【作者】 何国先；

【导师】 杨成忠；

【作者基本信息】 华东交通大学 ， 道路与铁道工程， 2011， 硕士

【摘要】 我国地处于世界两大地震带—欧亚地震带与环太平洋地震带之间,是个地震灾害严重的国家。随着我国改革开放政策的不断深入,西部地区公路工程的建设也得到了快速发展。西部山区的地形地貌条件十分复杂,路线中的高填深挖工程是不可避免的,因此高填方路堤已成为西部山区很常见的一种路基型式。考虑到道路的经济性和填挖平衡,高路堤采用土石料填筑已是一种发展趋势,但是这种高填石路堤一旦遭遇地震破坏,势必会给整个路堤造成严重的工程破坏,不但带来了巨大的经济损失而且给救灾行动带来很大阻碍。目前,我国针对高路堤抗震方面的研究很少,高路堤的建设也缺乏相应的系统理论和实践指导。因此,本文结合沪蓉西高速公路填筑高度达72m的干沟高填石路堤,应用专业软件Geoslope2004,建立二维有限元模型,采用等效线弹性理论,模拟地震荷载作用下高填方路堤的动力响应变形性状,分析了填筑高度、边坡坡度、填土类型、地震烈度和地震波类型对高路堤动力响应的影响,并通过对路堤土工加筋研究了土工格栅在路堤抗震中的作用,获得的主要成果如下:(1)在阅读了大量的相关文献的基础上,系统的归纳总结了高路堤的研究现状及其发展,概况了传统的静力稳定性分析法和动力稳定性分析法,还有地震反应谱法等边坡稳定性分析法的发展、应用和特点,并指出边坡动分析中主要研究的内容和存在的缺陷,反应谱分析法势必会成为今后工程边坡动稳定性分析法中的常用方法。(2)选取典型高路堤横断面建立有限元分析模型,输入地震波模拟地震荷载作用下高路堤的动力响应,并通过改变路堤填筑高度、边坡坡度、填土类型、地震烈度和地震波类型来分析这些因素对路堤动力响应的影响,结果表明:路堤填筑高度、填土类型和地震烈度对路堤动力响应影响很大;而边坡坡度和地震波类型对路堤动力响应也有一定的影响,但是效果比前三种因素较小。得出在实际工程许可的情况下,降低路堤高度、选取强度好的填土和提高路堤抗震震级设计都可以很好的降低路堤的动力响应。(3)通过对高路堤进行土工加筋,对比分析路堤加筋前后的动力响应变化,结果表明:路堤加筋后的动力响应和提高路堤填土强度、弹性模量及粘聚力的动力响应有相似的效果,这也符合土工加筋理论中的准粘聚力原理。路堤加筋后,路堤的侧向位移明显减小了36.22%,从而可以有效的防止边坡的滑移和路堤整体的开裂,土工格栅对路堤竖向位移减小并不明显,但还是可以很好的抑制路堤的整体沉降和提高路堤的抗震性能。更多还原

【Abstract】 China locates between the two major seismic belts in the world——the Eurasian seismic belt and the circum-Pacific seimic belt, thus, it is a serious seismic damage nation. As China’s deepning reform and opening up policy, the west highway constraction project has also been a rapid development. Because the western mountains has very complicated topography, so high filling and digging deep in the project is inevitable. Thus, high fill embankment has become a common embankment type in western mountain. Taking into account the economy and the road cut to fill balance, high embankment of stone filling with soil is a trend, but once this suffered earthquake damage, it is bound to give serious engineering damage to the whole embankment, not only with a huge economic losses but also great obstacles to the resure operations. At present time, there is little research for high embankment earthquake, and the construction of high embankment is also lack of corresponding system theory and pratical guidance. Thus, the paper bases on 72metres of dry-ditch high embankment in Shanghai- Chengdu Expressway West, using professional software to establishes two dimentioual finite element model,adopting Equivalent linear elastic theory, simulating deformation properties of dymamic response of high eambankment under earthquake loads, analysis of the impact of filling height, sloping gradient, filliing type,seismic intensity and type of the seismic wave on dymamic response of high embankment. In addition, by reinforcing soil to research function of geogrid in quakeproof of embankment, and the main results obtained are as follows:(1) After reading a lot of the relevant literature,in the paper, the researth situation and recent development of high embankment are summed up systematically,and the development, application and character of the traditional static stability analysis method ,dyramic stability analysis method, seismic response spectrum analysis method and so on slope stability analysis mothod are summarized. In addition, it pointed out the main contents and the defects of dynamic analysis of slope in the paper, and response spectrum analysis method must become a common analysis method in the future engineering.(2) Model Analysis selected a typical cross-section of high embankment to establish finite model analysis model and inputed seismie waves to simulate the dynamic response of high embankment under earthquake load. By changing the height of embankment, slope gradient,fill type., seismic intensity and type of seismic waves to analyze these factors on the impact of the dynamic response of embankment. The results show that : embankment height, fill types, and seismic intensity have great influence on the dynamic response of embankment; and the slope gradient and the type of seismic wave have a certain impact on the dynamic response of embankment, but its effect are less than the front three. reducing the height of embarment,choosing good strength soil and improving the seismic magnitude of embankment that all can reduce the dynamic response of embankment.(3) By adding greogrid in high embankment, to comparative analysis the change of dynamic response before and after, we can obtain the results from the analysis as follows: dynamic response of reinforced embankment has a similar effect as improving strength, elastic modulaus and the cohesive, This is also meet with the principle of associate cohesion. After the reinforced embankment, lateral displacement of the embankment is reduced by 36.22%, so it can effectively prevent slope sliding and cracking of the whole embankment, the influence is not obvious for the vertical displacement of the embankment to add in geogrid, but it still can have good inhibition of the settlement of the embankment and increase the capability of anti-seismic of embankment .更多还原