超高混凝土面板堆石坝的关键技术问题-毕业外文文献翻译名师(完整版)资料.doc

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1、超高混凝土面板堆石坝的关键技术问题-毕业外文文献翻译名师（完整版）资料(可以直接使用，可编辑 优秀版资料，欢迎下载）外文文献及翻译 Key technical problems of extra-highconcrete faced rock-fill damABSTRACTThis paper summarizes the main technical points related to 100 m-height-scale concrete faced rock-fill dams and analyzes the main problems and their causes occurr

2、ing during construction of 200 m-height-scale concrete faced rock-fill dams.This paper has raised the key technical problems which need to study for construction of 300 m-height-scale concrete faced rock-fill dams based on the main experiences on the extra-high concrete faced rock-fill dams built af

3、ter the year of 2000.1 IntroductionMore and more concrete faced rock-fill dams have been built nowadays at home and abroad thanks to its good adaptability to topographical and geological conditions, rainy and harsh climate, less demanding on goods and materials from outside areas, less amount of con

4、struction quantities, faster construction process, safer operation and easier maintenance.By the end of 2005 more than 150 concrete faced rock-fill dams have been built or under construction in the country, of which 37 have their height over 100 m and 14 have their height over 150 m; 15 concrete fac

5、ed rock-fill dams are founded on thick overburdens. The Shuibuya concrete faced rock-fill dam, 233 m high, which is to be completed by the end of 2007, will be the highest dam of this kind in the world. At present the 300 m height scale concrete faced rock-fill dams are to be built in the country.Pe

6、ople of the dam engineering circles hold that a concrete faced rock-fill dam with a height of over 150 m is called an extra high concrete faced rock-fill dam. The key technology of an extra high concrete faced rock-fill dam refers to the major technical problems encountered in construction of a conc

7、rete faced rock-fill dam with a height of about 200 m on the basis of ripe experiences in both design and construction of 100 m-height-scale concrete faced rock-fill dams.This paper makes an attempt to summarize the key technical points of the 100 m-height-scaleconcrete faced rock-fill dams, analyze

8、s the major technical problems occurring in construction of the 200 m-height-scale concrete faced rock-fill dams and ponders on the key technical problems of the 300 m-height-scale concrete face rock-fill dams.2 Key technical points of 100 m-height-scale concrete faced rock-filldamThe technology of

9、a 100 m-height-scale concrete faced rock-fill dam is matured after 20 years development and its key design points include dam body stability analysis and embankment zoning design two aspects.2.1 Stability problemCook holds that the concrete faced rock-fill dam is regarded as a dam constructed by vir

10、tue of experiences, there have been no precedents in instability of dam slopes and no stability analysis is required for it. He maintains that the upstream and downstream dam slopes shall be both 1:1.3. In order to protect the dam from damage by rolling stones a slope of 1:1.4 for either upstream si

11、de or downstream side of the dam has been adopted in our country.2.2 Key zoning design points of dam embankment materials Seepage flow control. The purpose of seepage flow control is to avoid losses of a great quantity of fine-grained material contained in the rock-fill materials, which would cause

12、additional settlement and thus further damage to concrete facing slabs.The seepage flow control is focussed on selection of suitable zoned material grading, mainly of cushion material grading. Sherard favours the opinion that the concrete membrane be provided with a cushion material with a low perme

13、ability coefficient and without segregation during construction, which can not only limit seepage but also create conditions for stopping seepage of the concrete face slabs under water.Other seepage flow control requirements: As for the suitable graded transition materials,cushion materials shall no

14、t be placed until the oversize rock material with a grain size of larger than 10 cm have been cleared away from the interface of cushion materials. And the material shall be compacted by roller along the junction of the edges of two layers of material after placement. The maximum grain size shall no

15、t exceed the thickness of a placement layer and the content of fine material shall be less than 20%. It is quite easy to obtain transition material. Tunnel dregs are usually used for transition material, which can also be obtained directly by blasting at a quarry site.The maximum grain size of main

16、rock-fill material shall not exceed the thickness of a placement layer and the content of fine material shall be less than 20%. General speaking, the content of fine material in hard rock-fill material is below 10%. Zoning of rock-fill to reduce deformation of concrete face slab. The width of zone 3

17、B of the main rock-fill shall be calculated based on the deflection of face slab and determined accordingto the condition of material sources. Efforts shall be made to reduce the width.Cook and Sherard proposed zoning of dam rock-fill and named the zones of rock-fill in 1987.Cook emphasized the stan

18、dardization of zoning of rock-fill and stipulated the construction parameters for various zones. The philosophy of rock-fill zoning presented in the Chinese specification for design of concrete faced rock-fill dams (ST228-98) is basically inconformity with Cooks. The Chinese specification has stipul

19、ated the requirement for grading,especially for grading of cushion materials, but not for construction parameters. Cook said that the concrete faced rock-fill dam was in fact a dam constructed by virtue of experience, which mainly came from the Foz do Areia dam completed in 1990 in Brazil. Its main

20、technical data are given below: Dam height, 160 m; dam crest length, 828 m; width-to-height ratio,5.17; valley coefficient (A/h2), 5.4; upstream and downstream dam slopes, 1:14. Compaction parameters: main rock-fill 0.8 m, adding water 25%, vibrating roller weight 10 t, 4 times of compaction; downst

21、ream rock-fill 1.6 m each, 25%, 10 t, 4 times. Rock-fill properties: main rock-fill porosity, 33%; modulus of compression, 47.5 MPa; modulus of compression of downstream rock-fill, 32 MPa. The deflection of the face slab was 69 cm when the first full impounding was reached. The maximum compressive s

22、train (horizontal) of the face slab was665106. The Foz do Areia dam is considered as a milestone in construction of concrete faced rock-fill dams for its successful operation with such parameters after completion.3 Major problems occurring during construction of 200 m-height-scaleconcrete faced rock

23、-fill damsThe concrete faced rock-fill dam completed in the late 1990s, which is higher than the Foz do Areia dam is called an extra-high concrete faced rock-fill dam, such as the Aguamilpa dam (187 m, 1995) in Mexico and the Tianshengqiao-1 dam (178 m, 1999) in China. Generally speaking, there are

24、two major problems in construction of extra-height-scale concrete faced rock-fill dams: One is the occurrence of structural cracks in face slabs, which causes a large quantity of seepage; the other is the damage to the face slab caused along the vertical joint. After finding such damage in Baragrand

25、 dam (185 m) and Camposnovos dam (202 m) in Brazil it is regarded necessary to work out quantitative indexes to control deflection of a concrete faced rock-fill dam.4 Main experiences in extra high concrete faced rock-fill dams builtafter 2000The experience in design, construction and operation of t

26、he Tianshengqiao-1 concrete faced rock-fill dam has afforded a salutary lesson for construction of the 200 m-height scale concrete faced rock-fill dams built or to be built after the year of 2000. It can be deemed that the Tianshengqiao-1 concrete faced rock-fill dam is a landmark in construction of

27、 the 200 m-height scale concrete faced rock-fill dams after 2000. Since 2000 three 200 m-height cale concrete faced rock-fill dams have been built. They are the Hongjiadu concrete faced rock-fill dam, 179.5 m in height, completed in 2005; the Sanbanxi dam, 186.0 m in height, completed in 2006; and t

28、he Shuibuya dam, 233.0 m in height, completed in 2007. These three dams have produced small settlement and a small number of face slab cracks. The basic experiences in their construction can be summarized as follows.4.1 Dam construction materialThe dam rock fill material is composed of such rock tha

29、t it is characterized by medium or high hardness, well graded and low porosity of 20% or even lower, which helps reducing compressive deformation. For example, ultra hard rock material mixed with an appropriate quantity of weathered rock material was used for the purpose of obtaining even lower poro

30、sity and even higher dry density in construction of the Sanbanxi dam. The maximum settlement rates of the Hongjiadu, Sanbanxi and Shuibuya dams are 0.74% (the reference settlement rate is 0.41%), 0.78% (the reference settlement rate is 0.42%) and 0.96% (the reference settlement rate is 1.09%)respect

31、ively. Thus it can be seen that the reference settlement rates of the high dams of this kind built after the Tiangshengqiao-1 concrete faced rock-fill dam are only about 1/2 of that of the Tianshengqiao-1 dam each. For the concrete faced rock-fill dams that have the same compression modulus their ma

32、ximum settlement is proportional to the square of dam height, i.e. the settlement rate is proportional to the first power of dam height. The reference settlement rate is the settlement rate divided by H/100 m.This can represent the compression modulus of dam body rock fill. We suggest that the refer

33、ence settlement be calculated at the same time when the maximum settlement and settlement rate of a dam are calculated for the sake of making a comparison with compression modulus. The compression modulus of any of these dams is 22.5 times of that of the Tianshengqiao-1 dam, say,about 80100 MPa.4.2

34、Zoning of rock-fillThe area of main rock-fill zone shall be expanded downstream from the dam axis according to the height of dam and an underwater rock-fill zone shall be provided under the flood level downstream,which shall be well graded, have good scour resistance and high permeability coefficien

35、t. The content of fine material with grain size of smaller than 5 mm shall be lower than 20% and that with grain size of smaller than 0.075 mm lower than 5%. The porosity of both main rock-fill zone and other rock-fill zone shall basically be in consistence and difference in compression modulus shal

36、l not be big so that the upstream and downstream rock-fills of the dam become a uniform compact entirety, thus greatly reducing difference in settlement between the main rock-fill zone and the other rock-fill zone. The porosities of the main and other rock-fill zones of the Hongjiadu,Sanbanxi and Sh

37、uibuya dams are 19.6% and 20.02%, 17.62% and 19.48%, 19.6% and 20.7%,respectively, which are 2%4% lower than that of the Tianshengqiao-1 dam each4.3 Setting up pre-settlement time of rock-fill and controlling settlement rateAbout six months shall be arranged as a pre-settlement period before concret

38、ing face slabs. Face slabs shall not be concreted until settlement rate is less than 5 mm/month and the crest elevation of face slab shall be more than 20 m lower than the rock-fill.4.4 Selection of equipmentIt is necessary to select advanced large compaction equipment. In general 25 T vibrating rol

39、lers shall be used, 810 times of compaction shall be arranged and proper watering shall be given. It is recommended to sprinkle water from a watering car.The GPS technology was employed in construction of the Shuibuya concrete faced rock-fill dam,where the thickness of placement layer, number of com

40、paction and overlapping length were all controlled by computer.5 Key technical problems needing study for 300 m-height-scale CFRDsAs viewed from the experiences on construction and operation of the 200 m-height scale CFRDs,the rock-fills are their supporting structures and control of embankment defo

41、rmation is the core of key technology for construction of extra high CFRDs. The key technology of the 300 m-heightscale concrete faced rock-fill dam need further studying in the following aspects.(1) Systematically summing-up of experiences and lessons on the 200 m-height scale concrete faced rock-f

42、ill dams completed at home and abroad, inversion analysis of the operation monitoring results, modification of calculation models, and perfection of calculation models of elasticity,plasticity and viscosity which can reflect creep characteristics in particular.(2) Study of embankment zoning design.

43、The problems of cushion cracks, separation of face slab from cushion and face slab cracks of the 200 m-height scale concrete faced rock-fill dams indicatethat the traditional design principle of embankment zoning has not been suited for extra highconcrete faced rock-fill dams any longer. Zoning of r

44、ock-fill shall not only reduce deflection but also reduce difference in settlement between upstream and downstream parts of embankment.Besides, control of deflection shall be quantified. An extra high concrete faced rock-fill dam suffers from large settlement and creep of embankment, as well as stru

45、ctural cracks that can beeasily caused in top face slabs. Great importance shall be attached to philosophy of deformation coordination in zoning design of embankment. It is necessary to enlarge the main rock-fill zone,reduce compression modulus ratio between the main and other rock-fill zones, insta

46、ll an underwater rock-fill zone downstream below the flood level and a modulus increasing zone in the upper embankment.(3) Study of design theory and methodology of face slab structure. Study of new type slab structure suited to the 300m-height scale concrete faced rock-fill dams, including design c

47、riteria for zoning of face slab thickness, seepage control, crack control, structural characteristic of face slabs with compressive joints, necessity of face slab permanent horizontal joints, establishment of a calculation model for contact face between face slab and cushion material as well as cont

48、rol measures of reducing separation phenomena of face slab from cushion material.(4) Study of high-performance sealing materials. In consideration of relatively large deformation of an extra high concrete faced rock-fill dam it is necessary to study in a deeply-going way deformation characteristics,

49、 and joint water sealing treatment measures, as well as high-performance joint sealing materials that are suited to high head and large deformation.超高混凝土面板堆石坝的关键技术问题摘要本文总结了关于百米高度规模混凝土面板堆石大坝的的主要技术要点，并且解释了200 米高混凝土面板堆石坝施工过程中存在的主要问题和原因。基于2000年之后建成的超高混凝土面板堆石坝的主要经验，为了300高混凝土面板堆石坝的施工，本文提出了需要研究的关键技术问题。 1.引言由于面板堆石坝对地形地质条件、雨天与恶劣的气候条件具有良好的适应性，对区外的货物和材料的要求少，工程量量少，施工速度快，操作安全和维护简单，现在，国内外建成了越来越多的混凝土面板堆石坝。截止到2005年底，在我国，至少150个混凝土面板堆石坝已经建成或是正在被建设，其中，有37个坝高超过100