摘要
经典的地下水渗流理论是基于水均衡原理建立的,无法解释天然地震活动等外部荷载引起的井水位变化现象,也不利于深入认识地下水渗流运动在各种环境地质灾害中的作用。针对这一问题,基于流固耦合的动力学理论构建了地震波应力驱动承压含水层孔隙压力变化的数学模型,借助软件Comsol实现了对模型的有限元数值求解及影响因素分析,利用Cooper理论反演出井水位的变化特征,并将结果与强震引起川滇地区井水位的变化特征进行对比。结果表明:当地震波荷载作用于承压含水层时,孔隙压力会表现出与地震波同周期的振荡变化特征,且地震波振幅、频率以及水力坡度对孔隙压力的变化特征影响显著。地震波荷载施加初期,孔隙压力迅速增大,随后含水层中的部分水被缓慢排出,荷载压力逐渐转移到颗粒骨架上,孔隙压力的变化速率随之变缓并趋于新的平衡。井水位变化特征与孔隙压力密切相关,其振荡周期与变化形态与孔隙压力一致,但幅度不同,总体上表现出振荡上升且趋于稳定的变化特征,与川滇地区观测到的井水位变化形态基本相同。该成果对于应力作用下地下水渗流运动理论的建立和完善具有宝贵的探索意义,可以丰富和拓展传统地下水动力学和经典流固耦合理论的研究思路和应用领域。
The classical groundwater seepage theory was established on the basis of the principle of water equilibrium,which cannot explain the phenomenon of well water level change caused by natural seismic activities and other external loads,and is not conducive to the in-depth understanding of the role of groundwater seepage movement in various environmental geological disasters.To solve this problem,a mathematical model of pore pressure change of a confined aquifer driven by seismic wave stress is constructed based on the fluid-structure coupling dynamic theory.The numerical verification of the model is realized by using the software Comsol.The change characteristics of well water level are inversely performed by using the Cooper theory,and the results are compared with the change characteristics of well water level caused by strong earthquakes in the Sichian-Yunnan region.The influencing factors of seepage movement of a confined aquifer under earthquake are studied by changing the simulation parameters.The results show that when seismic wave loads act on the confined aquifers,pore pressure oscillates in the same period as the seismic waves,and the amplitude,frequency and hydraulic slope of the seismic waves have significant effects on the pore pressure,while the coefficient of permeability and porosity have little effect on the change characteristics.At the initial stage of seismic wave loading,pore pressure increases rapidly,and then part of the water in the aquifer is slowly discharged.The load pressure gradually transfers to the granular framework,and the rate of change of pore pressure slows down and tends to reach a new equilibrium.The variation characteristics of well water level are closely related to pore pressure,and the oscillation period and variation pattern are consistent with pore pressure,but the amplitude is different.Generally,the oscillation rises and tends to be stable,which is basically the same with the variation pattern of well water level observed in the Sichuan-Yunnan region.The results are of valuable exploration significance for the establishment and improvement of groundwater seepage theory under stress,and can enrich and expand the research ideas and application fields of traditional groundwater dynamics and classical fluid-structure coupling theory.
作者
梁文宇
兰双双
谷洪彪
乔鹏
毛政潭
LIANG Wenyu;LAN Shuangshuang;GU Hongbiao;QIAO Peng;MAO Zhengtan(Faculty of Architecture,Beijing University of Technology,Beijing 100124,China;College of Transportation Engineering,Nanjing Techbology University,Nanjing,Jiangsu 211816,China)
出处
《水文地质工程地质》
CAS
CSCD
北大核心
2023年第4期73-83,共11页
Hydrogeology & Engineering Geology
基金
北京市自然基金面上项目(8222003)
国家自然科学基金青年项目(41807180)。
关键词
渗流
孔隙压力
井水位
流固耦合
动力学理论
数值模拟
seepage
pore pressure
well water level
fluid-structure coupling
theory of dynamics
numerical simulation
