水工混凝土结构裂缝的稳定性分析

对于带缝运行的水工混凝土结构,裂缝的稳定性直接关系到整个结构的安全状况.针对水工混凝土结构中裂缝扩展的稳定性问题,主要从断裂力学的角度,以缝端应力强度因子为特征参数,结合某重力拱坝,讨论了裂缝稳定性随水压、温度以及二者的不同组合的演变过程,分析了裂缝的转异特征.对该重力拱坝,水位对应力强度因子的影响较小,裂缝的稳定性主要受温度变化的影响.低温较低水位对裂缝的稳定最为不利,高温低水位对裂缝的稳定性也有一定的影响.还讨论了裂缝的时间效应和转异特征.

Analysis on crack stability of concrete hydraulic structure

As for concrete hydraulic structure working with cracks, the stability of the crack is related to the safety of the structure. Stress intensity factor, the parameter of anomalous characteristics which can reflect stability of crack, was analyzed. On the basis of stress intensity factor in fracture mechanics, evolution of crack stability loss in some gravity arch dam, under hydrostatic pressure, temperature and their various combination was discussed. The results show that for the gravity arch dam hydrostatic pressure has little impact on stress intensity factor and the crack stability is mainly affected by temperature. The stability of the crack is most unfavorable when the dam is under combination of low hydrostatic pressure and low temperature and it is also evident when the dam is under combination of low hydrostatic pressure and high temperature. Finally the time dependent effect and anomalous characteristics of the crack were discussed.