论文部分内容阅读
以南水北调中线石京段古运河枢纽工程暗涵段为工程背景,采用理论分析和数值计算,提出了南水北调暗涵衬砌结构施工过程中钢筋混凝土内部温降的控制标准,即按最不利部位考虑,30 d内混凝土内部温降不应超过26.7℃,为选取合理的温控措施提供了依据。以衬砌内部温度场数值分析为理论依据,结合下穿段暗涵的地形条件、结构特点,并考虑工程气候特点,优化混凝土配比、降低水泥用量、掺入适量粉煤灰以及采用遮阳棚和地垄等工程措施,有效控制了混凝土结构的内部温度变化,成功解决了大体积混凝土施工温度裂缝问题,保证了结构工程的施工质量。理论计算与现场量测相结合,结果表明,实测值与计算值规律基本一致,说明计算模型和计算参数选取的合理性和计算结果的正确性,可为后续类似工程提供参考。
Taking the section of the Middle Grand Canal in Shijijing section of South-to-North Water Diversion as the project background, the control criterion for the internal temperature drop of reinforced concrete in the construction process of the South-North Water Diversion Project is put forward by means of theoretical analysis and numerical calculation. According to the most unfavorable site, Within 30 d of concrete temperature drop should not exceed 26.7 ℃, to provide a reasonable basis for temperature control measures. Based on the numerical analysis of the internal temperature field of the lining and the topographical conditions and structural characteristics of the culvert in the lower section, taking into account the climatic characteristics of the project, the proportion of concrete is optimized, the amount of cement is reduced, the amount of fly ash is blended, Ridge and other engineering measures to effectively control the internal structure of the concrete temperature changes, the successful solution to the mass concrete temperature cracking problems, to ensure the quality of construction of the construction process. The results show that the measured and calculated values are basically the same, which shows that the calculation model and calculation parameters are reasonable and the calculation results are correct, which can provide reference for the subsequent similar projects.