1、水利水电专业英语论文英文对照及翻译范本模板 Earth and rock damSummaryEarth and rock dam， with another name as local material dam”，is mainly built with earth and rock materials near the site. It can be classified based on the materials it used， earth dam mainly with earth， sand, grit, and gravel， and rock dam mainly with
2、rock ballast， gravel， and exploded rocks。Features of earth and rock damStrong pointsWith convenient supply of materials， many building materials such as steel， cement， and timbers can be saved.With granular structure more suitable to foundation deformation, it demands less on the foundation。Very fle
3、xible from simple artificial filling to highly mechanized construction, the procedure become simple, the construction become efficient， and the quality guarantee become easy.Simply structured， thecost is low, the operation is convenient， worksis reliable， and maintenance and height adding is convien
4、t. Weak pointsOverflow not allowed， spillway has to be built。Diversionless convenient, cost increases.Section larger, earth to be filled is easy to be affected by climate. This kind of difficult means possible extention of time limit and cost increaseEarth and rock dam typesBased on constructing way
5、s， earth and rock dams can be classified into rolled ones of earth rock, thrown rockfilled ones，rock-filled ones withdirectional detonation， ones with earth thrown into the water， and ones filled by hydraulic forces.Among them， rolled ones are most popular。Based on the earth proportion and the locat
6、ion of anti-seepageparts， there are homogeneous (evengranular） dams, zoned earth dams, and dams with artificial antiseepage materials。 Strong points of homogeneous dams： one fold materials, simple process weak points: flat gradient, large section, weather-limited, strong water pressure in holes. Zon
7、ed dams are classified into ones with core antiseepage and ones with front anti-seepage. Less amount of earth， less affect of season。 interfering with the filling of the dam body. Less interference with the construction of the dam body. weaker anti-earthquake and uneven sinking. The anti-seepage par
8、ts of dams with artificial anti-seepage materials use asphalt concrete, reinforced concrete or other artifical materials. Sometimes， the anti-seepage parts are in the dam front facing the upstream, sometimes, they are at the core of the dam。 Working conditionsTrapeziform sectionEarthrock dam is a wa
9、ter retaining structure built with loose granules of earth and rocksfilled and roller compacted. With weaker strength between these granules， both upsteam and downsteam slopes have to be kept at acertain degree to avoid landslide。 So the dam section is usuallytrapeziform。It can be destablized in two
10、 ways, simple slope sliding and sametime sliding of slope and foundation caused by shear damage。Its a difference from other structuresSeepage effectsWith a large section， the dam is generally kept from entire sliding unless caused by weak interlayers. Effected by water levels at the upsteam and down
11、steam, seepage is easy to happen with streams passing the faying surfaces between the dam and foundation, and between dam earth and concrete buildings. The seeping streamsform a free water surface inside the dam。 Under the surface， all the earth body is saturated. Dipped in the water， the earth beco
12、me lighter in effect。 And its angle of internal friction is narrowed, and cohesive force weakened. With the hydrodynamic pressure from the seeping steams， more sliding of dam slopes is possible。 When seeping steamsmove insoil,the dam body and foundation will be deformed from too steep hydraulic grad
13、ient.Sometimes the dam even crashes。Scour effectIts antiscour ability is weak because the cohesive force between earth granules is small. On the one hand， the rain water enters the dam and lower the stability of the dam, and on the other hand, the rain scour the dam surface along the slope. At the s
14、ame time, the waves inside the reservoir also wash out the dam surface， putting the surface in the risk of being damaged. Sometime,landslide even happens due to this.So effective protecting measures have to be taken for dam slopes both upstream and downstream。Sinking effectThe dam body and foundatio
15、n will sink under their self weight and water load besides the space between earth granules。 If it sinks too much， the elevation level will not be sufficient, and then the operation of the dam will be affected. And, too much uneven sinkage will cause fracture of the dam boday， and even a seepage pas
16、sage， putting the dam at risk.Other effectsIn freezing regions， an ice-covered layer will be formed over the reservoir when the temperature is below 0 degree. Then the bank slope and dam slope will be frozen together with the ice. When the ice expands, slopes will be pressed。 In this way， the protec
17、ting slopes will be damaged. Besides, the clay above the water level will have holes and cracks effected by freezing and thawing. In summer， with water lost, the clay will cracked, making seepage much easier。Earthquakes have to be taken into account。 They can make landslide more possible。 If the fou
18、ndation is made of silty sand, liquidified damage is more possible.Materials for building earth and rock damObtaining raw material locally is a basic design principle. Generally speaking, familiar earth and rock materials can be used. exceptions include swampy soil, bentonite, surface soil, and othe
19、r soil materials containing organic matter not completely decomposed. therefore， dam type is often determined based on availability of earth and rock materials nearby the site。 stockyard must be rich in storage and near in distance。 As for the selection， technical and economic factors will be consid
20、ered. The dam bodyis mainly made up of dam shell， antiseepage, drainage， and protection slope。 They work under different conditions, so they demand differently。 Materials must be durable and suitable to their purpose.Antiseepage and structure of dam crestSeepageproofing work for a dam must be based
21、on structural and constructing requirements， reducing seepage gradient， down-stream saturation line, and seepage to an allowance extent。 We can use terrene seepage-proofting materials andartificial materials including asphalt concrete and reinforced concrete。 terrene materials are more used。 Road is
22、 built on crest. If traffic is necessary， road has to be built based on relevant standard. If traffic is not anticipated, singlelayer masonry or gravels is sufficient for resisting rain scouring. antiwave wall is built upstream， and railings are built downstream. the wall, usually 1 to 1。3 meters hi
23、gh, is built with stone masonry or reinforcing concrete。its foundation must be firmly buried in the dam, protruding into antiseepage. For the sake of rain， the road on the crest is usually built with slopes on one side or on both sides。 When there is a anti-wave wall, the slope is towards downstream
24、, and there will be a lengthways drainage downstream the dam crest for gathering water. The water will go downstream through drainage.Dam slopeInfluencing dam stability and construction directly， dam slope is determined by dam type， dam height, dam scale， material of dam body and foundation, load to
25、bear， and conditions for construction and operation。 Generally speaking， dam slope is initially designed according to projects completed。 Then a proper section is decided after calculation in terms of stability. To slopes made of sand and soil in a rolled dam, their gradient is between 1:2 and 1:4。
26、Fordam foundation which is weaker， the gradient should be slow。For slope design， we have to consider the shearing strength which of earth will be reduced due to being soaked in up-stream water. So if the upstream and downstream slopes are made of same earth materials, the former one has to be slow.
27、for earth dams with inclined soil walls, their upstream slopes are slower than those of core dams, and their downstream slopes are steeper than those of core dams。 for homogeneous dams of sandy loam and loam, their slopes are slower than those of dams made of sand and gravels. slopes of homogeneous
28、dams made of cohesive soil have something to do with dam height. The higher the dam is， the slower the slope is。 however, gradients of dam slopes made of sand or gravel have little to do with dam height。Generally, there is a road on downstream slope every 10 to 30 meters。 When gradients changes， the
29、 road will be at the changing line. the road width is determined by its purposes， but never less than 1。5 to 2.0 meters。 drainage ditches are built on road for collecting rainwater， resisting wash, observing， repairing, and traffic.Slope protectionFor earth and rock dams, there must be protection up
30、stream and downstream. For upstream, damages caused by wave scouring， damwisestream scouring，ice, and floater must be avoided. For downstream of homogeneous dams， damages caused by rain scouring, storm, ice，stream， animal, swelling， and mud crack must be avoided.If there are rocks, cobbles, and grav
31、els downstream， no more protection is needed。 Revetments must be sturdy and durable, able to resist damages caused by various factors。 Their undercourse must not be scoured. Materials should be used as local as possible to lower the cost. Simple construction and convenient repairing should be guaran
32、teed。 Rocks， stonework， concrete, reinforced concrete, and asphalt concrete are used for building revetments upstream, and stonework, rocks， gravels, and turfs are used for those downstream。 Revetments protect the space from dam crest to the line a certain distance， normally2.5m， under the minimum water level of the dam upstream. For those downstream， they protect the space from dam crest to draining prism or to dam heel in event of no prism。概述土石坝又称“当地材料坝”,主要由坝址附近的土石料填筑而成,根据坝体所用材料不同又可分为土坝和堆石坝。坝体材料以当地土料和砂、砂砾、卵砾为主的称土坝,以石渣、卵石、爆破石料为主的称堆石坝。 土石坝的特点优点筑坝材料就
