Research On Check Valve Drainage System And Its Influence On Anti-floating Stability Of Concrete Lining For Chanel

Cannel is widely used in water transfer project. Concrete lining may be floated bygroundwater if channel was built in area with high groundwater table. It is necessary totake engineering measure to ensure the anti-floating stability of concrete lining, andone of the choices is the check valve-drainage system, which is used in the MiddleRoute Project of South-North Water Diversion. If groundwater pressure is greater thanthe water pressure in the channel, check valve will open to let groundwater flow intochannel. Otherwise, check valve will close to prevent channel water leakage. Checkvalve plays a key role in the system, as a result, the drainage system is named checkvalve drainage system. This thesis aims to study check valve drainage system and itsinfluence on anti-floating stability of concrete lining. The“one-way flow controltechnology research” is an immportant part o“fExpansive soil rock seepage control anddrainage technology”,which is“National Twelfth Five-Year”Plan for Science&Technical Support (No.2011BAB10B04).The author took part in this project. Mainwork includes research&development of the new check valve， research onperformance index of check valve&its test methods，and studies on the seepagecontrol effect of check valve&its application conditions.Main content of the thesis is listed as follow:(1) Exsiting problem and technical status of check valve is analyzed.Theperforming mechanics of check valve is expounded. The further development andtechnology improvement of check valve are put forward.(2) With check valve considered as overflow type drainage hole, finite elementmethod is studied for the simulation of seepage field in slopes and foundation of canal.(3) Pressure difference of two sides of lining and flow rate of the check valve arestudied for various arrangement of check valve-drainage system in typical section andengineering situation by numerical method. The influence of key factors of checkvalve-drainage system is studied according to simulation results, such as permeablematerial of blind drain, spacing of blind drain, diameter of check valve and permeableof soil layer, on the anti-floating of concrete lining.(4) New check valve with specil switching element was invented. The internalstructure style and structure material of the check valve was optimized. Based on theprinciple, the design idea of the pressure differential amplification check valve surpassoriginal similar equipment. The flow variation trend formula of check valve alongwith the head variation is formalized.(5) Performance index of check valve based on the Middle Route Project ofSouth-North Water Diversion are put forward. Test method is researched, and TestInstrument is designed and consummated.