小浪底工程高标号隧洞衬砌混凝土温控标准分析

混凝土设计标号采用圆柱坐标差分法 ,对小浪底工程隧洞衬砌混凝土施工期的温度及温度应力进行了分析 ,利用前后时段的温差 ,计算各时段混凝土温度自生应力及混凝土和围岩在接触面径向变位相容的约束应力 ,叠加计算温度弹性应力 ,由当量松弛系数法计算温度徐变应力 .确定了不同混凝土等级、不同衬砌厚度的温控标准和衬砌分段长度 .与实测资料对比 ,计算温度与实测温度接近

Study on Temperature Control Standard of High-grade Concrete Tunnel Lining in Xiaolangdi Project

As the concrete temperature during construction period is high, resulting in high temperature stress, the analysis on temperature and its stress are needed to establish suitable temperature control standard. Since there is no calculation method available for temperature and its stress analysis during construction of tunnel lining with concrete, a cylinder coordinate finite difference method is applied. The temperature difference between early and late time intervals is utilized to calculate autogenous stress of concrete temperature and restraining stress which makes radial deflection in the contact between concrete and surrounding rock identical,make superposition calculation of temperature elastic stress, and compute temperature creeping stress by equivalent relaxation coefficient method. After a large amount of calculations and analyses, different concrete grades, temperature control standard and lining length for varying lining thickness have been worked out. Compared with the observed data, calculated temperature is close to the recorded value.