| Water is the source of life,the source of production,and the basis of ecology.As an important project for people’s livelihood,water conservancy projects have multiple functions and benefits such as ensuring people’s life and property safety,promoting economic development,and improving the living environment and ecological environment.As an important hydraulic structure,the channel plays an important role in irrigation,shipping,power generation,water supply and other fields.When the channel passes through the section with high underground water level,the uplift pressure generated by groundwater will act on the bottom of the channel,and the rigid lining layer may be damaged by the uplift pressure.Therefore,in order to ensure the safe operation of the channel and the efficiency of water transmission,engineering measures should be taken to enable the groundwater outside the channel to be discharged in time and reduce the uplift pressure outside the channel.Through investigation and research,the reverse valve with one-way drainage function can effectively reduce the lifting pressure outside the channel.On the premise of summing up the previous research results,the author puts forward a new type of drainage decompression reverse check valve,and tests its performance.This thesis is completed by theoretical analysis,engineering investigation,experimental test and finite element numerical simulation.The main research contents and results are as follows:(1)Review a large number of literatures to understand the research status of channel lining stability;Examples of floating support failure of some related channels are described.To understand the research status of reverse drainage system,master the operating principle of reverse valve,summarize the technology and application status of reverse valve products and analyze the existing problems;At the same time,the research status of seepage theory at home and abroad is also known.(2)On the basis of mastering the operation and opening and closing mechanism of the reverse valve,a new type of drain pressure relief reverse valve for channel was developed and its performance was tested.The test results show that the new type of backstop valve has good performance of drainage and stopping water,which provides reference for the mass production and promotion of backstop valve in the future.(3)Based on the engineering example,the large-scale finite element software ABAQUS is used to simulate the operation effect of the reverse check valve in the actual channel engineering,and the influence of the reverse check valve on the anti-float stability of the channel lining is analyzed in detail.At the same time,the direction of further research and development and technical optimization are pointed out.The simulation results show that the reverse valve has a good effect on reducing pressure and protecting the lining of the channel. |
