A metadata model for collaborative experiments and simulations in earthquake engineering

Research projects in earthquake engineering yield a very large amount of complex data from experiments and computer simulations. Understanding and exchanging these complicated and voluminous data sets prompted the development of metadata models that document the processes of data generation, and facilitate the collaboration and exchange of information between researchers. The present metadata model was designed to document and exchange a large number of large data files in earthquake engineering, but is applicable to other fields of engineering and science. The model was conceived based on a series of former data models, which were unduly complicated and limited to few types of experiments. Simpler than its predecessors, the present metadata model applies to all kinds of earthquake engineering experiments. It was developed in the object-oriented framework using Protégé. Its applications are illustrated with examples from centrifuge experiments.     

GisFFE—an integrated software system for the dynamic simulation of fires following an earthquake based on GIS

Fires following earthquake (FFE) are dangerous secondary disasters occurring after large earthquakes, leading to severe property and life losses in certain cities with dense wooden buildings. In order to explore the complicated behavior of fire-spread and to assess the fire-induced losses after a large earthquake scenario, an integrated software system based on GIS (called GisFFE) was developed to perform a dynamic simulation of FFE. The purpose of this paper is to introduce the details of GisFFE, including its architecture, models and simulation flow, and to present a case study. The architecture of GisFFE consists of 4 components: an urban geo-database, a model library, a simulation center and outputs. The urban geo-database provides basic spatial and statistical data used in the GIS platform for FFE simulation; the model library contains three sub-models (ignition, fire-spread and fire-suppression models), which correspond to the three key stages involved in FFE; the simulation center serves as an operation center that integrates data and models; after the simulation is complete, statistical maps and charts are the resulting output.     

Remote Sensing Observations of Landslides and Ground Deformation from the 2004 Niigata Ken Chuetsu Earthquake

In recent years, major developments in remote sensing have made it possible to use these technologies to document the effects of earthquakes. Specifically, high-resolution satellite imagery and three-dimensional laser scanning (LIDAR) can provide important observations of earthquake damage that supplement traditional observations from field reconnaissance. The 2004 Niigata Ken Chuetsu earthquake provided an opportunity to use remote sensing to document the distribution of landslides in the epicentral region through the use of high-resolution satellite imagery and to document the detailed three-dimensional geometries of several failures using LIDAR. The satellite imagery was acquired the day after the earthquake, but at very large acquisition angles that resulted in image distortion. Nonetheless, the satellite imagery accurately identified the landslide distribution in the epicentral region, although the total area of landslides was underestimated by about 25% as compared with traditional aerial reconnaissance because of the large acquisition angle for the satellite imagery. Terrestrial LIDAR was used to collect three-dimensional data at several failure sites, including two large rock slides and a railroad tunnel portal affected by ground deformation. The LIDAR data allowed for precise measurement of failure deformations and geometries, and provided digital terrain models that could be archived and used in future analyses. In the future, satellite imagery and LIDAR, as well as other remote sensing technologies, will play an increasing role in documenting and understanding the effects of earthquakes.     

Reliability of an engineering system under a strong earthquake with application to offshore platforms

This paper presents a method developed for the performance evaluation of an engineering system during a strong earthquake. The seismic reliability of the system is evaluated by considering the different possible failure modes, and seismic reliability of the components of the system. The method is applied to the oil production system at the Statfjord Field in the North Sea. The objective of the analysis is to document the reliability of oil production from the field in the event of an exceptionally large earthquake, and to investigate the effect of spatial variation of earthquake loading parameters on the computed system reliability. It is shown that, with a realistic model of the spatial variation of earthquake motion, there is very little correlation between the earthquake loading parameters at different platform locations. The main consequence of this lack of correlation is that the computed failure probability of the oil production system under the design earthquake is about one order of magnitude smaller than the probability of failure of individual platforms at the Statfjord Field.     

工程勘察元数据研究

作为基础建设的首要环节,工程勘察通过对地形、地质及水文等要素的测绘、勘探、测试及综合评定,提供建设所需的基础资料与可行性评价。随着计算机技术发展和原始资料的积累,勘察信息的共享和知识的提取需要元数据描述和表达,借鉴地理空间元数据标准化研究成果,基于XML语言,组织工程勘察元数据信息服务模型。研究证明,基于XML提供工程勘察元数据服务是可行的、高效的。该方法同时为工程领域信息共享,知识提取等提供有意义的参考。     

黏滞阻尼器初始刚度的合理取值探讨

目前工程界关于黏滞阻尼器初始刚度的取值普遍较大,这与其实际性能差别较大。过大的初始刚度取值会大大高估黏滞阻尼器在风和地震下的耗能作用,使得结构设计偏于不安全。结合试验和有限元计算结果,验证了黏滞阻尼器加载刚度与其初始刚度数值上近似相等。结合一个工程案例,通过对非减震模型、不同减震模型的层间位移角、层间剪力、能量分布、附加阻尼比、滞回曲线的对比分析,阐述了黏滞阻尼器初始刚度的不合理取值可能会高估黏滞阻尼器的消能作用。     

基于Web的建设工程项目施工资料交互系统的设计研究

对应用于建设工程各参建方,达到远程监管、信息交互、施工资料管理的福建省建设项目施工资料交互平台展开详细描述。对施工资料交互系统功能进行介绍,在系统需求分析的基础上,确定了福建省建设工程项目施工现场信息交互系统的目标,明确定义了系统的主要功能,同时对施工资料交互系统架构进行了设计。     

复杂岩质边坡锚固工程地震敏感性分析

地震是使边坡及其支护结构产生变形破坏的诱发因素,地震敏感性分析对于边坡工程的优化设计具有重要意义。复杂岩质边坡具有不规则的破坏滑移面,岩土体结构复杂,其稳定性受地下水、地震等地质环境的影响。本文采用改进的Sarma边坡稳定性分析模型,探讨了复杂岩质边坡进行地震敏感性分析的方法,该方法不仅考虑了不规则滑面问题、坡面加固力问题,而且考虑了地下水和地震的作用。通过选择典型岩质边坡锚固工程进行实例分析表明,地震对边坡稳态的作用是十分显著的,它是边坡变形破坏最敏感的影响因素。该方法能够很好地揭示复杂岩质边坡工程稳定性对地震作用的动态响应,是边坡地震敏感性分析的有效方法。     

发震断层的永久位移概率评估方法

 基于Cornell地表地震动的概率方法,提出发震断层未来地震引起地表永久位移的概率分析方法,其中断层模型、地震发生模型、震级与破裂面的长度、宽度、地表位移之间关系的参数采用物探结果、震源运动学反演、历史地震资料、现场考察及测年确定。主要技术有2点：(1) 概率分析场点地震动是场点周围断层所有潜在地震的贡献,而场点的地表永久位移仅是该断层的贡献;(2) 场点所在断层发生的所有地震对场点的地震动均有贡献,而场点所在断层发生的少数地震才能对场点永久位移有贡献。应用提出的方法,结合海原断裂地震地质资料和地震活动性资料,给出2种特征地震模型下的不同概率水准的地震地表永久位移。发震断层不同概率水准下的地表永久位移评估为穿越断层的管线和桥梁工程提供基础数据,以便采取合理的抵抗永久地表位移措施,减小地震灾害带来的损失。     

地震数据质疑

地震数据在地震学,地震工程学及其它有关学科方面均有广泛用途,是一种基本数据,故其准确性至关重要.但目前的现状是,地震数据中有一部分的准确性较低,甚至存在差异十分悬殊的情况.经过检索,对一部分地震数据提出修正意见,以提高引用地震数据文献的科学性,使不正确的地震数据停止被引用.     

双塔连体结构抗震设计和研究

结合连体结构的应用，介绍了连体结构的分类和特点，探讨了连体结构模拟地震振动台试验研究现状，提出了双塔连体结构抗震设计要求，从而推广高层连体结构在工程中的应用。     

Deformation mechanism and stability evaluation for the left abutment slope of Jinping I hydropower station

There are very complicated engineering geological conditions in the left abutment slope of the Jinping I hydropower station with the stress-release opening of fractures along existing faults and where lamprophyre veins are present. Prior to the excavation for the dam, the slope generally consisted of a thick marble mass between fault f₅ and the free face. As a consequence of the removal of some of the marble to create the abutment, the stability of the slope would be reduced. The paper reports the stability assessments undertaken, based on engineering geological analysis and block theory and the results of the analysis of key rock masses under four conditions: natural, heavy-rain, earthquake and heavy-rain plus earthquake.     

水力–力学耦合的超固结非饱和土本构模型的隐式积分算法及其应用

超固结非饱和土经常出现于工程实践中,表现出复杂的力学性质。从已有的非饱和土水力–力学耦合的本构模型出发,将超固结的影响加入到了模型中,使模型可以考虑超固结对非饱和土力学性质的影响。超固结非饱和土本构方程的求解是一个复杂的非线性问题,给出了该超固结非饱和土水力–力学耦合模型的隐式积分算法和本构模型的一致切线模量,并对该算法进行验证,证明了该算法的正确性,最后采用该算法对某非饱和土质边坡在地下水位上升的情况下进行有限元分析。     

Peak Ground Acceleration Estimation by Linear and Nonlinear Models with Reduced Order Monte Carlo Simulation

Abstract: Estimation of the peak ground acceleration (PGA) is one of the main tasks in civil and earthquake engineering practice since it is an important factor for the design spectrum. The Boore–Joyner–Fumal (BJF) and the Crouse–McGuire formula are well‐known empirical models by estimating the PGA with the magnitude of earthquake, the fault‐to‐site distance, and the site foundation properties. It is obvious that a predictive model class with more effective free parameters often fit the data better. However, this does not imply that the complicated formula is more realistic since overfitting may happen when the formula has too many free parameters. In this article, 32 linear and 16 nonlinear predictive model classes are constructed and investigated. The Bayesian model class selection approach is utilized to obtain the most suitable predictive model class for the seismic attenuation formula. In this approach, each predictive model class is evaluated by the plausibility conditional on the data and it is proportional to the evidence which involves a high‐dimensional integral. This integral has closed‐form solution for the linear model classes. Analytic work was done to improve the original asymptotic expansion in this study. For the nonlinear model classes, the evidence integral can be reduced to two‐dimensional and then Monte Carlo simulation is utilized to evaluate the double integral. The most plausible model class is robust in the sense that it balances between the data‐fitting capability and the sensitivity to noise. A database of 266 strong‐motion records, obtained from the China Earthquake Data Center, is utilized for the analysis. The most plausible predictive model class and its updated model parameters are determined. It turns out that the most plausible model class is generally simpler than the full BJF empirical formula. In the case where no single model class has dominant plausibility, one can utilize the multi‐model predictive formula that is a plausibility‐weighted average of the prediction of different predictive models.     

基于多功能地震波孔压静力触探的唐山地区砂土液化特性再调查试验研究

 鉴于1976年唐山大地震后液化调查手段及液化评价方法研究的局限性,开展液化和非液化区的现场再调查是非常有用的。采用符合国际标准的多功能地震波孔压静力触探(SCPTu)在唐山及其邻近地区进行调查试验,为场地液化再调查提供近似连续的锥尖阻力、侧壁摩阻力、孔压及剪切波速数据。通过18个试验点的SCPTu、室内试验及历史震害调查资料的综合比较,对各场地现今的液化可能性进行分析,并对国内外常用的几种液化判别方法进行分析研究。国内规范法、国际常用的Robertson确定性方法及Moss概率方法的分析结果均表明,曾经发生过液化的场地现今仍然容易发生液化;基于CPTu的Robertson确定性方法及基于贝叶斯理论的Moss概率方法各有优缺点,均有完善的计算流程,前者在液化后场地沉陷及侧向大变形预测方面具有优势,后者可以给出各试验点的液化概率,进而服务于基于概率的工程抗震评估与设计;由于SCPTu试验技术在国内发展缓慢,现今基于SCPTu的几种国际常用液化评价方法在国内应用较少,也是今后在技术手段突破后急需加深研究的方向。     

混凝土宏观本构模型研究进展

近年来,随着结构工程的快速发展,对结构在罕遇地震和风载作用下的精准数值模拟与性能化设计提出了更高需求.结构工程中的混凝土属于准脆性材料,试验表明混凝土具有显著的受压软化、受拉软化、剪切软化和捏拢效应等特性.针对上述特性,概述了结构工程数值模拟中常用的6种混凝土数值模型,包括非线性弹性模型、脆性裂缝模型、弹塑性裂缝模型、...     

大型火电厂主厂房纵向框架-剪力墙结构抗震性能试验研究

框架 -剪力墙结构是应用较为广泛的一种结构体系 ,但对于大型工业厂房中的框架 -剪力墙结构 ,其抗震性能的研究还不够深入。通过对大型火电厂主厂房纵向框架 -剪力墙结构体系进行拟动力模型结构试验 ,研究它的受力特点、破坏过程及强度、刚度、变形、延性和耗能性能 ,并提出了改进结构抗震耗能性能的设计建议     

大连市某高层建筑风振和地震反应的主动质量阻尼(AMD)控制分析与设计

本文以大连市某大型高层钢筋混凝土结构为背景,进行了高层建筑结构抗风抗震的AMD主动控制分析和方案设计。首先,根据实际工程数据建立了结构动力分析的计算模型,编制了风荷载随机抽样程序,给出了用于分析的典型风荷载和地震波动荷载样本。其次,进行了脉动风荷载作用下AMD控制系统物理参数和控制算法软参数的优化分析,得到了AMD子系统的最优质量、刚度和阻尼等物理参数。然后,在AMD子系统取得最优参数的情况下,进行了结构脉动风荷载作用下和常遇地震作用下AMD主动控制的反应分析;计算结果表明,采用AMD主动控制系统可以使结构的风振加速度控制效果达40％以上,大幅度提高规范要求的风振舒适度,对常遇地震作用下位移反应的控制效果也可以达到40％左右。最后,仿真分析了AMD控制结构平动-扭转耦联振动的控制效果。此外,本文还给出了实际工程结构进行AMD主动控制设计的一般性步骤,可供类似高层建筑结构进行AMD主动控制分析和设计时参考。     

Seismic analysis of semi-gravity RC cantilever retaining wall with TDA backfill

The seismic behavior of Tire Derived Aggregate (TDA) used as backfill material of 6.10 m high retaining walls was investigated based on nonlinear time-history Finite Element Analysis (FEA). The retaining walls were semi-gravity reinforced concrete cantilever type. In the backfill, a 2.74 m thick conventional soil layer was placed over a 3.06 m thick TDA layer. For comparison purpose, a conventional all soil-backfill model was also developed, and the analysis results from the two models under the Northridge and Takatori earthquakes were compared. The FEA results showed that both models did not experience major damage in the backfill under the Northridge earthquake. However, under the Takatori earthquake, the TDA-backfill model developed substantially large displacement in the retaining walls and in the backfill compared with the soil-backfill model. Regions of large plastic strain were mainly formed in the TDA layer, and the soil over the TDA layer did not experience such large plastic strain, suggesting less damage than the soil-backfill model. In addition, the acceleration on the backfill surface of the TDA-backfill model decreased substantially compared with the soil-backfill model. If an acceleration sensitive structure is placed on the surface of the backfill, the TDA backfill may induce less damage to it.     

工程地震动模型化研究综述及展望（Ⅲ）：其它工程学模型与展望

综述了地震动的演变模型及其它工程模型，指出了目前工程地震支模型化研究的主要任务，对其发展方向及前景进行了展望。