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原文传递隧道充填型致灾构造突水突泥灾变演化机理及工程应用

论文题名：	隧道充填型致灾构造突水突泥灾变演化机理及工程应用
关键词：	Water inrush;Seepage Failure;Evolutionary Mechanism;Risk Assessment
摘要：	Groundwater can flow into tunnels through intact materials, joints and fissures, as wellas faults and karst conduits.The mechanical mechanism and evolutionary process ofwater inrush through faults and karst conduits have been investigated systematically inthe present study using a literature review, theoretical analysis, software development,experimental testing and numerical simulation.The MATLAB platform was used forsoftware package development, and the PFC3D software was used for numericalsimulation analysis. 　　(1) A novel research method is proposed for the analysis of the internal instabilityof granular soils to identify which type of water inrush will occur.To verify thefeasibility and accuracy of the novel method, four unimodal parametric PSD modelsand one bimodal parametric PSD model are compared, and dozens of soil specimensare studied.To determine the optimal parameter values of the PSD models, a softwarepackage termed Analysis Software for Internal Stability of Granular Soils (ASISGS) isdeveloped, which can also obtain the secant slope curves of soil PSDs automatically.Anew synthetic chart is proposed for the analysis of the internal instability of granularsoils, and the evaluation results are in good agreement with experimental tests. 　　(2) The microscopic mechanisms of suffusion initiation and development arerevealed.The theoretical formulas and models previously proposed for determining thecritical hydraulic condition of suffusion initiation are compared first, and then a newformula and a new theoretical model are proposed based on the seepage force and thevariable section capillary model, respectively.For calculation and comparison of theseformulas and theoretical models, a software package termed Calculation Program forCritical Hydraulic Gradient (CPCHG) is developed.The force condition and equilibriumstate of coarse particles under seepage flow are studied and expressed in mathematicalterms, and the critical hydraulic gradient of soil skeleton deformation is proposed. 　　(3) An experimental testing apparatus is developed for systematic research on theseepage failure of filling materials in faults and karst conduits subjected to seepage flow.The apparatus comprises an axial load application system, a pressurized water supplysystem, a permeameter cell, a particle collection system, a water collection system anda data acquisition system.A series of experiments on internally-unstable granular soilswith and without different clay contents, respectively, was conducted under differentaxial stresses.The variations of flow rate and hydraulic conductivity with the hydraulicgradient under different conditions are analyzed.The effects of axial stress and claycontent on the evolutionary process and the critical hydraulic condition are investigated,and the typical evolutionary process and phenomena of seepage failure are summarized. 　　(4) The mesoscopic evolutionary process of seepage failure of non-cohesive fillingmaterials under unidirectional seepage flow is reproduced by seeondary developmentof the PFC3D software.The effect of seepage direction on the evolutionary process ofseepage failure is studied by doing numerical simulations under different seepagedirections.The variations of porosity and flow rate with increasing hydraulic gradientare monitored, as well as the migration pathways of fine particles.Numerous basicscaling relationships and their limitations for a DEM scale model are summarized first,and then a new set of scaling relationship is proposed using a governing equationapproach for the DEM simulation of fluid-solid coupling problems, and numericalsimulations of the seepage failure with different scaling relationships indicate that it ismore reasonable and accurate than other scaling relationships. 　　(5) Several factors are selected as evaluation indices for risk assessment of waterinrush, and two evaluation index systems used in the design and construction stages,respectively, are established.An innovative and effective method named AttributeInterval Evaluation Theory (AIET) is proposed for risk assessment of water inrush.TheAIET can not only quantitatively prioritize risks by combining consequences andprobability of occurrence, but also analyze the reliability of the evaluation results.Sincethe AIET method is subjected to a large amount of calculations, a practical softwaretermed AIET software is developed.Engineering applications indicate that the AIETcan be successfully used in evaluating the risks of geological disasters.
作者：	周宗青
专业：	岩土工程
导师：	顾金才;李术才;Ranjith
授予学位：	博士
授予学位单位：	山东大学
学位年度：	2016
正文语种：	中文