沙牌碾压混凝土拱坝应力场仿真计算分析

目的分析坝体施工期和运行期应力场的分布特点和变化规律、诱导缝的状态和张开时间以及坝体损伤开裂状况.方法碾压混凝土拱坝的核心问题是温度应力问题,现阶段进行全过程诸多因素的耦合分析仍然面临许多困难.基于应力场隐式解法的基础上,讨论了碾压混凝土材料的本构模型、温度影响、非线性徐变、诱导缝的损伤开裂准则等问题.结果结合沙牌工程,进行了大坝施工期和运行期的应力场仿真计算分析,根据仿真计算结果结合大坝施工期的部分观测资料,分析了诱导缝的张开和坝体的损伤开裂情况.结论诱导缝和横缝显著改变了坝体的应力分布,施工期间坝体会出现局部开裂,蓄水后坝体应力状态有所改善,但是下游面和坝顶仍有开裂的可能.

Simulation Analysis of Stress Field of ShaPai RCC Arch Dam

The thermal stress is the most principal cause,which can lead to the damage and cracking of RCC arch dam.However,at present,if the coupling of multi-factors is considered,the full process of simulation analysis of RCC arch dam still faces many difficulties,which inspires a lot of challenging research.Based on implicit algorithm for stress field,some questions about simulation analysis of unsteady temperature field of RCC dam(i.e.constitutive model of RCC,temperature effect,nonlinear creep,damage and fracture criterion for induced joints and visualization of input data and calculated results) are discussed in this paper.According to the corresponding parameters of ShaPai RCC arch dam(i.e.physical dimension,environment,material,impounding scheme parameters),the analysis of temperature field and stress field during the period of construction and operation is performed.By the comparison between the calculated results and tested data during the period of construction,the distribution characteristics and variable regularity of stress field,the opening state and time for induced joints,and the damage of dam body during the construction and operation period are analyzed.It is concluded that the stress state is amended by setting induced joints and cross joints.The local cracking occurs during the period of construction,and cracking perhaps occurs in the downstream face and on top of dam body.