Water is one of the causes of softening of soft rocks in deep strata. Water absorption in soft rock with high clay content may cause strength softening and deformation. In this paper, soft rock samples from three deep strata are investigated, and the stratigraphic characteristics such as stratum physical parameters, mineral composition, and pore structure are systematically analyzed. The characteristics of water vapor adsorption curves of deep strata soft rock are obtained by water vapor adsorption experiments. The authors analyzed the main factors controlling water vapor adsorption capacity of the rock samples. The experimental results show that the water vapor adsorption capacity increases with increase in humidity. When the humidity exceeds 0.8, the adsorption of water vapor by soft rock increases rapidly. The adsorption capacity of shale is significantly higher than that of conglomerate samples, and the difference between coarse conglomerate and fine conglomerate samples is insignificant. It is shown that water vapor adsorption correlates positively with clay mineral content, particularly minerals with high specific surface area. Under low humidity the temperature has little effect on the adsorption of soft rock water vapor. As the humidity increases, a rise in temperature can significantly increase the water vapor adsorption capacity The results also show that the soft rock water vapor adsorption capacity correlates negatively with initial moisture content, porosity, and permeability. This study is of great significance for understanding the hydrological characteristics and catastrophic processes of deep strata soft rocks.

中文翻译：

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深层页岩水汽吸附及主控因素

水是深层软岩软化的原因之一。在粘土含量高的软岩中吸水会引起强度软化和变形。本文对三个深层软岩样品进行了研究，系统地分析了地层物理参数、矿物组成、孔隙结构等地层特征。通过水汽吸附实验得到深部软岩水汽吸附曲线特征。作者分析了控制岩石样品水蒸气吸附能力的主要因素。实验结果表明，水蒸气吸附能力随着湿度的增加而增加。当湿度超过0.8时，软岩对水蒸气的吸附量迅速增加。页岩的吸附能力明显高于砾岩样品，粗砾岩和细砾岩样品之间的差异不显着。结果表明，水蒸气吸附与粘土矿物含量呈正相关，特别是具有高比表面积的矿物。在低湿度下，温度对软岩水蒸气的吸附作用不大。随着湿度的增加，温度升高会显着增加水汽吸附能力。结果还表明，软岩水汽吸附能力与初始含水量、孔隙度和渗透率呈负相关。该研究对了解深部软岩水文特征及灾变过程具有重要意义。