石坝河水库堆石混凝土重力坝施工期工作性态仿真

Simulation of the working behavior of Shibahe reservoir rock-filled concrete gravity dam during construction

依托贵州省仁怀市石坝河水库堆石混凝土重力坝,基于大坝设计资料与温度监测数据,对大坝自密实混凝土、堆石混凝土以及常态混凝土的关键热学参数进行反演。在此基础上,模拟大坝浇筑过程、混凝土硬化过程以及气象变化过程,采用有限元仿真方法进行大坝施工期全过程工作性态仿真计算,对大坝的温度场和应力场的分布和演化规律进行分析,评估大坝整体安全性。分析结果表明,仿真反演得到的坝体温度过程能够真实反映施工期坝体的温度变化规律,坝体内部一般3~5d达到最高温度,水化热温升在4~7℃之间,夏季浇筑时最高温度约为35.0~39.5℃,冬季浇筑时最高温度约为25~28℃;除了大坝溢流坝段表面在低温季节局部拉应力较大外,其余部位应力均未超出混凝土的强度,大坝整体安全可以得到保障,说明堆石混凝土重力坝大仓面浇筑方式是可行的。

Key thermal parameters of self-compacting, rock-filled, and normal concrete of the rock-filled concrete gravity dam of Shibahe Reservoir in Renhuai City, Guizhou Province, are inverted based on its design data and temperature-monitoring data. On this basis, the finite element simulation method is used to simulate the working behavior during the construction of the dam, including the dam pouring, concrete hardening, and meteorological change processes. Next, the distribution and evolution law of the temperature field and stress field of the dam are analyzed to evaluate the overall safety of the dam. The results show that the temperature process of the dam body obtained by simulation inversion can truly reflect the temperature variation of the dam body. The maximum temperature in the dam body is typically reached within 3—5 d, and the temperature rise of hydration heat is between 4—7 ℃. The maximum temperature of pouring concrete in summer is about 35.0—39.5 ℃, while that in winter is about 25—28 ℃. Although the partial tensile stress on the spillway section surface is large in the low-temperature season, the stress in other parts does not exceed the concrete strength, and the dam safety can be guaranteed. The result indicates that pouring concrete on the large warehouse surface of the rock-filled concrete gravity dam is feasible.