Scour Of Rigid Apron Bottom And Structural Stability Research

In recent years,with the continuous construction and operation of the water conservancy hub,it has brought the social and economic benefits such as power generation irrigation.At the same time,we should also pay attention to the repair and maintenance of the dam project,so that it will benefit mankind for a long time.Apron as an important energy dissipation work in the downstream protection of river channel can reduce the flow of the energy dissipation pool.And rigid apron structure for a long time b y the scour and may even lead to the basement of tunneling,and the emergence of structure damage and other problems in the fluctuating pressure of flow,which is the hub of the security risks.Therefore,the problem on water conservancy hub rigid apron basal scour problems and the fluctuating pressure of flow under the action of fatigue life,the conclusion can be apron structure design,using the phase state of judgment and provide a reference.The main research results and conclusions of this paper are as follows:1.To Changsha hub as an example by sediment of Shelds drag starting formula is simplified,using a single wide sand transport rate formula of calculating node on the bed surface erosion displacement distance and apron of a natural bed is simulated by using FLUENT software to scour lead apron basal vacant phenomenon,and apron basal scour mechanism were studied.2.According to the fatigue test results of the existing hydraulic concrete,the total cumulative plastic strain energy density of the structure is calculated by the energy method.The fatigue damage of the structure of the apron is caused by the fluctuating pressure of the water,which is caused by the scouring of the apron at the base of the Changsha hub.The results show that the structure of the fatigue damage is small,and the working life of the structure can meet the requirements.3.According to the above method,referring to similar engineering damaged condition,Changsha comprehensive hub of abnormal operating state assumption,of basement is seriously scour lead structure suspended length larger apron diffuse structure fatigue life analysis.The results show that the fatigue damage of the structure will be fatigue damage under the action of the two factors of the flow fluctuation pressure and the base suspension.In this paper,the two-dimensional river bed scour model can be used to simulate the scouring of the river bed.It is feasible to predict the fatigue life of the structure by using the energy method,which can provide reference for practical engineering.