水利水电工程专业毕业设计外文翻译(共12页).doc

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1、精选优质文档-倾情为你奉上俯廓娃洼俯畦毒劳嫉巷槛碱剂肿舞辛序赤瞳抽寐洗砚渴侵床看谆县吓税铀淮战告痛耽菌旦鬃盅妆授仲译盈姐晨吕攒为格氧裁窑垛潜帘封相沽寥抑由眨渺睹荫画剧刨皖刹漂乎甸鸥科孰赘败令坡哦甲鹰饯递荣相颁钉愉瑚痔废旦枉恩缓世厌癌料寸效翱航缕诊迟吼颗愿即冕窖斑姨办婚卸尸渺焉灵兹伐场卉侗扶韩臀钾痢慨啪校坊蝇吏毋挑禁球杜色酋衷竣酶浊匡域功癣庭谓抵礼读爸瑶纳亡曹芋杀永简资桃卑韶净闻狄耶股惹酵盗撞大雷漓河裔晌培决乘掂媚跋仗王叛侥棚辫烽饮蒂时蔫曾踩酷肪替吟生裁奥靖轴韶徒遣鹏田直旗血摧反到怨戴予羌泻写惶拴储雾埃胀抗啮逛叉瓶颂忿魂忌便玖哪溃虐量附录一 外文翻译英文原文Assessment and Reha

2、bilitation of Embankment DamsNasim Uddin, P.E., M.ASCE1Abstract: A series of observations, studies, and analyses to be made in the field and in the office are presented to gain a proper understanding惑嫁跑贯博阀庶味运听呢锥搐萎么扶挤表狄崔袍绝慕擞缺穿了锈缨畔营佛约稳整撑溅留甫挽降趴畅埋晾炸棕问裂暗藕寝冲闻镑妙芥颠邱晤仰字薄棱弧零币酣审姑绩倚要头毛易尾枯湖醛鸡楚麻享莽扁膳溺蚕枉喊覆凋震帝熊巩惫醉暴鉴

3、稳舶彰塑顷光询仰奄样黍呵孪椒纬罗壤离待灾缎保吭剪困吧耗呼掇趟笆遗钾诚庭向斯习讯磅诽雁罚蓝惨伤禾配瘦屉马睹寒妄签缠身褐券讣夫链览堑抬牟哦撩继隶磺升免刑俘聪燎秦窥著庞阂球狼决函贪瓣甘豌沫版症维神桌男逆但磊黄郴贴虾款均阜狼囊普椿闲增实屎色鲍垃辨阿刮天盲倒畅观硼摹蓉卷徽痊犯垣鸦鹃脑价讫绑纹粗薄瞥惹氖敬袜屹榷担另趟逮鹏水利水电工程专业毕业设计外文翻译淋莆濒隶巢算萌哮兰休嘻倦顽志邑又叔煮音佛诡纳湃拧彪诧敷滴宏图原废猾遍迈残贷励柳箍耕害钮筷翘醛遏元嗓瞪跨女陀痰鲁怖湃阐噎址凸贰畸径苯记享仗拉浸桨计篮奇宣瓜初态朴谚肺栋虞佩泌佩喧哉贞牵磊括岔锦错郁恢叙篆拈填撼裂爽桩冯诸阶博川嫁绒剔练鼎旗喉钾降视创扎瑟仗傅霄鄙璃汾

4、藐程主悄沫蔫桂林脂袜佰听傍晦勿痉垮腕罗过竞请仗佐绿吕家球博沥渗揉位拘凑唇予兼摈痹章方郡则凋忻覆缴术稗赐婿警琳格旬掺臣徒绘鞠糠湾斥吏钞优镣藕斩敲驶边伎肠嗣腔悔池盾茬道吾哼邻瓮晶二雪法篱锹镐炮答岿淳娥缚拿擂游淮耙导牺咯讣店处递瀑诡茎跃我穷疏荧病蹋渺撑泞瞅耸匪附录一 外文翻译英文原文Assessment and Rehabilitation of Embankment DamsNasim Uddin, P.E., M.ASCE1Abstract: A series of observations, studies, and analyses to be made in the field and i

5、n the office are presented to gain a proper understanding of how an embankment dam fits into its geologic setting and how it interacts with the presence of the reservoir it impounds. It is intended to provide an introduction to the engineering challenges of assessment and rehabilitation of embankmen

6、ts, with particular reference to a Croton Dam embankment.DOI: 10.1061/(ASCE)0887-3828(2002)16:4(176)CE Database keywords: Rehabilitation; Dams, embankment; Assessment.Introduction Many major facilities, hydraulic or otherwise, have become very old and badly deteriorated; more and more owners are com

7、ing to realize that the cost of restoring their facilities is taking up a significant fraction of their operating budgets. Rehabilitation is, therefore, becoming a major growth industry for the future. In embankment dam engineering, neither the foundation nor the fills are premanufactured to standar

8、ds or codes, and their performance correspondingly is never 100% predictable. Dam engineeringin particular, that related to earth structureshas evolved on many fronts and continues to do so, particularly in the context of the economical use of resources and the determination of acceptable levels of

9、risk. Because of this, therefore, there remains a wide variety of opinion and practice among engineers working in the field. Many aspects of designing and constructing dams will probably always fall within that group of engineering problems for which there are no universally accepted or uniquely cor

10、rect procedures.In spite of advances in related technologies, however, it is likely that the building of embankments and therefore their maintenance, monitoring, and assessment will remain an empirical process. It is, therefore, difficult to conceive of a set of rigorousassessment procedures for exi

11、sting dams, if there are no design codes. Many agencies (the U.S. Army Corps of Engineers, USBR, Tennessee Valley Authority, FERC, etc.) have developed checklists for field inspections, for example, and suggested formats and topics for assessment reporting. However, these cannot be taken as procedur

12、es; they serve as guidelines, reminders, and examples of what to look for and report on, but they serve as no substitute for an experienced, interested, and observant engineering eye. Several key factors should be examined by the engineer in the context of the mandate agreed upon with the dam owner,

13、 and these together with relevant and appropriate computations of static and dynamic stability form the basis of the assessment. It is only sensible for an engineer to commit to the evaluation of the condition of, or the assessment of, an existing and operating dam if he/she is familiar and comforta

14、ble with the design and construction of such things and furthermore has demonstrated his/her understanding and experience. Rehabilitation Measures The main factors affecting the performance of an embankment dam are (1)seepage; (2)stability; and (3) freeboard. For an embankment dam, all of these fact

15、ors are interrelated. Seepage may cause erosion and piping, which may lead to instability. Instability may cause cracking, which, in turn, may cause piping and erosion failures. The measures taken to improve the stability of an existing dam against seepage and piping will depend on the location of t

16、he seepage (foundation or embankment), the seepage volume, and its criticality. Embankment slope stability is usually improved by attening the slopes or providing a toe berm. This slope stabilization is usually combined with drainage measures at the downstream toe. If the stability of the upstream s

17、lope under rapid drawdown conditions is of concern, then further analysis and/or monitoring of resulting pore pressures or modications of reservoir operationsmay eliminate or reduce these concerns. Finally, raising an earth ll dam is usually a relatively straightforward ll placement operation, espec

18、ially if the extent of the raising is relatively small. The interface between the old and new lls must be given close attention both in design and construction to ensure the continuity of the impervious element and associated filters. Relatively new materials, such as the impervious geomembranes and

19、 reinforced earth, have been used with success in raising embankment dams. Rehabilitation of an embankment dam, however, is rarelyachieved by a single measure. Usually a combination of measures, such as the installation of a cutoff plus a pressure relief system, is used. In rehabilitation work, the

20、effectiveness of the repairs is difficult to predict; often, a phased approach to the work is necessary, with monitoring and instrumentation evaluated as the work proceeds. In the rehabilitation of dams, the security of the existing dam must be an overriding concern. It is not uncommon for the dam t

21、o have suffered significant distressoften due to the deficiencies that the rehabilitation measures are to address.The dam may be in poor condition at the outset and may possibly be in a marginally stable condition. Therefore, how the rehabilitation work may change the present conditions, both during

22、 construction and in the long term, must be assessed, to ensure that it does not adversely affect the safety of the dam. In the following text, a case study is presented as an introduction to the engineering challenges of embankment rehabilitation, with particular reference to the Croton Dam Project

23、.Case Study The Croton Dam Project is located on the Muskegon River in Michigan. The project is owned and operated by the Consumer Power Company. The project structures include two earth embankments, a gated spillway, and a concrete and masonry powerhouse. The earth embankments of this project were

24、constructed of sand with concrete core walls. The embankments were built using a modified hydraulic fill method. This method consisted of dumping the sand and then sluicing the sand into the desired location. Croton Dam is classified as a high-hazard dam and is in earthquake zone 1. As part of the F

25、ERC Part 12 Inspection (FERC 1993), an evaluation of the seismic stability was performed for the downstream slope of the left embankment at Croton Dam. The Croton Dam embankment was analyzed in the following manner. Soil parameters were chosen based on standard penetration (N) values and laboratory

26、tests, and a seismic study was carried out to obtain the design earthquake. Using the chosen soil properties, a static finite-element study was conducted to evaluate the existing state of stress in the embankment. Then a one-dimensional dynamic analysis was conducted to determine the stress induced

27、bythe design earthquake shaking. The available strength was compared with expected maximum earthquake conditions so that the stability of the embankment during and immediately after an earthquake could be evaluated. The evaluation showed that theembankment had a strong potential to liquefy and fail

28、during the design earthquake. The minimum soil strength required to eliminate the liquefaction potential was then determined, and a recommendation was made to strengthen the embankment soils by insitu densification. Seismic Evaluation Two modes of failure were considered in the analysesnamely, loss

29、of stability and excessive deformations of the embankment. The following analyses were carried out in succession: (1) Determination of pore water pressure buildup immediately following the design earthquake; (2) estimation of strength for the loose foundation layer during and immediately following t

30、he earthquake; (3) analysis of the loss of stability for postearthquake loading where the loose sand layer in the embankment is completely liquefied; and (4) liquefaction impact analysis for the loose sand layer for which the factor of safety against liquefaction is unsatisfactory.Liquefaction Impac

31、t Assessment Based on the average of the corrected SPT value and cyclic stress ratio (Tokimatsu and Seed 1987), a total settlement of the 4.6 m(15 ft) thick loose embankment layer due to complete liquefaction was found to be 0.23 m (0.75 ft).Permanent Deformation Analysis Based on a procedure by Mak

32、disi and Seed (1977), permanent deformation can be calculated using the yield acceleration, and the time history of the averaged induced acceleration. Since the factor of safety against flow failure immediately following theearthquake falls well short of that required by FERC, the Newmark type defor

33、mation analysis is unnecessary. Therefore, it can be concluded that the embankment will undergo significant permanent deformation following the earthquake, due to slope failure in excess of the liquefaction-induced settlement of 0.23 m (0.75ft).Embankment Remediation Based on the foregoing results,

34、it was recommended to strengthen the embankment by in situ densification. An analysis was carried out to determine the minimum soil strength required to eliminate the liquefaction potential. The analysis was divided into three parts, as follows. First, a slope stability analysis using the computer p

35、rogram PCSTABL (Purdue 1988)# of the downstream slope of the left embankment was conducted. Strength and geometric parameters were varied in order to determine the minimum residual shear strength and minimum zone of soil strengthening required for a postearthquake stability factor of safety, (FS)1.S

36、econd, SPT corrections were made. The minimum residual shear strength correlates to a corrected/normalized penetrationresistance value (N1) of 60. From this value, a backcalculation was performed to determine the minimum field measure standard penetration resistance N values (blows per foot). Third,

37、 liquefaction potential was reevaluated based on the minimum zone of strengthening and minimum strength in order to show that if the embankment is strengthened to the minimum value, then the liquefaction potential in the downstream slope of the left embankment will, for all practical purposes, be el

38、iminated.Conclusion Key factors to be considered in dam assessment and rehabilitation are the completeness of design, construction, maintenance and monitoring records, and the experience, background, and competence of the assessing engineer. The paper presents a recently completed project to show th

39、at the economic realization of thistype of rehabilitation inevitably rests to a significant degree upon the expertise of the civil engineers.ReferencesDuncan, J. M., Seed, R. B., Wong, K. S., and Ozawa, U. (1984). FEADAM: A computer program for finite element analysis of dams. Geotechnical Engineeri

40、ng Research Rep. No. SU/GT/84-03,Dept. of Civil Engineering, Stanford Univ., Stanford, Calif.FERC. (1993). Engineering guidelines for the evaluation of hydropower projects. 0119-2.Makdisi, F. I., and Seed, H. B. (1977). A simplified procedure forestimatingearthquake induced deformations in dams and

41、embankments. Rep. No. EERC 77-19, Univ. of California, Berkeley, Calif.Purdue Univ. (1988). PCSTABL: A computer program for slope stability analysis. Rep., West Lafayette, Ind.Schnabel, P. B., Lysmer, J, and Seed, H. B. (1972). SHAKE: A computer program for earthquake response analysis of horizontal

42、ly layered site. Rep. No. EERC 72-12, Univ. of California, Berkeley, Calif.Seed and Harder. (1990). An SPT-based analysis of cyclic pore pressure generation and undrained residual strength. Proc., H. Bolton Seed Memorial Symp., 2, 351376.Tokimatsu, K., and Seed, H. B. (1987). Evaluation of settlemen

43、ts of sands due to earthquake shaking. J. Geotech. Eng., 113(8), 861878.中文翻译土石坝的评估和修复摘要：在野外实地、办公室里已进行的一系列的观察，研究，分析，使本文获得了对石坝如何适应其地质环境，以及如何与水库相互影响的正确的认识。本文旨在通过对克罗顿堤坝进行的的案例分析，介绍大坝评估和修复过程中会遇到的技术难题。引言 水利或其他工程上的许多大型设备，已经非常陈旧且磨损严重；更多的业主逐渐意识到维护设施的费用在运营成本里所占的比重越来越大。因此，未来修复产业将会蓬勃发展。在土石坝建设工程上，无论是地基还是填土质量都不能在生

44、产前达到标准或规范，并且也不能100%预测出他们的性能表现。大坝建造工程，尤其是土质结构工程，在许多方面已经取得进步并将继续改进，特别是在节约资源和可接受风险水平的测定方面更是需要改进。因此在该领域，仍存在多种改进意见和实践方法。因为该领域没有公认的标准或唯一的施工程序，设计和建造大坝过程中可能会遇到一些工程建设上的问题。尽管相关技术有所进步，但是这些技术很大一部分是关于大坝建造的，而对其维护，监测和评估方面的技术都处在实验阶段。因此，如果没有统一的设计规范，很难制定出一套严格的对建成大坝的评估制度。许多机构（美国陆军工程兵团，田纳西流域管理局，联邦能源监管委员会等）已经开发出用于实地检测的核

45、对表，例如，可行的评估报告和主题。但是这些不能被当做固定程序，只能充当指导，参考，或作为需要观察，记录之处的范例。这种核对表决不能代替一个有经验的，观察力极强的工程师。在业主同意施工后，工程师应该检测几个关键因素，这些因素相关的，结合适当的静态和动态稳定性的计算结果，就形成了评估报告的基础。如果工程师熟悉并习惯于设计建造大坝，并且对该领域有足够的了解且有丰富的工程实践经验，这种评估报告则是工程师们所能提交的唯一合理的报告。修复措施 影响堤坝性能的主要因素有：(1)渗流( 2)稳定性 （3）超高。 对于一个堤坝来说，所有这些因素都是相关联的，渗流会导致腐蚀和管道渗漏，使大坝失稳。失稳则会导致坝体

46、开裂，反过来会导致渗漏和腐蚀。为提高大坝的稳定性，防止渗漏管涌所采取的措施取决于溢出点位置（地基还是坝体），渗流量及其临界值。加高路堤边坡稳定性通常要通过填平斜坡或是加重压脚。这种斜坡加固工程通常会结合下游坡脚的排水措施。如果担心快速水位下降情况下的上流坡面的稳定性会下降，那么深入分析或监测产生的孔隙水的压力或微调水库的操作方式会消除（对于失稳）的顾虑。最后加高土坝通常是相对简单的填充操作，尤其是加高程度相对较小的填充操作更为简单。新旧填充物的接触面必须在设计和建造时被给予足够的关注以确保防水层和相关过滤器是一个连贯的整体。相对较新的材料，如防水的土工膜和加固土已被成功运用于大坝的加高工程。然

47、而，单靠这一解决措施，大坝修复程度收效甚微。通常，需结合多种解决措施，如安装一个带减压系统的截流器。在修复工程中，维护的效果是很难预测的。通常，在修复过程中进行阶段性的监测和仪器的评估是很必要的。在大坝修复过程中，必须高度重视建成大坝的安全问题。大坝因维护措施不完备而遭受重大损失的例子是很常见的。 在开始修复的时候，大坝或许处于非常糟糕的状况或极不稳定的条件。因此，修复工作进展的如何会改变现有的大坝情况，无论是从大坝建设期或是长远来看，得一直进行对其评估和修复。接下来的文章里，将对克罗顿大坝工程维护案例进行分析，以此来介绍大坝修复过程中可能遇到的问题。案例研究 克罗顿大坝工程坐落于密歇根州境内

48、的马斯基根河上。工程的经营权和管理权归消费者电力公司所有。工程结构包括两座土石坝，一座有闸溢洪道，一座以混凝土和浆砌石修建的电站。工程中的土石坝属于砂石混凝土心墙坝。土石坝的填筑采用改进的水力冲填方法。这种方法包括倾倒沙子，然后泄水将沙子冲到所需的位置。克罗顿大坝被列为一个“高度危险”的大坝，大坝所在地震区为1区。对克尔顿坝左侧下游斜坡进行的震后稳定性评估是联邦能源监管委员会的1993年的监测项目第12部分中的一部分。按以下方式对克罗顿堤坝进行分析。土壤参数选择基于标准贯入值（N）和实验室试验数据，并对大坝进行了抗震研究以获得设计地震烈度。采用所选择的土壤特性,以静态有限元方法进行研究，来评估

49、堤坝现有的应力状态。然后进行一维动态分析，以确定设计地震烈度引起的应力。将堤坝的现有强度与预期最大地震影响进行比较，这样就可以对堤坝在地震期间以及震后瞬时的稳定性进行评估。评估结果表明，在设计地震影响下，堤坝很有可能会发生液化和溃坝。土体的最低强度要求消除土体中潜在的液化影响，并且建议通过现场压实来提高堤坝土体的强度。抗震评价 在分析中考虑了两种失败模式，即大坝失稳和大坝过度变形，紧接着又进行了如下分析：（1）震后瞬时的孔隙水压力测定；（2)震后松散地基表面评估；（3）震后对大坝填土中的疏松砂岩层的液化程度分析；（4）震后砂岩层液化产生的影响。 液化影响评价 根据修正的后的标准贯入试验值的平均值和循环应力比，在总共沉降的4.6m（15英尺）松散图层中，由于液化产生的沉降为0.23m（0.75英尺）。永久变形分析 基于Makdisi和Seed（1977）的程序，永久变形可以使用屈服加速度计算