高海拔地区混凝土坝热力学参数反演和温控措施优化
Inversion of thermodynamic parameters and optimization of temperature control measures for concrete dams in high altitude areas
高寒高海拔地区气象环境复杂，设计条件与实际条件存在较大差异，在特定条件下可能增大混凝土的开裂风险，因此需要对施工期热力学参数和温度场进行反演分析，优化温控措施以确保施工安全和质量。采用全坝全过程仿真分析方法，结合施工期实测温度数据，全面对比分析室内热学和力学参数与现场实际参数之间的差异。采用反演的温度参数和实际浇筑进度，通过仿真分析对陡坡坝段的温控措施进行优化研究。反演分析显示，三级配常态混凝土的绝热温升值调整至27.5℃后，计算值与实测值相符；二级配常态混凝土的绝热温升终值为35℃时，计算值与反演分析值最为接近。设计绝热温升与反演分析的对比表明，反演的早期温度高于设计值，但终值低于设计值。仿真计算结果显示，基础强约束区常态混凝土的最大顺河向应力为1.50 MPa,安全系数为1.64;其他区域的应力和安全系数均在合理范围内，但基础强约束区和垫层常态混凝土的安全储备略低。在准确反演热力学参数的基础上，结合仿真分析成果发现基础强约束区和垫层常态混凝土的温控措施需进一步优化，特别是需要进一步严格控制最高温度并加强表面保护。本文采用的参数反演和温度应力场的反馈方法可以更准确地反映实际施工情况，为大体积混凝土施工标准和措施的优化提供更可靠的技术支撑。
The meteorological environment in the high cold and high altitude area is complicated, and there are great differences between the design conditions and the actual conditions, which may increase the cracking risk of concrete under certain conditions. Therefore, it is necessary to conduct inverse analysis of the thermodynamic parameters and temperature field during the construction period, and optimize the temperature control measures to ensure the construction safety and quality. The whole process simulation analysis method of the dam and the measured temperature data during the construction period are used to comprehensively compare and analyze the differences between the indoor thermal and mechanical parameters and the actual parameters on site. By using the inversion temperature parameters and the actual pouring progress, the temperature control measures of the steep slope dam section are optimized by simulation analysis. The inversion analysis showed that the calculated value was in agreement with the measured value after the adiabatic temperature appreciation was adjusted to 27.5 ℃. When the final value of adiabatic temperature rise of secondary normal concrete is 35 ℃, the calculated value is the closest to the inverse analysis value. The comparison between design adiabatic temperature rise and inversion analysis shows that the early temperature of inversion is higher than the design value, but the final value is lower than the design value. The simulation result show that the maximum stress along river is 1.50 MPa and the safety factor is 1.64. The stress and safety factor in other areas are within the reasonable range, but the safety reserve of foundation strong confinement area and normal concrete bedding is slightly lower. On the basis of accurate inversion of thermodynamic parameters, combined with the result of simulation analysis, it is found that the temperature control measures of the foundation strongly confined area and the normal concrete bedding need to be further optimized, especially the maximum temperature should be further strictly controlled and the surface protection should be strengthened. The inversion of parameters and the feedback method of temperature stress field used in this paper can reflect the actual construction situation more accurately, and provide more reliable technical support for the optimization of construction standards and measures of mass concrete.
mass concrete / temperature control / parameter inversion / temperature control measures optimization
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