本研究利用單向度剪力波傳理論推導一地盤最大加速度(PGA)隨土層深度折減之解析模式,探討PGA與地盤特性及深度之關係;並利用吉普生土層,採取「假設基盤」之分析模式,以SHAKE程式進行地盤受震反應之統計分析,歸納出30m深度可為動力分析之輸入基盤,最後則以高鐵嘉南平原段之震測剖面為例,說明其應用之可靠性。 To conduct a seismic ground response analysis for earthquake resistant design, argument usually raised is where to put the base motion, especially for the case when the depth of base rock is very deep or even unknown. The purpose of this paper is to investigate the influence of depth of input motion to the amplification of acceleration at surface ground. Analytical model used is the SHAKE-type convolution analysis by applying 40 earth-quake records at different depths of a Gibson soil profile. Results obtained show that the coefficient of PGA amplification is insensitive to the depth of input motion when the assumed base has a depth larger than 30 meters. For engineering applications, seismic ground response analyses were performed for 50 soil profiles of Chianan Plain to deduce the variation of amplification coefficients with respect to the intensity of ground shaking.
中華民國力學學會第二十屆全國力學會議論文集(二)=Proceedings of the 20th National Conference on Theoretical and Applied Mechanics (II)，頁404-411