【作者】 许增光；

【导师】 柴军瑞；

【作者基本信息】 西安理工大学 ， 水工结构工程， 2008， 硕士

【摘要】 目前,在岩土工程中,渗流-应力-温度-溶质的耦合分析已成为整个工程界非常关注的问题之一,而其中的渗流-温度耦合分析正是非常重要的一项研究内容。它是影响工程正常运转与工程安全性的重要因素,被广泛应用于水利水电工程、岩土工程、土木建筑工程、水资源开发与利用、环境工程、水文地质、工程地质、石油开发、煤炭天然气开发、地热开发、地震预报与控制、地下工程以及核废料处理等领域。对于裂隙岩体而言,目前广泛采用的是等效连续介质模型,因为其有成熟的理论基础和计算方法;然而对存在稀疏裂隙或大的断层的岩体来说,采用非连续介质模型(裂隙网络模型)进行渗流温度耦合分析在理论上应是一种更加符合实际情况的方法。但是,与连续介质模型相比,采用离散裂隙网络模型对裂隙岩体进行渗流温度耦合分析研究才刚刚开始,将成为裂隙岩体研究的一个崭新的组成部分。针对裂隙岩体本身的特殊性,假设岩块本身不透水,水流只存在于由裂隙面组成的裂隙网络中,因此将基于裂隙网络的渗流-温度耦合分析看作是存在于裂隙中的渗流场、水流温度场和存在于岩体中的岩块温度场三者之间的耦合分析。在此基础之上,主要完成了以下几方面的工作:1.在了解当前裂隙网络渗流理论和温度场基本理论的基础之上,首先从渗流-温度相互作用的二维数值模拟出发,分析了连续介质中考虑渗流热学效应的大坝工程稳定温度场;分析了岩体裂隙网络考虑温度影响的稳定渗流场;分析了考虑裂隙水流影响的岩体裂隙网络非稳定温度场。通过定性定量地考虑渗流-温度之间的相互影响关系,为分析三维渗流温度的耦合机理、模型建立以及数值计算奠定了很好的基础。2.三维裂隙岩体渗流-温度耦合分析是本论文的核心部份,从分析三维裂隙岩体中渗流场、水流温度场和岩块温度场之间的相互影响作用机理出发,推导了三者的耦合方程,并从考虑耦合作用的单场数值计算开始,进而到两场之间的耦合迭代,最终实现了三场的耦合数值计算,达到了预期的目标。3.基于一定的基本理论和数值计算方法的基础之上,最终实现了3-D CoupledSeepage-Temperature Program in Fractured Network程序的开发。4.将前面理论、模型和数值计算方法应用到某实际工程中验证自主开发3-D CoupledSeepage-Temperature Program in Fractured Network程序的正确性,对该工程的坝基进行了裂隙网络模拟,然后对连通区域组成的裂隙网络和岩块一起进行了渗流-温度的耦合分析。就相同的边界条件和初始条件,对上游水头瞬降、上游水头不发生变化、上游水头瞬升和上游水头缓降四种工况进行了对比分析。结果分析表明,对于坝基而言,边界水头变化与不变化,水头变化的过程是否相同,从而得到的渗流场水头、水流温度值和岩块温度值都有一定的区别。因此,采用裂隙网络方法考虑渗流场、水流温度场和岩块温度场的耦合作用有一定的必要性,为工程的设计施工提供一定的参考依据。更多还原

【Abstract】 At present,coupling analysis about seepage-stress-temperature-solute is one very important problem for all engineering field in rock-soil project.Coupling analysis about seepage-temperature is one important research contents in them.It is one important factor about normal operation and security of project.It is applied in the following domain:Hydraulic and Hydro-Power Engineering,geotechnical engineering,civil engineering and building construction,development and application of Water Resources,environmental engineering, hydrogeology,engineering geology,oil development,coal and natural gas development, geothermal development,prediction and control in earthquake,underground engineering and nuclear waste disposal etc.In terms of fractured rock mass,equivalent continuum model is widely adopted at present because of its mature theoretical basis and calculation method.However,discontinuous model (fracture network model)used to seepage-temperature coupling analysis is method of accordance with practical case in theory for rock mass having sparse cranny or big faults. Comparing with continuum model,its development is just starting.It will bca brand-new component part in fractured rock mass domain.Aiming at particularity of fractured rock mass,it considers that rock mass is impervious itself and water flows in fracture network structured by fracture surface.This paper thinks that coupling analysis of seepage-temperature in fracture network is coupling analysis of seepage field,flow temperature field in fracture surface and rock block temperature field in rock mass. Based these foundations,the following works has finished:1.Based seepage theory of fracture network and temperature field at present,starting from two-dimensional numerical simulation of seepage-temperature interaction,it has finished the following numerical calculation:steady temperature field calculation of dam engineering considering thermal effect of seepage in continuous medium;steady seepage field calculation considering temperature effect in fracture network;unsteady temperature field calculation considering fissure flow in fracture network.All these qualitative and quantitative analysis between seepage and temperature lays a foundation for mechanism research,model building and numerical calculation of there-dimensional coupled seepage-temperature.2.Because there-dimensional coupling analysis of seepage-temperature in fractured rock mass is core part of the paper,starting from analyzing action mechanism of 3-D seepage field, flow temperature field and rock block field in fractured rock mass,their coupling equation has been deduced.Firstly,numerical calculation of single field considering coupling effect has been researched,secondly,coupling iteration between two fields has been done;finally,coupling numerical calculation among three fields has been achieved.It comes true our object.3.Based on some basic theory and numerical method,the program named "3-D Coupled Seepage-Temperature Program in Fractured Network" is developed finally.3.The former theory,model and numerical calculation method is applied to one actual project to verify correctness of self-developed program called "3-D Coupled Seepage-Temperature Program in Fractured Network".Firstly,fracture network of dam foundation has been simulated;secondly,it has done coupling analysis between seepage and temperature fields for fracture network structured by connected domain and rock block.In terms of the same boundary condition and initial condition,it does comparative analysis for 4 project cases:sharp drop of upstream water head;constant upstream water head;sharp rise of upstream water head;slow drop of upstream water head.It has been shown that there are certain difference among water head,flow temperature and rock block temperature from coupling analysis for change,changeless and change process of water head in dam foundation.Thereby, using fracture network method analyzing coupled seepage-flow temperature-rock block temperature fields is necessary and will provide some reference basis to design and construction of engineering.更多还原