本文選題：地震安全性評(píng)價(jià) + 強(qiáng)度包絡(luò)函數(shù)��； 參考：《中國(guó)地震局工程力學(xué)研究所》2015年碩士論文

【摘要】：人造地震動(dòng)是工程場(chǎng)地地震安全性評(píng)價(jià)工作的重要組成部分,目的是為土層地震反應(yīng)分析提供基巖地震動(dòng)輸入。對(duì)于同一目標(biāo)反應(yīng)譜而言,利用不同的強(qiáng)度包絡(luò)函數(shù)參數(shù)人工合成出的地震動(dòng)時(shí)程是有一定差別,這勢(shì)必影響土層地震反應(yīng)分析結(jié)果以及基于此結(jié)果確定出的設(shè)計(jì)地震動(dòng)參數(shù)。因此,研究強(qiáng)度包絡(luò)函數(shù)參數(shù)的不確定性對(duì)土層地震反應(yīng)分析結(jié)果的影響具有很強(qiáng)的工程應(yīng)用價(jià)值。本文采用三段式的強(qiáng)度包絡(luò)函數(shù)模型,結(jié)合近年來(lái)在實(shí)際工程場(chǎng)地地震安全性評(píng)工作中廣泛應(yīng)用的幾種地震動(dòng)時(shí)程強(qiáng)度包絡(luò)函數(shù)參數(shù)確定公式,討論了該模型中兩個(gè)主要參數(shù)(上升段截止時(shí)間T1和相對(duì)平穩(wěn)強(qiáng)地震動(dòng)持續(xù)時(shí)間Td)在不同震級(jí)和震中距下的取值范圍,研究了T1與Td變化對(duì)土層地震反應(yīng)分析結(jié)果的影響。完成了以下主要工作:1.簡(jiǎn)要闡述了強(qiáng)度包絡(luò)函數(shù)參數(shù)研究在地震安全性評(píng)價(jià)工作中的重要作用,系統(tǒng)介紹了強(qiáng)度包絡(luò)函數(shù)研究的發(fā)展歷程和近年來(lái)研究成果。2.采用俞言祥博士中國(guó)東部地區(qū)基巖峰值地震動(dòng)加速度和地震加速度反應(yīng)譜衰減關(guān)系,計(jì)算得到了人工合成地震動(dòng)所需的目標(biāo)譜,采用四種常用的強(qiáng)度包絡(luò)函數(shù)參數(shù)計(jì)算公式確定了不同震級(jí)和震中距組合下的參數(shù)取值范圍。3.以典型的6級(jí)和7級(jí)地震為例,針對(duì)每一種震級(jí)和震中距工況,在參數(shù)取值范圍內(nèi),調(diào)整T1和Td,人工合成一系列地震動(dòng)時(shí)程,并將其折半作為基巖地震動(dòng)輸入,針對(duì)四種典型場(chǎng)地類別的土層地震反應(yīng)進(jìn)行了分析。4.對(duì)土層地震反應(yīng)計(jì)算結(jié)果進(jìn)行了統(tǒng)計(jì)分析,結(jié)果表明:(1)總體而言,Td值變化對(duì)地表水平向峰值加速度和地表水平向加速度反應(yīng)譜的影響程度較T1值變化更為顯著;(2)近場(chǎng)地震動(dòng)情況下,Td和T1的變化對(duì)土層反應(yīng)分析結(jié)果影響較大,而遠(yuǎn)場(chǎng)地震動(dòng)情況下影響較小;(3)Ⅰ類場(chǎng)地的放大系數(shù)受參數(shù)變化影響較小,Ⅱ、Ⅲ、Ⅳ類場(chǎng)地的放大系數(shù)受參數(shù)影響程度較大。(4)強(qiáng)度包絡(luò)函數(shù)參數(shù)變化對(duì)不同場(chǎng)地類別的影響程度不同,Ⅰ類場(chǎng)地受影響程度較小,Ⅱ、Ⅲ、Ⅳ類場(chǎng)地受影響程度稍大。
[Abstract]:Artificial ground motion is an important part of seismic safety evaluation of engineering site. The purpose of this work is to provide ground motion input for seismic response analysis of soil layer. For the same target response spectrum, the time history of ground motion synthesized by using different parameters of intensity envelope function is different, which will inevitably affect the seismic response analysis results of soil layer and the design ground motion parameters based on these results. Therefore, it is of great value to study the influence of the uncertainty of intensity envelope function parameters on the results of soil seismic response analysis. In this paper, a three-segment strength envelope function model is used to determine the parameters of time-history intensity envelope function of ground motion, which has been widely used in the seismic safety assessment of practical engineering sites in recent years. The values of two main parameters (the cutoff time T _ 1 and the duration of relatively stationary strong ground motion T _ d) under different magnitude and epicentral distance in the model are discussed. The influence of the variation of T _ 1 and T _ d on the results of soil seismic response analysis is studied. Completed the following main work: 1. This paper briefly describes the important role of the study of the parameters of the intensity envelope function in the evaluation of seismic safety, and systematically introduces the development course of the study of the intensity envelope function and the research achievements in recent years. By using the relationship between peak ground motion acceleration and seismic acceleration response spectrum attenuation of the bedrock in eastern China, the target spectrum required for artificial synthetic ground motion is calculated. Four commonly used formulas for calculating the parameters of the intensity envelope function are used to determine the range of values of the parameters under different magnitude and epicenter distance combinations. Taking a typical earthquake with M 6 and M 7 as an example, according to each magnitude and epicentral distance, adjusting T1 and Td within the range of parameters, synthesizing a series of earthquake time history artificially, and taking it as the input of ground motion. The seismic response of soil layer of four typical site types is analyzed. The calculation results of soil seismic response are statistically analyzed. The results show that the variation of Td value has a more significant effect on the response spectrum of horizontal acceleration and horizontal acceleration than T1.) the variation of Td and T1 in near-field ground motion has a more significant effect on soil layer response. The results of the analysis have a great influence on, However, the magnification factor of type 鈪，

本文編號(hào)：1823574