本文選題：長周期地震動　切入點：功率譜密度　出處：《湖南大學(xué)學(xué)報(自然科學(xué)版)》2014年04期

【摘要】：從各個國家和地區(qū)的地震記錄庫中尋找出一些具有良好記錄質(zhì)量和基本場地資料的強震記錄,并從中挑選出較為典型的長周期地震波,對比分析了不同場地條件下長周期地震波和普通地震波的平均加速度反應(yīng)譜及其規(guī)范形式的分段擬合曲線.選取軟土場地擬合反應(yīng)譜作為目標(biāo)反應(yīng)譜,用迭代方法求取與目標(biāo)反應(yīng)譜相對應(yīng)的功率譜密度函數(shù),分析了基于長周期地震動加速度功率譜密度的特點.在此基礎(chǔ)上,以某超大跨斜拉橋結(jié)構(gòu)為背景,利用ANSYS軟件建立三維有限元分析模型,分別以文中擬合的長周期地震動功率譜密度和普通地震動功率譜密度作為輸入,采用直接求取位移的改進虛擬激勵法,對超大跨斜拉橋結(jié)構(gòu)進行了不同視波速下的行波效應(yīng)分析.結(jié)果表明:長周期地震動功率譜密度的卓越頻率明顯低于普通地震動功率譜密度的卓越頻率.長周期地震動功率譜作用下的橋梁左橋塔頂、右橋塔頂和橋面板跨中節(jié)點的位移響應(yīng)功率譜值均明顯大于普通地震動功率譜作用下的結(jié)果,橋梁塔頂位移響應(yīng)功率譜均呈雙峰分布.在本文算例中,考慮行波效應(yīng)使超大跨斜拉橋結(jié)構(gòu)的位移響應(yīng)和彎矩響應(yīng)結(jié)果有所減小.
[Abstract]:Some strong earthquake records with good recording quality and basic site data are found from the seismograms of various countries and regions, and typical long-period seismic waves are selected from them.The average acceleration response spectra of long-period seismic waves and ordinary seismic waves under different site conditions are compared and analyzed, as well as the piecewise fitting curves of their normative forms.The fitting response spectrum of soft soil is selected as the target response spectrum and the power spectral density function corresponding to the target response spectrum is obtained by iterative method. The characteristics of power spectral density based on long-period ground motion acceleration are analyzed.On this basis, taking a super large span cable-stayed bridge as the background, a three-dimensional finite element analysis model is established by using ANSYS software. The power spectral density of long-period ground motion and the power spectral density of ordinary ground motion are respectively used as inputs in this paper.An improved virtual excitation method for calculating displacement is used to analyze the traveling wave effect of long-span cable-stayed bridge structure under different apparent wave velocities.The results show that the excellent frequency of power spectral density of long-period ground motion is obviously lower than that of ordinary ground motion.The displacement-response power spectrum of the bridge at the top of the left bridge, the top of the right bridge and the mid-span of the deck of the bridge under the action of the power spectrum of long-period ground motion is obviously higher than that under the action of the power spectrum of the ordinary ground motion.The power spectrum of the top displacement response of the bridge tower is distributed with two peaks.In this paper, considering the traveling wave effect, the displacement response and the moment response of the long-span cable-stayed bridge are reduced.
【作者單位】： 同濟大學(xué)土木工程防災(zāi)國家重點實驗室;
【基金】：國家自然科學(xué)基金重大研究計劃資助項目(91315301)
【分類號】：U448.27;U441.3

【參考文獻】

相關(guān)期刊論文 前7條

1 謝禮立,周雍年,胡成祥,于海英;地震動反應(yīng)譜的長周期特性[J];地震工程與工程振動;1990年01期

2 李春鋒;張e，

本文編號：1721319