Abstract Site period maps at various strain levels were developed for the combined cities of Ottawa and Gatineau in eastern Ontario and western Quebec. These maps were developed to support earthquake response studies in areas containing post-glacial, soft, silty-clayey sediments, which comprise 60% of the urban areas. Approximately 21,700 boreholes and over 1000 surface and downhole geophysical measurements were utilized to prepare the maps. The maps include the following: 1) A T0,ESL map is based on an equivalent single-layer modelling method (ESL) as described in the National Building Code of Canada using the 4H/V approach. 2) A T0,HVSR map is based on the micro-tremor HVSR method, which systematically deviates from T0,ESL for weak motion. Such variances between the calculated T0,ESL and measured T0,HVSR may be associated with significant shear wave velocity-depth gradients in the near-surface soft sediments. 3) A T0,100 map is based on finite element modelling at the 100 cm/s/s level of shaking (0.1 g) at the onset of the “gray zone” between the linear and nonlinear soil responses. 4) A T0,400 map is developed from a finite element model at the 400 cm/s/s level of shaking (0.4 g being the “design” earthquake for the city of Ottawa) This model evaluates the effect of nonlinear soft soil behaviour. The differences between these maps were examined and compared. The results indicated that nonlinear soil response at high levels of shaking strongly altered the resonance response toward much longer fundamental periods over large areas within the two cities.

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加拿大渥太华市非线性土壤的地震现场周期研究

摘要 为安大略省东部和魁北克西部的渥太华和加蒂诺联合城市开发了不同应变水平的站点周期图。开发这些地图是为了支持在包含冰川后、软质、粉质粘土沉积物的地区进行地震反应研究，这些地区占城市地区的 60%。大约 21,700 个钻孔和 1000 多个地表和井下地球物理测量被用于绘制地图。这些地图包括以下内容： 1) T0,ESL 地图基于加拿大国家建筑规范中描述的等效单层建模方法 (ESL)，使用 4H/V 方法。2) T0,HVSR 图基于微震 HVSR 方法，该方法系统地偏离 T0,ESL 用于弱运动。计算的 T0,ESL 和测量的 T0 之间的这种差异，HVSR 可能与近地表软沉积物中显着的剪切波速度-深度梯度有关。3) T0,100 地图基于有限元建模，在线性和非线性土壤响应之间的“灰色区域”开始时，100 cm/s/s 振动水平 (0.1 g)。4) T0,400 地图是根据 400 cm/s/s 振动水平的有限元模型开发的（0.4 g 是渥太华市的“设计”地震）该模型评估非线性软土行为的影响. 检查并比较了这些地图之间的差异。结果表明，在两个城市的大范围内，高强度振动下的非线性土壤响应强烈地改变了共振响应向更长的基本周期。100 地图基于有限元建模，在线性和非线性土壤响应之间的“灰色区域”开始时，在 100 cm/s/s 振动水平 (0.1 g) 下。4) T0,400 地图是根据 400 cm/s/s 振动水平的有限元模型开发的（0.4 g 是渥太华市的“设计”地震）该模型评估非线性软土行为的影响. 检查并比较了这些地图之间的差异。结果表明，在两个城市的大范围内，高强度振动下的非线性土壤响应强烈地改变了共振响应向更长的基本周期。100 地图基于有限元建模，在线性和非线性土壤响应之间的“灰色区域”开始时，在 100 cm/s/s 振动水平 (0.1 g) 下。4) T0,400 地图是根据 400 cm/s/s 振动水平的有限元模型开发的（0.4 g 是渥太华市的“设计”地震）该模型评估非线性软土行为的影响. 检查并比较了这些地图之间的差异。结果表明，在两个城市的大范围内，高强度振动下的非线性土壤响应强烈地改变了共振响应向更长的基本周期。400 地图是从 400 cm/s/s 振动水平的有限元模型（0.4 g 是渥太华市的“设计”地震）开发的。该模型评估非线性软土行为的影响。检查并比较了这些地图之间的差异。结果表明，在两个城市的大范围内，高强度振动下的非线性土壤响应强烈地改变了共振响应向更长的基本周期。400 地图是从 400 cm/s/s 振动水平的有限元模型（0.4 g 是渥太华市的“设计”地震）开发的。该模型评估非线性软土行为的影响。检查并比较了这些地图之间的差异。结果表明，在两个城市的大范围内，高强度振动下的非线性土壤响应强烈地改变了共振响应向更长的基本周期。