Study On Stability Evaluation And Supports Of Slope Excavation In The Nearby High-rise Buildings

In recent years,there have been more and more cases of building roads in residential areas.The construction of highways often leads to the excavation of slopes,especially in the case of deep excavation of high-rise building slopes.Protection measures of deformation control are particularly necessary.Exceeding a certain amount of deformation will seriously affect the safe use of buildings above.Therefore,this paper combines the actual engineering cases to evaluate the stability of different excavation methods of the slope.In addition,the final deformation value is used as a criterion to evaluate the validity and rationality of the support measures to control the excavation deformation value of the slope..Provide design reference for engineering construction.Therefore,on the basis of field investigation,this paper uses three-dimensional numerical simulation to restore slope prototypes,obtain deformation displacement values of slopes under different conditions,simulate different excavation methods and support measures,and make corresponding analysis and evaluation.It provides reference and reference for the construction of similar projects.The paper has got the following results:(1)Developmental regularity of joints in the study areaBy investigating the development orientation,filling conditions,opening degree and roughness of the joints in the site,the development of different lithologies and overall joints in the study area was obtained,and the potential deformation failure mode of the slope was predicted to be flat.plane Slip damage and wedge damage;(2)Slope rock mass classificationFor the excavation of rock masses in the trench section,rock mass classification is carried out.The classification methods are BQ method,RMR method,and SMR method.According to the classification results,the slope rock mass grades are III-IV rock masses.The Maocaopu Formation dolomite is mostly type II rock mass,the type III rock mass is moderately weathered muddy dolomite,part of the marl,and the IV type rock mass is mudstone,strongly weathered muddy dolomite,marl,etc.The rock masses are mudstones,strong or fully weathered marls and rock and soil cover.(3)Value of rock mechanical parametersIn order to further obtain the mechanical strength parameters of rock masses and structural planes,field large-scale direct shear tests and indoor structural face shear tests were designed.In the field large-scale direct shear tests,three groups were designed: Class II rock dolomite,Class III rock muddy dolomite,and Class IV rock mudstone.Three groups of structural plane design were recorded as type I(math dolomite,Mud-rich),Type II(Dolomite),Type III(Dolomite mud).According to the test results,the strength parameters of rock mass and structural plane in the study area were finally determined.(4)Stability Analysis of Rigid Body Ultimate Equilibrium SlopeThe section 8-8 of the study area was selected as the research object.With drilling video and drilling engineering,the longer and larger structural planes developed in the section 8-8 were carefully analyzed and analyzed.The analysis of the occurrence of the structural plane,the extension direction,the extension length and the mutual combination of the structural planes was carried out on the 8-8 section to identify potential destabilized and unstable boundaries.The natural slopes and the slopes under natural conditions were analyzed separately under different excavation conditions.The coefficient of stability under heavy rainfall and seismic conditions.Evaluation of slope stability based on stability factor(5)Determination of displacement criteria and research on supporting methodsDue to the existence of buildings above the slope,it is necessary to consider the deformation of the building under excavation conditions,consult relevant data and specifications,and finally determine that the criterion for the “instability” of the slope is that the lateral deformation is greater than 30 mm,with the help of Flac3 d numerical analysis software analyzes the internal stress,displacement and monitoring curve of the slope under natural slope,under different excavation conditions and under different support measures.Judging the "stability" of slopes and evaluating the effectiveness of support measures.