岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
z2期
363-367
,共5页
传递函数%土层特性参数%Monte Carlo%变异性
傳遞函數%土層特性參數%Monte Carlo%變異性
전체함수%토층특성삼수%Monte Carlo%변이성
site transfer function%site characteristic parameter%Monte Carlo%variability
采用Monte Carlo模拟手段,提出描述场地土层特性变异性对传递函数变异性影响的分析方法。选取日本Kik-Net强震数据库中软(FKSH14)、硬(FKSH12)两类场地,建立场地概率模型。应用Monte Carlo技术随机生成50组场地剖面,分别计算场地的传递函数STF及STF标准差,讨论场地土层厚度、剪切波速,以及二者组合情况下场地传递函数的标准差及场地特征频率的变化。结果显示:对于硬土场地而言,场地特征频率标准差相对于软土场地较大,且剪切波速变异性影响比土层厚度变异性的影响略大,而二者组合工况下最大;而软土场地,土层厚度、剪切波速变化工况下场地特征频率的标准差相当,比二者组合工况下略低;软、硬两类场地,土层厚度与剪切波速二者组合工况下 STF 的标准差比单一量变化情况下略大,但3种工况下场地STF标准差相差不明显;场地STF的标准差在场地自振频率附近的频率段取值较大,极值点与场地STF的极值点相对应。
採用Monte Carlo模擬手段,提齣描述場地土層特性變異性對傳遞函數變異性影響的分析方法。選取日本Kik-Net彊震數據庫中軟(FKSH14)、硬(FKSH12)兩類場地,建立場地概率模型。應用Monte Carlo技術隨機生成50組場地剖麵,分彆計算場地的傳遞函數STF及STF標準差,討論場地土層厚度、剪切波速,以及二者組閤情況下場地傳遞函數的標準差及場地特徵頻率的變化。結果顯示:對于硬土場地而言,場地特徵頻率標準差相對于軟土場地較大,且剪切波速變異性影響比土層厚度變異性的影響略大,而二者組閤工況下最大;而軟土場地,土層厚度、剪切波速變化工況下場地特徵頻率的標準差相噹,比二者組閤工況下略低;軟、硬兩類場地,土層厚度與剪切波速二者組閤工況下 STF 的標準差比單一量變化情況下略大,但3種工況下場地STF標準差相差不明顯;場地STF的標準差在場地自振頻率附近的頻率段取值較大,極值點與場地STF的極值點相對應。
채용Monte Carlo모의수단,제출묘술장지토층특성변이성대전체함수변이성영향적분석방법。선취일본Kik-Net강진수거고중연(FKSH14)、경(FKSH12)량류장지,건립장지개솔모형。응용Monte Carlo기술수궤생성50조장지부면,분별계산장지적전체함수STF급STF표준차,토론장지토층후도、전절파속,이급이자조합정황하장지전체함수적표준차급장지특정빈솔적변화。결과현시:대우경토장지이언,장지특정빈솔표준차상대우연토장지교대,차전절파속변이성영향비토층후도변이성적영향략대,이이자조합공황하최대;이연토장지,토층후도、전절파속변화공황하장지특정빈솔적표준차상당,비이자조합공황하략저;연、경량류장지,토층후도여전절파속이자조합공황하 STF 적표준차비단일량변화정황하략대,단3충공황하장지STF표준차상차불명현;장지STF적표준차재장지자진빈솔부근적빈솔단취치교대,겁치점여장지STF적겁치점상대응。
Adopting Monte Carlo simulation technique, a method for describing the variability of site transfer function (STF) with respect to the variability of site characteristic parameters is proposed. Two Kik-Net seismic strong-motion stations, which were installed on hard ground (FKSH12) and soft site (FKSH14) in Japan, were selected and corresponding probability site models were established. 50 site soil profiles were randomly generated for hard ground and soft site via Monte Carlo simulation;and then the STFs were calculated as well their standard deviations, respectively. The standard deviations of STFs and the site characteristic frequencies were discussed in three cases, i.e. varying subsoil thicknesses (case I), varying subsoil shear wave velocities (case II), and varying subsoil thickness and shear wave velocities (case III). The results show that:the standard deviations of site characteristic frequencies of hard ground is overall larger than those of soft site;the standard deviation of site characteristic frequency of hard ground is the smallest in case I, followed by case II, while in case III the standard deviation of site characteristic frequency is the largest; the standard deviations of soft site characteristic frequencies in case I and case II are comparative but weakly smaller than that in case III;the standard deviations of STFs in case III for soft site and hard ground are slightly larger than those in case I and case II;but the standard deviations in the three cases are not considerably different;the standard deviations of STF are fairly large in the vicinity of site predominant frequencies with peak values corresponding to peak values of relevant mean STF.