Sensitivity Analysis And Grouting Material Research Of Submerged Inclined Well Under Fractured Weathered Granite

Underground inclined shaft is a common temporary structure in the process of urban underground space construction.It is mainly used for main slag discharging and feeding passage.Most of them are constructed by mining method.The nature of the rock mass in the excavation section and the load effect of the surrounding structures(structures)directly affect the stability of the inclined shaft.During excavation,it is necessary to maintain the stability of surrounding buildings,especially those directly related to the structural safety of ground buildings.Therefore,in the process of design and construction of underground inclined shaft,it is necessary to study and analyze many factors,and strengthen the feedback of monitoring information.Based on the inclined shaft project of Wusi Square Station of Qingdao Metro Tunnel,this paper simulates the stability of inclined shaft by combining the field monitoring data,and makes sensitivity analysis of the parameters affecting the stability.According to the analysis results,suitable grouting materials are prepared,which provides a new idea for the preparation of grouting materials for similar inclined shaft passages.The details are as follows:(1)Collect and consult relevant literature,briefly summarize the research status of stability and sensitivity analysis of underground inclined wells at home and abroad,introduce the application of grey correlation method in sensitivity judgment of various influencing factors in underground inclined wells,and select the relevant theories needed in this paper by drawing lessons from existing research results.(2)Firstly,the excavation condition of inclined shaft is simulated by MIDAS/GTS NX software,and the result nephogram is analyzed.Comparing the monitoring data with the simulation results,there are some differences between the simulation results and the monitoring data.The simulation results are basically consistent with the monitoring data in deformation properties,which shows that the model has certain application value in the sensitivity analysis of influencing factors.(3)The strength reduction method was used to reduce the main mechanical parameters of the soil by 25%,50%and 75%,and the corresponding results were simulated.In this paper,the influence of various parameters of soil on the inclined well is reflected by the displacement variation index,and the gray correlation analysis method is used to classify the sensitivity.The results show that the main factors affecting the stability of the buried digging well are the soil cohesion,the soil friction angle and the soil elastic modulus.(4)According to the sensitivity ranking,the parameters of surrounding rock and soil are optimized from the point of grouting material,and the grout is selected to gradually optimize the grout design parameters.The grout tested can better reinforce the fractured surrounding rock mass,balance the internal pressure of the surrounding rock,and the stone body formed can better improve the overall stability of the weathered fractured rock stratum.