严寒地区胶凝砂砾石材料冻融仿真研究

Study on the Freezing and Thawing Simulation of CSG in Severe Cold Region

胶凝砂砾石坝研究起步较晚,故其冻融作用下的理论研究较少。在前人研究基础上,借鉴混凝土冻融损伤机理及模型和试验结果,建立了胶凝砂砾石冻融损伤模型;基于混凝土非线性控制微分方程及非线性热学特性的温度场、应力场理论,编制了适用于胶凝砂砾石的流固耦合三维有限元冻融全过程仿真分析程序,并进行案例分析。结果表明,不同地区胶凝砂砾石的冻融(负温)深度与最低月均气温及低温持续时间有关,冻融使得胶凝砂砾石受冻区域的应力分布极为复杂,胶凝砂砾石坝开裂风险增大。

Cement sand and gravel （ CSG ） d a m is a new type of d a m between concrete-faced rock-fill dam （ C F R D ） and roller compactedconcrete d a m （ RCC ） .The design theory of CSG during freezing and thawing is scarcely due to its starts relatively late. Based on the previousstudies, this paper established damage model of the freezing-thawing of the CSG in the application of damaging theory under the freezing andthawing of concrete. The three-dimensional finite element, fluid-solid coupling simulation analysis program of frozen-thaw process suitable forthe CSG was compiled and used in practical engineering. The results show that the freezing-thawing depths of CSG in different areas arerelated to the lowest monthly mean temperature and the low temperature duration. The rule of stress is extremely complex in the freezingregional,the cement sand and gravel dam has an increased risk of cracking, so engineering measures and material modification methods toreduce this risk are needed.