【導(dǎo)讀】們就會發(fā)現(xiàn)長和大的鋼橋建設(shè)實際已經(jīng)完成了。于是最近主要工作焦點是老化。橋梁和現(xiàn)有橋梁的地震改型維護。生不利的影響對這些橋梁進行恢復(fù)和重建是由必要的。應(yīng)該是經(jīng)濟合理的工作。國家應(yīng)該以JSCE公布的土木工程師工程規(guī)范為基礎(chǔ)來。改型現(xiàn)有的橋梁，使這些橋梁能夠抵御災(zāi)害和緩和橋梁對周圍環(huán)境的不利影響，以此來了解這些工作的必要性和重要性。高速發(fā)展時期，每年修建的橋梁數(shù)量減少到全部最高數(shù)量的一半。的鋼橋數(shù)量下降到大約最高量的百分之四十。是運用鋼橋構(gòu)件和結(jié)構(gòu)的延展性。震的發(fā)生而被破壞，但是這些工作在不久的將來歸于完成。鋼橋中損壞的部分。主要分為橋墩、承力構(gòu)件和保護橋梁不倒塌的約束構(gòu)件。的地震改型工作正在進行，這是一座主跨度為510m的大懸臂行架橋。為60億日元，工期為五年。路橋的規(guī)定荷載。在新建工程區(qū)段，鋼橋產(chǎn)業(yè)和混凝土橋產(chǎn)業(yè)之間存在著嚴(yán)重的競爭。抗震設(shè)計程序在Hyogo-kenNambu地震后又一下

　　

【正文】 tion 300 gal. – Level 2 Type I (ocean plate slip type): Maximum elastic response acceleration 1000 gal. 外文翻譯譯文 22 – Level 2 Type II (inland fault slip type): Maximum elastic response acceleration 2021 gal. （ 2） Elastic design is carried out against the Level 1 earthquake with the safety factor of . （ 3） Elastoplastic deformation is allowed against Level 2 earthquakes. The safety of a bridge dimensioned on the basis of a Level 1 earthquake is verified by using a Level 2 earthquake. （ 4） Two types of seismic design methods against Level 2 earthquakes。 – Design method A in which the seismic load is reduced by taking into account the elastoplastic deformation of main structural members. – Design method B in which the seismic load is reduced by introducing seismic dampers, fuse members, key plastic members, bracing members, and so on. . Design tools （ 1） Analytical methods The puter programs developed in Japan are principally used for almost all the elastic linear analyses associated with bridge design. In investigating issues to which JSHB can not be applied, the elastoplastic and finite displacement analyses for framed structures are sometimes carried out, for example, by the puter program EPASS developed by our laboratory and JIP Techno Science Corporation. However, corresponding analyses for plated structures are carried out using puter programs developed mainly in other countries, such as ABAQUS, MARC, NASTRAN etc. and sometimes our own USSP. Dynamic, elastoplastic and finite displacement analyses for steel bridge piers subjected to the Level 2 earthquakes are carried out by using puter 外文翻譯譯文 23 programs using the yield criterion developed in Japan in terms of cross sectional forces (rather than stresses). Our laboratory and JIP Techno Science Corporation have developed a puter program EPASS/USSP , a multipurpose static/dynamic, elastoplastic and finite displacement solver for spatial bridge structures consisting of thinwalled steel and posite members considering the local buckling of constituent stiffened plate panels of the members and the elastoplastic behaviour of the encased concrete of the posite members. （ 2） Experimental methods After the Hyogoken Nambu Earthquake, pseudodynamic tests have bee very popular in Japan. Kyoto University and our Osaka City University have developed a multiphase pseudodynamic testing system, which can simulate the dynamic behavior of a structure with multimass involving collaboration of many different laboratories connected through the inter. . New materials and technologies New highperformance materials are continually developed for bridges. Examples include highperformance steel, highperformance bearings, highductility and highstrength bolts, carbon fiber reinforced plastic sheets, carbon fiber reinforced plastic cables and so on. Among them, carbon fiber reinforced plastic sheets are used for the repair of superannuated steel girder bridges and RC slabs, and the seismic retrofitting of steel bridge piers with circular cross section. However, it seems to be very difficult to identify structural members to which these highperformance materials can be properly applied. 外文翻譯譯文 24 On the other hand, various highperformance technologies are being developed for seismic design, seismic retrofitting, cost reduction, control of vibration, and so on .