Stability Analysis On The Deposition Slope Of Wuwei Tiantan Grottoes And Its Treatment

The Tianti Mountain Grottoes?Wuwei?,known as the originator of China's Buddhist grottoes,are the source of the inheritance and development of Buddhist architecture such as Yungang Grottoes and Dunhuang Mogao Grottoes.It has important artistic and historical research value.At the same time,it is also a national key cultural relic protection unit.At present,it has attracted the attentions of the museum managers and people from all walks of life because of the serious development of building cracks and the obvious slip signs of the existing mountain.Therefore,it is urgent to find out the causes of diseases in the museum and fundamentally control them.The landslide mass of the Tianti Mountain Grottoes Museum is taken as the object of this study.Based on the analysis of the causes of building diseases in the museum,the stability of the landslide behind the museum wall is researched.On the basis of full investigation of the geological environment of topography,geological structure,hydrogeology and so on,the characteristics of existing environment of landslide mass are analyzed.The high density resistivity method is used to reveal the characteristics such as the thickness of the cover layer,the depth of bedrock and the distribution of moisture content of the soil.Using the inversion of resistivity profile and the characteristics of the soil slope,the potential slip surface of the landslide is preliminarily judged,and these results above are mutually verified with the geological drilling.Through the analysis of the causes of landslides on the basis of geological environment,the main factors such as slope excavation and water infiltration causing the landslide damage are determined.Finally,the failure mechanism of landslide mass is analyzed.Based on the qualitative analysis of the landslide mass,combined with the test data of the laboratory mechanical test of the soil and rock mass,the quantitative evaluation of the landslide steady state is carried on.In this paper,the landslide state is divided into three stages: before excavation,after excavation,and after a large amount of surface water infiltration.The numerical simulation is carried out by strength reduction finite element method to compare and analyze the variation of axial displacement,?₃ and ?₁-?₃ stress,and yield range of the slope.The results of the numerical analysis show that the landslide is in the form of creep deformation,which occurs after excavation,especially after surface water infiltration,and prove that after the construction of the museum,the main factor that causes the landslide deformation is the lots of watering infiltration for the landscaping.Meanwhile,the results above demonstrate that the main reason for the cracks in the museum is the landslide thrust rather than the differential settlement of the foundation.According to the economic and special requirements of the disease management in the cultural relics scenic spot,based on the landslide creep thrust and characteristics of stratigraphic lithology,a comparative study on the common measures of landslide treatment,such as pressure slope toe protection scheme,framed anchor scheme,slide-resistant pile scheme,and stabilizing pile with anchor cables scheme,is carried out.Finally,the scheme of using the stabilizing pile with anchor cables to manage the project is put forward,and the measures of interception and drainage in the landslide mass are emphasized.