水利水电专业英语论文英文对照及翻译

Earth and rock dam

Summary

Earth 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 rock ballast, gravel, and exploded rocks.

Features of earth and rock dam

Strong points

With 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 flexible from simple artificial filling to highly mechanized construction, the procedure become simple, the construction become efficient, and the quality guarantee become easy.Simply structured, the?cost is low, the operation is convenient, works?is reliable, and maintenance and height adding is convient.

Weak points

Overflow not allowed, spillway has to be built.Diversion?less 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 increase

Earth and rock dam types

Based on constructing ways, earth and rock dams can be classified into rolled ones of earth & rock, thrown rock-filled ones,?rock-filled ones with?directional 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 location of anti-seepage?parts, there 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

筑坝材料就地取材。可节省大量钢材、水泥、木材等建筑材料。适应地基变形能力强。土石坝散粒体结构具有适应地基变形的良好条件，对地基的要求比混凝土坝低。施工方法选择灵活性大。能适应不同的施工方法，从简单的人工填筑到高度机械化施工都可以；且工序简单、施工速度快，质量也易保证。结构简单。造价低廉、运行管理方便、工作可靠，便于维修加高。

缺点

坝顶不能溢流，常须另开溢洪道施工。导流不如混凝土坝方便，因而相应增加了工程造价坝体断面大，土料填筑的质量易受气候影响。这给施工带来困难，甚至延长工期、增加造价。

土石坝的类型

土石坝按施工方法的不同可分为：碾压式土石坝，抛填式堆石坝，定向爆破堆石坝，水中倒土坝和水力冲填坝等。其中尤以碾压式土石坝应用最广。

按土料在坝体中配置和防渗体的位置不同，又可分为均质坝，分区坝，人工防渗材料坝。均质坝优点：材料单一、工序简单；缺点：

are homogeneous (even-granular) dams, ?zoned earth dams, and dams with artificial anti-seepage materials. Strong points of homogeneous dams: one fold materials, simple process weak points: flat gradient, large section, weather-limited, strong water pressure

in holes. Zoned dams are classified into ones with core anti-seepage 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 parts 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 conditions

Trapeziform section

Earth-rock dam is a water retaining structure built with loose granules of earth and rocks?filled and roller compacted. With weaker strength between these granules, both upsteam and downsteam slopes have to be kept at a?certain degree to avoid landslide. So the dam section is usually?trapeziform.?It can be destablized in two ways, simple slope sliding and sametime sliding of slope and foundation caused by shear damage.?It's

a difference from other structures Seepage effects

With a large section, the dam is generally kept from entire sliding unless caused by weak interlayers. Effected by water levels at the upsteam and downsteam, seepage is easy to happen with streams passing the ?faying surfaces between the dam and foundation, 坝坡较缓、剖面大，受气候限制，坝体孔隙水压力大，高坝很少采用。分区坝分心墙坝、斜墙坝等，前者优点：土料占总方量比重不大，施工受季节影响小。缺点：心墙与坝体大体要同时填筑，相互干扰。后者优点：与坝体施工干扰小。缺点：抗震性能和适应不均匀沉陷的能力不如前者。人工防渗材料坝的防渗体由沥青混凝土、钢筋混凝土或其他人工材料组成，其余部分由土石料筑成。其中防渗体在上游的称为斜墙坝（面板坝），在坝体中央的称为心墙坝。

工作条件

梯形剖面

土石坝是由松散颗粒土石料填筑碾压而成的挡水建筑物。由于土粒间的抗剪强度小，上下游坡如不维持一定的坡度，就可能发生坍塌现象。所以，土石坝的剖面一般呈梯形。失稳的形式则是坝坡滑动或坝坡连同地基一起滑动的剪切破坏，这是与其他建筑物的不同之处. 渗流影响

土坝挡水后，由于坝体断面较大，除坝基有水平软弱夹层外，产生整体滑动的可能性较小。但在上下游水位的作用下，水流经过坝身及坝基（包括两岸）的结合面和坝体土与混凝土等建筑物的结合面易产生渗漏。渗流在坝体内形成自由水面，浸润线以下的土体全部处于饱和状态。饱和区的土体受水的浸泡而使土的有效重量减轻，并使土的内摩擦角和粘结力减小。同时，渗透水流