Three-dimension Stability Research On Slope In Complicated Stress Condition

The Cuipingshan Park is the second largest "forest park" and one of the most famous landscapes in our country, also, it is an important institution of cultural relic protest in Sichuan province. From fifties of the twentieth century when the landslide was just coming into being, a total economic loss added up to thousands upon thousands yuan , After the anti-slide projects had been put into practice on Jan., 1999, it was stable at that time by the inspection. But many people have been building constructions since Mar., 1999, and the building area has come to 15,000 square meters. The stability of the Cuipingshan landslide once more becomes the heated and cared question of the government and people of Yibin city. So, this thesis is written to analyze the stability of Cuipingshan landslide in such a condition, and the comprehensive steps is as followings:Firstly, the paper discusses the selection of strength parameters of the slide surface, and on the basis of former researches, the thesis points out that it is more reasonable to use the residual strength parameters. And at the same time, this paper analyzes the relations between friction angle, moisture content, plastic index and contents of stickiness, furthermore, it determines the strength parameters of slide surface.Secondly, the paper expatiates particularly the character of three-dimension geometry of the slide and the loads at the top of slope and so on. Based on the basic theory of limit equilibrium, it discusses the three-dimension limit equilibrium stability analysis which can apply to the analysis of the Cuipingshan landslide. At last, the thesis discusses the influence of groundwater, loads, and seismic force on the stability of the landslide.In the part of finite element analysis, safety factor is calculated by strength reduce FEM. At the same time, it simulates the changes of stress, strain, safety factor and the spread of yield area at the nature and rainfall condition and so on according to the mohr-columb equivalency area yield rule assigned by professor Yingren Zheng. Throughcomparing and analyzing the results of inspection and calculation, it is indicated that the strength parameters of slide surface is rational, and the three dimension limit equilibrium is feasible. At the same time, it is also indicated that a reasonable and effective method is necessary to analyze the stability of slope. At last, this thesis evaluates the stability of the slide, and gets a conclusion that the landslide is stable at present loads condition. Because the loads have reached to 84.3% of the critical loads, if continue increasing the loads at the top of the sliding body, the slide may relive and threaten the safety of lives and properties. And the paper gives some advice on the protective construction in future at the same time.