Study On The Influence Of Lining Defects Of Hydraulic Tunnel And Its Coping Technology

Hidden works in tunnel engineering,the cavities behind the lining and lining thickness defects exists in construction,so the hydraulic tunnel,and water rich in hydraulic tunnel,it may affect the safe operation of the tunnel,so it is necessary to study the influence of water environment on the tunnel lining defects,and put forward the corresponding technology.Based on the previous studies,the main work and conclusions are as follows:(1)Through the literature survey to understand the common tunnel lining defect location and defect status,for the development of numerical simulation program to provide the necessary parameters.(2)Based on the fluid solid coupling theory,using the finite element software to establish the model of hydraulic tunnel lining are empty,analyzes the influence of hole position and size and internal pressure and other factors on the stress characteristics of lining.The analysis shows that the cavities behind the lining defects affect the tunnel lining stress distribution,especially near the hole lining hole location,size and water pressure,Before the water filling of the tunnel,the stress around the lining is "lateral compression,internal tension",the tensile and compressive stresses are small,and the stress distribution law is basically unchanged after water filling,but the stress value increases greatly;If there are cavities behind the lining,the lining of the stress distribution in the vicinity of the "lateral tension,inner compression " trend,this trend in the process of change will appear in the state tension of the whole section,this state is unfavorable to the lining structure,especially the internal water pressure is large,but the empty distance stress distribution the basic law is not affected by the above factors.(3)Considering the effect of inner water exosmosis coupling,establish the model of hydraulic tunnel lining thickness lack by finite difference software FLAC3 D,analyzes the effect of lining thickness lack location,degree of defect and internal pressure on the stress characteristics of lining.Analysis shows that the law of the lining water pressure and the effective stress is similar to the influence of cavity,but need lining thickness lack serious to some extent,the whole section tension condition was more obvious,with the water pressure increases.Therefore,when the lining itself is flawed,when filled with water before the impact is not great,but the stress will change after filling water,which will appear in tension conditions detrimental to the whole section,the structure of the force,especially the water pressure is large,prominent,must strengthen the construction process control and operation periodmaintenance,reduce defects,reduce the risk.(4)The technology of handling lining defects mainly includes the prevention of the survey,design and construction,and the renovation of the operation stage(backfill grouting,inner surface reinforcement,bolt reinforcement,etc).