为了改善地震总输入能谱建立过程中峰值计算精度和计算效率，根据美国西部强震数据库中I类场地（剪切波速大于750 m/s）的69条地震记录的能量谱峰值，研究了等效速度谱（ V I谱）峰值的主要影响因素以及相关性。采用傅里叶变换和线性拟...为了改善地震总输入能谱建立过程中峰值计算精度和计算效率，根据美国西部强震数据库中I类场地（剪切波速大于750 m/s）的69条地震记录的能量谱峰值，研究了等效速度谱（ V I谱）峰值的主要影响因素以及相关性。采用傅里叶变换和线性拟合方法，研究了VI谱峰值和地震波频率成分之间的关系。进而提出了基于傅里叶谱的VI谱峰值参数α，建立了简化的谱峰值计算公式。研究结果表明：具有相近场地条件、地震动峰值和持时的地震波可能导致较大的VI谱峰值差异；地震动傅里叶幅值谱的低频集中度、幅值谱峰值与单自由度体系的VI谱峰值有较大的关联度，其中0～10 Hz频率段的关联度最大。展开更多
The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident...The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.展开更多
文摘为了改善地震总输入能谱建立过程中峰值计算精度和计算效率，根据美国西部强震数据库中I类场地（剪切波速大于750 m/s）的69条地震记录的能量谱峰值，研究了等效速度谱（ V I谱）峰值的主要影响因素以及相关性。采用傅里叶变换和线性拟合方法，研究了VI谱峰值和地震波频率成分之间的关系。进而提出了基于傅里叶谱的VI谱峰值参数α，建立了简化的谱峰值计算公式。研究结果表明：具有相近场地条件、地震动峰值和持时的地震波可能导致较大的VI谱峰值差异；地震动傅里叶幅值谱的低频集中度、幅值谱峰值与单自由度体系的VI谱峰值有较大的关联度，其中0～10 Hz频率段的关联度最大。
基金National Natural Science Foundation of China under Grant No.51478247National Key Research and Development Program of China under Grant No.2016YFC1402800
文摘The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.
