水管冷却作用下岩锚梁混凝土施工温度应力分析

Analysis on temperature stress of rock anchor beam concrete under influence of pipe cooling

针对水电站地下厂房中岩锚梁混凝土结构施工期易开裂的问题及其结构特点,采取了水管冷却和表面保温相结合的温控措施。依托某岩锚梁工程,利用考虑水管冷却的不稳定温度场和应力场的有限元方法,对典型岩锚梁施工段进行仿真计算,从温度、第一主应力以及抗裂安全度3方面分析了水管冷却和表面保温措施的温控效果。结果表明,水管冷却和表面保温相结合的温控措施能够把岩锚梁施工期应力控制在允许范围内,使其满足允许抗裂安全度,并认为运用抗裂安全度的方法评价混凝土结构的抗裂能力更为合理。

Aiming at the problem that the rock anchor beam is sensitive to crack in the construction period and its structure features,the temperature control measure combined pipe cooling with superficial thermal insulation is adopted to improve the anti-crack performance of rock anchor beam concrete.Based on the rock anchor beam of a project,a numerical simulation of the construction section of typical rock anchor beam is conducted by using FEM and considering the unstable temperature field and stress field.The temperature control effect of pipe cooling and the superficial thermal insulation are analyzed from the aspects of temperature,first main stress and anti-cracking safety.The result shows that the stress of rock anchor beam is controlled in the allowable range,which meets the anti-cracking safety,after taking the measures of pipe cooling and superficial thermal insulation,and it is more reasonable to evaluate the anti-crack performance of the rock anchor beam concrete by using the anti-cracking safety method.