自生体积变形对高拱坝温度应力的影响研究

Research on influence of autogenous volume deformation on thermal stress of high arch dam

自生体积变形是评价混凝土抗裂性能的一个重要参数.在温度场仿真的基础上对小湾高拱坝混凝土自生体积变形进行温度应力敏感性分析,对自生体积变形进行假定时,考虑混凝土为收缩型和膨胀型.计算结果表明,早期膨胀、早期收缩型混凝土只对坝体早期温度应力影响较大,对坝中心温度应力最大值影响不大;膨胀期越长,坝中心温度应力最大值越小,最终残余温度应力越小,对坝体混凝土的抗裂性有利.

Autogenous volume deformation is an important parameter of anti-cracking behaviors of concrete. The sensitivity analysis of influence of concrete autogenous volume deformation on thermal stress of Xiaowan high arch dam is carried out based on simulation of temperature field. When presuming autogenous volume deformation, expansion concrete and shrinkage concrete are considered. The results show that early expansion and early shrinkage concretes have obvious influence on arch dam＇s early thermal stress; however have less influence on dam center＇s maximum thermal stress. The longer of expansion period, the smaller of darn center＇s maximum thermal stress; and the final residual thermal stress, which can benefit the concrete＇s anti cracking quality.