多层砖房的震害概率

本文用统计分析的方法给出了多层砖房的宏观震害概率、砖墙体的破坏概率和房屋的倒塌概率.并以此为基础,提供了多层砖房抗裂抗倒设计计算的有关参数.还通过对现有多层砖房抗震能力的估计,指出按目前抗震规范设计的五、六层砖混结构房屋,在7度区的设防标准偏低.     

结构概率寿命估计

本文着重讨论了结构可靠度、结构寿命、结构概率寿命和设计基准期之间的相互联系，给出了结构概率寿命估计的方法。本文的研究可为结构设计基准期的合理确定和结构的耐久性设计提供一定的参考。     

一种估计结构面迹长的新方法及其工程应用

为了研究结构面迹长与其产状之间的概率关系。根据结构面交切测量窗口的几何条件与交切频度之间的概率关系，拓展了H-H迹长估计方法。建立了结构面平均迹长与其在测量窗口中视倾角的关系表达式。在此基础上,结合Laslett迹长估计方法，提出了广义H-H迹长估计方法，进一步完善了H-H方法，并通过工程实例证明了其正确性。该方法使用简单方便，有很高的推广价值。     

基于可拓-Markov沥青路面使用性能预测模型实现

根据目前路面管理系统路面使用性能模型以及存在的问题,提出采用可拓概念区间化路面破损状况指标PCI的优、良、中、差划分,形成沥青路面在综合作用下的Markov过程,利用最小二乘法估计一步转移概率矩阵,从而建立PCI单指标评价可拓-Markov预测模型,并通过实例研究证实了可拓一Markov预测模型的优势。     

串、并结构体系可靠度分析及失效概率界的估计

本文用串、并联结构的可靠度理论,对静定和超静定结构体系进行了可靠性分析的研究,并讨论了失效概率界限的估计问题.     

在结构工程中混凝土非破损测试技术的应用与展望

在我国各类工程建设中混凝土结构占据着主导地位,每年结构混凝土量估计可达1亿立方米以上,数量和规模都十分可观,因此对结构混凝土强度与缺陷进行非破损检测,对保证工程质量具有重要的意义。长期以来,对混凝土和钢筋混凝土结构     

少筋砼大板结构抗侧力破损试验的计算机模拟方法

本文将过去仅用于弹性结构计算的连续化分析法,推广应用于弹-塑性结构计算,利用计算机来模拟结构试验,逐步计算出结构的破损过程。本文方法与现有的离散化有限元法相比,具有输入数据简单,运算速度快,大量节省计算机内存的优点。它与大型结构试验(四层1/2缩尺模型破损试验)进行对比验证,表明本文方法的计算结果与试验结果基本符合。     

基于实测样本值和Bayesian方法的服役结构抗力随机时变模型

分析了服役结构可靠性计算中的抗力随机时变性影响因子 ,研究了基于样本值的抗力概率特性的Bayesian方法。提出了基于检测的样本值的服役结构抗力的随机时变模型 ,可较为简便和有效地进行服役结构可靠度分析中的抗力估计。     

新疆阿拉尔地区市政道路病害成因及对策探讨

针对阿拉尔地区市政道路病害,统计了该地区不同结构层次设计的道路出现的破损情况,分析了造成主要病害的成因,为该地区城市道路的设计和现有病害的维修处理提供了一些可供参考的基本资料。     

排水管道结构性修复用内支架有限元计算及试验研究

现有的排水管道非开挖修复技术并不能解决破损管道结构承载能力下降的问题。为解决此问题,本文主要研究了一种用于排水管道结构性修复的管道内支架,该型内支架采用开合管片的设计,使其与原管道结构共同受力。通过拼装结构设计,简化修复工艺。经有限元计算及荷载试验验证,该型管道内支架能有效增强破损管道的承载能力,为需要结构补强的管道修复提供参考依据。     

既有网格结构损伤检测与模拟方法研究进展

网格结构在使用过程中会产生不同程度的损伤,损伤的累积会导致结构承载性能的降低甚至倒塌.基于现有研究成果,首先阐明了结构损伤检测过程中样本选取方法的研究进展与不足,指出了概率抽样方法的合理性与局限性;在结构损伤的参数化表征方面,总结了基于损伤力学与断裂力学等研究方法的成果,指出了不同方法在应用过程中面临的问题;在结构损伤...     

Subjective probabilities for earthquake damage and loss

This paper presents a method for developing consensus probability distributions of damage from subjective probability densities provided by individual experts. The method employs Bayesian statistical theory and incorporates weighting of expert judgements in evaluating the consessus distributions. Earthquake ground motion vs. damage relationships are developed in the form of damage probability matrices using Gaussian quadrature methods. The main advantage of this approach over existing distribution discretization techniques is that no error is introduced in the mean value of the random variable and errors in the variance are reduced significantly with even a small number of value-probability pairs. As a consequence, expected loss estimates obtained by the proposed method contain no error due to discretization. The results from this paper are particularly useful for forecasting damage and losses in geographical areas with large numbers of structures and with a variety of engineering characteristics.     

Limit states design in geotechnical engineering

The paper outlines the ultimate and serviceability limit states in geotechnical engineering practice. The magnitude of conventional partial and total safety factors in earthworks, earth retaining structures and foundations are discussed in terms of the reliability of the subsoil and loading conditions and the probability and seriousness of failure of the structure during its service life. The serviceability of structures and foundations are treated on the basis of empirical damage criteria related to relative rotation and deflection ratios of foundations supporting different types of buildings and engineering structures.     

Effect of structural uncertainty on seismic response of steel moment-resisting frames equipped with tuned mass dampers

Tuned mass dampers (TMDs) can be used to absorb the input energy of the applied loads, and reduce the response of building frames. However, inherited uncertainties in structural characteristics of building frames can significantly affect their response and counteract the effectiveness of vibration absorbing devices such as TMDs. In this study, by calculating cumulative damage indices for stories of the structure, failure probability of two steel moment-resisting frames equipped with TMDs has been studied in presence of uncertainty in characteristics of the structure. Cumulative inelastic deformation of structural elements in each story has been used to calculate the damage representative of that story, based on weighted average approach. Even though the cumulative response of the deterministic model of the structures is reduced by installing TMDs, the results of the numerical simulations on the probabilistic response of the sample structures indicate that for the records that cause excessive damage in the lower stories of the structures, the effect of TMDs on failure probability of the structure can be detrimental.     

Assessment of ROC curves for inspection of random fields

Inspection by non-destructive testing (NDT) techniques of existing structures is not perfect and it has become a common practice to model their reliability in terms of probability of detection (PoD), probability of false alarms (PFA) and receiver operating characteristic (ROC) curves. These results are generally the main inputs needed by owners of structures in order to achieve inspection, maintenance and repair plans (IMR). The assessment of PoD and PFA is even deduced from intercalibration of NDT tools or from the modelling of the noise and the signal. In this last case when the noise and the signal depend on the location on the structure PoD and PFA are spatially dependent. This paper presents how to define PoD and PFA when damage and detection are stochastic fields or spatially dependent. Corrosion of coastal structures in harbours is considered for illustration and ROC curves are deduced. Identification of probability density functions on polynomial chaos is shown to be more suitable than predefined probability distribution functions (pdf) in view of fitting noise and signal plus noise distributions.     

钢筋混凝土框架结构的损伤状态相关余震易损性分析

一次主震过后通常伴有多次余震发生,由于主、余震间隔时间较短,主震损伤结构通常要遭受进一步的余震作用.为了评估震损结构的余震安全,提出了一种损伤状态相关的余震易损性分析方法.该方法采用有限次整体调幅的主余震序列作为输入,利用Park-Ang指数描述结构在主余震序列作用下的主震损伤和累积损伤,基于logistic回归方法生...     

基础隔震大跨异形钢连廊连体结构地震易损性分析

针对地震中大跨连廊与主体结构连接处容易破坏的特征,以某大跨异形钢连廊连体结构为研究对象,开展基础隔震与非隔震连体结构的地震易损性对比分析.首先,对原连体结构进行基础隔震设计,并采用有限元软件SAP2000分别建立隔震与非隔震连体结构的数值模型.然后,定义隔震连体结构中框架-剪力墙结构、连廊橡胶支座端、连廊预埋锚固端和基...     

基于地震易损性解析函数的概率地震风险应用研究

在采用全概率方法的基于性能的地震工程研究中,定量反映地震作用和工程结构中存在的不确定性是研究的关键。利用地震易损性和地震风险的概率解析函数,针对一栋按我国相关规范设计的五层三跨钢筋混凝土框架结构进行了地震易损性分析和风险评估。采用100条实际地震动作为输入以考虑地震动的不确定性,提出了基于控制变换拉丁超立方体抽样技术的随机Pushover方法以考虑结构不确定性对其抗震能力的影响。结果表明：算例结构在50年内发生完全破坏的概率不超过2%,发生严重破坏的概率不超过10%,发生轻微破坏的概率基本不超过63.2%,基本满足我国“小震不坏、中震可修、大震不倒”的三水准要求。     

Probabilistic assessment of earthquake insurance rates for important structures: Application to Gumusova–Gerede motorway

A probabilistic model is presented for the assessment of the earthquake insurance rates for important engineering structures, for which the seismic losses could be quite significant. The proposed model is used to estimate the earthquake insurance premiums for the structures taking place in the Bolu Mountain Crossing in the Gumusova–Gerede motorway Section, Turkey. The model requires two types of studies, namely: seismic hazard analysis and estimation of potential damage to structures based on damage probability matrices (DPM). The computations are carried out according to the proposed model by using the seismic hazard results and the best estimate DPM’s developed in the study and the annual pure risk premiums are obtained for the different components of the motorway system by making a distinction between sections completed and sections under construction.