基于三维有限元法的碾压砼拱坝应力仿真计算研究

为防止大坝因局部拉应力过大而产生坝体拉裂现象,基于拱坝温度场和温度徐变应力场基本原理,以江西省萍乡市山口岩水利枢纽工程拦河坝为例,利用三维有限元法对拱坝施工期与运行期的温度场和应力场进行了仿真计算。结果表明,拱坝的施工与设计中未采取温控措施、不设置分缝,坝体拉应力过大,超出了碾压砼的抗拉强度,对大坝防裂稳定不利;对拱坝合理地设置横缝和诱导缝,采取温控措施,坝体高拉应力区的应力可得到有效改善,应力得到了释放,最大拉应力小于碾压砼的抗拉强度,有利于大坝防裂,为坝体稳定提供了保障。

Simulation Calculation of RCC Arch Dam Stress Based on Three-Dimensional FEM

In order to prevent dam cracking caused by local excessive tensile stress, based on the basic principle of arch dam temperature field and temperature creep stress field, three-dimensional finite element method is used to simulate temperature field and stress field of arch dam in construction period and operation period by taking Shankouyan hydro-junction dam across river project in Pingxiang city of Jiangxi Province for an example. Owing to not taking measures for control of temperature and setting joint in dam design and construction, the tensile stress of the dam is large and it exceeds the tensile strength of roll compacted concrete, which is unfavorable for crack control of dam stability. According to the calculation results, the high tensile stress area of the dam can be improved by setting transverse joints and induced joints, and taking measures for temperature control. At the same time, it indicates that the effect of stress release is extremely significant and the maximum tensile stress is less than the tensile strength of roll compacted concrete, which is favorable for crack control of the dam. Thus, it provides guarantee for dam stability.