| The intake tower is an important part of the water conservancy project.In recent years,more and more water conservancy projects have been constructed in the high-intensity earthquake zone in the west.The height of the intake tower has gradually increased.The seismic performance of the intake tower has an impact on the entire water conservancy project.The importance of is becoming more and more prominent.Due to the characteristics of the water intake tower structure,the contact effect of the water intake tower with rocks and backfilled concrete,the seismic characteristics of the water intake tower are very complicated.In order to study the impact of different seismic effect calculation methods and boundary treatment methods on the seismic performance of high-rise intake tower structures,this paper uses ANSYS finite element software to conduct in-depth research on the structure of the intake tower of a hydropower station’s power diversion tunnel.The specific research content and conclusions It can be summarized as follows:(1)Establish a three-dimensional finite element model of the intake tower,use the mode superposition response spectrum method to calculate the seismic effect,and calculate and check the displacement,stress and overall stability of the intake tower structure under seismic conditions.According to the calculation of response spectrum analysis method,the three-directional displacement value of the water intake tower is not large,but the maximum value of concrete tensile stress in most parts exceeds the design tensile strength of concrete,and when the overall stability is checked by the material mechanics method,the bearing capacity of the foundation And anti-overturning stability cannot meet the requirements.(2)Using artificial seismic waves to perform linear elastic time history analysis on the water intake tower,and comparing the results with the response spectrum analysis method,the maximum value of the three-dimensional displacement and the maximum value of the tensile stress of each part are reduced,and there is only a cross-flow connection.The maximum tensile stress along the axial direction of the beam and the downstream connecting beam end exceeds the design tensile strength of the concrete,and the overall stability safety factor meets the requirements.(3)Perform contact nonlinear time history analysis on the intake tower structure,and systematically investigate the influence of boundary treatment methods on the dynamic response and overall stability of the intake tower structure.Compared with the linear elastic time history analysis,the maximum three-dimensional displacement increases However,the maximum tensile stress of each part is reduced and only the maximum tensile stress of the front row cross-flow connecting beam exceeds the design tensile strength.The overall anti-sliding stability and anti-overturning stability of the intake tower structure meet the requirements.Compared with the results of linear elastic time history analysis,the foundation compressive stress value increases,and the overall anti-sliding stability and anti-overturning stability safety factors of the intake tower structure are reduced.Whether it is considered that the contact between the bottom surface of the intake tower floor and the bedrock has little effect on the displacement and stress of the intake tower structure under seismic conditions.(4)The calculation result of linear elastic time history analysis is used for the structural reinforcement of the intake tower.On the basis of considering the nonlinearity of boundary contact,the material nonlinearity of concrete is also considered.The three-way displacement is further improved,especially the maximum value of the downstream displacement increases significantly.The overall concrete cracks of the intake tower structure are mainly distributed in the middle and upper cross-flow connecting beams and downstream connecting beams,and the maximum cracks in each part do not exceed the limit.Compared with the calculation results considering only the contact nonlinearity,the safety factor of the overall anti-sliding stability of the intake tower structure is slightly reduced after the material nonlinearity is considered,and the safety factor of the anti-overturning stability is slightly increased. |
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