岩石和水耦合参数在破裂过程中的演化规律

EVOLVEMENT LAW OF ROCK AND WATER COUPLING PARAMETERS DURING THE FAILURE PROCESSES

该文在理论研究的基础上,建立了岩石与水相互作用的力学模型和耦合参数的表述形式,证明了Biot系数取值范围为大于孔隙率而小于1,通过岩石在不同偏应力状态下的注水试验、不排水试验、在不排水条件下水压力加载和卸载试验、在不排水条件下的比例加载试验等,提出了以不排水试验方法确定比例极限点的观点,证明了岩石在破裂过程中其耦合力学参数是逐步演化的,水压力致使岩石峰值强度下降、变形增加。试验显示Skempton系数分散性较大,在注水和不排水试验条件下,水压力的作用机理也不尽相同;Biot系数在轴向和径向具有不同的演化规律等观点。这种研究对石油开采及高放废物处置等研究具有重要意义。

On the bases of the theoretical analyses, the mechanical model of rock and water interaction is established, and the formula of coupling mechanical parameters between rock and water interaction is deduced. It is proved that the scope of Biot coefficient is between the initial porosity and 1. A new determination method for the yield stress by the virtue of non-drainage test is proposed, which is based on such tests as grouting tests at different deviatoric stress states, non-drainage tests, tests with water pressure change under non-drainage, and proportional loading tests under non-drainage, etc. The evolvement of coupling mechanical parameters is observed during the rock failure process. The water pressure decreases the failure strength of rock, but increases its deformation. Laboratory tests demonstrate the large scattering of Skempton coefficient. The mechanism of water pressure under grouting water is different with that under drainage. The Biot coefficient in axial direction has different evolvement law with that in radial direction. This research is very important in the field of oil exploit and high radioactive nuclear waste material deposit.