水利专业混凝土重力坝中英文对照外文翻译文献

1、 中英文资料外文翻译混凝土重力坝基础流体力学行为分析摘要：一个在新的和现有的混凝土重力坝的滑动稳定性评价的关键要求是对孔隙压力和基础关节和剪切强度不连续分布的预测。本文列出评价建立在岩石节理上的混凝土重力坝流体力学行为的方法。该方法包括通过水库典型周期建立一个观察大坝行为的数据库，并用离散元法（DEM）数值模式模拟该行为。一旦模型进行验证，包括岩性主要参数的变化，地应力，和联合几何共同的特点都要纳入分析。斯威土地，Albigna大坝坐落在花岗岩上，进行了一个典型的水库周期的特定地点的模拟，来评估岩基上的水流体系的性质和评价滑动面相对于其他大坝岩界面的发展的潜力。目前大坝基础内的各种不同几何的岩

2、石的滑动因素，是用德国马克也评价模型与常规的分析方法的。裂纹扩展模式和相应扬压力和抗滑安全系数的估计沿坝岩接口与数字高程模型进行了比较得出，由目前在工程实践中使用的简化程序。结果发现，在岩石节理，估计裂缝发展后的基础隆起从目前所得到的设计准则过于保守以及导致的安全性过低，不符合观察到的行为因素。关键词：流体力学，岩石节理，流量，水库设计。简介：评估抗滑混凝土重力坝的安全要求的理解是，岩基和他们上面的结构是一个互动的系统，其行为是通过具体的材料和岩石基础的力学性能和液压控制。大约一个世纪前，Boozy 大坝的失败提示工程师开始考虑由内部产生渗漏大坝坝基系统的扬压力的影响，并探讨如何尽量减少其影响

3、。今天，随着现代计算资源和更多的先例，确定沿断面孔隙压力分布，以及评估相关的压力和评估安全系数仍然是最具挑战性的。我们认为，观察和监测以及映射对大型水坝的行为和充分的仪表可以是我们更好地理解在混凝土重力坝基础上的缝张开度，裂纹扩展，和孔隙压力的发展。图.1 流体力学行为：（一）机械;（二）液压。 本文介绍了在过去 20 个来自 Albigna 大坝，瑞士，多年收集的水库运行周期行为的代表的监测数据，描述了一系列的数值分析结果及评估了其基础流体力学行为。比较了数值模拟和实际行为在实地的监测结果。在此基础上比较了一系列的结论得出了基本孔隙压力在节理岩体的影响可以考虑在其他工程项目，认为那里的岩石节

4、理流体力学行为应予以考虑。这些项目包括压力管道，危险废物处置，以及对流动行为的控制断面沿岩石地质遏制依赖的其他情形。nnKni KKVniKniana行为，i. e，两者在液压机械孔径由于孔径的变化变化的关系，鉴于a其中 是剩余的水力孔径hr因此，用经典的立方定律表示通过岩石节理流率：h是沿岩石节理头部下降;是水（11.005wa 流地下 G=W/L（其中 W 和 L 是宽度和长度，分别联合），为不同径向流，G =2/ln(re)/,另外，岩体等效渗透，公里，可以以同样的形式作为修改后的定律，或在液压口径计算，同样的形式占关节间距，S:在裂隙岩体渗透性的变化，由于覆盖层和围应力，计算。 1 -

5、 3。岩体的渗透性，K，理论的深度关系的结果高达 1000 米，采用当量。 5载于图 2。孔的液压随Vakmchoni在深露天矿在巴西花岗岩开采项目获得的场渗透率测量在图 2 中绘制与理论的关系比较。联合间距从钻孔岩心观察值都在数米范围内，从而产生了一个 5 米间距是常数的计算假设。阿霍的价值在 300 -1000m 范围被用来确定公里= f 的理论关系（z）的，其中 Z 是深度，以实地测量和比较这两个钻孔测量值相对渗透率在 100 至 200 米深处的高，可能表明的一个区或剪切节理岩带更多的存在。所测岩石渗透率稳步下降，在深度的增加，然而，它们的值与对应的岩体渗透性的理论与模型估计趋势良好。

6、K典型液压孔径 400 -500m 的和后关节僵硬=10V 的双曲线关系，与三菱商Va似乎同意这些结晶岩体观测场行为良好。ho Hydromechanical analysis of flow behavior in concrete gravity damfoundationsAbstract: A key requirement in the evaluation of sliding stability of new and existingconcrete gravity dams is the prediction of the distribution of pore pressu

7、re and shearstrength in foundation joints and discontinuities. This paper presents a methodology forevaluating the hydromechanical behavior of concrete gravity dams founded on jointed rock.The methodology consisted of creating a database of observed dam behavior throughouttypical cycles of reservoir

8、 filling and simulating this behavior with a distinct elementmethod (DEM) numerical model. Once the model is validated, variations of keyparameters including litho logy, in situ stress, joint geometry, and joint characteristics canbe incorporated in the analysis. A site-specific simulation of a typi

9、cal reservoir cycle wascarried out for Albigna Dam, Switzer land, founded on granitic rock, to assess the nature ofthe flow regime in the rock foundations and to evaluate the potential for sliding surfacesother than the damrock interface to develop. The factor of safety against sliding of variousroc

10、k wedges of differing geometry present within the dam foundations was also evaluatedusing the DEM model and conventional analytical procedures. Estimates of crackpropagation patterns and corresponding uplift pressures and factors of safety againstsliding along the damrock interface obtained with the

11、 DEM were also compared withthose from simplified procedures currently used in engineering practice. It was found thatin a jointed rock, foundation uplift estimates after crack development obtained frompresent design guidelines can be too conservative and result in factors of safety that are toolow

12、and do not correspond to the observed behavior.Key words: Hydromechanical, jointed rock, flow, dam design.Introduction: Evaluating the safety of concrete gravity dams against sliding requiresan understanding that rock foundations and the structure above them are an interactivesystem whose behavior i

13、s controlled by the mechanical and hydraulic properties ofconcrete materials and rock foundations. About a century ago, the failure of Boozy Damprompted dam engineers to start considering the effect of uplift pressures generated by This paper presents behavior representative of cycles of reservoir o

14、peration in the last20 years collected from monitored data of Albigna Dam, Switzerland, and also describesthe results of a series of numerical analyses carried out to assess the hydromechanicalbehavior of its foundations. Comparisons are made between results of numerical modelingand the actual behav

15、ior monitored in the field. Based on these comparisons, a series ofconclusions are drawn regarding basic pore-pressure buildup mechanisms in jointed rockmasses with implications that may be considered in other engineering projects, where thehydromechanical behavior of jointed rock should be consider

16、ed. Such projects include pressure tunnels, hazardous waste disposal, and other situations dependent on geologiccontainment controlled by flow behavior along rock discontinuities.Hydromechanical behavior of natural jointsnnThe magnitude of the closure per unit of stress decreases rapidly, however, a

17、s the stressKlevel increases. The hyperbola is defined by the initial tangent stiffness, , and theniV. This relationship is also nonlinear and hystereticKVFor natural and induced fractures in granite, these parameters are interrelated and rangebetween the following limits Alvarez et al. (1995):KVis

18、in mmcRough joints exhibit the largest joint maximum closure and the lowest initial jointVKstiffness, whereas smooth joints have the lowestand the largestmcniThe hydraulic behavior of the rock joint is characterized by the linear relationship abetween hydraulic aperture, , which controls the magnitu

19、de of flow, and mechanical jointhclosure, which depends on stress levels. Hydraulic apertures are plotted versus theirnacorresponding joint closure (Fig.1b)to obtain the line intercept,initial hydraulichofaperture, and the coupled slope coefficient, ,which characterizes the hydromechanicalbehavior o

20、f the joint ,i. e., the relationship between changes in hydraulic aperture due tochanges in mechanical aperture, given byahrhWhere Q is the flow rate;wajoint hydraulic aperture; and G is the shape factor, which depends on the geometry of flow.For straight flow, G=W/L (where W and L are the width and

21、 length, respectively, of therjoint); and for divergent radial flow, G=2/ln (re/ ), whereand re are the borehole andiexternal cylindrical surface radiuses, respectively.Jointed rock mass permeability change with depthAlternatively, the rock mass equivalent permeability, km, can be expressed in thesa

22、me form as the modified cubic law, or in terms of hydraulic aperture, to account forspacing of the joints, S: permeability that decreases with an increase in depth fromVaThe rock mass permeability estimates were obtained assuming f=1.0,=mckniout in granitic formations(Alvarez et al.1995)similar to t

23、hose of the Brazilian test locationdescribed in this section. Overburden stresses were estimated using a unit weight of 26.0kN/m3.In this case it was assumed that horizontal and vertical stresses are about the same(coefficient of earth pressure at rest Ko=1.0), which are also considered to bereprese

24、ntative of the igneous formations at the Brazil test location, but other values of insitu stresses could be estimated, e.g., for Ko1.0, vertical joints would have largerpermeabilities.Field permeability measurements obtained in Packer tests at a deep open-pit miningproject in granitic rock in Brazil are also plotted in Fig.2 for comparison with thetheoretical relationship. Values of joint spacing observed from borehole cores are in therange of a few meters, and thus a constant spacing of 5m was assumed in the computations.Values of aho in the range of 3001000m were