Study On Safety Warning Criterion For Deformation And Failure Of Combined Pipe Gallery With Loess Excavation And Filling

The construction of high fill projects has provided a large number of construction sites,but also changed the original loess hilly and gully landforms,bringing new and urgent problems to be solved.The settlement and deformation of high fill sites are large and stable for a long time.There may be safety problems of underground pipelines in engineering construction.Based on the planning and design of the construction site of the Loess Hilly and gully area in Shaanxi Province,the paper introduces the theory of fault diagnosis and the method of combining the similar physical model test with the ABAQUS numerical simulation,and makes a series of discussions on the deformation characteristics of the comprehensive tunnel in the Loess fill area.The conclusion is combined with the results of simulation analysis,and the following conclusions are drawn:1.The failure factors in the comprehensive pipe gallery fault diagnosis can be divided into three categories: pipe gallery deformation,fire and human factors.Finally,determining the deformation and failure of pipe gallery is the most important factor;2.There are 3 kinds of monitoring indices for the deformation and failure of composite pipe Corridors: axial strain,interaction force between pipe and soil,and displacement.According to the monitoring index,strain gauge is used to monitor strain and earth pressure box to monitor the interaction force between pipe and soil,and displacement data to collect displacement data;3.The deformation and failure of the integrated pipe gallery mainly includes two forms: crack and buckling.4.The rule of stress and displacement along the axis of the integrated pipe gallery under the uneven settlement of loess under excavation.5.The law of the stress,displacement and earth pressure of the soil under the uneven settlement of loess in the excavation site.6.Through the combination of test results and structural mechanics,3 mechanical models and 3 early warning criteria for the deformation and failure of integrated pipe gallery are obtained.In this paper,on the basis of literature analysis and on the basis of the existing research results,the deformation and stress of the comprehensive tunnel in the Loess fill area are studied and analyzed,and some regular knowledge is obtained.The research method and the regularity of this study will be of great significance to the study of the early warning criteria for the combination of excavation and filling.