随着地震工程研究的深入,尤其是强震观测仪器、动力试验设备和电子计算机的发展,近几年来,世界各国抗震设计规范都有较多的改进。主要表现在:(1)设防标准,明确规定了对不同发震概率,按两个地震强度等级分别,作弹性设计和极限设计,即;在中小地震时保持使用功能;在大地震时保证不倒塌。对结构的变形和倒塌作出明确的控制。(2)抗震计算方法,充分运用经验,使历来的方法各得其所,如 With the deepening of seismic engineering research, especially the development of strong earthquake observation instruments, dynamic test equipment and electronic computers, in recent years, there have been many improvements in seismic design specifications in various countries in the world. The main manifestations are: (1) The fortification standards clearly stipulate that for different seismogenic probabilities, two seismic intensity grades are respectively used for elastic design and limit design, that is, to maintain the use function in small earthquakes; collapse. A clear control of the deformation and collapse of the structure. (2) Seismic calculation methods, making full use of experience, so that the historical methods are well-founded, such as