软岩饱水试验与软化临界现象研究

针对华南地区广为分布的“红层”软岩遇水软化问题，选择粉砂质泥岩、泥质粉砂岩等典型软岩为研究对象，在软岩饱水软化试验的基础上，采用“自组织临界性”理论深入分析了软化试验中的临界现象，结合软岩物理力学性质、微观结构以及水溶液离子浓度变化的试验结果，得出：在饱水3个月和6个月时，对应于所研究软岩软化的临界时间点，其物理、力学性质与水溶液离子浓度的变化在前3个月内变化幅度较大，3个月后较为平缓，并可能出现波动，6个月后开始趋于稳定；而其微观结构变化满足1～3个月变化较小，3～6个月自行调整而趋于有序，6个月之后结构类型完全改变。在此基础上，分析了软岩系统自组织临界现象中最显著的两个特征：自组织性和临界特性，并从系统演化的角度探讨了饱水软岩系统中一种具有一定稳定性的非平衡自组织有序结构的产生过程，给出了水作用下软岩工程特性变异达到稳定的临界时刻。

Research on saturation test and softening critical phenomena of soft rocks

Aiming at the softening of some typical saturated soft rocks widely distributed in South China areas, such as silty mudstone and mud siltstone, self-organization criticality theory is adopted to analyze the critical phenomena in the softening process of soft rocks in the saturation test; and based on the test data, some conclusions are drawn as follows: the time points of three months and six months are two critical points for the interaction between water and rock; and the variation of physico-mechanical properties of soft rocks and concentration of aqueous solution both satisfy the same regularity; all the factors are changing greatly in the first three months, gently in the following three months and keeping stable after six months; while the response variation regularity of microstructures satisfies keeping original appearance during first to three months, self-adjusting to order during three to six months and entirely changing to another structure types after six months. Meanwhile, two key characteristics for self-organization criticality of soft rocks are analyzed; and from the angle of system evolvement, the developing process of a non-equilibrium self-organizing order structure in soft rock system is discussed; and the stable critical time of engineering properties variation of soft rocks is proposed.