文献类型：期刊文献

中文题名：围压加卸载过程中单一裂隙渗透率滞变性试验和数值模拟研究

英文题名：Experimental and numerical study on permeability hysteresis of a single fracture subjected to loading and unloading of confining pressure

作者：王雪 孙长伦 喻龙 邹良超 庄丽

第一作者：王雪

机构：[1]重庆大学资源与安全学院,重庆400044;[2]贵州理工学院矿业工程学院,贵州贵阳550003;[3]瑞典皇家理工学院可持续发展与环境工程系,瑞典斯德哥尔摩10044

第一机构：重庆大学资源与安全学院,重庆400044

年份：2026

卷号：48

期号：5

起止页码：1071-1081

中文期刊名：岩土工程学报

外文期刊名：Chinese Journal of Geotechnical Engineering

收录：;EI(收录号：20262420892636);北大核心:【北大核心2023】；

基金：新重庆YC项目(CSTB2024YCJH-KYXM0092)。

语种：中文

中文关键词：硬度;渗透率滞变;粗糙度;单一裂隙;接触比

外文关键词：hardness;permeability hysteresis;roughness;single fracture;contact ratio

摘要：地下水在裂隙岩体中的流动主要取决于裂隙网的水力传导特性,尤其是对于花岗岩一类的低渗透性岩石,明确裂隙渗透性随应力的变化规律对于高放废物地质处置库等地下工程的长期安全性评估十分必要。主要研究了材料硬度和花岗岩裂隙接触特性对渗透性的影响,分析了围压加卸载作用下渗透率滞变特性。一方面,选取铝合金、工程塑料(PEEK)和花岗岩3种不同硬度材料,开展了3~20 MPa围压加卸载单次循环条件下单一裂隙渗流试验。研究发现单一裂隙的渗透率均随围压的增加呈非线性下降,在围压卸载后无法恢复到初始状态,即存在滞变性。将加卸载前后裂隙的渗透率变化率定义为滞变系数,试验结果表明光滑单一裂隙的滞变系数在PEEK和铝合金中最高可达60%和99%,而在花岗岩中最低约为55%,较低硬度导致更高的裂隙渗透率滞变性。另一方面,开展了不同初始接触状态的花岗岩裂隙在围压加卸载作用下接触和渗透性演化有限元模拟,得到的花岗岩单一裂隙的渗透性滞变规律与室内试验结果一致。数值模拟表明裂隙表面接触分布不均匀,较大的初始接触比造成加卸载过程中裂隙表面粗糙体产生塑性变形更大,单一裂隙渗透率滞变系数与接触比对数呈近似线性关系。
Groundwater flow in fractured rock mass mainly depends on the hydraulic conduction characteristics of fracture network,especially for low permeability rocks,such as granite.It is necessary to clarify the variation of fracture permeability with stress for long-term safety assessment of underground projects,such as deep geological repository for high-level radioactive waste disposal.This study focuses on the influence of material hardness and fracture contact characteristics of granite on permeability of a single fracture,and analyzes permeability hysteresis under loading-unloading of confining pressure.Water flow-through test on a single fracture is conducted at confining pressures varying from 3 to 20 MPa in a loading-unloading cycle using three materials with different hardness,i.e.,aluminum alloy,engineering plastic(PEEK)and granite.Experimental results show that permeability of a single fracture decreases nonlinearly with the increase of confining pressure,and will not completely recover when the confining pressure is unloaded to the initial value,which means that permeability hysteresis occurs.We define the ratio of permeability change of the fracture subjected to loading-unloading as hysteresis coefficient.Experimental results show that hysteresis coefficient of the smooth fracture in PEEK and aluminum alloy are 60%and 99%,respectively,while the lowest is about 55%in granite.Lower hardness leads to higher permeability hysteresis.Additionally,we employ finite element method to simulate evolution of contact and permeability of different granite fractures subjected to loading-unloading of confining pressure.Permeability hysteresis behavior of granite single fractures is consistent with the experimental observations.Simulation results show that contact area on the fracture surface distributed unevenly,and higher initial contact ratio causes larger plastic deformation at the fracture surface during the loading-unloading process,permeability hysteresis coefficient has an approximately linear relationship with the logarithm of the contact ratio of the single fracture.