Study On The Deformation And Stability Characteristics Of Slope Containing Vugs

Based on the background of a building foundation pit slope engineering project in Chenzhou City,this paper establishes the model of experimental analysis on the basis of two typical karst cave section in the slope.Through model test and numerical simulation,the deformation and stability characteristics of building slope containing karst cave are studied.The main conclusions and results are as follows:(1)In this paper,through the analysis of karst topography and hydrological geological conditions in Chenzhou Hengda a building foundation pit slope project,the instability and failure mode of slope is summarized in karst area in Chenzhou,on the basis of this analysis to determine the simulation range of construction slope model containing cave,grounding on similarity theory and combined with field typical slope section of rock test parameters,similar materials for model test are selected.Based on the orthogonal experiment design,the ratio of similar materials was developed confrom to the principle of similarity.(2)Under the action of vertical excavation and top loading,deformation and failure characteristics of slope are analyzed through two different groups of karst cave distribution type of slope model test.Research shows that cave surrounding rock deformation,rock stress force change and excavation horizontal displacement of slope can well reflect the karst slope stability and deformation failure shape in the process of top building loading and vertical excavation.The three have a sharp increase and good consistency.The destruction from of building slope containing cave is typical shear failure mode that collapse of karst cave roof leads to overall instability failure of slope.Acoustic emission characteristics of the activities of the measurement results show that there are a large number of characteristics and overloading damage in the process of the slope excavation and overloading damage,and acoustic emission in slope occurs first in the cave roof and near the cave.The prediction performance of the acoustic emission in the monitoring of failure of building slope containing cave is reflected.(3)Based on FLAC3D software,stability factors affecting sensitivityanalysis of slope containing vugs was carried out using the orthogonal design method.The influence of different sizes and positions of the different karst caves on the excavation slope of the building foundation pit is studied.Research shows that the size and distribution of karst cave have adverse effect on the stability of building slope under the same influence factors,but its distribution has little effect beyond a certain range.When the slope is excavated,the different size and location of karst cave have different influence on the deformation characteristics of the slope.The influence of karst cave on the stability of its deformation is more prominent while the karst cave is located in the middle of the slope.In addition,the model test was simulated and analyzed by this software,the calculation results with the model test results in accordance with the rules of scientific research.