Dynamic Response Analysis Of High Fill Embankment Under Earthquake Loads

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 .