Finite Element Analysis Of Induced Joints In Xiangbiling RCC Arch Dam

RCC arch dam usually adopt continuous warehouse thin-layer roller compaction construction method.Although roller compacted concrete' s adiabatic temperature rise of the hydration heat is lower than normal concrete,the RCC quick construction speed will make the internal hydration heat send out difficultly.Dam temperature cooling to stable temperature field during construction and operation period will appear in the process of large tensile stress,and the temperature crack problem is very prominent.Arch dam belongs to the massive concrete structure,in order to prevent the dam disorderly cracking by the excessive temperature stress,so the induced joints are set in the local key parts of arch dam.Depend on RCC arch dam of xiangbiling hydropower station,ANSYS is applied to establish integral finite element of dam body-dam foundation,analysising the integral model's temperature field and stress field in construction period and operation Period;In order to better reveal the mechanical behavior of the induced joints,selecting the typical dam section(induced joint L1)to establish a subtle induced joint's sub-model on the basis of the overall model calculation results,analysising of the stress field' s distribution regularity about the induced joint during construction period and operation period,evaluating the effect of induced joint,Based on this,some reasonable suggestions and engineering measures are put forward.The main results of this paper are as follows:(1)The temperature field of RCC arch dam from construction period to operation period is simulated.Through the analysis of temperature field simulation calculation results,the arch dam temperature field changing law with the time and space is obtained.(2)Based on the analysis results of temperature field,induced joints and cross joints simulate as the degraded model of jointed rock masses reinforced by passive and fully-grouted bolts while the rest of the dam units are the common units,this thesis obtained the arch dam stress field and displacement filed during construction period and operation period under the elastic nonlinear finite element calculation.The simulation results analysis of the integral model' s stress field and displacement filed,the arch dam stress field and displacement filed changing law with the time and space is obtained.Analysis results show that concrete in the arch dam surface and the contact area between casting layer produce large tensile stress which surpass the tensile strength of RCC in local area and maybe generate temperature crack.(3)The finite element model is established by selecting the typical section of induced joint L1,the physical quantities of the sub-model boundary nodes are interpolated as the boundary conditions of the sub-model in the integral model calculation results,analysising the stress field and displacement filed of induced joint L1,sub-model mothed is adopted to study the local mechanical behavior of the induced joint L1,obtains tensioning status of indured joints along the elevation during construction period and operation Period.The results show that the arrangement scheme of induced joint L1 is reasonable,and it can play a role in releasing the tensile stress.(4)According to local tensile stress exceeds the tensile strength of RCC,there may be a problem of temperature cracks,combined with the results of this calculation and the previous research results proposed a plan for improvements and suggestions.