Seismic Performance And Sensitivity Analysis Of Intake Structure Of High Arch Dam

Arch dam intake,the use of arch dam front space to layout hydropower station intake,with a compact layout,space-saving,economical and practical advantages,has become a common arch dam subsidiary structure.In the case of an earthquake,the arch dam inlet serves as an upstream cantilever structure with numerous beams.If the structure is not properly designed,the key parts of the inlet will often generate large tensile stress.The safety of the inlet of the arch dam is not only related to the safety of the entire water diversion system,but also related to the safety of the arch dam body.Therefore,in order to meet the stress requirements of the inlet of the arch dam under earthquake conditions,various parts of the inlet.It is very important to set the proper size of the structure.This article can provide some reference value for the study of other similar tall or cantilever structures.In this paper,the numerical simulation analysis method is used to analyze the stress of the inlet and outlet of the arch dam under the static and dynamic load conditions to find out the key parts that affect the safety of the inlet.Then,a sensitivity analysis is performed on the relevant factors that may affect the stress at the critical site,and the sensitivity factors(No.1 pull beam size,sidewall thickening position and sidewall thickness)and non-sensitivity factors(No.2 pull beam size)are distinguished.Finally,through the adjustment of the size or arrangement of the sensitive factors(the size of the No.1 beam,the thickening of the side wall and the thickness of the side wall),in order to achieve the desired goal.The main research contents and results are as follows:(1)Through the stress analysis of the static and dynamic load conditions of the inlet of the arch dam,it is found that under the seismic conditions,the Z-direction tensile stress(axial tensile stress)of the beams at the inlet is relatively large;The X-direction(in the direction of the flow)tensile stress and Y-direction(vertical direction)tensile stress are relatively large.(2)By studying the influence of the change in the size of the No.1 pull beam on the key parts of the intake of the arch dam,it is found that the appropriate increase in the size of the puller beam far from the dam can effectively reduce the Z-direction tensile stress and the Y-direction tensile stress of the side wall.However,it has little effect on the tensile stress in the Z direction of other pull beams and the X tensile stress on the side walls.(3)By studying the influence of the change in the size of the #2 pull beam on the key parts of the intake of the arch dam,it is found that the increase in the size of the puller beam closer to the dam has little influence on the Z-direction tensile stress of all the pull beams.(4)Based on the principle of whiplash effect,through the study of the thickening of the side wall,we found that when the thickening of the side wall is 0+0m~0+40m,that is,when the overall length is thickened,it is the most appropriate solution.Through studying the influence of the thickness of the side wall on the key parts of the inlet of the dam,it is found that when the thickness of the side wall increases within a certain range,the Z-direction tensile stress of all the pull beams can be effectively reduced;and the X-direction of the left and right side walls is also made.Tensile stress and Y-direction tensile stress are reduced.