外文翻譯---高層建筑及結(jié)構(gòu)設(shè)計(jì)-wenkub
2023-02-02 14:58:56 本頁面
【正文】 panels ( or even all panels ) without increasing the sizes of the columns and girders otherwise required for vertical loads.Unfortunately , this is not is for highrise buildings because the problem is primarily resistance to moment and deflection rather than shear alone . Special structural arrangements will often have to be made and additional structural material is always required for the columns , girders , walls , and slabs in order to made a highrise buildings sufficiently resistant to much higher lateral deformations . As previously mentioned , the quantity of structural material required per square foot of floor of a highrise buildings is in excess of that required for lowrise buildings . The vertical ponents carrying the gravity load , such as walls , columns , and shafts , will need to be strengthened over the full height of the buildings . But quantity of material required for resisting lateral forces is even more significant . With reinforced concrete , the quantity of material also increases as the number of stories increases . But here it should be noted that the increase in the weight of material added for gravity load is much more sizable than steel , whereas for wind load the increase for lateral force resistance is not that much more since the weight of a concrete buildings helps to resist overturn . On the other hand , the problem of design for earthquake forces . Additional mass in the upper floors will give rise to a greater overall lateral force under the of seismic effects . In the case of either concrete or steel design , there are certain basic principles for providing additional resistance to lateral to lateral forces and deflections in highrise buildings without too much sacrifire in economy . Increase the effective width of the momentresisting subsystems . This is very useful because increasing the width will cut down the overturn force directly and will reduce deflection by the third power of the width increase , other things remaining cinstant . However , this does require that vertical ponents of the widened subsystem be suitably connected to actually gain this benefit.Design subsystems such that the ponents are made to interact in the most efficient manner . For example , use truss systems with chords and diagonals efficiently stressed , place reinforcing for walls at critical locations , and optimize stiffness ratios for rigid frames . Increase the material in the most effective resisting ponents . For example , materials added in the lower floors to the flanges of columns and connecting girders will directly decrease the overall deflection and increase the moment resistance without contributing mass in the upper floors where the earthquake problem is aggravated . Arrange to have the greater part of vertical loads be carried directly on the primary momentresisting ponents . This will help stabilize the buildings against tensile overturning forces by prepressing the major overturnresisting ponents . The local shear in each story can be best resisted by strategic placement if solid walls or the use of diagonal members in a verti
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