BREACH模型在土石坝中的应用分析

第四章土石坝自测题一、填空题1．土石坝按施工方法可分为、、和等形式。

2．土坝按防渗体的位置分为、、、。

3．土石坝的剖面拟定是指、、和的拟定。

4．在土石坝的坝顶高程计算中，超高值Y= （写出公式）。

公式中各字母代表的含义是：、、。

5.碾压式土石坝上下游坝坡常沿高程每隔10～30m设置，宽度不小于～，一般设在。

6.当有可靠防浪墙时，心墙顶部高程应，否则，心墙顶部高程应不低于。

7.由于填筑土石坝坝体的材料为，抗剪强度低，下游坝坡平缓，坝体体积和重量都较大，所以不会产生。

8.土石坝挡水后，在坝体内形成由上游向下游的渗流。

坝体内渗流的水面线叫做。

其下的土料承受着，并使土的内磨擦角和粘结力减小，对坝坡稳定。

9..土石坝可能滑动面的形式有、和复合滑裂面。

10.土石坝裂缝处理常用的方法有、、等。

11.土石坝管涌渗透变形中使个别小颗粒土在孔隙内开始移动的水力坡降；使更大的土粒开始移动，产生渗流通道和较大范围内破坏的水力坡降称。

12.在土石坝的坝坡稳定计算中，可用替代法考虑渗透动水压力的影响，在计算下游水位以上、浸润线以下的土体的滑动力矩时用重度，计算抗滑力矩时用重度。

13.土石坝的上游面，为防止波浪淘刷、冰层和漂浮物的损害、顺坝水流的冲刷等对坝坡的危害，必须设置。

14.土石坝砂砾石地基处理属于“上防”措施，铅直方向的有、板桩、和帷幕灌浆。

15.砂砾石地基一般强度较大，压缩变形也较小，因而对建筑在砂砾石地基上土石坝的地基处理主要是解决。

16.土石坝与混凝土坝、溢洪道、船闸、涵管等混凝土建筑物的连接，必须防止接触面的，防止因而产生的裂缝，以及因水流对上下游坝坡和坝脚的冲刷而造成的危害。

17.土坝的裂缝处理常用的方法有、、等。

18.土石坝的渗漏处理时，要遵循“”的原则，即在坝的上游坝体和坝基、阻截渗水，在坝的下游面设排出渗水。

二、单项选择题1.土石坝的粘土防渗墙顶部高程应（）。

A、高于设计洪水位B、高于设计洪水位加一定超高，且不低于校核洪水位C、高于校核洪水位D、高于校核洪水位加一定安全超高2.关于土石坝坝坡，下列说法不正确的有（）。

第３９卷第２２期２００８年１１月人民长江ＹａｎｇｔｚｅＲｉｖｅｒＶ０１．３９．Ｎｏ．２２ＮＯＶ．，２００８文章编号：１００１—４１７９（２００８）２２—００７９—０４唐家山堰塞湖溃坝洪水分析及泄流冲刷模拟朱勇辉范北林卢金友张细兵杨文俊渠庚（长江水利委员会长江科学院，湖北武汉４３００１０）摘要：土石坝渍坝数学模型ＢＲＥＳＺＨＵ建立在渍坝试验及原型渍坝案例中所观察到的溃坝机理基础之上。

模型先后用不同国家的多组溃坝试验资料进行率定和验证，并被成功应用于原型堤坝溃决案例的模拟，结果良好。

“５·１２”地震唐家山堰塞湖险情发生后，其不断升高的水位和不断增大的湖容给下游百万群众的生命财产安全造成了巨大威胁。

运用ＢＲＥＳＺＨＵ模型并结合坝下游溃坝洪水演进模型针对堰塞湖上游可能出现的不同频率洪水、坝体的不同溃决方案和不同溃决过程等对数１０种工况下唐家山堰塞湖的调洪、溃坝及洪水传播过程进行了计算与分析，为抢险方案和应急预案的制定提供了有力的技术支持。

险情结束后运用ＢＲＥＳＺＨＵ模型及时对湖水下泄过程中泄流渠断面发展及坝址处洪水过程等进行了模拟，结果表明模型计算的下泄洪水过程（水位、流量）及泄流渠断面发展等与实测情况符合较好。

关键词：渍坝；洪水；泄流；冲刷；模型；唐家山堰塞湖中图分类号：ｐ３１５．９文献标识码：Ａ１唐家山堰塞湖形成及除险概况２００８年５月１２１３四川汶川发生特大地震，距＝ｊＥ川县城约４ｋｍ的涪江支流通口河右岸唐家山发生大规模滑坡，滑坡堵塞通口河形成堰塞坝，通口河水壅高形成唐家山堰塞湖。

通口河系涪江一级支流，主河长１７３ｋｍ，控制集水面积４５２０ｋｍ２。

，流域内多年平均年降水量为１３５５．４ｍｍ，降雨主要集中在５～９月，占全年降水的８６．３％，历年１ｄ最大降水量为３２３．４ｍｍ。

，多年平均流量１１８ｍ３／ｓ，年径流量３７．１亿ｍ。

径流年内分配不均，其中７～９月多年平均流量２４９ｍ３／ｓ，相应径流量１９．８亿ｍ３，占全年径流量的５３．５％。

毕业设计（论文）外文文献翻译文献、资料中文题目：土石坝的评估和修复文献、资料英文题目：文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期： 2017.02.14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 in 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 embankments, 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.IntroductionMany major facilities, hydraulic or otherwise, have become very old and badly deteriorated; more and more owners are coming 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 arepremanufactured to standards or codes, and their performance correspondingly is never 100% predictable. Dam engineering—in particular, that related to earth structures—has 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 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 correct 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 rigorous assessment procedures for existing 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 procedures; 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, 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 comfortable with the design and construction of such things and furthermore has demonstrated his/her understanding and experience.Rehabilitation MeasuresThe main factors affecting the performance of an embankment dam are (1)seepage; (2)stability; and (3) freeboard. For an embankment dam, all of these factors 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 the seepage (foundation or embankment), the seepage volume, and its criticality. Embankment slope stability is usually improved by flattening 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 slope under rapid drawdown conditions is of concern, then further analysis and/or monitoring of resulting pore pressures or modifications of reservoir operationsmay eliminate or reduce these concerns. Finally, raising an earth fill dam is usually a relatively straightforward fill placement operation, especi ally if the extent of the raising is relatively small. The interface between the old and new fills 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 reinforced earth, have been used with success in raising embankment dams. Rehabilitation of an embankment dam, however, is rarely achieved 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 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 to have suffered significantdistress—often 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 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.Case StudyThe 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 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 ‗‗h igh-hazard‘‘ dam and is in earthquake zone 1. As part of the FERC 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 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 by the design earthquake shaking. The available strength was compared withexpected 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 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 EvaluationTwo modes of failure were considered in the analyses—namely, loss 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 the 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 Impact AssessmentBased 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 AnalysisBased on a procedure by Makdisi and Seed (1977), permanent deformation can be calculated using the yield acceleration, and the time history of the averagedinduced acceleration. Since the factor of safety against flow failure immediately following theearthquake falls well short of that required by FERC, the Newmark type deformation 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 RemediationBased on the foregoing results, 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 program 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.Second, 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, 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 eliminated.ConclusionKey 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 that the economic realization of this type 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.‘‘ GeotechnicalEngineering 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 forestimatingea rthquake induced deformations in dams and 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, an d Seed, H. B. (1972). ‗‗SHAKE: A computer program for earthquake response analysis of horizontally layered site.‘‘ Rep. No. EERC72-12, 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, 351–376.Tokimatsu, K., and Seed, H. B. (1987). ‗‗Evaluation of settlements of sands due to earthquake shaking.‘‘ J. Geotech. Eng., 113(8), 861–878.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。

第 6 期水　利　水　运　工　程　学　报No. 6 2023 年 12 月HYDRO-SCIENCE AND ENGINEERING Dec. 2023 DOI:10.12170/20221116001马黎，钟启明，杨蒙，等. 新疆射月沟水库溃坝过程数值模拟[J]. 水利水运工程学报，2023（6）：195-204. （MA Li, ZHONG Qiming, YANG Meng, et al. Numerical simulation of dam breach process of Sheyuegou Reservoir in Xinjiang[J]. Hydro-Science and Engineering, 2023（6）: 195-204. （in Chinese））新疆射月沟水库溃坝过程数值模拟马黎1，钟启明2, 3，杨蒙2，吴迪1，李大成1，梅胜尧2(1. 中国电建集团贵阳勘测设计研究院有限公司，贵州贵阳 550081； 2. 南京水利科学研究院，江苏南京210029； 3. 水利部水库大坝安全重点实验室，江苏南京 210029)摘要: 近年来，由强降雨引发超标准洪水导致小型水库漫顶溃坝的事件在我国时有发生，2018年7月31日新疆射月沟水库发生的漫顶溃坝就是其中的典型案例。

因拥有较为详尽的调查资料，对本案进行反演分析具有重要理论意义和工程价值。

基于溃坝视频和灾后调查资料，明晰了射月沟水库的溃坝过程，总结了溃坝水流的冲蚀特性。

建立了可考虑溃口形态在纵、横断面演化规律的溃坝数值计算方法，并采用射月沟溃坝案例对其合理性进行验证。

通过计算值与实测值的对比发现，重要溃坝参数（如溃口峰值流量、溃口最终顶宽/底宽/深度、峰值流量出现时刻）的相对误差均在±15%以内，溃坝模型计算结果具有较高的精度。

参数敏感性分析表明，坝料冲蚀系数对溃坝过程具有重要影响，尤其是溃口峰值流量和峰值流量出现时刻；陡坎运移系数对溃坝过程也具有一定影响，决定了峰值流量出现时刻。

HEC-RAS模型在二维溃坝洪水研究中的应用宁聪;傅志敏;王志刚【摘要】为准确模拟大坝失事后溃坝洪水的下游演进,运用HEC-RAS二维水动力学模型,修正面板坝溃口发展曲线,设计两种闸门开度的小井沟面板坝漫顶溃坝工况,模拟水库泄洪影响下溃坝洪水的下游演进并生成相应的洪水风险图、最大流速分布图、滞留时间图.研究结果展现了溃坝洪水在中下游平原丘陵地区的泛滥情况、洪水风险的分布差异以及水库泄洪对溃坝洪水的影响.分析得出不同闸门开度下溃坝洪水在中下游平原丘陵地区的淹没水深和范围差异明显,最大流速和洪水滞留时间区别不大,说明水库全力泄洪能有效降低溃坝洪水对下游人员聚居的平原地区的危害.研究成果对后续的人员疏散和损失估计具有重要参考意义.【期刊名称】《水利水运工程学报》【年(卷),期】2019(000)002【总页数】7页(P86-92)【关键词】二维模型;漫顶;面板坝;HEC-RAS;小井沟水库【作者】宁聪;傅志敏;王志刚【作者单位】河海大学水文水资源学院,江苏南京210098;河海大学水文水资源学院,江苏南京210098;黄河水利水电开发总公司,河南济源459017【正文语种】中文【中图分类】TV133.2水库大坝作为水利枢纽的重要组成部分，在防洪，发电，灌溉等功能中发挥着重要作用。

水库大坝失事将危及下游地区人民的生命财产安全与社会稳定[1- 2]。

为了对水库溃坝进行有效的风险防范，需在溃后影响区域进行洪水模拟计算。

目前主流的洪水数值模拟软件包括丹麦的MIKE11/21，荷兰的Delft3D和美国的HEC-RAS。

其中HEC-RAS为美国陆军工程兵军团水文中心开发的免费河道水力计算软件，前人利用HEC-RAS在洪水数值模拟方面已进行大量工作。

周毅[3]利用HEC-RAS和GIS平台模拟了疏勒河地区2000年一遇洪水在下游区域的演进情况；贺娟等[4]利用HEC-RAS对长河坝水电站进行了溃坝洪水模拟；吴博等[5]利用HEC-RAS和GIS平台对小东川河流域的山洪淹没范围做出了较为准确的预测；孙锐娇等[6]利用HEC-RAS模拟多种工况下某水库溃坝洪水演进。