恒定水头岩体混凝土裂纹水入浸过程分析

Process Analysis of Water Infusion in Rock Mass or Concrete Fracture Under Constant Water Head

针对自然营造力作用下岩体或混凝土裂纹的水力劈裂特点,基于裂纹水流运动的立方定律建立了恒定水头作用下裂纹内水流入浸过程计算模型与迭代步骤。通过对不同裂纹张开宽度、裂纹表面起伏差、裂纹形状等因素变化,分别计算了水流入浸过程。计算结果表明,裂纹内水流入浸过程是先快后慢,随着时间的推移,裂纹内水压会发展为全水头。当裂纹张开宽度大于0.02mm,水流入浸过程及其短暂,裂纹内水流很快就达到裂尖,而且水压基本就是全水头。当裂纹的张开宽度特别小,达到微米级,水流就很难进入,即产生不透水的现象。裂纹表面的起伏差对于裂纹张开宽度较小的裂纹影响程度要大于宽度较大的裂纹。

According to the characteristics of hydraulic fracturing of rock mass and concrete fracture under natural power,the water infusion model and iteration procedure of rock or concrete fracture under constant water head were built based on the cube law of water moving in fracture. The different infusion processes were calculated by changing opening width,inner surface off-set and shape of fracture. The results showed that the water moving in fracture is fast in initial infusion stage,and slow in final. The water pressure along the fracture is gradually developed to full pressure as lapse. When the opening width of fracture is larger than 0. 02 mm,there is shorter time to arrive tip and the pressure along the fracture is a whole head. When the opening width of fracture is micrometer,it is difficulty to fill fracture,which is an impermeable fracture. The influence of fracture water pressure on relative smaller opening width fracture due to inner surface off-set is more significant than that with wider opening width of fracture.