Stochastic energy analysis of seismic isolated bridges   总被引：1，自引：0，他引：1  

Giuseppe Carlo Marano  Sara Sgobba 《Soil Dynamics and Earthquake Engineering》2007,27(8):759-773

In this paper, a parametric stochastic analysis of isolated bridge is proposed with the aim to assess isolation performance and to investigate effects of energetic influence on protection efficiency. The analysis has been carried out in terms of two stochastic parameters of pear-deck maximum displacement and hysteretic energy response, of which a qualitative trend has been observed.Isolated bridge is described by a simple two degree of freedom (TDoF) Bouc–Wen hysteretic model, which has been introduced for its intrinsic ability in reproducing a wide range of real devices behavior. With the aim of taking into consideration intrinsic stochastic nature of seismic events, the ground motion and the structural response have been described by random vibration approach. Results obtained show that protection achieved by shifting structural natural period and reducing input energy by devices dissipation have counteracting effects if related to deck lateral displacement.  相似文献   

Paleoseismological evidence for non-characteristic behavior of surface rupture associated with the 2004 Mid-Niigata Prefecture earthquake, central Japan     

Tadashi Maruyama  Katsutoshi Iemura  Takashi Azuma  Toshikazu Yoshioka  Masaru Sato  Riichiro Miyawaki   《Tectonophysics》2007,429(1-2):45-60

The 2004 Mid-Niigata Prefecture earthquake sequence (mainshock magnitude, M_JMA 6.8), which occurred in an active fold-and-thrust belt in northern central Japan, generated a small thrust surface rupture (< 20 cm of vertical displacement) along a previously unmapped northern extension of the active Muikamachi–Bonchi–Seien fault zone, on the eastern margin of the epicentral region. To better understand past seismic behavior of the rupture, we conducted a paleoseismic trenching study across the 10-cm-high west-side-up surface rupture at the foot of a pre-existing 1.8-m-high east-facing scarp, which probably resulted from past earthquake(s). A well-defined west-dipping thrust fault zone accompanied by drag folding and displacing the upper Pliocene to lower Pleistocene strata and the unconformably overlying upper Pleistocene (?) to Holocene strata was exposed. The principal fault zone is connected directly to the 2004 surface rupture. From the deformational characteristics of the strata and radiocarbon dating, we inferred that two large paleoseismic events occurred during the past 9000 years prior to the 2004 event. These two pre-2004 events have a nearly identical fault slip (at minimum, 1.5 m), which is ≥ 15 times that of the 2004 event (∼ 10 cm). These paleoseismic data, coupled with the geological and geomorphological features, suggest that the 2004 event represented non-characteristic behavior of the fault, which can potentially generate a more destructive earthquake accompanied by meter-scale surface displacement. This study provides insight into the interpretation of past faulting events and increases our understanding of rupture behavior.  相似文献   

基于蚁群行为仿真的影像分割   总被引：1，自引：1，他引：1  

郑肇葆 《武汉大学学报(信息科学版)》2005,30(11):945-949

提出以像元的灰度值、能量值和分形维作为信息素的蚁群行为仿真的图像分割原理和方法。由该方法对3幅航空影像进行图像分割试验,得到图像的粗分割。利用本文提出的精处理方法,得到图像分割的最终结果。采用标记点量测的方法,对分割图像作出质量评价,结果表明,该方法很有应用前景。  相似文献   

钢结构建筑轻质砂加气混凝土墙体的抗震性能试验研究   总被引：1，自引：2，他引：1  

李国强  方明霁  陆烨 《地震工程与工程振动》2005,25(2):82-87

本文介绍了一钢结构建筑轻质砂加气混凝土外墙板和砌块填充墙的足尺模型振动台试验，并通过试验结果分析，重点研究砌块填充墙的抗震性能、砌块墙体与墙板墙体抗震性能的对比以及两者对钢结构动力特性的影响对比。文中得出了与带墙体钢结构抗震设计有关的结论。  相似文献   

旅华外国游客旅游消费偏好的实证研究   总被引：12，自引：0，他引：12  

马耀峰  梁旺兵  苏红霞  杨瑾 《地理与地理信息科学》2005,21(6):96-99

为了探索旅华外国游客的旅游消费偏好规律,利用国家基金项目组2004年7-8月在全国6个旅游热点城市的旅游市场调查资料,通过定性、定量分析得出旅华外国游客的旅游决策可控 因素和旅游消费偏好行为;提出旅游偏好既和外国游客本身特质有关,又与目的地国的国度 形象、旅游宣传促销密切相关;形象导向模式在一定程度上决定了游客的选择偏好. 研究表明旅华外国游客具有明显旅游消费偏好行为.  相似文献   

Nonlinear identification of the soil response at Dahan downhole array site during the 1999 Chi–Chi earthquake     

O. Pavlenko  C.-H. Loh 《Soil Dynamics and Earthquake Engineering》2005,25(3):241-250

Records of the 1999 Chi–Chi earthquake, provided by the Dahan downhole array were analyzed, and nonlinear hysteretic stress–strain relations in the soil layers were estimated by the method previously used for studying the response of soils during the 1995 Kobe and the 2000 Tottori earthquakes. The obtained models of the soil behavior were applied for evaluating changes of the shear moduli in the soil layers and for the nonlinear identification of the soil behavior at Dahan site during the Chi–Chi earthquake. We found that reduction of the shear moduli in the soil layers did not exceed 5%, and the soil response was virtually linear. The content of the nonlinear components in the soil response was about 5% of the intensity of the response, and it was mostly due to the odd-order nonlinearities. A similarity in the stress–strain relations describing the behavior of soils during the 1995 Kobe earthquake, the 2000 Tottori earthquake, and the 1999 Chi–Chi earthquake was found, which indicates the possibility to describe the behavior of similar types of soils at different sites by similar stress–strain relations and predict soil behavior in future earthquakes.  相似文献   

Relation of deformation behavior with precipitation and groundwater of the Babaoshan fault in Beijing     

黄辅琼  陈颙  白长清  张晶  晏锐  杨明波  兰丛欣  张晓东  江在森 《地震学报(英文版)》2005,18(6):686-696

Introduction The surface of the Earth is the main location where the fluid strongly interacts with solid, and where the atmosphere, hydrosphere, biosphere, and lithosphere strongly interact. Obviously, fault zones as the channels of fluid (water) flow are the focus area of this strong interaction. Earth-quakes, as the products of tectonic activity, occurred near or on the fault zones, can be regarded as one of the results of this strong interaction. Bolt (1999) pointed out that if there were …  相似文献   

重庆市农村剩余劳动力转移的经济行为分析——以万州龙宝区为例   总被引：2，自引：0，他引：2  

彭国川  田洪 《地域研究与开发》2001,20(1):83-86

市场经济下的农户是经济人，其行为目标是为了追求家庭收入的最大化，文章通过对重庆农村家庭收入目标和行为决策的分析，建立了农村劳动力外出就业决策的理论模型，运用主成分分析法得出了影响重庆市农村劳动力外出就业的主要因素。  相似文献   

复杂加载路径下堆石料动力本构模型及数值模拟   总被引：6，自引：0，他引：6  

吴兴征  栾茂田  李相菘 《世界地震工程》2001,17(1):9-14

采用所发展的亚塑性边界面模型，对堆石料在不同固结应力状态、排水条件和加载方式下的典型试验进行了数值模拟分析。在本构模型的数值实施中，联合应用自适应多步回退欧拉积分规律和局部迭代加快了迭代收敛的速度，提高了积分精度，进而编制了计算程序TESTROCK。数值模拟结果与已有试验成果的对比分析表明，该模型能够合理、有效地反映堆石料在复杂加载路径下的变形和强度特性，为深入揭示堆石料变形和孔隙水压力的发展特性和进行高混凝土面板堆石坝的非线性耦合静动力分析提供了理论基础。  相似文献   

基岩风化带的工程地质特性与缩小防护煤柱机理研究   总被引：1，自引：0，他引：1  

刘效云  杨本水等 《中国煤田地质》2001,13(4):41-42,52

以大量实验数据和现场测试资料为依据，研究了隐伏煤田基岩风化带岩体的分布特点及工程地质特性，重点论述了邻近风化带开采的覆岩破坏和矿山压力显现规律以及缩小防护煤柱的机理，为类似矿井的资源回收与安全开采提供了依据。  相似文献