2023年全國(guó)碩士研究生考試考研英語(yǔ)一試題真題(含答案詳解+作文范文)_第1頁(yè)
已閱讀1頁(yè),還剩4頁(yè)未讀 繼續(xù)免費(fèi)閱讀

下載本文檔

版權(quán)說(shuō)明:本文檔由用戶提供并上傳,收益歸屬內(nèi)容提供方,若內(nèi)容存在侵權(quán),請(qǐng)進(jìn)行舉報(bào)或認(rèn)領(lǐng)

文檔簡(jiǎn)介

1、<p><b>  附錄1:</b></p><p><b>  題目: 土方工程</b></p><p>  由于土方挖遠(yuǎn)的施工方法與費(fèi)用,比起土木工程中任何其它工種的施工方法與費(fèi)用都變化的快,因此對(duì)于有事業(yè)心的人來(lái)說(shuō),土方工程是一個(gè)大有作為的領(lǐng)域。在1935年,目前采用的用輪胎式機(jī)械設(shè)備進(jìn)行土方挖運(yùn)的方法大多還未出現(xiàn)。大部分土方是

2、采用窄軌鐵路運(yùn)輸,這在目前來(lái)說(shuō)是很少采用的,主要的開挖方法是使用正鏟、反鏟、垃鏟或抓斗等挖土機(jī),盡管這些機(jī)械現(xiàn)在仍在廣泛的使用,但只不過(guò)是目前許多方法中的一小部分。那時(shí),挖土機(jī)的主要?jiǎng)恿κ亲詿哄仩t的蒸汽,而目前連盛產(chǎn)煤礦的英國(guó)也不用這種動(dòng)力了,除有電力施工的工地外,目前各地都用內(nèi)燃機(jī)。因此,一個(gè)工程師為使自己在土方搬運(yùn)設(shè)備方面的知識(shí)跟的上時(shí)代的需要,他應(yīng)當(dāng)花時(shí)間去研究現(xiàn)代的機(jī)械,并且要重心認(rèn)真考率任何已使用了數(shù)年的陳舊方法。一般說(shuō)來(lái),

3、有關(guān)挖土機(jī)、裝載機(jī)和運(yùn)輸機(jī)械的唯一可靠而又最新的資料可從制造廠商處取得。</p><p>  土方工程或土方挖運(yùn)工程指的是把地表面過(guò)高處的土壤挖去(挖方),并把它傾卸到地面過(guò)低的其它地方,(填方)。為了降低土方工程的費(fèi)用,填方量應(yīng)等于挖方量,而且挖方地點(diǎn)應(yīng)盡可能靠近土方量相等的填方地點(diǎn),以減少運(yùn)輸和三次搬運(yùn)。土方設(shè)計(jì)這項(xiàng)工作落到了從事道路設(shè)計(jì)工程師的身上,因?yàn)橥练焦こ痰脑O(shè)計(jì)比任何其它項(xiàng)目更能決定工程造價(jià)是否低廉。

4、根據(jù)現(xiàn)有的地圖和標(biāo)高,道路工程師應(yīng)在設(shè)計(jì)繪圖室中畫出土方工程的橫斷面圖并可能制定出盡可能多的方案。在現(xiàn)場(chǎng)若取得更確切的資料,他可以變動(dòng)他所做的斷面圖和設(shè)計(jì)圖,但設(shè)計(jì)制圖室的工作并非徒勞。它將幫助他在最短的時(shí)間內(nèi)得到最優(yōu)的方案。</p><p>  費(fèi)用最低的運(yùn)土方法是用同一臺(tái)機(jī)械直接挖方取土并卸土為填方。這一點(diǎn)并非總是能夠做到的。但如果能做到,則就十分理想,因?yàn)檫@樣即快又省。拉鏟挖土機(jī)、推土機(jī)和正鏟都能做道這點(diǎn)。

5、拉鏟挖土機(jī)的工作半徑最大,推土機(jī)所推土的數(shù)量也最多,只是運(yùn)距很短,拉鏟挖土機(jī)的缺點(diǎn)是只能挖本身比它低的土,不能施加壓力挖入壓實(shí)的土壤內(nèi),不能在陡坡上 挖土,而且挖卸都不準(zhǔn)確。</p><p>  正鏟介于推土機(jī)和拉鏟挖土機(jī)之間,其作用半徑大于推土機(jī),但小于推鏟挖土機(jī),正鏟能挖取豎直陡峭的工作面,其操作方式對(duì)推土機(jī)司機(jī)來(lái)說(shuō)是危險(xiǎn)的,而對(duì)拉鏟挖土機(jī)則是不可能的。每種機(jī)械設(shè)備的作業(yè)應(yīng)最適合它的性能,正鏟不能挖比其停機(jī)

6、平面底很多的土,而深挖豎直土壤時(shí),反鏟挖土機(jī)最合用,但其卸料半徑比其裝有正鏟的同一挖土機(jī)的卸土半徑卻小的很多。</p><p>  在比較平坦的場(chǎng)地開挖,如用拉鏟或正鏟挖土機(jī)運(yùn)距太大時(shí),則裝有輪胎的斗式鏟運(yùn)機(jī)就是必不可少的,它能在相當(dāng)平的地面上挖較深的土(但只能挖機(jī)械本身下的土),需要時(shí)可將土運(yùn)到幾百米遠(yuǎn),然后卸土并在卸土的過(guò)程中將土初步攤平。挖掘硬土?xí)r,人們發(fā)現(xiàn)這樣的施工方法是經(jīng)濟(jì)的,即在開挖場(chǎng)地經(jīng)常保持一臺(tái)助

7、推拖拉機(jī)(輪式或履帶式)對(duì)返回挖土的鏟運(yùn)機(jī)進(jìn)行助推。一但鏟運(yùn)機(jī)裝滿,助推拖拉機(jī)就回到開挖的起點(diǎn)去幫助下一臺(tái)鏟運(yùn)機(jī)。</p><p>  斗式鏟運(yùn)機(jī)通常是功率非常大的機(jī)械,不少?gòu)S家制造的鏟運(yùn)機(jī)鏟斗容量為8立方米,滿載時(shí)可達(dá)10立方米。最大的自行式鏟運(yùn)機(jī)鏟斗為19立方米(滿載時(shí)25立方米),用430馬力的牽引擎驅(qū)動(dòng)。</p><p>  在土壩工地,大多數(shù)開挖面都底于四周的地面,一種纜索式鏟運(yùn)

8、機(jī)往來(lái)于裝在河兩岸高處的兩個(gè)塔架之間,可以經(jīng)濟(jì)而又迅速的進(jìn)行大部分的開挖和填筑作業(yè);其跨度之大是拉鏟挖土機(jī)所遠(yuǎn)遠(yuǎn)不能達(dá)到的。一個(gè)塔架是尾塔,僅裝有纜索回程滑輪。另一個(gè)塔架是主塔,在塔架底座附近沒有卷?yè)P(yáng)機(jī)及兩個(gè)卷筒,在塔頂裝有一個(gè)纜索滑輪。尾塔是可以移動(dòng)的,而且通常把它裝設(shè)在軌距很寬的輪子上。軌距應(yīng)有足夠的寬度以保持穩(wěn)定,以便能抵抗正在牽引滿載土斗的纜索的張力,以及在持續(xù)挖土?xí)r所能容許的最強(qiáng)風(fēng)力。如果塔頂很高或施工工地易遭強(qiáng)風(fēng),那么最好規(guī)

9、定在發(fā)生最不利的大風(fēng)時(shí)停止開挖,以免尾塔為保持穩(wěn)定性而需要做的過(guò)寬過(guò)重。過(guò)重就的需要很多的輪子和鋼軌,從而使得軌道成本太高。一臺(tái)索道可容易跨越峽谷進(jìn)行施工,即可以澆注混凝土,也可以開挖土方,但用抓斗時(shí),只能是向挖土?,F(xiàn)在未考慮費(fèi)用較高的土方挖運(yùn)方法,挖土機(jī)挖土可將土裝入輪胎式卡車或采用其它運(yùn)輸方法。例如皮帶運(yùn)輸機(jī)就非常經(jīng)濟(jì)而且能夠運(yùn)輸大量的物料,但是很難找到一個(gè)土木工程工地能長(zhǎng)期使用皮帶運(yùn)輸機(jī)以補(bǔ)償其它大的初次投資。</p>

10、<p>  翻斗車可能是使用最為普遍的輪胎式運(yùn)輸設(shè)備,因?yàn)樗鼈冞€適于運(yùn)輸混凝土或其它建筑材料。翻斗車的車斗位于大橡膠輪胎車輪前軸的上方,盡管鉸接式翻斗車的卸料方向有很多種,但大多數(shù)土斗是向前傾翻的,在最小型的翻斗車中,步行控制型翻斗車的車斗容量約為200升,司機(jī)是在車旁邊步行,最小型翻斗車的容量約為500升,司機(jī)是在車上駕駛,而最大的翻斗車的容量約為4.5立方米。特殊型的翻斗車包括容量達(dá)4立方米的自裝式翻斗車和容量約為50

11、0升的鉸接式翻斗車。翻斗車和自卸式卡車之間的區(qū)別必須記住。翻斗車車斗向前傾翻而司機(jī)生在所裝物料的后方。自卸卡車是經(jīng)過(guò)加固的重型翻斗車,司機(jī)在物料的前方駕駛,物料在司機(jī)的后方卸載,因此有時(shí)稱它 為后翻卡車,這個(gè)名稱倒更為切合實(shí)際。</p><p><b>  附錄2:</b></p><p><b>  英文翻譯</b></p>&l

12、t;p><b>  Earthwork</b></p><p>  Because earthmoving methods and costs change more quickly than those in any other branch of civil engineering ,this is a field where there are real opportunitie

13、s for the enthusiast. In 1995 most of the methods now in use for carrying and excavating earth with rubber-typed equipment did not exist .Most earth was moved by marrow rail track, now relative rare ,and the main methods

14、 of excavation, with face shove backward, or dragline or grab, though they are still widely used, are only a few of the </p><p>  Earthwork or earthmoving means cutting into ground where its surface is too h

15、igh(cuts), and dumping the earth in other places where the surface is too low(fills). To reduce earthwork costs, the volume of the fills should be equal to the volume of the cuts and wherever possible the cuts should be

16、place near to fills of equal volume so as to reduce transport and double handling of the till. This work of earthwork design falls on the engineer who lays out the road since it is the layout of the eart</p><p

17、>  The cheapest way of moving earth is to take it directly out of the cut and drop it as fill with the same machine. This is most always possible, but when it can be done it is ideal ,being both quick and cheap, dragl

18、ines, bull dozers and the largest tonnage of earth is moved by the bulldozer, though only over short distances. The disadvantages of the dragline are that it must dig below itself, it cannot dig with force into compacted

19、 material, it cannot dig on steep slopes, and its dumping and digg</p><p>  Face shovels are between bulldozers, and draglines, having a larger radius of action than bulldozers but less than draglines, they

20、are able to dig into a vertical cliff face in a way which would be dangerous for a bulldozer operator and impossible for a dragline. Each piece of equipment should be given the work for which it is best suited. Face shov

21、els cannot dig much below the level of their tracks and for deep digs in compact material a backward is most useful, but its dumping radius is consid</p><p>  Rubber-typed bowl scrapers are indispensable for

22、 fairly level digging where the distance of transport is too much for a dragline or face shovel. They can dig the material deeply (but only below themselves) to a fairly flat surface, carry it hundreds of meters if need

23、be, then drop it and level, it roughly during the dumping. For hard digging it is often found economical to keep a pusher tractor (wheeled or tracked )on the digging site, to push each scraper as it returns to dig. As so

24、on as the sc</p><p>  Bowl scrapers are often extremely powerful machines; many makers build scrapers of 8 cubic meters struck capacity, which carry 10m3 heaped. The largest self-propelled scraper are of 19m

25、3 struck capacity (25m heaped) and they are driven by a tractor engine of 430 horse-power.</p><p>  At an earth dam, where most of the digging is below the level of the surrounding ground, a rope-operated sc

26、raper carried between two masts on the high ground at each bank of the river may do most of the digging and filling cheaply and quickly, over spans which would be far too larger for a dragline (fig .14).one mast, the tai

27、l mast, carries only the return pulley for the rope. The mast, the main mast has the winding engine and its two drums at its foot, with a pulley at its head for the rope. Th</p><p>  Considering now the more

28、 expensive methods of the earth moving, an excavator digs and may load in to a rubber-typed truck or may use other methods of transport. Belt conveyors for example are highly economical and move large quantities of mater

29、ial, bur it is rare to find a civil engineering site where they can be used for long enough to pay for their heavy first cost.</p><p>  Dumpers are probably the commonest rubber-typed transport since they ca

30、n also conveniently be used for carrying concrete or other building materials. dumpers have the earth container over the front axle on large rubber-typed wheels, and the container tips forwards on most types, thought in

31、articulated dumpers the direction of tip can be widely varied. In the smallest dumpers, the pedestrian-controlled type, the driver walks beside the machine which has a capacity of about 200 liters. The smalles</p>

溫馨提示

  • 1. 本站所有資源如無(wú)特殊說(shuō)明,都需要本地電腦安裝OFFICE2007和PDF閱讀器。圖紙軟件為CAD,CAXA,PROE,UG,SolidWorks等.壓縮文件請(qǐng)下載最新的WinRAR軟件解壓。
  • 2. 本站的文檔不包含任何第三方提供的附件圖紙等,如果需要附件,請(qǐng)聯(lián)系上傳者。文件的所有權(quán)益歸上傳用戶所有。
  • 3. 本站RAR壓縮包中若帶圖紙,網(wǎng)頁(yè)內(nèi)容里面會(huì)有圖紙預(yù)覽,若沒有圖紙預(yù)覽就沒有圖紙。
  • 4. 未經(jīng)權(quán)益所有人同意不得將文件中的內(nèi)容挪作商業(yè)或盈利用途。
  • 5. 眾賞文庫(kù)僅提供信息存儲(chǔ)空間,僅對(duì)用戶上傳內(nèi)容的表現(xiàn)方式做保護(hù)處理,對(duì)用戶上傳分享的文檔內(nèi)容本身不做任何修改或編輯,并不能對(duì)任何下載內(nèi)容負(fù)責(zé)。
  • 6. 下載文件中如有侵權(quán)或不適當(dāng)內(nèi)容,請(qǐng)與我們聯(lián)系,我們立即糾正。
  • 7. 本站不保證下載資源的準(zhǔn)確性、安全性和完整性, 同時(shí)也不承擔(dān)用戶因使用這些下載資源對(duì)自己和他人造成任何形式的傷害或損失。

評(píng)論

0/150

提交評(píng)論