枝状管网水力仿真计算软件的开发

通过对现有供热管网水力仿真计算模型的分析，开发了一个图形化的枝状管网和水力仿真计算软件，建立起枝状管网数学模型，完成了图形化供热管网水力计算图形的识别工作，导出管网流量分配的矩阵方程式，确定了求解数学模型的算法，大大减少了计算的工作量，提高了计算精度。     

集中供热管网的水力平衡优化

为了对集中供热管网二次网进行水力平衡优化，基于质量守恒、能量守恒和图论，提出了水力数学模型，给出了数值迭代求解算法。基于粒子群优化算法，提出了阻力系数辨识优化算法，可根据用户管段流量测量值，对用户管段的实际阻力系数进行寻优。然后提出了水力平衡优化算法，基于对用户管段流量均衡加以优化的目标，找出阻力系数最优值以用于平衡阀调整。最后应用该水力平衡优化方案对洛阳某小区进行仿真模拟，仿真结果表明该方案可以实现管网水力平衡。     

自动喷水灭火系统管网的水力模型分析

采用有限元法分析了自喷系统管网的水力平衡数学模型，集合各个管段水力平衡的单元矩阵方程为管网水力平衡的整体矩阵方程，通过引入节点水压边界条件并求解整体矩阵方程，自动配管，迭代计算喷头的流量，得出管网水力工况。给出了编程算法步骤，经实例运算，可快捷准确地完成水力平衡计算。     

枝状供热管网水力工况模拟分析

应用图论理论建立了枝状管网水力工况模拟分析的数学模型，编制了水力工况计算程序，并对某一管网水力工况进行了分析。     

基于在线迭代寻优算法的供热二次管网水力平衡调试方法研究与应用

本文在分析总结现有的供热二次管网水力失调现状及现有的水力平衡调试方法的不足之上,提出了一种基于在线迭代寻优算法的供热二次管网水力平衡调试方法,并给出了该方法的调试过程和算法流程图。在该水力平衡调试方法的基础上,研发了一套在线水力平衡调试系统与软件,并将该软件应用于实际项目中。结果表明:基于在线迭代寻优算法的供热二次管网水力平衡调试方法与工具,可以实现实际系统的二次管网水力平衡,调试后水流量绝大部分满足与设计流量的10%偏差;通过水力平衡,实现了供热系统的巨大节能,在本应用中,系统节能率约为17.66%。     

基于互补算法的水力裂缝与天然裂缝相互作用边界元模型

水力裂缝与天然裂缝的相互作用力学机制是确定水力压裂裂缝扩展形态的关键。基于天然裂缝变形与受力状态,推导天然裂缝变形的互补约束条件,并结合间断边界元,建立水力裂缝与天然裂缝相互作用的力学分析模型。通过压剪裂缝理论解和求解天然裂缝力学响应的试算法验证模型可靠性。以页岩气多段压裂水平井为例进行实例分析,并探讨水力裂缝与天然裂缝力学响应特征和变化规律,结果表明:基于互补算法的边界元模型计算结果与实例井微地震结果一致;水力裂缝靠近或接触天然裂缝时,水力裂缝尖端会发生钝化,天然裂缝面会发生张开或剪切,并以剪切为主;逼近角大于60°时,天然裂缝面很难发生张开;逼近角不等于90°时,水力裂缝和天然裂缝接触点与天然裂缝破裂点存在偏移;逼近角、净压力和天然裂缝摩擦因数越大,水力裂缝穿过天然裂缝可能性越大。     

大型泵站虹吸式出水流道水力特性分析

采用计算流体力学方法对大型泵站虹吸式出水流道的内部流场进行了数值模拟。在分析了影响虹吸式出水流道水力特性的主要设计参数、数值模拟流道内部的三维流动和定性分析流道内部流态的基础上，建立了虹吸式出水流道水力特性评价指标体系。通过分析两个设计方案的虹吸式出水流道的流场，定量比较了驼峰和出口断面的流速分布均匀度和流道水力损失，客观评价了虹吸式出水流道的水力特性，为实现水力设计优化提供了可靠依据，可有效地节省物理模型试验费用和时间，提高水泵装置的效率。     

燃气管网的邻接矩阵描述及相应的水力计算算法

介绍了用邻接矩阵描述燃气管网的方法和对应的水力计算算法，并总结了用邻接矩阵描述燃气管网方法的特点。     

多热源环状热网水力计算研究

利用图论理论建立多热源环状热网通用水力计算数学模型,采用节点方程法对数学模型进行求解,编制了计算程序。以某市规划热网为例进行计算,证明了数学模型的正确性,算法合理,收敛性好。     

环状热网泄漏检测模型研究

基于图论理论、变流理论及贝叶斯算法建立环状热网泄漏工况水力模型、预测误差模型.在模拟管网泄漏工况时,将泄漏归结在节点处,将泄漏流量视为该节点流量的一部分,泄漏程度用泄漏面积反映.将由热网泄漏工况水力模型得到的热网泄漏数据库数据作为测量数据,将水力模型的模拟结果作为预测数据,采用预测误差模型计算预测数据的最优估计概率,指导确定泄漏位置.     

Hydromechanical effects of shaft sinking at the Sellafield site

Under the auspices of the DECOVALEX II project, the coupled hydromechanical responses, in the fractured volcanic rocks at Sellafield site, to a pump test and shaft sinking were studied. The aim of this paper is to describe the methodology for determining the hydromechanical effects of the shaft excavation. This methodology is based on the discrete fracture network (DFN) approach for hydraulic analysis and the discrete approach, where the main discontinuities are explicitly represented in the mechanical model. The principal advantage of using the DFN approach is to easily change the scale of the study without important modifications of the network. Hydraulic properties of the different types of discontinuities were evaluated by calibration of the flow rates induced by a long-term pump test in borehole RCF3 drilled on the centreline of one of the proposed shafts. The same fracture network generated to analyse the RCF3 pump test was used to predict the hydromechanical responses of the rock mass to the excavation of a shaft centred on the RCF3 borehole. This methodology offers some additional possibilities such as studies of the excavation damaged zone (EDZ) and its influence on hydraulic conductivity.     

Rôle des fluides dans le comportement hydromécanique des roches fracturées hétérogènes: Caractérisation in situ et modélisation numérique

Hydromechanical coupled processes in a shallow fractured rock mass were investigated in situ through field experiments and numerical simulations. The experimental approach consists of performing simultaneous and multi-frequency measurements of fluid pressures and displacements at different points and on different fracture types within a carbonate reservoir. Two kinds of experiments were conducted at the Coaraze Laboratory Site (France):

1. At the fracture network scale, a global hydraulic loading by groundwater level change shows that the coupling between fluid flow and deformation is simultaneously governed by a dual-permeability hydraulic behaviour and a dual-stiffness mechanical behaviour. The following fluid flow and hydromechanical conceptual scheme was established: first, a transient flow only occurs in faults with high permeability; second, when a steady-state flow is reached in faults, water flows from faults into lower permeability bedding planes. The intact rock matrix is practically impervious but the connectivity between the discontinuities is high. When fluid pressure changes occur within the fracture network, the hydromechanical coupling is direct in the highly permeable faults where a pressure change induces a deformation change. No direct hydromechanical coupling occurs within the lower permeability zones where deformation is not directly correlated with pressure changes. This means that the mechanical deformation of the bedding planes and rock matrix is induced by the fault deformation.
2. At the single fracture scale, the hydromechanical behaviour was evaluated by performing hydraulic pulse injection testing. This test was monitored using high-frequency (f = 120 Hz) hydromechanical measurements conducted with innovative fiber-optic borehole equipment. The hydromechanical response is simultaneously monitored at two measuring points spaced about 1 m apart within the plane of the sub-vertical fracture. Observed fluid pressure versus normal displacement curves shows a characteristic loop-shaped evolution in which the paths for loading (pressure increase) and unloading (pressure decrease) are different. The test was evaluated by coupled hydromechanical modelling using a distinct element technique. By matching the loop behaviour, modelling indicates that the pulse pressure increase portion allows the fracture hydromechanical properties to be determined while the pulse pressure decrease portion is strongly influenced by the hydromechanical effects within the surrounding fractured rock mass. A sensitivity study shows that the key parameters to coupled hydromechanical processes in such fracture systems are the initial hydraulic aperture and normal stiffness of the fracture, the stiffness of the rock matrix and the geometry of the surrounding fracture network.

     

基于三维激光扫描技术的岩体结构面智能识别与信息提取

岩体结构面几何参数是评价岩体稳定性与渗流特征的重要研究基础。采用三维激光扫描技术,获取岩体露头点云数据,利用改进的区域生长法与解析几何理论,实现了岩体结构面智能识别与信息提取。研究结论如下:(1)通过对区域生长法进行改进,引入节点法向量判别指标,设置平整性检测阈值_1与区域生长阈值_2,可以有效地进行岩体结构面的智能识别。基于提出的信息提取算法,获取了识别结构面的产状、间距与尺寸信息;(2)选取不同的平整性检测阈值_1与区域生长阈值_2,研究了阈值对识别结果的影响规律,并提取了阈值选取的一般建议。通过规则平面与公路边坡两实例应用分析,对所提方法的可靠性进行了验证。     

Hydromechanical interactions in a fractured carbonate reservoir inferred from hydraulic and mechanical measurements

Hydromechanical coupled processes in a shallow fractured carbonate reservoir rock were investigated through field experiments coupled with analytical and numerical analyses. The experiments consist of hydraulic loading/unloading of a water reservoir in which fluid flow occurs mainly inside a heterogeneous fracture network made up of vertical faults and bedding planes. Hydromechanical response of the reservoir was measured using six pressure–normal displacement sensors located on discontinuities and two surface tiltmeters. A dual hydraulic behavior was characterized for low-permeability bedding planes well connected to high-permeability faults. Displacement responses show high-variability, nonlinear changes, sometimes with high-frequency oscillations, and a large scattering of magnitudes. Initial normal stiffnesses and effective normal stresses along fault planes were estimated in the field by interpreting pressure–normal displacement relations with a nonlinear function between effective normal stress and normal displacement. Two-dimensional discontinuum modeling with transient fluid flow was performed to fit measurements during hydraulic loading tests. Results show that the hydromechanical behavior of the reservoir is restored if a high stiffness contrast is allocated between low- and high-permeability discontinuities. Thus, a dual-permeability network of discontinuities will likely also be a contrasting stiffness network, in which the deformation of major flow-conducting discontinuities is significantly influenced by the stiffness of the surrounding less-permeable discontinuities.     

Numerical modeling of discontinuous rock slopes utilizing the 3DDGM (three-dimensional discontinuity geometrical modeling) method

The geometry of discontinuities in a rock mass is one of the most important influences on the behavior and characteristics of that rock mass. The geometry of discontinuities largely determines the stability of the rock mass, as well as appropriate methods for reinforcing and stabilizing that mass. This study introduces the 3DDGM (three-dimensional discontinuity geometrical modeling) method, which is based on the 3DGM (three-dimensional geometrical modeling) algorithm that was developed using the Mathematica software package. The 3DDGM method provides essential input data for the stability analysis of a discontinuous rock mass using block stability assessment techniques or block modeling codes. The 3DDGM method developed in the present work was designed to model discontinuities in rock masses and to provide accurate values for discontinuity parameters (i.e., location, spacing, separation, system, orientation, etc.). This algorithm was developed to increase the accuracy of the discontinuity model based on the Heliot algorithm. The 3DDGM algorithm was tested by applying it to a real case, the sloping discontinuous rock mass at the phase 7 gas flare site in the South Pars Gas Complex in Assalouyeh, Iran, and the algorithm was successful in providing a three-dimensional model of the discontinuities in the rock mass at the site.     

不连续岩体温度场的复合单元模型初步研究

 基于复合单元法原理和不稳定温度场的隐式解法,提出针对不连续岩体温度场的复合单元法。该算法的特点是每个复合单元可以含有任意的不连续面,如断层或节理,且当结构中含有需在计算中离散处理的不连续面时,网格的生成不受不连续面的数量、位置和方向的影响。初步研究针对含1条节理的复合单元模型展开,假定岩块中无对流和辐射影响,推导岩块子单元和不连续面的热传导计算式,得到不连续岩体温度场的复合单元算法基本方程组,然后将该算法整合到传统有限元分析程序中。分别采用传统有限单元和复合单元法模拟热水流过单条裂隙时岩体温度场的变化过程,二者的计算结果非常接近,表明不连续岩体温度场的复合单元算法是合理和有效的,但其配套的温度场等值线后处理程序有待进一步完善。该算法的提出为深部岩体的多场耦合研究提供又一思路。     

节理岩体三维综合抗剪强度数值模拟研究

采用不确定性理论建立的三维节理网络模拟技术是计算机技术在岩体力学领域应尉的一个重要方面。该技术利用野外不连续面现场地质调查所获得的原始数据，建立结构面几何参数分布的概率统计模型，进而应用蒙特卡罗模拟方法构筑不连续面在三维空间的组合形态，借助计算机生成三维网络模型。在建立三维网络模型的基础上，通过搜索不连续面和岩桥组合破坏的临界路径来确定连通率并提供三维综合抗剪强度指标，在搜索过程中应用了具有鲜明生物背景的遗传算法。     

循环荷载下岩体结构面本构关系与积分算法研究

地下结构中广泛存在的各种不连续面是影响岩体工程力学特性的重要因素,研究结构面在循环荷载作用下的力学行为具有重要的工程意义。基于非关联塑性理论,同时定义加载剪胀段和反向剪缩段,建立了岩体结构面剪胀与塑性耦合本构关系;从结构面的基本损伤机制出发,基于拉、剪分离的思路,建立了一类基于能量原理的岩体结构面拉、剪损伤本构模型,该模型基于有效应力空间塑性力学基本原理,定义了岩体结构面拉、剪塑性Helmholtz自由能分量及损伤能释放率,建立了岩体结构面拉、剪损伤破坏准则。针对结构面在循环荷载作用下的强非线性问题,引入算子分解的思想,将弹塑性演化与损伤演化过程分开进行求解,提出了结构面弹塑性损伤本构关系的混合积分算法。分别进行了岩体结构面直剪和循环剪切试验的数值仿真,计算结果与模型试验基本一致,表明该模型在模拟非连续岩体复杂变形方面是合理有效的。     

Polyhedral modelling of rock mass structure

The development and application of polyhedral modellers to geo-mechanics has been an important advance in the accurate modelling of rock mass structure. The representation of rock mass discontinuities with finite persistence has necessitated the development of modellers capable of automatic identification of complex polyhedra (rock blocks). The work described in this paper extends previous developments and details a robust algorithm capable of identification of rock blocks generated from the partial or complete intersection of large numbers of both planar and curved rock mass discontinuities. It summarises some important modifications to the published literature on polyhedral modelling theory as it pertains to the synthesis of rock mass structure.     

岩质边坡最危险滑裂面的GA-Sarma算法研究

 基于现有国内外边坡极限平衡法稳定性分析软件在岩质边坡滑裂面搜索中的局限性,将遗传算法(GA)和Sarma法相结合,提出岩质边坡最危险滑裂面的GA-Sarma算法。GA-Sarma算法解决以折线形为滑面形态、以层面等结构面为边界任意条分并满足条块间边界力平衡原理、滑裂路径可追踪顺坡向不连续结构面的岩质边坡最危险滑裂面的全局优化问题。