单裂缝混凝土结构水力劈裂试验

Hydraulic fracturing test of concrete structures with single crack

针对不同强度单裂缝混凝土试件开展了两组应力状态下的水力劈裂试验,研究了应力状态、荷载施加方式对试件裂缝扩展过程的影响,分析了裂缝扩展路径上缝内水压演化规律,拟合得到了混凝土试件临界劈裂水压预测模型的定量关系式。试验结果表明,两组不同应力状态下的试件均发生水力劈裂破坏;临界劈裂水压值与轴压的差值均小于试件的劈拉强度值;试件水压尖端的发展滞后于干裂缝的发展。

Two groups of hydraulic fracturing tests were carried out on concrete specimens of different strengths with a single initial crack under different stresses. The effects of stress state and loading pattern on the crack propagation process of concrete specimens were studied. The evolution law of water pressure within crack along the crack propagation path was analyzed,and the quantitative relation for the critical fracturing pressure prediction model of concrete specimens was obtained. Results show that damages induced by hydraulic fracturing occurred to the two groups of specimens under different stresses. Besides,the differences between the critical fracturing pressure and axial pressure of the two groups of specimens were less than the splitting strength of the specimens,and the development of the sharp cutting edge under water pressure lagged behind that of the dry crack.