建筑類英文及翻譯.doc

1、外文原文出處:Geotech ni cal. Geological, and Earthquake Engin eeri ng, 1, Volume 10, Seismic RiskAssessme nt and Retrofitti ng, Pages 329-342補充垂直支撐對建筑物抗震加固摘要：大量的鋼筋混凝土建筑物在整個世界地震活躍地區(qū)有共同的缺陷。弱柱，在一個 或多個事故中，由于橫向變形而失去垂直承載力。這篇文章提出一個策略關(guān)于補充安裝垂直支撐來防止房子的倒塌。這個策略 是使用在一個風(fēng)險的角度上來研究最近 實際可行的性能?；炷林?、動力失穩(wěn) 的影響、多樣循環(huán)冗余的影響降低了建 筑系

2、統(tǒng)和組件的強度。比如用建筑物來 說明這個策略的可行性。1、背景的介紹：建筑受地震震動，有可能達(dá)到一定程度上的動力失穩(wěn)，因為從理論上說側(cè)面上有無限的位移。許多建筑物，然而，在較低的震動強度下就失去豎向荷載的支撐，這就是橫向力不穩(wěn)定的原因（見圖16.1）。提出了 這策略的目的是為了確定建筑物很可能 馬上在豎向荷載作用下而倒塌，通過補 充一些垂直支撐來提高建筑物的安全。 維護(hù)豎向荷載支撐的能力，來改變水平在過去的經(jīng)驗表明，世界各地的地震最容易受到破壞的是一些無筋的混凝土框架結(jié) 構(gòu)建筑物。這經(jīng)常是由于一些無關(guān)緊要的漏洞，引起的全部或一大塊地方發(fā)生破壞，比 如整根梁、柱子和板。去填實上表面來抑制框架的內(nèi)

3、力，易受影響的底層去吸收大部分 的內(nèi)力和沖力。這有幾種過去被用過的方法可供選擇來實施：1、加密上層結(jié)構(gòu)，可以拆卸和更換一些硬度不夠強的材料。2、加密上層結(jié)構(gòu)，可以隔離一些安裝接頭上的裂縫，從而阻止對框架結(jié)構(gòu)的影響。3、底樓，或者地板，可以增加結(jié)構(gòu)新墻。這些措施 （項目1、2和3）能有效降低自 重，這韌性能滿足于一層或多層。然而，所有這些都有困難和干擾。在美國，這些不尋 常的代價換來的是超過一半更有價值的建筑。4、在一些容易受到破壞的柱子裹上鋼鐵、混凝土、玻璃纖維、或碳纖維第四個選項可以增加柱子的強度和延性，這足以降低柱子受到破壞的風(fēng)險在大多數(shù) 的建筑物中。這個方案雖然成本比前面低，但是整體性能

4、也會降低，對比較弱的地板破壞會更加集中。加強柱子的強度在美國很流行，但它的成本依舊是很高的。在發(fā)展中國 家，這些先進(jìn)的技術(shù)對某些種類的加料或加強，還不能夠做到隨心所欲這個程序的提出包含了另一個選擇， 美國已經(jīng)運用這個選擇用來降低房子倒塌的風(fēng)險。這個方法是增加垂直支 撐，來防止建筑在瞬間豎向荷 載作用下就倒塌（見圖16.3）。 這是為支撐轉(zhuǎn)移做準(zhǔn)備的，當(dāng) 柱子被剪切破壞和剪切衰弱時。這個補充支撐通常是鋼結(jié)構(gòu)、管道支撐或木材支撐。他們通常安裝在單獨的柱子上, 但（圖16.3）鋼柱也可以被放置在能承擔(dān)的水平框架上。這種技術(shù)能有效的降低自重，從 而降低了建筑在瞬間豎向荷載下就遭到破壞。在水平方向的強烈

5、震動，產(chǎn)生的不穩(wěn)定大 概很少被想到。補充的安裝垂直技撐相對比較便宜。一些有用的空間可能通過安裝支撐 被影響，可是這是一些微不足道的比較。在美國為建筑安裝一些補充支撐現(xiàn)在非常流行Suppleme ntal Vertical Support as a Means for Seismic Retrofit ofBuildi ngsCraig D. Comarti nGeotech ni cal, Geological, and Earthquake Engin eeri ng, 1, Volume10, Seismic Risk Assessme nt and Retrofitti ng, Page

6、s 329-342Abstract A large nu mber ofcon crete buildi ngs in seismically active areas throughout the world exhibit a com mon deficie ncy. Weak colu mns, in one or more stories, lose vertical load-carry ing capacity as a result of lateral distorti on.This chapter prese nts a con ceptual strategy for r

7、etrofit compris ing the in stallatio n of suppleme ntal vertical supports to preve nt collapse. This procedure utilizes arisk-based perspective based on rece nt research on the realistic capacity of con crete colu mns, dyn amic in stability, and the effects of in-cycle degradati on of stre ngth in b

8、uild ing systems and comp onen ts. An example build ing is used to illustrate the applicati on of the con cept.1 In troducti on and Backgro undBuild ings subject to earthquake shak ing have a pote ntial to reach a point of dyn amic in stability at which they collapse due to theoretically un limited

9、lateral displaceme nt.Many build in gs, however, lose the ability to support vertical loads and collapse at smaller levels of shak ing in ten sity tha n that which would otherwise cause lateral dyn amic in stability (see Fig. 16.1). The procedures proposed here are inten dedto identify buildings pro

10、ne to preemptive vertical load collapse and improve their safety by the installation of supplemental vertical supports. Maintaining the capabilityto support vertical loads cha nges the critical collapse mechanism to lateral dynamic stability which occurs at larger and less probable lateral displacem

11、e nts (see Fig. 16.2). Experie nee in past earthquakes around the world in dicates that con crete frames in filled with unrein forced masonry (URM) have bee nparticularly prone to collapse. This most ofte n is due to a weak first story caused by the omissi on of all or a substa ntial porti on of the

12、 in fill to allow for retail, park ing, or other uses con ducive toope n spaces. The in fill in upper stories restrai ns frame acti on and forces the flexible lower floor to absorb most of the en ergy dema nd and drift.There are several alter natives for retrofit strategy that have bee n impleme nte

13、d in the past:1. The in fill on upper floors could be removed and replaced with less stiff and less stro ng materials.2. The in fill on upper floors could be isolated from the structure by in stalli ng joi nts with gaps to preve nt in teracti on with the frame.3. The lower floor, or floors, could be

14、 stre ngthe ned with new structural walls These Measures (Items 1,2, and 3) are effective in reduc ing the ductility dema nd in the weak story or stories. However, all of them are costly and intrusive. In the US, it is not unu sual for the costs of these types of retrofit to exceed half of the repla

15、ceme nt value of the buildi ng.4. Wrap the colu mns in the weak story with jackets of steel, con crete, fiberglass, or carb on fiber.The fourth opti on can in crease both the stre ngth and ductility of the colu mnseno ugh to reduce the collapse risk for most build in gs. The cost is somewhat less th

16、a n for the first three alter natives; however the overall performa nee would also be less with more damage focused in the weak floor. Column jacketing is popular in the US, but the costs can still be high. In developing countries, the advanced technologies for some types of jackets may not be readi

17、ly available.The procedure proposed here incorporates another alternative that has been used in the US to reduce collapse risk. This strategy is to provide supplemental vertical supports designed to prevent preemptive vertical load collapse (see Fig. 16.3). These are intended to support loads that a

18、re transferred from shear critical columns as they are damaged and begin to fail. The supplemental supports are typically steel shapes, pipe shoring, or timber shores. They are often installed near individual columns, but also can be placed beneath capable horizontal framing. This technique is effective in reducing collapse risk by avoiding the preemptive vertical collapse mode。The inten sity of shak ing required for lateral dyn amic in stability is gen erally higher and less likely to occur. The installation of supplemental vertical support