamen area was collected as the representative soil sample, and five samples with different moisture content were prepared. The relationship between moisture content and internal cohesion, internal friction angle was tested by direct shear test. Thus, the effect of moisture content on the mechanical properties of residual soil is revealed. 3. Taking slope of soil slope and rainfall intensity as control variables, 16 kinds of rainfall landslide simulation test schemes were designed. Under the condition of different rainfall intensity, the model of soil slope with different angles is simulated, and the statistical analysis of the test results is carried out, and the law of soil instability and failure is discussed from the macroscopic point of view, and on the basis of this, The prototype test and investigation results of soil failure are summarized to verify the rationality of the model test results. 4. A large number of images and photographs are collected by using the geotechnical mesoscopic change image acquisition and analysis system. Through image processing technology and computer language, the image processing program is compiled to calculate and process the mesoscopic motion data and track of soil particles. From the view of meso, the law of microcosmic evolution of soil mass instability and failure of rainfall landslide is revealed, and the relationship between the macroscopic failure form of soil mass instability and the evolution of mesoscopic motion is revealed.
【学位授予单位】：厦门大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P642.22;TU43

【参考文献】