【作者】 邹维勇；

【导师】 文江泉；

【作者基本信息】 西南交通大学 ， 工程地质， 2008， 硕士

【摘要】 膨胀土是一种富含亲水性矿物并具有特定结构和特殊工程性质的粘土,多以非饱和的状态存在,遇水则膨胀变形,失水则收缩干裂,具有较大的往复胀缩性。膨胀土是一种区域性土,在世界上分布十分广泛,而我国是世界上膨胀土分布最广、面积最大的国家之一。膨胀土给我国的铁路、交通、水利、工民建等工程都带来了严重的灾害,造成的经济损失也是触目惊心的。在国外,膨胀土被称为“昂贵土”,我国工程界曾将膨胀土看作“坏土”,具有“逢堑必崩、无堤不塌”之说。因此,膨胀土的工程问题已成为一个世界性的研究课题。本论文结合玉蒙线膨胀土,通过对膨胀土研究现状的理解和认识,针对当前膨胀土研究的重点和难点,本论文通过室内土工试验和现场科研段测试,主要就膨胀土的变形特性、强度特性等从理论、室内土工试验和数值分析三个方面开展研究。重点研究了不同含水率不同防治措施下膨胀土边坡的变形和稳定性状以及现场对路堤沉降、位移等测试。其主要研究内容为:1.现场调查沿线膨胀性红土、膨胀性泥岩及其全风化残积土的成因、分布特征。并通过常规土工试验测试膨胀土(岩)的主要物理力学指标,并进行统计分析。相关的土工试验包括:含水量、容重、击实试验、直剪试验等。2.通过室内土工试验研究膨胀土(岩)的膨胀率、膨胀力、抗剪强度及含水量、密实度的关系。3.依照膨胀土(岩)的膨胀率和膨胀力等特性指标,针对路堤不同高度、不同部位对填料的要求。分析膨胀土(岩)用作路堤填料的可行性和适用范围以及加筋及夹层等方法对膨胀土路堤边坡稳定的适用性。4.根据上面的研究成果,采用离心模型试验方式,模拟膨胀土(岩)加筋边坡路堤在不同加筋分层厚度、不同压实度和含水量下的路堤的稳定性。5.采用FLAC数值模拟软件,基于强度折减方法对建水盆地膨胀土路堤填筑边坡的稳定性分析。更多还原

【Abstract】 Expansive soil is a special clay which contains the mineral that gets close to water and has particular structure and particular character of engineering, it mostly exists by not-saturated, swelled with water and shrank without water, this character can be changed extensively.Expansive soil is a regional soil, it distributes widely in the world, and China is one of the countries which has the most area of expansive soil. The expansive soil has brought up serious disasters to the railway, traffic, water conservancy and resulted in large losses of the economy. Abroad, the expansive soil is called "expensive soil", and it had been looked as "bad soil" in our country. Therefore, the problem of expansive soil has been a cosmopolitan research subject.The author based on the research of predecessor carried on the research on theoretic, indoor experimentation and numerical value analysis through indoor experimentation and locale testing. and stressed to research the stability and distortion of the road bank of expansive soil at one containing water percent and with different reinforcing steel bar. It main contents that:1. investigate the cause of formation and distributing character of the expansive laterite and expansive muddy stone and completely weathering eluvium along the line locally. And take Statistic analysis by doing routine experimentation to test the main physics mechanics index of the expansive soil, the correlative experimentation contains water percent, density, tramp, straight cut experimentation.2. Research the relationship among the swelling rate, expansibility, shear strengthen, water percent and density by indoor experimentation.3. Accordingly to the index of swelling rate and expansibility of expansive soil, analyze the feasibility and the applicable range and the applicability of the way of adding reinforcing steel bar to different height of road bank and the request of padding in different parts.4. Accordingly to the above production, use the way of off center model experimentation to simulate the stability of the road bank with adding different thickness of reinforcing steel bar and different density and different containing water percent. 5. Use FLAC numerical value simulation software to analyze the stability of expansive soil road bank in Jianshui basin based on the method of intensity decreasing.更多还原