企业战略论文高液限土强度特性及路堑边坡稳定性研究.doc
高液限土强度特性及路堑边坡稳定性研究 高液限土强度特性及路堑边坡稳定性研究 The Study on Strength Characteristic and Cutting Slopes Stability of High-liquid Limit Soil【中文摘要】 广东省境内广泛分布的高液限花岗岩残积土,由于母岩的影响,与其他成因的高液限土相比,它不但具有天然含水量高、饱和度大、液限高、孔隙多、压缩性大、渗透性差、不易压实等共性,还具有自身特殊的工程性质。本文以广梧高速公路沿线分布的高液限花岗岩残积土为对象,通过室内试验和微观试验从不同的角度研究其物理力学性质,发现高液限花岗岩残积土与典型高液限粘土、粉土相比,最大的不同在于粗颗粒含量较高,属于混粒土,由此而造成其工程性质的独特性:其内部结构松散、膨胀性很弱、粘性很差、遇水易散、粘聚力很低,应力一应变关系没有明显的应变软化现象,强度的衰减来源于粘聚力遇水后的丧失,内摩擦角的降低并不明显。而室内反复剪切试验无法对这种土的残余强度作出很好的测定,其结果可信度不大,有待改进。利用试验资料对广梧高速公路的路堑边坡进行了整体稳定分析和土工离心模型试验,结果表明高液限花岗岩残积土路堑边坡的破坏特征不仅表现为整体失稳,出现坍塌、滑坡等,而且坡面极易发生冲蚀、溜塌等现象,因此开挖过程中,应边开挖边加固,并及时地进行排水和坡面防护工作。【英文摘要】 There is a wide range of granite weathering residual soil distributed in Guangdong Province.Compared with other high-liquid limit soil,influenced by parent rock it has special engineering characteristics besides the common traits of high natural water content,high saturation,high liquid limit,porosity,high compressibility,low permeability and hard to compact.The high-liquid limit granite weathering residual soil along Guangwu Expressway was taken to study the physical-mechanical characteristics from different angle with laboratory tests and microcosmic-test.The most important difference between high-liquid limit granite weathering residual soil and other high-liquid limit clay or silt is the large content of coarse particle.It is a kind of mixed particle soil so that high-liquid limit granite weathering residual soil has its own specificities.It has loose microstructures,weak expansibility,bad cohesiveness,and no obvious strength softening.It is easy to loose when wet and cohesion reduces quickly.This is the main reason of strength decaying after wet,for internal friction angle is influenced less evidently.Besides,laboratory repeat-shear test can not determine the residual strength of this kind of soil well.So reliability of the results is not satisfactory.There is improvement to be expected.General stability analyses and centrifugal test were taken with the model of Guangwu Expressway cutting slopes and the data of laboratory tests.The traits of failure in high-liquid limit granite weathering residual soil cutting slope is not only general instability but also collapse,landslide and face impact erosion,slip in surface layer.So when excavating, reinforcement must follow closely an drainage and slope protection must be taken in time.【中文关键词】 高液限土; 花岗岩残积土; 含粗粒细粒土; 残余强度; 路堑边坡; 离心模型试验 【英文关键词】 high-liquid limit soil; granite weathering residual soil; fine-grained soil containing coarse particle; residual strength; cutting slope; centrifugal model test 【论文目录】摘要 4-5 ABSTRACT 5 目录 6-7 第1章 绪论 7-20 1.1 高液限土的定义 7 1.2 研究背景及意义 7-8 1.3 研究现状 8-19 1.4 本文研究内容 19-20 第2章 高液限土基本物理性质 20-34 2.1 工程概况 20-22 2.2 高液限土基本物理性质 22-23 2.3 试验概况 23-24 2.4 基本物理性质试验 24-27 2.5 微观认识 27-32 2.6 试验成果分析 32-34 第3章 强度及软化特性 34-44 3.1 抗剪强度试验 34-36 3.2 抗剪强度与含水量的关系 36-37 3.3 残余强度 37-42 3.4 浸水软化试验 42-43 3.5 高液限土强度特性结论 43-44 第4章 高液限土路堑边坡稳定分析 44-57 4.1 高液液土路堑边坡常见病害 44-45 4.2 边坡稳定分析概述 45-48 4.3 整体稳定分析模型 48-51 4.4 实例计算 51-55 4.5 结论 55-57 第5章 离心模型试验 57-74 5.1 土工离心模型试验概述 57-58 5.2 模型参数选取 58-59 5.3 试验步骤 59-68 5.4 试验结果 68-72 5.5 结论 72-74 第6章 结论与展望 74-76 6.1 主要结论 74-75 6.2 进一步研究的建议 75-76 参考文献 76-80 致谢 80
