Abstract:Amplification effect of harmonic plane SH waves due to the sedimentary valley with multiple sedimentary layers embedded in a layered half-space is investigated by using a multi-domain indirect boundary element method (multi-domain IBEM), in which the half space is decomposed into a set of enclosed sedimentary domains and open layered half-space domain with irregular boundaries, and fictitious uniform loads are applied on the boundaries of all domains. The scattered wave fields in the enclosed domains are constructed by calculating the full-space Green’s functions, and the layered half-space Green’s functions are employed to simulate the scattered wave fields in the open layered half-space domain. The new approach inherits the advantages of both the full-space IBEM and half-space IBEM, with great flexibility and high accuracy, and the results from the new approach have good agreements with those published. To study the effect of sedimentary sequence of sedimentary valley on the ground motions near valley, those cases such as normal sediment, soft interlayer sediment and inverted-sequence sediment are investigated. Numerical results show that the inverted-sequence sedimentary valley appears to be a good shock insulation under the intermediate- and high-frequency wave; sedimentary sequence has a significant effect on both the natural frequency and predominant frequency of ground motion; the change of sedimentary sequence may lead to the change of the dynamic characteristics of sediments, which in turn affects the mechanism of dynamic interaction between sedimentary valley and layered ground.
巴振宁 印枭 梁建文. 沉积层序对谷地场地地震反应的影响-SH波入射[J]. 土木工程学报, 2017, 50(1): 91-103.
Ba Zhenning Yin Xiao Liang Jianwen. Effects of sedimentary sequence on the seismic response of valley sites-incident SH waves. 土木工程学报, 2017, 50(1): 91-103.