The Stability Analysis And Treatment Of Technical Research For Expensive Soils Cut Slope In Nanning-YouYiGuan Expressway

While passing through the edge of Ningming county town , The Nanning-Youyiguan expressway under construction encouters expansive soil with continuous distributed and 14 kilometres long and all cut slope seems to have sign to lose stability . Most cut slopes have already collapsed and slided in various degree with time passing and project proceeding, that even influence normal construction of the road foundation seriously. How to take the effective project to treat and guarantee the stability of the cut slope, has become the largest technological difficult problem badly in need of solution in The Nanning-Youyiguan expressway's construction. According to this, the stability analysis and treatment of technical research for expensive soils cut slope in Nanning-YouYiGuan expressway have been studied in this paper. First of all, along the Nanning-Youyiguan expressway's expansive soil distribute district, The general geological investigation on the spot has been carried on by the slide slope and collapse, especially for 23 among the slide slope ,of which detailed reconnaissance and analyse have been launched to find the destruction reasons one by one. On this basis, combine the laboratory experiments results of the soil testing, the soil property and geological features in engineering and the factors affecting stability of the expansive soil cut slope have been carefully analysed and summarized to get the unsteady main reason, thus it laid the foundation of establishing the destroy mode and stability analytical method corresponding to reality and proposing the effective project in engineering. In the light of the present situation that the existing destruction mode of slide slope and stability analytical method can not be suitable for slippery and collapse analysis in the Nanning-Youyiguan expressway's expensive soil cut slope, on the basis of reconnoitering, the slope stability analytical method in side, which has been thought and proposed by considering the crack , crevice water , weak structure obeys one layer, has been utilized to analyse the stability of the Nanning-Youyiguan expressway's expensive soil cut slope, The result proves that this kind of analytical method can reflect the reality of cut slope destruction in the Nanning-Youyiguan expressway. Meanwhile, to set up a method of stability prediction for new cut slope and prevent and cure it in time, equally based on the detailed geologic investigation and the study of cut slop, 5 leading factors , namely: Water content , rainfall , crevice rate, geological structure surface inclination, crevice and weak structure obey one layer, human project activity have been regard as index for the first time , so that the stability of slop can be forecasted accurately by gray control system model. The results indicate the method not only tallies with the objective reality but also it can be handled easily, it can look on as a simple and easy method for landslide forecast in expensive cut slope and for engineering reference.　At the foundation of summarizing the existed treatment experience of expansive soil cut slope both at home and abroad, and in view of the reality in the Nanning-Youyiguan expressway , for the first time the method of flexibility supports and protects has been adopted to, so as the new treatment technique by flexible retaining wall reinforced by geotextile for expansive soil cut slope, it obtain good treatment result, by which the difficult technological problem that "have slope must collapse "in expansive soil cut slope will be solved to expect. It has also carried on the preliminary discussion to reinforcement principle and main design philosophy of this technology in the article. Finally, through the entity of project of The Nanning-Youyiguan expressway's build, the construction craft of root pile and flexible retaining wall reinforced by geotextile has been put forward and summarized.