外文翻譯----對水電站混凝土壩工程建設(shè)的研究

1、<p>　　對水電站混凝土壩工程建設(shè)的研究</p><p><b>　　簡介</b></p><p>　　施工方法與材料的創(chuàng)新能促進(jìn)大壩施工技術(shù)的改進(jìn)。憑借面板堆石壩、碾壓混凝土壩和其他一些新壩的結(jié)構(gòu)的技術(shù)革新，極大地促進(jìn)了大壩的建設(shè)。</p><p>　　最近的幾年因面板堆石壩明顯的優(yōu)越性，它的發(fā)展已廣泛地出現(xiàn)了。由于混凝土面板堆石

2、壩的高度是有限的，這可能導(dǎo)致混凝土面板堆石土壩和高混凝土面板堆石壩周邊密封防水縫破壞結(jié)構(gòu)大變形。一般說來，對面板堆石壩的變形，有許多因素的影響。例如建筑材料的屬性是一種基本的因素要求。</p><p>　　為了解決這個(gè)問題，郭承乾于1993年介紹了對改性后的堆石壩的概念，其中提到添加面板堆石壩中的一些水泥，然后壓縮它，這可以極大地改善其變形模量和壓應(yīng)力，甚至類似于軟巖或低年級碾壓混凝土。測試說明改進(jìn)后的堆石壩具有

3、巨大的變形模量，可以降低大壩變形效率。這描述了堆石壩的施工，對大壩的恢復(fù)和保管修改面板堆石壩的財(cái)產(chǎn)，可能使壓應(yīng)變消除。郭承乾提出了一項(xiàng)計(jì)劃，完全用改良性填石料來建壩，但并沒能進(jìn)行下去。</p><p>　　改良型堆石也被稱為凝成堆石，這是一種石料與混凝土的混合，國外也在進(jìn)行研究。</p><p>　　拉裴爾設(shè)想是有關(guān)水泥土的的一個(gè)想法，其基本思想是設(shè)計(jì)一個(gè)用土和混凝土材料建造，于重力壩和土

4、壩之間的中間型壩。后來Londe 引進(jìn)和開發(fā)了Hardfill通俗概念。</p><p>　　自從20世紀(jì)90年代，日本的工程師們做了很多工作發(fā)展Hardfill技術(shù)，它有了自己特定的字符，被稱為南玻大壩。南玻是一種材料加入少量的巖石類材料混合，如河床礫石或挖掘的淤泥，這些材料可以在壩附近容易獲得，簡單地混合與壓路機(jī)振動、滾動，形成一種碾壓混凝土。南玻大壩是對稱的梯形壩，南玻的實(shí)力相對于混凝土不強(qiáng)。另一方面，在一

5、個(gè)對稱的梯形壩中產(chǎn)生的壓力體積小，其要求的材料強(qiáng)度可以很低。這就是說，南?？梢宰鳛樘菪螇蔚慕ㄖ牧稀?lt;/p><p>　　在前人研究的基礎(chǔ)上，在此文件上，對水泥堆石材料的特點(diǎn)以及水泥堆石大壩的設(shè)計(jì)和施工進(jìn)行了研究。</p><p><b>　　水泥堆石的特點(diǎn)</b></p><p>　　水泥堆石是一種物質(zhì)加入一點(diǎn)水泥巖石般的堆石或沙礫等材料制成

6、的，它只是混合和壓路機(jī)的振動、滾動，形成的碾壓混凝土。圖1顯示了典型的水泥堆石應(yīng)力應(yīng)變曲線。從圖中顯示的水泥堆石的彈塑性行為，對水泥堆石的設(shè)計(jì)只有在彈塑性被認(rèn)為的范圍內(nèi)。</p><p>　　圖1 典型的水泥堆石材料的應(yīng)力-應(yīng)變曲線</p><p>　　水泥堆石具有以下特點(diǎn)：</p><p>　　水泥堆石是一種材料添加少量水泥巖石般的堆石（人工采礦）和砂礫（自然存在

7、），通過冷軋和壓實(shí)形成的。它的機(jī)械性能高于堆石的，但低于混凝土的。</p><p>　　壩料與一些水泥經(jīng)軋制后成為水泥堆石，但未形成粒狀物料。因此，大壩有良好抗沖刷能力、大的剪切力和抗壓抗腐蝕力。良好的抗沖刷能力是這種壩型的突出優(yōu)點(diǎn)，這樣可以降低整個(gè)施工導(dǎo)流標(biāo)準(zhǔn)讓洪水通過，在大壩施工期間，提高安全性，有防滲作用，并允許在洪水期使用漫頂。</p><p>　　水泥堆石具有更大的變形模量，參考

8、文獻(xiàn)【6】提到水泥堆石的變形模量可以達(dá)到10，大約是堆石的10～100倍。高的變形模量可以減少大壩的急劇變形，對上游壩體有很好的防滲作用。</p><p>　　水泥堆石主要維持大壩壩體不透水和保持大壩的穩(wěn)定，并把載荷傳遞到基地。因此，只要求筑壩材料要有一定的強(qiáng)度、變形模量、抗沖刷能力，并沒要求防滲作用。這可以水泥滲入量（相對于混凝土），下料的要求放松。與此同時(shí)，裂縫控制、界面治療、局部離散化和一些其他的要求可以放

9、松。</p><p>　　Londe 總結(jié)國外的經(jīng)驗(yàn)而提出：然而混合水泥50～60公斤/立方米的堆石壩，其強(qiáng)度可達(dá)9兆帕（90日齡），能夠滿足100米高大壩的強(qiáng)度要求。水泥滲入量低，意味著降低水化熱和溫升較低。因此，溫度應(yīng)力比碾壓混凝土壩小。此外，大壩沒有防滲要求，甚至很少有裂縫的結(jié)構(gòu)功能的影響。因此，可以構(gòu)建正常的堆石壩，不必設(shè)置伸縮縫。</p><p>　　降低水泥的使用可以降低總成本

10、。</p><p>　　松散的聚合（堆）的要求可以簡化準(zhǔn)備部分，降低成本，減少制造廢物渣，可以保護(hù)植被，縮小采石場的規(guī)模及降低運(yùn)輸成本。</p><p>　　水泥堆石壩施工方法維護(hù)正常的堆石壩的施工特點(diǎn)，簡單和快捷。</p><p><b>　　實(shí)驗(yàn)研究</b></p><p><b>　　A 聚合體的特征&l

11、t;/b></p><p>　　水泥堆石的技術(shù)特點(diǎn)是：攪拌水泥和堆石的強(qiáng)度。對于鞏固水泥起著重要的作用?？紤]利用中國豐富的巖石和砂礫資源，室內(nèi)試驗(yàn)，不僅研究了水泥墻堆石壩，也鞏固了以粉煤灰混合堆石，并比較它們的技術(shù)性能。沒有溫度的控制要求及雜質(zhì)相對數(shù)量較小的膠結(jié)材料。堆石是從河里的自然梯度。根據(jù)篩選結(jié)果，項(xiàng)目區(qū)位于河的上游，總體上可以看出部分的礫石顆粒是粗的，細(xì)顆粒含量是少數(shù)。所以它的混凝土工作性能差。在這

12、個(gè)實(shí)驗(yàn)中，消除了超級尺寸的礫石和最大粒徑小于100毫米的晶粒。</p><p><b>　　B 實(shí)驗(yàn)室測試</b></p><p>　　實(shí)驗(yàn)室主要從事的實(shí)驗(yàn)是壓實(shí)和抗壓強(qiáng)度后音量大小的工作性測試。研究結(jié)果表明，具有同樣的含水量，水泥堆石體積重量隨材料用量的增加而加強(qiáng)；當(dāng)一定量的塑料材料，首先作為容重隨用水量，水的消耗量超過最優(yōu)值，壓實(shí)密度降低。水泥堆石的抗壓強(qiáng)度隨大量

13、塑料材料的增加而單調(diào)上升。經(jīng)過28天抗壓強(qiáng)度（混合粉煤灰）有輕微的減少。當(dāng)總塑膠材料在60～80公斤/立方米，最優(yōu)用水量為90公斤/立方米。</p><p><b>　　C 現(xiàn)場測試</b></p><p>　　根據(jù)實(shí)驗(yàn)室的測試結(jié)果，現(xiàn)場碾壓實(shí)驗(yàn)已經(jīng)完成了建設(shè)準(zhǔn)備工作相結(jié)合?？紤]到經(jīng)濟(jì)性能和使用性能，現(xiàn)場做了80公斤/立方米和60公斤/立方米代替100公斤/立方米和4

14、0公斤/立方米兩組的水泥用量的蹤跡。根據(jù)蹤跡已做了大量的最優(yōu)耗水量（90公斤/立方米）。因?yàn)檫\(yùn)輸距離遠(yuǎn)，粉煤灰不用于小型的工程工作。經(jīng)過混合的材料和消除超粒徑碎石，然后制成標(biāo)本，抗壓強(qiáng)度的結(jié)果非常接近實(shí)驗(yàn)室的測試結(jié)果。</p><p>　　現(xiàn)場試驗(yàn)表明，水泥堆石和碾壓混凝土具有相同的特點(diǎn)。挖掘坑表明，從表面到底層壓實(shí)的影響較大，但整體密度小于碾壓混凝土。根據(jù)抗?jié)B實(shí)驗(yàn)解析結(jié)果，水泥堆石具有較低的抗?jié)B能力，水泥堆石的

15、滲透系數(shù)從到cm/s，所以面對上游水密應(yīng)考慮作為滲漏控制措施。</p><p>　　研究水泥堆石壩的建設(shè)</p><p><b>　　A 施工程序</b></p><p>　　水泥堆石壩的施工程序不同于水泥壩的。在圖2說明了水泥堆石的攪拌設(shè)備。</p><p>　　圖2 水泥堆石的攪拌設(shè)備</p><

16、p><b>　　B 施工方法</b></p><p>　　大于150毫米的碎石被耙消除了，然后通過自我卸卡車運(yùn)輸?shù)蕉褕?。這是水泥煤粉灰混合后第一次有卡車混合，然后倒均勻。軋制厚度為17厘米，振動壓路機(jī)軋制8倍。</p><p><b>　　C 結(jié)構(gòu)特點(diǎn)</b></p><p>　　只要求材料有一定的強(qiáng)度、變形模量和抗

17、沖刷能力。因此，裂縫控制、界面治療和局部離散化、一些其他的要求可以放松。</p><p>　　由于沒有必要水泥堆石質(zhì)量如碾壓混凝土好，簡化了施工程序，可以考慮加快建設(shè)速度，降低成本。為此，本文提出了一種假設(shè)，引用灌漿充實(shí)振搗混凝土和堆石混凝土施工程序，取消混合的程序，采取“卸載”“鋪路”“鋪灑（自填）” “壓路機(jī)壓實(shí)”，此方法可稱為“自我填充軋壓實(shí)”。取消混合的程序，不僅可以取消攪拌站和其他一些設(shè)備，還可以加快施

18、工速度，工程量（體積）是遠(yuǎn)小于普通混凝土面板堆石壩，因此施工時(shí)間可以大大縮短。</p><p>　　圖3 “自填和碾壓”水泥堆石壩壩體施工的工藝流程</p><p>　　Ⅴ水泥堆石壩的結(jié)構(gòu)形式</p><p>　　可能的新類型的大壩基于該技術(shù)提出了如下。</p><p>　　A 面板泥沙堆石大壩（CFRD）</p><p&

19、gt;　　如圖4，在面板泥沙堆石壩，一個(gè)為水密性的不透水膜，被放在了上游坡、混凝土面，在過去，在現(xiàn)在被廣泛地運(yùn)用于堆石壩。目前，雙梯度壓實(shí)碾壓混凝土傾向于在面板水泥堆石壩中占絕對優(yōu)勢，水泥堆石因有更大的變形模量和較高的抗剪強(qiáng)度，溢洪道可放置在壩體上。</p><p>　　圖4 面板泥沙堆石壩（圖中的虛線表示面板堆石壩的剖面）</p><p>　　面板泥沙堆石壩邊坡的范圍從1：0.5到1：0

20、.7。在上游的混凝土防滲墻面就像一種泥沙堆石壩防滲障礙。面板泥沙堆石壩的優(yōu)勢是有更大的安全性，施工周期短和建造成本低。</p><p><b>　　B 泥沙堆石混合壩</b></p><p>　　如圖5，在泥沙堆石混合壩中，設(shè)置泥沙堆石的主要區(qū)域和堆石整理二次填石料區(qū)。它和面板泥沙堆石壩相比較，項(xiàng)目數(shù)量更少、更安全。</p><p>　　圖5

21、泥沙堆石混合壩（圖中的虛線表示的是面板泥沙堆石壩的剖面）</p><p>　　在泥沙堆石混合壩的上游邊坡的范圍通常是從1：0.3到1：0.4，下游邊坡的接近面板泥沙堆石壩的?；炷练罎B面在上游地區(qū)就如面板泥沙堆石壩的防滲層。泥沙堆石混合壩更大的有點(diǎn)是安全、施工周期短和工程造價(jià)低。</p><p>　　C 泥沙堆石壩的特點(diǎn)</p><p>　　泥沙堆石壩屬于滲透性較低

22、，不能滿足自由排水的需要，以確保大壩的安全，需要在大壩的上游地區(qū)設(shè)置豎向排水和水平排水連接大壩的底部，這可以在下游區(qū)保持干燥。</p><p>　　穿透性的不同，區(qū)域的填充材料應(yīng)從上游至下游逐漸增加，滿足水力過渡的要求。一般來說，這個(gè)不需要設(shè)置過濾器和過渡。</p><p>　　上游面防滲可以采用混凝土面板，但不限制混凝土材料。其他經(jīng)濟(jì)、可靠的防滲材料，如瀝青混凝土、土工膜，可以被考慮是提

23、高其競爭力的重要手段。在實(shí)際應(yīng)用中，兩個(gè)分級碾壓混凝土應(yīng)作為首選，其施工方便、成本低和有良好的防滲效果。</p><p>　　Study on Cemented-rockfill Dam in Hydropower Station Construction</p><p>　　I. INTRODUCTION</p><p>　　The improvem

24、ent of construction methods and innovation of materials can promote the dam construction technologies. With these technical renovations, CFRD and RCCD and some other new dam structures have greatly promoted the dam const

25、ruction [1]. </p><p>　　The CFRD has been developed and sprung up in recent years because of its obviously advantages [2][3]. As the great deformation of rockfill which may lead to concrete face and watertigh

26、t seal structure of peripheral joints destroyed in high CFRD, the height of CFRD has been limited. Generally, there are many factors which influence the deformation of CFRD, such as properties of construction materials i

27、s a fundamental factor.</p><p>　　To solve this problem, Guo Chengqian [4] introduced the concept of modified rockfill in 1993, which referred to add some cement in the rockfill and then compact it, this can

28、greatly improve its deformation modulus and compressive strength, or even similar to soft rock or low grade RCC. Tests</p><p>　　show that modified rockfill has great deformation modulus, and can decrease the

29、 dam deformation efficiently. The modified rockfill meliorate the property of dam rockfill, eliminate the possibility to cause compressive strain, and keep the rockfill dam construction characterize. Guo Chengqian broach

30、ed a plan to build the dam with modified rockfill entirely, but did not go further.</p><p>　　Modified rockfill is also called cemented-rockfill, which is a material between concrete and rockfill, has been st

31、udied abroad. The first ideas related to the cement-soil were envisioned by Raphael [5], whose basic idea was the design of an intermediate type of dam between gravity and earthfill dam, using a material between concrete

32、 and soil. Later, Londe [6] developed and introduced worldly the concept of Hardfill. Since 1990′s, Japanese engineers have done a lot of work to develop Hardfill tec</p><p>　　Based on the former study, the

33、characteristics of cementedrockfill material and the design and construction of cementedrockfill dam have been studied in this paper.</p><p>　　II. CHARACTERISTICS OF CEMENTED-ROCKFILL</p><p>　　C

34、emented-rockfill is a material made by adding little cement to rock-like material such as rockfill or gravel, mixing it simply and rolling with vibration rollers, which can be considered as a lean RCC. Figure 1 shows the

35、 typical stressstrain curve of Cemented-rockfill [8]. From the figure, Cemented-rockfill shows the elasto-plasticity behavior, only the elastic range of cemented-rockfill is considered in designing.</p><p>　

36、　Figure 1. Typical stress-strain curve of cemented-rockfill material</p><p>　　The cemented-rockfill have following characterizes:</p><p>　　(1) Cemented-rockfill is a kind of material which is ro

37、lled and compacted by adding little cement in rockfill (artificial mining) or gravel (nature existing). Its mechanical property is higher than rockfill but lower than concrete.</p><p>　　(2) The dam material

38、with some cement became cementedrockfill after rolled but not granular material. Therefore, the dam has good anti-scouring ability and great shear and compressive resistance ability. Good anti-scouring ability is an outs

39、tanding advantage of this dam type, which can lower construction diversion standard as allowing flood across the dam during the construction period and increase safety degree as can anti-seepage and allowing flood overto

40、pping in use period.</p><p>　　(3) Cemented-rockfill has greater deformation modulus. Reference [6] referred that the deformation modulus of cemented-rockfill can reach 10GPa, which is about 10 or 100 times o

41、f rockfill. Higher deformation modulus can decrease dam deformation sharply, that’s good for upstream impervious body.</p><p>　　(4) Cemented-rockfill dam mainly to sustain impervious body and keep dam stabil

42、ity, and also transmit the load to the base. Therefore, there only require the dam materials have certain strength, deformation modulus and anti-scouring ability, but no anti-seepage requirement. So that can decrease<

43、/p><p>　　cement mixing amount (compared to concrete) and relax aggregate requirement. Meantime, cracks control, interface treatment and local discretization and some other requirement</p><p>　　can

44、be relaxed.</p><p>　　(5) Londe [6] summarized foreign experiences and put forward that: while mix cement 50~60 kg/m³ in rockfill, its strength can reach to 5 MPa (90d age), that can satisfy 100 m high d

45、am strength requirement. Lower cement mixing amount means lower hydration heat and smaller temperature rise.</p><p>　　Therefore, the temperature stress is much smaller than RCCD. Besides, the dam has no anti

46、-seepage requirement; even micro cracks have little influence to the structure function. So there need not to set expansion joint and can construct as normal rockfill dam.</p><p>　　(6) Lower cement usage can

47、 decrease the total cost.</p><p>　　(7) The loose aggregate (rockfill) requirements can simplify the preparation section and reduce the cost, produce less waste slag that can protect vegetation and shrink the

48、 scale of quarry plant and reduce transport cost.</p><p>　　(8) Cemented-rockfill dam construction method maintains normal rockfill dam construction features, simple and fast.</p><p>　　III. EXPER

49、IMENTAL RESEARCH</p><p>　　A. Aggregate characteristics</p><p>　　The technical characteristics of cemented-rockfill are that strength mixing cement with the rockfill. Cement plays a major role in

50、 cementing. Considering advantage of China's rich rock and sand gravel resource, the indoor experiments not only study the cemented rockfill but also the cemented rockfill mix with fly-ash, and compare the technical

51、performance of them. There have no temperature control requirements and admixture in view of the relatively small amount of cemented material. The rockfil</p><p>　　B. Laboratory test</p><p>　　Ma

52、inly work of Laboratory experiments are the volume weight after compaction and compressive strength workability test. Research results show that with the same water content , volume weight of cemented-rockfill increase w

53、ith cemented material dosage; when a certain amount of plastic material, the volume weight increases with water consumption firstly, as water consumption exceeds the optimal value, compaction density decrease. Compressiv

54、e strength of cemented-rockfill increases with the amount </p><p>　　C. Field test</p><p>　　According to lab test results, the site roller compaction trial had been done combined with preparation

55、 work of construction. Considering the economy and workability, the field tests done with the two groups of cement dosage trail of 80kg/m3 and 60kg/m3 instead of 100kg/m3 and 40kg/m3. The trail has been done according to

56、 the optimal water consumption (90kg/m3).Fly-ash does not used in the small engineering work because far transport distance. Materials are taken after mixed and eliminate the su</p><p>　　Field tests show tha

57、t the cemented-rockfill has the same characteristics as RCC. Digging pit shows that compaction effect from surface to the bottom is greater, but the overall density is less than RCC. According to the results of impermeab

58、ility test, the cemented-rockfill has lower impermeability capability; the permeability coefficient of cemented-rockfill is from 10-2 to 10-5cm/s, so the watertight upstream facing should be took into consideration as se

59、epage control measure.</p><p>　　IV. CONSTRUCTION RESEARCH OF CEMENTED-ROCKFILL</p><p>　　A. Construction procedure</p><p>　　Construction procedure of the cemented-rockfill dam is dif

60、ferent from the rockfill dam. Proper mixing equipment of cemented-rockfill is illustrated in figure 2. </p><p>　　Figure 2. Mixing equipment of cemented-rockfill</p><p>　　B. Construction method&

61、lt;/p><p>　　The gravel larger than 150mm is to be eliminated by rakes, and then be transported to stockyard by self-unload truck. It is mixed by load truck for the first time after mix into cement flyash, and t

62、hen blunged to uniformity. The rolling thickness is 17 cm; rolling 8 times with vibration rollers.</p><p>　　C. Construction features</p><p>　　There is only a certain strength, deformation modulu

63、s and anti-scouring ability to the material requirement. Therefore, cracks control, interface treatment and local discretization and some other requirement can be relaxed. </p><p>　　As there no need to make

64、the quality of cemented-rockfill as good as RCC, simplify the construction procedure can be considered to quicken construction speed and reduce the cost. This paper proposed an assumption, to reference grout enriched vib

65、rated concrete (GEVR) and rockfill concrete construction procedure, cancel mixing procedure, adopt “Unload” → “Paving” → “Cement sprinkling (self-fill)” → “Roller compaction”, this method can be called “self-fill roller

66、compaction”. Cancel mixing procedur</p><p>　　Figure 3. Technological process of cemented-rockfill dam construction by “self-fill and roller compaction”</p><p>　　V. STRUCTURAL TYPES OF CEMENTED-R

67、OCKFILL DAM</p><p>　　The possible new types of dam based on this technology are presented as follows.</p><p>　　A. Face cemented-rockfill dam (FCRD)</p><p>　　As shown in figure 4, in

68、 FCRD, an impervious membrane for water tightness is placed on the upstream slope, concrete face is widely used for rockfill dams in the past, at present, the two-graded compacted RCC tend to dominant in FCRD; and the sp

69、illway can be placed on the dam body because of the greater deformation modulus and higher shear strength of cemented-rockfill.</p><p>　　Figure 4. Face cemented-rockfill dam (the dotted line in the figure sh

70、ows the CFRD profile)</p><p>　　The range of slope of FCRD is generally from 1:0.5 to 1:0.7. The concrete impervious face in the upstream acts as a impervious barrier like CFRD. The FCRD has the advantages of

71、 greater safety, shorter construction period and lower construction cost.</p><p>　　B. Cemented-rockfill mixing dam(CRMD)</p><p>　　As shown in figure 5, In CRMD, the cemented-rockfill is arranged

72、 on the main rockfill zone, and the rockfill is arranged on the secondary rockfill zone. It is less project quantity and more safety compared to CFRD.</p><p>　　Figure5. Cemented-rockfill mixing dam (the dott

73、ed line in the figure shows the CFRD profile)</p><p>　　The range of upstream slope of CRMD is usually from 1:0.3 to 1:0.4 and the downstream slope similar with the CFRD. The concrete impervious face in the u

74、pstream area acts as an impervious barrier like CFRD. The CRMD has the advantages of greater safety, shorter construction period and lower construction cost.</p><p>　　C. Characteristics of cemented-rockfill

75、dam</p><p>　　(1) As cemented-rockfill belongs to lower medium penetrability, that can not satisfy free drainage requirement, to ensure the dam safety, there need to set vertical drainage in dam upstream area

76、 and connect to horizontal drainage in the dam bottom so that can keep dry in the downstream area.</p><p>　　(2) The penetrability of different area fill material should gradually increase from upstream to do

77、wnstream and satisfy the hydraulic transition requirement. Generally, there need not to set filter and transition.</p><p>　　(3) Upstream impervious face can adopt concrete face, but not limit in concrete mat

78、erial. Other economical and reliableimpervious materials such as asphalt concrete, geomembrane can be considered to improve its competition. In practical application, two graded aggregate RCC should be the first priority