水平弹性双参数位移谱模型

为了得到可供基于位移抗震设计使用的水平弹性位移谱，首先采用Campbell-Bozorgnia地面运动预测方程，研究了矩震级、断层距和场地类别对水平弹性位移谱的影响；然后指出了我国《建筑抗震设计规范》GB 50011-2010中设计反应谱存在的问题；最后针对设计反应谱的不足，提出了包含场地地震动峰值加速度和速度的水平弹性双参数位移谱模型.研究表明：位移谱平台段起始周期是确定位移谱谱形的重要参数，其主要受矩震级的影响，随矩震级的增加而显著增加；场地地震动峰值速度与峰值加速度之比与矩震级存在正的强相关性，矩震级的影响可以通过在位移谱模型中包含该比值来体现；本文提出的双参数位移谱能较好地拟合实际强震记录位移谱；提供每一设防水准的地震动峰值加速度和速度区划图，并在抗震规范中给出每一设防水准的各类场地地震动峰值加速度和峰值速度的场地放大系数，可在规范中实现本文提出的双参数位移谱模型.本文的研究结果可为我国抗震设计规范的制订和修改提供参考.
To obtain the elastic horizontal displacement spectra that can be applied to displacement-based seismic design, the influences of moment magnitude, rupture distance, and site classes on the displacement spectra were examined using the ground motion prediction equation of Campbell and Bozorgnia. The deficiencies of design spectra in existing seismic design code of buildings (GB 50011-2010) were pointed out and an elastic horizontal displacement spectra model using double parameters, peak ground acceleration (PGA) and peak ground velocity (PGV), was proposed to compensate for the deficiencies. The results show that the starting period of the constant displacement plateau (TD) is an important parameter to determine the spectral shape of the displacement spectra. It is mainly affected by moment magnitude and is increased significantly with the increases of the moment magnitude. The peak ground velocity-to-acceleration (PGV/PGA) ratio is strongly dependent on the moment magnitude, and thus the significant influence of the moment magnitude can be captured by the inclusion of the PGV/PGA ratio in the model. The proposed model is capable of fitting real displacement spectra and can be applied to the seismic design codes by providing the peak acceleration and velocity zonation maps for each seismic precautionary level and giving the peak acceleration and velocity site amplification factor corresponding to the each level in the seismic design codes. The results can provide the reference for the revisions of seismic design codes in our country.