Study On The Deformation And Bearing Behavior Of The Wall With Inclined Shaft Cross Flow Sand

In order to meet the needs of the inclined shaft construction with flow sand formation inthe western region of China, based on the engineering background of Li Giaba coal inclinedshaft construction through flow sand layer, according to engineering and hydrologic geologyof the flow sand formation in the mining and the features of inclined shaft lining structure,through the combination of indoor experiment, numerical simulation and field measurement,the research of deformation and bearing characteristics of wall with inclined shaft throughflow sand formation was conducted, some research results wre obtained which not only haspractical guiding significance in the inclined shaft construction safely, but also can providetheoretical basis for the design of inclined shaft lining structure in the special strata.Through the thesis we got many findings and conclusions such as:(1) According to the geomechanical properties of flow sand strata of Li Giaba coal, byaccess to literature referring to the flow sand formations engineering characteristics andformation conditions of flow sand was analysised. Combined with laboratory experiments, theshear strength characteristics under different moisture content in the same sand was resarched,the variation of shear strength, cohesion and internal friction angle variation with moisturecontent were obtained. In addition, the factors affecting the inclined wellbore stability wassummarized.(2) Useing the numerical software FLAC3D, through the establishment of large-scalethree-dimensional numerical model, under the influence of the different thickness of flowsand, the operator loads and influence of grouting effect, the interaction between convectionand the inclined wall of sand were studied, deformation and force characteristics undervarious factors formations, formation of displacement and stress along different pathsvariation, characteristics of deformation and force of inclined wall structure, displacement andhoop stress variation of typical points of different wall and deformation and stress distributioncharacteristics along the edge of the path and outside wall were obtained. Interaction law ofinclined wall and flow sand strata was sastered.(3) The wall as a beam element, through the establishment of two-dimensional numericalcalculation model for analyzing the internal force bearing characteristics of the shaftliningstructure, the internal force distribution characteristics of borehole wall and the formationpressure, bottom arch radius and Side-wall height on the influence law of internal forcedistribution of shaft wall were getted; Through the establishment of three-dimensionalmonolithic reinforced concrete finite element model, the ultimate bearing characteristics ofshaft wall was further studied, the laws between the ultimate bearing capacity of shaft wall and the strength of concrete, wall thickness, wall height, bottom arch radius and thereinforcement ratio were getted.(4) Combined the project―Technology research of inclined shaft through flow sandformation of Li Giaba coal‖, according to the project overview of special water containingsand of Li Giaba coal, supporting way of steel and reinforced concrete structures was chosedand wall structure parameter was obtained through checking bearing capacity. and thenthrough the field test of stress and deformation of wall, the variation of contact pressurebetween the steel and formation, contact pressure between the steel and the wall,reinforcement force, wall deformation and water pressure has been the contact pressurebetween the contact pressure and formation of steel, steel and the wall between thereinforcement force, wall deformation and changes of water pressure after linin wereobtained.Research conclusion can afford information and services for latter designs, constructionsof Li Jiaba mning as well as similar condition about other flow sand formation inclined shaftin China.