The wetting-drying (W-D) cycle is a type of water–rock interaction. The pore structure of rock, such as shape, size, distribution and pore throat, affects fluid storage and transport. Fractal theory and experimental research on the evolution characteristics of pore damage during the wet-dry erosion process are highly important for determining W-D damage. The mass and velocity of liquid migration are related to the pore size, porosity, fluid properties, etc. Experimental data show that the water absorption quality and velocity in rocks decrease with the number of wet-dry cycles. At the same test time, the mass and velocity of the SI water absorption method are smaller than those of the FI method. Under these two conditions, the amount and rate of water absorption represent the degree of water–rock interaction. Considering the pore evolution during the wet-dry cycling, an equation describing the motion of liquid in porous media was derived based on the imbibition-type separation model. The experimental data are in excellent agreement with the calculated values of the model. Permeability characteristics can affect the area and degree of rock deterioration as well as the development rate of pores and microcracks. Based on the interaction between permeability and pores, quantitative analysis of the weakening process (local damage) of rocks under W-D cycles can provide good reference indicators for evaluating the stability of geotechnical engineering.

中文翻译：

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基于 NMR 的湿润和干燥交替条件下水分迁移对砂岩孔隙结构的影响分析


干湿循环 （W-D） 是一种水-岩石相互作用。岩石的孔隙结构，如形状、大小、分布和孔喉，都会影响流体的储存和运输。分形理论和关于干湿侵蚀过程中孔隙损伤演变特征的实验研究对于确定 W-D 损伤具有重要意义。液体迁移的质量和速度与孔径、孔隙率、流体性质等有关。实验数据表明，岩石中的吸水质量和速度随着干湿循环次数的增加而降低。在相同的测试时间内，SI 吸水法的质量和速度都小于 FI 法。在这两种条件下，吸水量和吸水率代表水与岩石相互作用的程度。考虑到干湿循环过程中的孔隙演变，基于渗吸型分离模型推导出了描述液体在多孔介质中运动的方程。实验数据与模型的计算值非常吻合。渗透特性会影响岩石劣化的面积和程度，以及孔隙和微裂纹的发展速度。基于渗透率与孔隙的相互作用，定量分析W-D循环作用下岩石的弱化过程（局部损伤），可为评价岩土工程的稳定性提供良好的参考指标。