低弹模地基大体积混凝土施工期温度应力分析

Temperature stress analysis of mass concrete in low-elastic modulus rock foundation area in construction period

为了研究低弹模基岩地区大体积混凝土施工期的温度应力,选取低弹模基岩地区两个坝块尺寸差异较大的实际工程为研究对象,采用有限元法对坝体温度及温度应力进行了仿真计算,并用弹性地基梁法对其进行了复核。结果表明：对于基岩弹模明显低于混凝土弹模地区的大体积混凝土工程,由于基岩对上部混凝土温度变形时的约束较小,对温控防裂较有利,可参照基岩弹模和混凝土弹模相近的基础允许温差标准,适当放宽基础温差标准1℃~2℃,坝体温度应力仍可控制在设计允许应力范围内;当放宽基础温差标准后,坝体分缝、温度控制措施等要求均相对降低,可减少温控投入,为加快工程施工进度创造有利条件,具有较好的现实意义。

In order to study temperature stress of mass concrete in low-elastic modulus rock foundation area,selecting 2 concrete blocks with large size difference in low-elastic modulus rock foundation area as objects,we simulate their temperature and temperature stress by FEM and check the results by elastic foundation beam method.The results show that for the mass concrete project with the elastic modulus of rock foundation smaller than that of concrete block,the rock foundation has relative smaller restriction on the above concrete block,which is favorable to temperature control,so that the temperature difference control standard could be relaxed by 1℃~2℃ by referencing the permitted temperature difference of the foundation with elastic modulus similar to that of the concrete.Therefore,the requirements on temperature control measures and dam joints could be relaxed.The construction process can be accelerated and the cost on temperature control can be reduced.