Sliding fragility of block‐type non‐structural components. Part 1: Unrestrained components     

D. Lopez Garcia  T. T. Soong 《地震工程与结构动力学》2003,32(1):111-129

Motivated by the development of performance‐based design guidelines with emphasis on both structural and non‐structural systems, this paper focuses on seismic vulnerability assessment of block‐type unrestrained non‐structural components under sliding response on the basis of seismic inputs specified by current seismic codes. Two sliding‐related failure modes are considered: excessive relative displacement and excessive absolute acceleration. It is shown that an upper bound for the absolute acceleration response can be assessed deterministically, for which a simple yet completely general equation is proposed. In contrast, fragility curves are proposed as an appropriate tool to evaluate the excessive relative displacement failure mode. Sample fragility curves developed through Monte‐Carlo simulations show that fragility estimates obtained without taking into account vertical base accelerations can be significantly unconservative, especially for relatively large values of the coefficient of friction. It is also found that reasonable estimates of relative displacement response at stories other than the ground in multistorey buildings cannot in general be obtained by simply scaling the ground acceleration to the peak acceleration at the corresponding storey. Failure modes considered in this study are found to be essentially independent of each other, a property that greatly simplifies assessment of conditional limit states. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Comparative study of the inelastic response of base isolated buildings   总被引：1，自引：0，他引：1  

Daniel Ordoez  Dora Foti  Luis Bozzo 《地震工程与结构动力学》2003,32(1):151-164

This article presents a numeric comparative study of the inelastic structural response of base isolated buildings. The comparative study includes the following isolation systems: laminated rubber bearings, New Zealand one, pure friction and the frictional pendulum ones. The study is based on obtaining non‐linear response spectra for various design parameters using six earthquake records. Usually the base isolation of a new building seeks to maintain the structure in the linear elastic range. The response of old weak buildings or the response of new ones subjected to extreme earthquakes may not be, necessarily, in the aforementioned ideal elastic range. Consequently, it is important to characterize the response of isolated buildings responding inelastically. A conclusion from this research is that the isolators affect significantly the structural response of weak systems. Rubber isolators seem slightly less sensitive to plastification that may occur in the structure compared to friction isolators. Ductility demands in the structure are affected significantly by friction and neoprene protected systems, in particular sliding ones where larger demands are obtained. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

辽宁义县—北票地区义县组地层层序——义县阶标准地层剖面建立和研究之一   总被引：30，自引：1，他引：30  

王五力  张宏  张立君  郑少林  杨芳林  李之彤  郑月娟 《地层学杂志》2003,27(3):227-232

义县地区广义的义县组可解体为王家屯组 (暂命名 )和义县组 ;分属王家屯和义县火山旋回 ,前者为偏酸、偏碱性 ,后者主体为中基性、末期为中酸性火山岩系 ,并广泛发育潜火山岩相的玄武玢岩、安山玢岩和火山集块角砾熔岩筒。该区有七个主要沉积层 ,自下而上分别为王家屯组马神庙层、义县组老公沟层、业南沟层、砖城子层、大康堡层、朱家沟层和金刚山层 ;产有较丰富的无脊椎动物、脊椎动物和植物化石。以砖城子层、大康堡层和金刚山层为界 ,义县火山旋回可划分为 4个亚旋回 ,分别代表火山活动的初始期、主期、晚期和末期。北票四合屯地区的义县组相当义县地区义县组的第一和第二亚旋回 ,含鸟类化石的主沉积层 (尖山沟层和上园层 )可与砖城子层对比  相似文献   

吐哈盆地中央构造带正反转演化特征   总被引：5，自引：3，他引：5  

朱文斌  马瑞士  郭令智  孙岩  徐鸣洁  胡德昭  王锋 《大地构造与成矿学》2003,27(2):125-131

吐哈盆地中央构造带由火焰山构造和七克台构造组成。中央构造带形成于三叠纪晚期至侏罗纪早期,表现为伸展构造特征,生长断层上盘地层厚度明显大于下盘,并于断层上盘所在的台北凹陷形成沉降中心。晚侏罗世,由于拉萨陆块与欧亚大陆的碰撞作用导致吐哈盆地由伸展盆地转变为挤压盆地,中央构造带也于此时发生构造反转,由早期的伸展正断层转变为挤压逆断层。发生于55Ma的喜山构造事件对天山地区产生了深刻的影响,但影响时间略有滞后,大致发生在晚渐新世至早中新世,中央构造带即在此次构造事件中强烈变形,逆冲出露于地表。  相似文献   

Stochastic Structural Modeling   总被引：3，自引：0，他引：3  

Lars Holden  Petter Mostad  Bjørn Fredrik Nielsen  Jon Gjerde  Chris Townsend  Signe Ottesen 《Mathematical Geology》2003,35(8):899-914

A consistent stochastic model for faults and horizons is described. The faults are represented as a parametric invertible deformation operator. The faults may truncate each other. The horizons are modeled as correlated Gaussian fields and are represented in a grid. Petrophysical variables may be modeled in a reservoir before faulting in order to describe the juxtaposition effect of the faulting. It is possible to condition the realization on petrophysics, horizons, and fault plane observations in wells in addition to seismic data. The transmissibility in the fault plane may also be included in the model. Four different methods to integrate the fault and horizon models in a common model is described. The method is illustrated on an example from a real petroleum field with 18 interpreted faults that are handled stochastically.  相似文献   

Architecture of coastal and alluvial deposits in an extensional basin: the Carboniferous Joggins Formation of eastern Canada   总被引：1，自引：0，他引：1  

S. J. Davies  M. R. Gibling† 《Sedimentology》2003,50(3):415-439

Abstract The Joggins Formation was deposited in the Cumberland Basin, which experienced rapid mid‐Carboniferous subsidence on bounding faults. A 600 m measured section of coastal and alluvial plain strata comprises cycles tens to hundreds of metres thick. The cycles commence with coal and fossiliferous limestone/siltstone intervals, interpreted as widespread flooding events. These intervals are overlain by coarsening‐upward successions capped by planar‐based sandstone mounds, up to 100 m in width that represent the progradation of small, river‐generated delta lobes into a standing body of open water developed during transgression. The overlying strata contain sand‐rich heterolithic packages, 1–8 m thick, that are associated with channel bodies 2–3 m thick and 10–50 m wide. Drifted plant debris, Calamites groves and erect lycopsid trees are preserved within these predominantly green‐grey heterolithic sediments, which were deposited on a coastal wetland or deltaic plain traversed by channel systems. The cycles conclude with red siltstones, containing calcareous nodules, that are interbedded with thin sandstones and associated with both single‐storey channel bodies (1–1·5 m thick and 2–3 m wide) and larger, multistorey channels (3–6 m thick) with incised margins. Numerous channel bodies at the same level suggest that multiple‐channel, anastomosed river systems were developed on a well‐drained floodplain. Many minor flooding surfaces divide the strata into parasequences with dominantly progradational and aggradational stacking patterns. Multistorey channel bodies are relatively thin, fine grained and modestly incised, and palaeosols are immature and cumulative. The abundance and prominence of flooding surfaces suggests that base‐level rise was enhanced, whereas the lack of evidence for abrupt basinward stepping of facies belts, coupled with the absence of strong fluvial incision and mature palaeosols, suggests that base‐level fall was suppressed. These architectural features are considered to reflect a tectonic architectural signature, in accordance with the high‐subsidence basinal setting. Evidence for restricted marine influence and variation in floral assemblages suggests modulation by eustatic and climatic effects, although their relative importance is uncertain.  相似文献   

用卫星高光谱数据提取江西德兴铜矿矿山废水的pH值污染指标     

刘圣伟  甘甫平  王润生 《地质通报》2003,(Z1)

在对德兴铜矿矿山废水的光谱特征深入分析研究的基础上,总结了不同类型水体(酸性水、碱性水以及河流水)的特征光谱,并利用地物谱特征开展矿山废水pH值污染指标提取研究。针对水体光谱反射率低、特征光谱不明显的特点,采用矿区卫星Hyperion高光谱数据,应用ISA算法和掩膜技术识别出水体分布并进一步与MNF变换有效结合,根据波段散点图进行不同pH值水体的有效分割。为矿山废水污染的诊断和监测提供了新技术和理论支撑。  相似文献   

柯树背岩体的副矿物特征及地质意义   总被引：1，自引：1，他引：1       下载免费PDF全文

胡恭任  刘丛强  陈培荣  于瑞莲 《地球学报》2003,24(3):231-236

本文详细研究了柯树背岩体的岩石学及副矿物学特征，研究发现F9大断裂以西部分(西体)与F9大断裂以东部分(东体)在岩性、矿物组成、副矿物特征、锆石群型特征上存在很大差别，副矿物特征、锆石群型特征指示东体与寨背岩体类似，为同熔系列花岗岩；西体为重熔再生岩浆成因的改造型花岗岩。这一认识对于该区的铀金找矿具有一定的指导意义。  相似文献   

广西2002年度气候特点及其影响评价     

李艳兰  黄雪松  罗莹 《气象研究与应用》2003,24(1):26-32

2002年度(2001年12月～2002年11月),广西各地平均气温17.1～23.5℃,大部地区偏高0.3～1.2℃。年度降水量1035.0～2897.1mm,桂东大部偏多1～4成,桂西大部正常。日照时数1019～2323h,大部地区偏少10～412h。2002年度主要气候事件以春旱、暴雨洪涝、热带气旋、寒露风较为突出,年度内气候条件对各行业的影响有利有弊。  相似文献   

山东省龙卷风发生的气候特征   总被引：9，自引：0，他引：9  

薛德强  杨成芳 《山东气象》2003,23(4):9-11

根据藤田-皮尔森强度分类法对1950年～2000年山东省出现的351次龙卷风进行分类，其中F0级61次，F1级256次，F2级34次。山东半岛、鲁中、鲁南出现次数较多，鲁西北较少。1950～1972年发生次数明显高于1973～2000年。龙卷风发生存在明显的季节变化，夏季发生较多。龙卷风主要发生于午后至傍晚，多数龙卷风仅能维持几分到十几分钟。  相似文献