預(yù)應(yīng)力混凝土現(xiàn)狀與發(fā)展中英文

橋梁預(yù)應(yīng)力混凝土現(xiàn)狀與發(fā)展簡介：本文從組組成混凝土的的材料，張拉拉技術(shù)和施工工方法及結(jié)構(gòu)構(gòu)抗震性能上上的發(fā)展?fàn)顩r況來進(jìn)行闡述述，提出了提提高預(yù)應(yīng)力混混凝土工藝水水平的建議。關(guān)鍵字：混凝土土，鋼材，施施工工藝，抗抗震性能引言預(yù)應(yīng)力混凝凝土是在第二二次世界大戰(zhàn)戰(zhàn)后迫切要求求恢復(fù)戰(zhàn)爭創(chuàng)創(chuàng)傷，從西歐歐迅速發(fā)展起起來的。半個個多世紀(jì)以來來，從理論，材材料，工藝到到土建工程中的的應(yīng)用，都取取得了巨大的的發(fā)展。尤其其是隨著部分分預(yù)應(yīng)力概念念的逐步成熟熟，突破了混混凝土不能受受拉與開裂的的約束，大大大擴(kuò)展了它的的應(yīng)用范圍。目目前預(yù)應(yīng)力混混凝土已成為為國內(nèi)外土建建工程最主要要的一種結(jié)構(gòu)構(gòu)材料，而且且預(yù)應(yīng)力技術(shù)術(shù)已擴(kuò)大應(yīng)用用到型鋼，磚磚，石，木等等各種結(jié)構(gòu)材材料，并用以以處理結(jié)構(gòu)設(shè)設(shè)計，施工中用常規(guī)規(guī)技術(shù)難以解解決的各種疑疑難問題。我我國預(yù)應(yīng)力混混凝土的起步步比西歐大約約晚10年，但發(fā)展展迅速，應(yīng)用用數(shù)量龐大。我我國近年來在在土木工程投投資方面，建建設(shè)規(guī)模方面面均居世界前前列。在混凝凝土工程技術(shù)術(shù)，預(yù)應(yīng)力技技術(shù)應(yīng)用方面面取得了巨大大進(jìn)步。近來來二三十年來來，我國預(yù)應(yīng)應(yīng)力混凝土橋橋梁發(fā)展很快快，無論在橋橋型，跨度以以及施工方法法與技術(shù)方面面都有突破性性發(fā)展，不少少預(yù)應(yīng)力混凝凝土橋梁的修修建技術(shù)已達(dá)達(dá)到國際先進(jìn)進(jìn)水平。本文文著重從其組組成材料和特特性上探討預(yù)預(yù)應(yīng)力混凝土土發(fā)展現(xiàn)狀及及前景?；炷翉奈覈呀ńǔ傻念A(yù)應(yīng)力力混凝土橋梁梁來看，大多多都采用40~50混凝土，進(jìn)進(jìn)而采用減水水劑等添加劑劑制備塑性混混凝土，并發(fā)發(fā)展了泵送混混凝土工藝。隨隨著橋梁跨度度的增加，為為減少橋梁結(jié)結(jié)構(gòu)的自重，混混凝土逐漸向向高強(qiáng)，輕質(zhì)質(zhì)方向發(fā)展。日日本早在70年代采用80混凝土修建建了幾座跨徑徑為45的簡支預(yù)應(yīng)應(yīng)力混凝土鐵鐵路橋，德國國在主跨136的富林格爾爾橋上采用了了輕質(zhì)混凝土土。我國目前前在高強(qiáng)，輕輕質(zhì)混凝土方方面已經(jīng)有所所成就。如建建設(shè)中的重慶慶大佛寺長江江大橋，是一一座主跨450米的雙塔雙雙索面預(yù)應(yīng)力力混凝土斜拉拉橋。由重慶慶大佛寺長江江大橋試驗忠忠心研制成功功的60微硅粉高強(qiáng)強(qiáng)混凝土首次次在該橋主梁梁澆注使用。作作為混凝土的的改性材料，微微硅粉高強(qiáng)混混凝土具有易易澆注，整體體密實(shí)，長期期穩(wěn)定及強(qiáng)度度高等特點(diǎn)，可可提高建筑的內(nèi)在質(zhì)質(zhì)量，在橋梁梁建筑市場上上具有極大的的推廣應(yīng)用價價值。鋼材目前使用的的預(yù)應(yīng)力鋼材材主要有高強(qiáng)強(qiáng)鋼絲，鋼絞絞線及高強(qiáng)度度粗鋼筋三大大類。橋梁上上使用的預(yù)應(yīng)應(yīng)力鋼材一直直在朝著高強(qiáng)強(qiáng)度，低松弛弛，大直徑的的方向發(fā)展。80年代中期以以前，我國的的預(yù)應(yīng)力鋼材材的性能比國國際上落后較較多，近20年差距逐漸漸縮小。預(yù)應(yīng)應(yīng)力鋼材的生生產(chǎn)過程由于于工廠的不斷斷改進(jìn)而成為為性能更好，更更經(jīng)濟(jì)的材料料。為提高效效率，近年來來，材料強(qiáng)度度有所增加，但但在某些情況況下，強(qiáng)度的的增長是以降降低材料的延延性與韌性為為代價的。強(qiáng)強(qiáng)度較高的預(yù)預(yù)應(yīng)力鋼材，有時會增加氫的應(yīng)力腐蝕的危險。這些不利的特性應(yīng)予以重視。新型材料如纖維增強(qiáng)塑料，過去主要用于航天和航空工業(yè)，現(xiàn)已進(jìn)入建筑工業(yè)。采用這些材料主要由于下列優(yōu)點(diǎn):在各種環(huán)境下具有耐久和抗腐蝕的特性，重量輕，高強(qiáng)度和無磁性等性能。纖維增強(qiáng)塑料可用作預(yù)應(yīng)力與非預(yù)應(yīng)力材料。這些材料具有線彈性的應(yīng)力-應(yīng)變關(guān)系，直到拉斷。它們的性能與鋼筋和預(yù)應(yīng)力鋼材性能不同，還需要采用新的設(shè)計方法。自從1939年法國首創(chuàng)式體系與比利時首創(chuàng)體系后，預(yù)應(yīng)力技術(shù)實(shí)現(xiàn)了從先張到后張的進(jìn)步，為各種大跨預(yù)應(yīng)力結(jié)構(gòu)的發(fā)展開辟了道路。預(yù)應(yīng)力錨具與所錨固的預(yù)應(yīng)力筋相對應(yīng)，分為粗鋼筋錨具，鋼絲束錨具及鋼絞線錨具3類。近年來用于鋼絞線錨固的群錨體系，被廣泛采用。隨著質(zhì)量地不斷提高，其錨固性能也越來越好。使用時可根據(jù)需要由多根鋼絞線組成一束，整束張拉，國內(nèi)目前已發(fā)展到1200。大噸位預(yù)應(yīng)力鋼束的采用大大簡化了后張拉工藝。對于采用懸澆施工的橋梁，每一循環(huán)預(yù)應(yīng)力束數(shù)可大大減少，且通過預(yù)應(yīng)力束平彎使錨點(diǎn)位置在斷面上的布置固定，大大節(jié)省了穿束，張拉，壓漿等工序所用的時間，從而加快施工進(jìn)度。另外采用大噸位預(yù)應(yīng)力束，布束容易，經(jīng)合理選擇后可以做到因不易布束而加大結(jié)構(gòu)尺寸，造成材料浪費(fèi)，可減少繁雜的錨固齒塊，便于簡化模板，加快工期。無粘結(jié)預(yù)應(yīng)力筋是指帶潤滑防銹涂層的后張預(yù)應(yīng)力筋，施工時這種預(yù)應(yīng)力筋可以和普通鋼筋一樣直接安裝在模板中。無粘結(jié)預(yù)應(yīng)力筋無需預(yù)留孔道，后期穿束，壓漿等工序并可節(jié)省材料，加快施工進(jìn)度。因此具有施工簡便，施工效率高等優(yōu)點(diǎn)。但其強(qiáng)度和剛度與相應(yīng)的有粘結(jié)預(yù)應(yīng)力筋相比稍低。從耐久性能看，應(yīng)對其防銹及認(rèn)真處理錨具封端。有粘結(jié)預(yù)應(yīng)力筋由于壓漿工藝問題也存在耐久性問題，預(yù)應(yīng)力管道壓漿往往存在壓漿不滿或不密實(shí)等問題，由此可能導(dǎo)致的預(yù)應(yīng)力筋銹蝕問題不容忽視。在我國無粘結(jié)預(yù)應(yīng)力筋在大跨徑橋梁上的應(yīng)用正日益增加。無粘結(jié)筋因其自身的優(yōu)點(diǎn)將會越來越受到重視，但關(guān)于其強(qiáng)度和耐久性問題仍然需要進(jìn)一步加強(qiáng)研究，不斷完善。體外索在預(yù)應(yīng)力混凝土結(jié)構(gòu)中的使用是近來建筑工業(yè)發(fā)展的方向之一。用體外預(yù)應(yīng)力的方式修建混凝土橋梁在國際上已有近90年的歷史。但早期因防腐工藝不完善，造價高等原因，取得的效果并不理想。但自80年代以來，由于技術(shù)的進(jìn)步，體外預(yù)應(yīng)力技術(shù)幾經(jīng)改進(jìn)后，日趨完善，其應(yīng)用也越來越多。從預(yù)加應(yīng)力方式來看，它把絕大部分的預(yù)應(yīng)力鋼束布置在混凝土截面外，通過錨固端和變向裝置來傳遞預(yù)加應(yīng)力。該方法不但可以應(yīng)用于新建結(jié)構(gòu)，還可以用來加固原有結(jié)構(gòu)。在預(yù)應(yīng)力使用早期，體外預(yù)應(yīng)力筋已被應(yīng)用于橋梁建設(shè)，不過，由于當(dāng)時技術(shù)條件的制約，這種方法在20世紀(jì)50年代幾乎被人們放棄了?？垢g(纖維增強(qiáng)塑料)索，高性能鋼索以及體外索防護(hù)系統(tǒng)的發(fā)展，為體外預(yù)應(yīng)力技術(shù)的再次興起提供了有利的條件。使用體外預(yù)應(yīng)力技術(shù)的橋梁工程具有以下優(yōu)點(diǎn):1)由于板內(nèi)沒有安裝管道，減小了板的厚度，從而減輕了橋梁的重量;2)預(yù)應(yīng)力索安裝簡便;3)易于檢查預(yù)應(yīng)力索，有利于索的養(yǎng)護(hù);4)預(yù)應(yīng)力索的替換或者再次張拉成為可能;5)大大地縮短施工工期，特別是使用預(yù)制分段拼裝方法施工的橋梁。體外預(yù)應(yīng)力技術(shù)廣泛應(yīng)用于混凝土橋梁建設(shè)中。并已被用于高速公路和高架鐵路分段預(yù)制橋梁建設(shè)。體外預(yù)應(yīng)力技術(shù)另一個極具潛力的用途是對原有混凝土結(jié)構(gòu)進(jìn)行加固與修復(fù)。近年來，該技術(shù)已應(yīng)用于許多新型結(jié)構(gòu)中，其中包括:在大偏心結(jié)構(gòu)設(shè)置體外預(yù)應(yīng)力索以提高結(jié)構(gòu)的受力性能，可以被應(yīng)用于由混凝土翼緣與波形鋼腹板構(gòu)成的組合結(jié)構(gòu)之中，高性能輕質(zhì)材料的使用減輕了結(jié)構(gòu)的自重施工工藝預(yù)應(yīng)力混凝凝土橋梁的發(fā)展與與施工技術(shù)的發(fā)發(fā)展是密不可可分的，施工工技術(shù)水平直直接影響橋梁梁的跨徑，線線型，截面形形式等。預(yù)應(yīng)應(yīng)力混凝土連連續(xù)梁在初期期大多采用滿滿布支架法施施工，其跨度度一般在40以內(nèi)，且施施工周期長，施施工用料多。60年代預(yù)應(yīng)力力混凝土橋梁梁引入懸臂施施工法以后，預(yù)預(yù)應(yīng)力連續(xù)梁梁橋得以迅速速發(fā)展，其跨跨越能力達(dá)200以上，適用用范圍也不斷斷擴(kuò)大。懸臂臂拼裝法將大大跨橋梁化整整為零，施工工簡便，拼裝裝工期短，速速度快，特別別對于多跨長長聯(lián)橋(跨度在100以內(nèi))是一種效率率高而且經(jīng)濟(jì)濟(jì)的施工方法法。預(yù)應(yīng)力連連續(xù)梁的施工工方法還有頂頂推法，移動動模架法，逐逐孔架設(shè)法等等。近年來由由烏克蘭的工工程師發(fā)明的的新型預(yù)應(yīng)力力技術(shù)是介于于先張拉法和和后張拉法之之間的工藝。它它是在澆搗混混凝土尚未凝凝固的時候施施加預(yù)應(yīng)力，混混凝土在壓力力的情況下固固結(jié)。施加這這種預(yù)應(yīng)力需需要用特殊的的可滑動的模模板及能把壓壓力傳給混凝凝土的裝置。它它可使同樣配配筋率情況下下梁的承載力力提高25-344%，柱的承載載力提高75%，抗裂度不不變。該方法法已在重達(dá)30噸的橋梁結(jié)構(gòu)構(gòu)中使用。預(yù)應(yīng)力混凝土結(jié)結(jié)構(gòu)抗震問題題當(dāng)前國際混混凝土結(jié)構(gòu)工工程界對預(yù)應(yīng)應(yīng)力混凝土結(jié)結(jié)構(gòu)的抗震問問題給予了重重視。日本在在1995年神戶大阪阪地震之后，結(jié)結(jié)合混凝土結(jié)結(jié)構(gòu)(包括預(yù)應(yīng)力力混凝土結(jié)構(gòu)構(gòu))在地震中的的實(shí)際表現(xiàn)進(jìn)進(jìn)行了調(diào)查并并作了大量研研究工作，其其它國家也作作了不少研究究工作。研究究表明預(yù)應(yīng)力力結(jié)構(gòu)在地震震區(qū)是能夠應(yīng)應(yīng)用的，和普普通鋼筋混凝凝土結(jié)構(gòu)一樣樣，需要的是是合理的設(shè)計計和施工。采采用豎向預(yù)應(yīng)應(yīng)力加固普通通鋼筋混凝土土結(jié)構(gòu)可提高高結(jié)構(gòu)抗震性性能。采用豎豎向預(yù)應(yīng)力的的混凝土結(jié)構(gòu)構(gòu)，可以提高高結(jié)構(gòu)抵抗水水平荷載的能能力，并在地地震之后又能能很快的復(fù)原原。在地震作作用下，預(yù)制制的預(yù)應(yīng)力混混凝土結(jié)構(gòu)會會發(fā)生屈服，產(chǎn)產(chǎn)生塑性鉸，提提高整個結(jié)構(gòu)構(gòu)的延性和耗耗能能力而避避免損壞，因因而具有良好好抗震性能。展望為適應(yīng)我國國經(jīng)濟(jì)的發(fā)展展，緩解交通通問題給人們們生產(chǎn)生活帶帶來的不便，預(yù)預(yù)應(yīng)力混凝土土結(jié)構(gòu)的應(yīng)用用范圍將更加加廣闊，因此此我們應(yīng)加強(qiáng)強(qiáng)提高預(yù)應(yīng)力力技術(shù)水平的的科研工作。和和發(fā)達(dá)國家相相比，我們預(yù)預(yù)應(yīng)力混凝土土工程的研究究相對落后。憑憑借我們已有有的強(qiáng)大隊伍伍，和一些單單位在預(yù)應(yīng)力力技術(shù)推廣應(yīng)應(yīng)用中的創(chuàng)收收實(shí)力完全可可以承擔(dān)和完完成這項重要要的科研任務(wù)務(wù)。同時，設(shè)設(shè)計和施工的的分離也是影影響我國預(yù)應(yīng)應(yīng)力混凝土結(jié)結(jié)構(gòu)迅速發(fā)展展的因素之一一。因此有必必要成立大型型強(qiáng)而有力的的預(yù)應(yīng)力混凝凝土工程公司司，承擔(dān)重大大預(yù)應(yīng)力混凝凝土工程，并并擔(dān)負(fù)新技術(shù)術(shù)開發(fā)研究，并并做好與設(shè)計計和施工之間間的聯(lián)系，以以提高我國的的預(yù)應(yīng)力技術(shù)術(shù)水平。PrestreessedconcrretebbridgeethestatuusquooanddevellopmenntDesscripttion:Thisarticclefrromthhecommposittionoofconncreteemateerialss,tecchnoloogyanndTennsionconsttructiionmeethodandsstructtureoofseiismicperfoormancceonthesstateofdeeveloppmenttoellaboraate,ppropossedtooraissetheeleveelofpresttresseedconncreteepropposalss.Keyyword::conccrete,,steeel,coonstruuctionntechhnologgy,seeismiccperfformannceINNTRODUUCTIONNPresstresssedcooncretteaftterthheSeccondWWorldWariispreessinggfortherrestorrationnoftthewooundsofwaar,frromthheWessterndevellopedrapiddly.MMoretthanhhalfaacentturyssince,,inttheoryy,matterialls,teechnollogyttotheeappllicatiionoffciviilenggineerring,havemadetremeendoussdeveelopmeent.PParticcularllyaspartofthheconnceptofPrrestreessedgraduuallymaturre,brrokettheteensionnandconcrreteccannootbebounddbyccrackiing,ggreatllyexppandedditsscopeeofaappliccationn.Currrentllypreestresssedcconcreetehaasbeccomeaaciviilenggineerringmmajorathoomeanndabrroadaasasstructturalmaterrial,andpprestrresseddtechhnologgyhassexpaandedintosteell,briick,sstone,,wooddandotherrstruucturaalmatterialls,anndtodealwithstruccturalldesiign,cconstrructioonusiingcoonventtionalltechhnologgiesDDifficcultttosollvevaarioussdiffficulttprobblems..Chinna'spprestrresseddconccretestarttingllaterthaninWeesternnEuroopeabbout110yeaars,bbutraapidddeveloopmenttoftthelaargennumberrofaappliccationns.Chhina'ssinveestmenntinrecenntyeaarsinnciviilenggineerring,consttructiion,ssizerrankhhighesstinthewworld..Incconcreeteenngineeeringtechnnologyy,preestresssedttechnoologyhasmmadettremenndousprogrress.Recenntlyttwotoothreeedeccades,,ChinnahassdeveelopeddveryyrapiidlyPPrestrresseddConccreteBridgge,boothinnthebridgge,thhespaananddconsstructtionmmethoddsanddtechhnicallaspeectsoofabbreaktthrouggh,maanyoffpresstresssedcooncrettebriidgecconstrructioontecchnoloogyhaasreaachedtheiinternnationnaladdvanceedlevvel.TThisppaperfromtheccompossitionnofmmateriialsaandprroperttiesoofpreestresssedcconcreetedeeveloppmentonthhepreesentsituaationandpprospeects.ConcrreteCChinahasbbuiltfromthepprestrresseddconccretebridgge,ussedmoostly40too50cconcreete,tthenuuseoffplassticwwaterreduccersuuchassconccreteaddittivesandtthedeeveloppmentofapumpiingcooncretteproocess..Withhtheincreeaseiinlonng-spaanbriidges,,thebridggestrructurretoreduccetheeselff-resppect,graduuallytothhehiggh-strrengthhconccrete,,lighhtweigghtdiirectiion.JJapanaseaarlyaasthee19700s,addoptedd80cconcreetefoortheeconsstructtionoofsevverallong--spanof455simppleprrestreessedconcrreterrailwaaybriidge,Germaanyinnthemainspanof1336-Linngleuusedttheliightoofconncreteebriddge.CChina''scurrrenthigh--strenngth,lighttweighhtconncreteehasbeensomesucceess.SSuchaastheeconsstructtionoofaBBuddhiistteempleinChhongqiingYaangtzeeRiveerBriidgeiisammainsspanoof4500meteersdooublethettwinttowerssofpprestrresseddconccretecablee-stayyedbrridgecablee.FroomtheeBudddhisttemplleinChonggqingYangttzeRiiverBBridgeeTesttloyaalsucccessffullydevellopeda60--siliccafummeintheffirsthigh--strenngthcconcreetepoouringguseofthhebriidgeggirderr.Asaconncreteemodiifiedmaterrials,,micrro-sillicaffumewwithhhigh-sstrenggthcooncrettepouuring,,theoveraalldeensityyandlong--termstabiilityandhhighiintenssity,caniincreaasethheinttrinsiicquaalityofcoonstruuctionn,theebriddgecoonstruuctionnmarkketissofggreatpromootionaalvallue.SSteelAtprresentttheuseoofpreestresssedmmainlyyhighh-streengthsteellwiree,steeelcaableaandhiigh-inntensiitycrrudessteelthreeecateegoriees.Brridgeonthheuseeofpprestrresseddsteeelhavvebeeeninthehhigh-iintenssity,lowrrelaxaation,,la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tiionsyystemssinvvitroandddeveloopmenttofiinvittroteechnollogypprestrresseddriseeagaiintoproviidefaavorabblecoonditiions.Theuuseoffinvvitrotechnnologyypresstresssedbrridgeprojeecthaastheefolllowinggadvaantagees:1))Theboarddisnnotinnstallledinnthepipelline,reduccingtthethhickneessofftheplatee,soastooreduucethheweiightooftheebriddge,22)preestresssedccableinstaallatiionsiimple;;3)rreadillyacccessibblefoorinsspectiionprrestreessedcableeAndiscoonduciivetootheconseervatiioncaable44)preestresssedccablereplaacemenntorre-teensionningppossibble,55)willlgreeatlyshorttenthheconnstrucctionperiood,paarticuularlyytheuseoofsubb-asseemblyofprrefabrricateedconnstrucctionofthhebriidgeaapproaach.IInvittroteechnollogywwidelyyuseddinpprestrresseddconccretebridggeconnstrucction..Andhasbbeenuusedfforhiighwayyandtheeelevattedraailwayybriddgeseectionnofpprefabbricattedbuuildinng.Prrestreessedanothherinnvitrrotecchnoloogyoffgreaatpottentiaaluseeisttheorriginaalconncreteestruuctureereinnforceementandrrepairr.Inrecenntyeaars,ttheteechnollogyhhasbeeenappplieddtommanynnewsttructuure,iincludding:theeeccenttricsstructturessetuppinttheinnvitrropreestresssedccabletoimmproveethestrucctureofthheforrce,ccanbeeapplliedttotheeflanngeanndconncreteewithhcorrrugateedsteeelweebsoffacoomposiitesttructuure,High--perfoormancceligghtweiightmmateriialsttoredducettheusseofthesstructtureooftheeselff-resppectCConstrructioonTecchnoloogyPrrestreessedconcrretebbridgeethedevellopmenntanddconsstructtionooftheedeveelopmeentarreineextriccablylinkeed,diirectllyafffectttheleeveloofconnstrucctiontechnnologyyofllong-sspanbbridgees,liinear,,crosss-secctionform..Conttinuouuspreestresssedcconcreetebeeamsaareussedinntheinitiialsttageoofconnstrucction滿布stentt,usuuallyinthhespaanoflessthan40,aandthhelonngcycclecoonstruuctionn,connstrucctionmaterrialsandmmore.The11960s,,theintrooductiionoffpresstresssedcooncrettebriidgeccantilleverconsttructiionmeethod,,thepresttresseedconntinuoousbrridgetothherappiddeeveloppmentandiitsabbilityytolleapoover2200,tthesccopehhasbeeenexxpandeed.Caantileeveraassembblyoffalaarge-sspanbbridgeesHuaazhenggweiliing,tthecoonstruuctionnisssimplee,asssembleedasshortperiood,faaster,,partticulaarlyfformuulti-sspanooftheebriddge(iintheespannofllesstthan1100)iisahhighlyyeffiicienttandeconoomiccconstrructioonmetthod.Presttresseedconntinuoousbeeamcoonstruuctionnmethhodsaarepuusherss,movvingDDie-laaw,caase-byy-holeesetuplaaw.UkkraineeinrrecenttyearrsbytheeengineeersiinventtedanewttypeooftecchnoloogyisspresstresssedbeetweennRafaahanddthefirstt-postt-Rafaahbettweenthepprocesss.Ittiscchoppeedintheppourinngofconcrretehhadnootyettsoliidifieedwheentheeimpoositioonofpresttresseedconncreteepresssureinthhecasseofconsoolidattion.Pre-sstresssedthheneeedtoimpossesucchasspeciaaltemmplateecanbesllidinggandpresssureccanpaasscooncrettedevvices..Itwwilleenableethesamecircuumstanncesbbeamrreinfoorcemeentraateinncreasse25--34peercenttofccapaciity,iincreaasecaapacitty,inn75ppercennt,crrackinngofthessame.Themmethoddhasbeenweighhing330tonnsuseedinthesstructtureooftheebriddge.PPrestrresseddconccretestrucctureseismmicprroblemmsTheecurrrentiinternnationnalenngineeeringconcrretesstructtureoofpreestresssedcconcreetesttructuureoffseissmiciimporttancetothhequeestionn.Jappaninnthe1995earthhquakeeinKKobe,Osakaa,theecombbinatiionoffconccretestruccture(inclludinggpresstresssedcooncrettestrructurre)inntheearthhquakeeinttheacctualperfoormancceconnducteedaninvesstigattionaandmaadeaconsiiderabbleammountofreesearcchworrk,ottherccountrriesaalsommadeaalotofreesearcchworrk.Reesearcchshoowsthhatprrestreessedstrucctureinthheearrthquaakezoonecaanbeappliied