ANSYS-based Panel Rockfill Dam Model Construction And Stress-deformation Analysis

Panel-stacked rock dam is a type of dam that uses layered stone(or gravel)as the main body,which is compacted with thin layers of vibration and pressure.The stacked stone body serves as the load-bearing structure,and a concrete panel is set on the upstream surface of the dam as a seepage prevention structure.Panel-stacked rock dam has the advantages of strong adaptability,simple structure,and high safety,and therefore has been widely used and developed rapidly.With the increasing height of the dam and the increasingly complex topography of the dam site,the requirements for stress-deformation analysis theory and methods of panel-stacked rock dam are becoming higher and higher.Therefore,revealing the general law of stress-deformation of panel-stacked rock dam and correctly predicting the deformation trend of the dam body under various working conditions is still the main problem of safety design of panel-stacked rock dam.To address this issue,this paper takes a panel-stacked rock dam in Yunnan Province as an engineering example,based on the ANSYS finite element software and using the improved Duncan-Zhang E-B model as the constitutive model of the stacked stone body.The contact between the panel and the cushion layer is simulated,and the panel is divided into segments to simulate the real dam construction and water storage process to analyze the stress-deformation law of panel-stacked rock dam under various working conditions.The main research contents and achievements of the paper are as follows:(1)Three-dimensional modeling based on ANSYS finite element software combined with actual engineering cases.The material parameter definition,element selection,and load application are realized by command flow.In addition,the ANSYS software is secondarily developed using the APDL programming language to write the Duncan-Zhang E-B model and its improved model calculation program modules.(2)Use the improved Duncan-Zhang model to construct the constitutive model of the stacked stone body.Based on the panel-stacked rock dam in Yunnan Province,the stress-deformation results of the dam body calculated using the model before and after the improvement are compared with the real monitoring data.The results show that the Duncan-Zhang E-B model considering the intermediate principal stress is closer to the real monitoring result,which can better reflect the stress-deformation characteristics of the stacked stone body.Therefore,the improved Duncan-Zhang model is used for subsequent research.(3)Study the impact of panel vertical joints on panel stress and deformation under contact problems.The Goodman no-thickness element is used to simulate the contact between the panel and the cushion layer,and the no-thickness hexahedral connection element model is used to divide the panel into segments.A finite element model of panel-stacked rock dam with and without segments is established to analyze the stress-deformation law of the panel under different working conditions,and the calculation results of the segmented and non-segmented models are compared.The study verifies that panel segmentation can adapt to panel deformation and effectively avoid the overall damage of the panel.(4)Apply the constructed model to actual engineering.Simulate the real dam construction process and water storage process of the panel-stacked rock dam.The stress-deformation of the panel-stacked rock dam is calculated,and the stress-deformation law of the dam body under several working conditions during construction and water storage stages(normal water level,design flood level,and verification flood level)is obtained.