【摘要】 本文回顾了关于建筑物地震力的理论的发展过程,对于现行的几种理论进行了评论;认为在我国目前条件之下,可以采用一种基于动力原则的地震力系数;最后对今后的研究方向提供了一些意见。更多还原

【Abstract】 In this paper, a survey is made over the existing theories of seismic forces onstructures. It is found that all the theories fall into one of the following cate-gories: 1) the so-called "statical theory" which considers the structure subject toan equivalent constant acceleration; 2) theories based upon simulated simplified ground motions; 3) theories based upon recorded actual ground motions; 4) theories based upon random impulses. Critical comments have been given to the above theories, especially to thefourth one. The writer further gives a brief but cpmplete description of the responsespectra of the structure and on this basis, all the theories are co-related. Computations made by G. W. Housner for major American earthquakes dis-close that the acceleration spectra for damped system are flat curves withoutoutstanding peak value. For this reason, the writer deems that for certain typeof structures, variation of the acceleration spectral value for different modes of vibration will be small, and may be taken approximately as a constant. As aresult, the seismic forces reduce to this constant spectral acceleration times the.mass of the structure. It is suggested to use this method for estimatingthe base shear but make proper adjustment in its distribution along the height ofthe structure. It is also proposed to tie up this spectral acceleration to the earth-quake intensity scale. Finally, the writer stresses that further development of the theory of seismicforces on structures depends upon researches along following lings: 1) strong-motion program; 2) dynamical properties of structures and materials; 3) effectsof foundation conditions; 4) vertical and torsional seismic forces; 5) co-relationbetween seismic forces and earthquake intensity.更多还原