Study On Stability Of Rock Fill Embankment In The Passenger Line From Guiyang To Guangzhou

In the railway construction at mountain areas which is rich in stone, it is not only affordable but also green and sustainable to construct rock fill embankment. At some kind of degree, the forms of rock fill embankment can not be avoid, but considering the specificity of the materials, further research is needed, that will be helpful to guide the design and construction further.This paper was written with some parts of the research of "the key technology in constructing embankment of the passenger line from Guiyang to Guangzhou with hard rock " which was chaired by professor Luo Shu Xue, and the main research direction of this paper is overall stability of the rock fill embankment and stability of its slope.Considering the actual situation of the experimental section of the passenger line from Guiyang to Guangzhou, the internal and external factors which affect the stability of embankment are analysised, and eight factors which include thickness of soft soil,height,slope rate,spacing of pile,diameter of pile,depth of pile,spacing of geogrid and load on the top of embankment. The mechanism between those factors and stability is discussed by the using of PLAXIS which is a geotechnical finite element software.After the analysis of FEM, a new regression estimation model based on principal component analysis and support vector regression is proposed which can be used in the analysis of rock fill embankment, the model is applied to two engineering examples which proved that it is scientific and applicable. And the predicted results of the slope stability are obtained efficiently by using this model in additional analysis of the passenger line from Guiyang to Guangzhou.Considering the analysis of FEM, the main conclution is:cement fly-ash grave pile can significantly improve the stiffness of embankment and its ground, and the pile-board program is better than the pile-cap program; The stability of rock fill embankment is related to the diameter and the depth of pile, but anti-related to pile spacing,geogrid spacing,height of embankment,slope rate,thickness of soft soil and load on the top of embankment. In order to improve the stability of rock fill embankment, it is necessary to take measures to improve not only the strength but also the stiffness of embankment and its ground.By using a method combined principal component analysis and support vector regression calculation, advantages of the new method such as"small sample size,high accuracy, strong generalization, high efficiency, high efficiency" is proved and demonstrated. so the method has better applicability and broad development space in the analysis of slope stability prediction.