土木工程外文翻译---抗震钢筋混凝土结构设计原则

土木工程外文翻译---抗震钢筋混凝土结构设计原则内容摘要：

bracing)to prevent excessive the vertical load carrying members are not rigid enough,very high second order moments can result as shown in Figure 1967 Adapazari and 1985 Mexico earthquakes numerous failures have been observed in buildings with flexible floors and slender columns. For a more detail discussion on configuration,the reader is directed to Reference 2. and Detailing The dimensions of structural members not only influence the strength,but also the overall stiffnes of the the light of experience gained from the past earthquakes,the author believes that the ratio of the sum of the crosssectional areas of vertical load carrying members to the floor area is an important parameter in seismic ratio will be called theDensity Ratio.The author has studied the variation of this ratio in the monumental historical buildings in Istanbul,which have withstood several severe earthquakes during the past was found out that this ratio varied between and an example,the floor plan of the S252。 leymaniye. Mosque is shown in Figure author would like to point out the symmetry in the arrangement of load carrying S252。 leymaniye the density ratio was about . Another investigation made on modern reinforced concrete buildings built in seismic areas in Turkey reveal that the average density ratio is less than author finds the ratio rather low and suggests that it should be about . In the city of Vina del Mar,Chile the average density ratio in reinforced concrete buildings(4 to 23 stories)is quite high,(3).This seems to be one of the reasons why relatively small damage occurred during the 1985 Chile earthquake,which created quite a severe ground motion. It should be pointed out that although density ratio is a very important parameter for lateral stiffness,the relative stiffness of floor members have also a significant influence on the stiffness. Ductility required for energy dissipation during an earthquake is closely related to well designed R/C structure can suffer considerable damage if it is not properly detailed. Detailing is an art which cannot be realized unless the seismic behaviour of reinforced concrete is well basic principle in detailing is to provide the necessary strength and ductility at critical sections and cutting the bars and in making lapped splices,adequate anchorage length should be critical regions where plastic hinging is expected to occur should be well confined by closely spaced experience in Turkey shows that inadequate detailing played a very important role in the earthquake damage observed during the past 30 of the damages attributed to detailing were due to inadequate anchorage or splice length and inadequate confinement. Basic rules for detailing of beams,columns and structural walls are summarized in Figures 7,8 and 9. The earthquake will be resisted by the structure which is actually built and not by the structure shown on the design matter how good the design methods used are,it is not possible to produce a seismic resistant building unless the structure is constructed in accordance with the design project under proper most of the developing countries emphasis is on the design stage。 quality control and supervision are usually looked down upon and ignored by the engineer. The engineer should realize that the important requirements for seismic resistance, strength,ductility and stiffness depend on the actual dimensions,material qualities and reinforcement details acplished on the supervision results in poor material quality and errors in the placement of the reinforcing experience in Turkey shows that inadequate supervision has been the most important cause of structure damage during past earthquakes. In the light of these discussions one can conclude that,for better seismic resistance,the first step should be in the direction of correcting the mistakes made in the configuration,detailing and construction supervision cannot be improved,well written codes and sophisticated methods of analyses will not be able to prevent damage and failures in future earthquakes. 4 RECOMMENDATIONS FOR DESIGN The main objective of this section is to specify some simple rules for the design of ordinary reinforced concrete ordinary,the author means regular structures up to say ten stories. of Facts Before stating the design rules,it would be useful to state some basic facts about the seismic action and seismic resistance of reinforced concrete structures. The characteristics of the ground motion expected cannot be fully defined. The structure cannot remain elastic when subjected to a strong ground will occur at different locations and most of the energy will be dissipated at these sections. Response of the structure depends not only on the ground motion,but also on the dynamic characteristics of the structure,such as mass。