震后建筑进度BIM估计模型改进

传统震后建筑进度BIM估计模型,未考虑精益管理对建筑施工的影响,造成建筑成本浪费较多,影响后期建筑施工进度。本文构建基于BIM和精益管理的震后建筑进度评估模型,根据模型细分震后建筑进度评估过程,在此基础上根据BIM实施三维算量,采用进度计划编制子模型获取各分项工程量,确定建筑施工的主要进度计划,实现对建筑进度计划的编制;通过虚拟施工和现实施工两条主线,利用进度控制子模型实现对施工状态的模拟和精益管理。以此为基础,进行挣值分析比较计划施工成本、实际施工成本和挣值曲线,获取震后建筑的施工进度与成本情况。实验结果说明,本文构建的模型可对震后建筑进度和工程成本进行精准估计,能够减少成本浪费。     

BIM技术在震后灾区居民装配式建筑设计中的应用

为解决震后灾区地形复杂,建筑建设困难问题,将BIM技术应用在震后灾区居民装配式建筑设计中,基于BIM体系框架设计震后灾区居民装配式建筑建造流程,通过设计阶段、工厂预制阶段、运输阶段以及安装阶段完成震后灾区居民装配式建筑项目的构建,采用Revit软件和Tekla软件构建装配式建筑的建筑模型和结构模型,利用BIM技术的可视化、参数化以及高合作性优势,优化模型以及构件,再通过Navisworks软件依据建筑模型实现建筑工程的碰撞检测,减少施工过程中的变更,降低建筑工程施工成本;通过基于BIM的震后建筑进度管理模型,实现建筑进化计划编制以及进度控制;利用Lumion软件输入工程材质实现建筑项目的实时漫游,直观了解装配式建筑效果。     

BIM技术在地震灾后重建房屋建筑工程造价控制方法中的研究

基于系统动力学控制重建房屋造价结果时,缺乏对地震后建筑成本数据的归集和处理过程,无法深入控制各个成本环节,控制效果差。深入研究地震灾区灾后重建房屋建筑工程造价控制方法,采用引入BIM技术的重建房屋建筑工程造价控制模型,通过该模型对建筑工程的造价成本进行预算,依据预算结果使用BIM技术归集成本数据后使用BIM数据平台存储和控制归集后的成本数据。通过造价控制体系实现地震灾后重建房屋建筑工程造价的有效控制,并采用财务ERP系统把控每个成本环节,实现工程造价优化控制。实验结果显示,该研究方法预算造价值与实际造价值差距小,约为1 000元,并在控制所有费用后节省了原始预算造价费用的11.91%,说明该方法造价控制效果好,能够有效节约震后灾区重建房屋工程造价成本。     

准实时地震灾情综合评估系统的研发

震后如何快速获取灾区震情信息、准确评估地震灾情,是震后应急救援的关键问题。本研究从县市地震灾害应急救援需求出发,开发了准实时地震灾情综合评估系统,基于MEMS强震台网的强震观测数据、县域承灾体基础数据和手机终端获取的震后地震现场实时灾情信息,综合采用承灾体地震易损性分析方法和灾情动态修正算法,实现了县市地震灾区灾情准实时评估,为灾区地震应急指挥、救援和辅助决策提供科学依据。     

利用遥感图像对震损建筑结构变形检测的识别研究

为识别震后建筑变形损坏状况,提出震损建筑结构变形检测的遥感图像识别分析方法。利用无人机采集震灾区域的遥感图像,将建筑结构变形检测问题转变为构件间坐标测量问题,提取所采集遥感图像中样本矢量点,将其划分为不同种类区域,在此基础上对图像进行聚类分割,以获得震后图像的不同类别建筑结构特征,实现识别不同样本矢量点的地震受灾情况。通过实验分析发现,所提出的图像识别分析方法在一定程度上可以识别出损毁建筑物,但仍需要进一步研究,以提高其识别精度。     

基于模糊数学的震后建筑火灾危险性评估模型研究

震后建筑火灾涉及因素多,传统评估模型忽略了建筑截面温度变化与建筑形变程度的影响,导致评估准确度较低。为解决此问题,通过模糊数学方法建立震后建筑火灾危险性评估模型。在建立判断矩阵的基础上,获取评估模型权重,确定隶属度矩阵;通过确定震后建筑火灾后截面温度变化评估的因素集与评语集,进行单因素评判,为评估因素集中的因素赋予权重,实现一级模糊评估;再将一级评估结果作为二级评估的单因素评估,结合模糊数学分析完成对震后建筑火灾危险性的评估。实验中以建筑横梁截面温度变化与形变程度为指标,对震后建筑火灾危险性进行评估。实验结果表明,采用所提模型进行危险性评估,震后在发生火灾时建筑结构受到火灾影响,横梁截面温度越高,导致形变程度越大,危险性更高,模拟实验结果与实际情况更加接近,所提模型评估精度高。     

三维测量光流恢复算法结合BIM对震后建筑倾斜度测量的研究

震后危险建筑倾斜度的移动测量过程较为复杂,常规测量方法会存在对称偏差。为了提高震后危险建筑倾斜度测量的准确性,设计三维测量光流恢复算法结合BIM的震后建筑倾斜度测量方法。采用BIM技术采集并整合全部建筑倾斜度信息,构建危险建筑信息模型;采用三维测量光流恢复算法获取所构建建筑信息模型内多个目标特征点,设计震后危险建筑倾斜度的三维测量模型。仿真实验说明,所提方法测量震后危险建筑三维坐标值误差率均小于0.4%,平均评估时间仅为2.5 s,说明该方法可提高建筑倾斜度评估效果。     

钢结构建筑钢板外部震动下承载力有限元分析

传统钢结构建筑钢板外部震动下承载力分析方法,是基于总体钢板结构以及受力特征,获取载荷同振动频率间的关系,实现承载力的分析,并未对钢板同混凝土间的应力-应变关系进行分析,导致分析结果存在较高的偏差。提出新的钢结构建筑钢板外部震动下承载力有限元分析方法,将钢结构建筑钢板横截面简化成混凝土的矩形截面和波纹钢板的工字形梁截面,采用ANSYS有限元软件中的CONTACI2接触单元仿真分析钢板同混凝土两者的影响,分析混凝土及钢板的应力-应变关系、界面模块的应力-滑移关系,采用力平衡迭代法获取外部震动下钢板荷载增量;在上述基础工作上采用有限元软件,对外部震动下钢结构建筑钢板实施有限元接触单元建模及承载力分析。实验结果表明,该方法能够实现钢结构建筑钢板外部震动下承载力有限元分析,并且分析结果具有准确性高和效率高的优点。     

基于共享数据平台的云南漾濞和青海玛多地震应急物资配置分析

灾后信息缺失易导致应急决策失效和调整困难,针对2021年5月下旬云南大理州漾濞县及青海果洛州玛多县分别发生6.4级和7.5级地震,本文设计了一种基于共享数据平台实时信息的灾后应急物资配置方法。该方法主要利用基于地震台网发布灾害信息确定灾区范围,基于人口分布数据估测需求与供给缺口,并通过高德开放平台接口获取交通态势确定可供通行的路网与实时最优运输路径,利用这些实时信息做出震后物资分配调度快速决策。通过漾濞和玛多地震案例分析结果显示:通过震后第一时间数据,可快速处理收集数据并进行供需评估与物资调度辅助决策。当灾区存在供需缺口,利用相邻县物资可维系震后短期内物资需求;对于物资运输,实时更新的信息可为其选择最佳路线。本方法为震后应急物资动态配置中决策实时更新与调整提供依据,为日后地震应急响应提供参考。     

考虑修/改造方案优选的桥梁震后可恢复性和可持续性研究

为了实现基于性能的桥梁结构全寿命设计,针对某桥梁修/改造方案案例,提出了桥梁震后可恢复性和可持续性的评估方法框架。针对2种备选的桥梁修/改造方案,建立考虑时效的时变易损性曲线,通过计算桥梁不同损伤状态的超越概率和震后恢复时间,实现对桥梁震后可恢复性能的评估。基于不同地震动强度的震后恢复时间计算社会成本、环境成本和修复成本,考虑模型参数不确定性,使用蒙特卡洛模拟对社会、环境和经济指标进行定量分析,实现对桥梁震后可持续性的评估。结果表明:不同的备选修/改造方案震后可恢复性能差异较大,提出的评估计算方法为修/改造方案优选提供了理论支撑;并且根据经济、社会、环境影响因素,由可持续性三个指标导出的成本差异,可更好地优选修/改造方案。     

高层抗震结构造价的改进控制模型研究——基于一恢复重建高层的实例分析

采用WSR模型分析建筑工程抗震结构造价控制问题时,存在造价控制效果差的弊端。通过设计的高层建筑工程抗震结构造价控制模型构建造价控制的递阶层次结构,获取高层建筑工程造价控制的多种方案,从多种方案中通过三标度法和权重向量法获取造价控制的最优方案;另外采用质量量化QoS调度方法进行高层建筑工程造价效益控制约束均衡设计,以获取最优方案中高层建筑工程抗震结构造价控制的结果。实验结果表明,所设计模型可有效分析高层建筑的质量化特征,可改进控制高层抗震结构工程造价,预估消耗成本可控制在1.8万元以下,且分析耗时均值为0.15 h,具有节省成本和效率快的优势,控制效果较好。     

Approximating peak responses in seismically isolated buildings using generalized modal analysis

Although the ability to simulate accurately the detailed behavior of nonlinear isolation bearings and the effects of this nonlinearity on dynamic response of the isolated building is desirable, such detailed analyses are not feasible during initial design stages when bearing properties are being selected. However, it would be very beneficial to be able to estimate accurately key engineering demand parameters at the early stages of design to understand the dynamic response characteristics of the isolated structure and to balance and optimize the bearing and structural characteristics to achieve the performance goals set for the building. Unfortunately, classical modal response spectrum analysis methods do not provide accurate results for problems with large, nonclassical damping, as is characteristic of isolated buildings. To find a method capable of predicting peak building responses even with large nonclassical damping, generalized modal response spectrum analysis is implemented. The responses of several buildings having different heights and isolated by linear viscous as well as triple friction pendulum and single friction pendulum isolation systems are investigated. Generalized modal response spectrum analysis methods were found to give significantly better predictions for all systems compared with classical methods. The behavior of buildings isolated with single friction pendulum systems exhibiting sudden changes in stiffness could not be well predicted by either general or classical modal response spectrum analysis when effective damping was increased. Copyright © 2013 John Wiley & Sons, Ltd.     

基于多元线性回归方法的砌体结构加固费用估算模型研究

为建立适用于砌体结构的加固费用快速估算模型,对中国陕西、山西、四川等地砌体结构建筑物的历史加固费用及相关建筑参数进行统计,建立涵盖35栋砌体结构建筑物加固费用估算模型的回归与验证数据库,同时对影响加固费用的各建筑参数作显著性分析,并基于后向消去的多元线性回归方法,利用SPSS统计分析软件对已采集的加固数据进行回归,得到4个费用估算模型;按照相应评价准则分别对各模型进行评价,提出一套最优的砌体结构加固费用快速估算模型,并对该回归模型进行验证分析。回归得到的费用估算模型满足精度要求,具有一定的工程应用价值。     

适用于结构时程分析法的输入地震波

本文对建筑结构抗震设计时程法所需的输入地震波提出一种基于规范反应谱的、与设防烈度、场地条件、设计近震或远震、结构自振特性有关的选择原则和方法。按远、近震和四类场地标定了反应谱、延性谱和积累损伤谱。通过对六幢不同高度的剪切和弯曲型结构模型的弹塑性分析,表明离差很小。建议在进行结构时程法分析时,按地震加速度反应谱特定的分布规律选择4条加速度记录作为输入计算。两个实际的例子表明按上述方法计算的结果与按底部剪力法计算的结果基本相符。     

Fuzzy rule based seismic risk assessment of one-story precast industrial buildings

Efficient tools capable of using uncertain data to produce fast and approximate results are more practical in rapid decision-making applications when compared to conventional methods. From this point of view, this study introduces a risk assessment model for one-story precast industrial buildings by fuzzy logic which builds a bridge between uncertainty and precision. The input, output and relations of the fuzzy based risk assessment model(FBRAM) were determined by reference buildings. The Monte Carlo simulation method was used to handle uncertainties associated with the structural characteristics of the reference buildings. Section dimension, longitudinal reinforcement ratio, column height related to building elevation, confinement ratio and seismic hazard are regarded as input and the plastic demand ratio is considered as the output parameter by the mathematical formulation of strength and deformation capacity of the buildings. The supervised learning method was used to determine the membership function of fuzzy sets. Fuzzy rules of FBRAM were constructed from Monte Carlo simulation by mapping of inputs and output. FBRAM was evaluated by a group of simulated buildings and two existing precast industrial buildings. Comparisons have shown significant agreement with analytical model results in both cases. Consequently, it is anticipated that the proposed model can be used for the seismic risk mitigation of precast buildings.     

按现行规范设计的Ⅷ度区RC框架结构的倒塌性能评估

选取按照现行规范设计的既有建筑进行有限元建模,考虑地震动的不确定性对其进行大量增量动力分析(IDA),得到模型的IDA曲线簇。在此基础上对其进行地震需求概率分析和概率抗震能力分析,拟合得到结构的易损性曲线,据此对结构的倒塌概率进行定量评估,并比较基于非线性分析与性能评估软件PERFORM-3D的纤维模型和塑性铰模型的分析结果。结果表明:按照我国现行规范设计的钢筋混凝土(RC)框架结构,在预期的罕遇地震作用下倒塌概率较小,可满足"大震不倒"的要求;基于PERFORM-3D的截面纤维模型所得的RC框架结构,经非线性分析所得的倒塌概率相对保守,安全储备更高。     

A macro‐element model for inelastic building analysis

A three‐dimensional model for approximate inelastic analysis of buildings is presented herein. The model is based on a single macro‐element per building storey. The inelastic properties of the model are characterized by the so‐called ultimate storey shear and torque (USST) surfaces. Different algorithms for the construction of these surfaces, as well as their applications in building modelling, are presented and discussed. Two alternative procedures are developed to integrate the force‐deformation constitutive relationship of the macro‐elements. The first one follows the exact trajectory of the load path of the structure on the USST, and the second uses linear programming without ever forming the USST surface. The accuracy of the model and integration procedure is evaluated by means of the earthquake response of single‐storey systems. The model and integration procedure developed is finally used to compute the inelastic response of a seven‐storey R/C building. The results of this investigation show that the model proposed, although approximate, can be effective in estimating the inelastic deformation demand of a building. It also enables the engineer to capture and interpret important features of the three‐dimensional inelastic response of a structure even before performing any inelastic dynamic analysis. Copyright © 2000 John Wiley & Sons, Ltd.     

Inelastic seismic response of code-designed multistorey frame buildings with regular asymmetry

Based on an asymmetric multistorey frame building model, this paper investigates the influence of a building's higher vibration modes on its inelastic torsional response and evaluates the adequacy of the provisions of current seismic building codes and the modal analysis procedure in accounting for increased ductility demand in frames situated at or near the stiff edge of such buildings. It is concluded that the influence of higher vibration modes on the response of the upper-storey columns of stiff-edge frames increases significantly with the building's fundamental uncoupled lateral period and the magnitude of the stiffness eccentricity. The application of the equivalent static torsional provisions of certain building codes may lead to non-conservative estimates of the peak ductility demand, particularly for structures with large stiffness eccentricity. In these cases, the critical elements are vulnerable to excessive additional ductility demand and, hence, may be subject to significantly more severe structural damage than in corresponding symmetric buildings. It is found that regularly asymmetric buildings excited well into the inelastic range may not be conservatively designed using linear elastic modal analysis theory. Particular caution is required when applying this method to the design of stiff-edge frame elements in highly asymmetric structures.     

Evaluation of Rayleigh damping and its influence on engineering demand parameter estimates

The effects of Rayleigh damping model on the engineering demand parameters of two steel moment‐resisting frame buildings were evaluated. Two‐dimensional models of the buildings were created and response history analysis were conducted for three different hazard levels. The response history analysis results indicate that mass‐proportional damping leads to high damping forces compared with restoring forces and may lead to overestimation of floor acceleration demands for both buildings. Stiffness‐proportional damping, on the other hand, is observed to suppress the higher‐mode effects in the nine‐story building resulting in lower story drift demands in the upper floors compared with other damping models. Rayleigh damping models, which combine mass‐proportional and stiffness‐proportional components, that are anchored at reduced modal frequencies lead to reasonable damping forces and floor acceleration demands for both buildings and does not suppress higher‐mode effects in the nine‐story building. Copyright © 2012 John Wiley & Sons, Ltd.     

Seismic fragility assessment of low-rise stone masonry buildings

Many historic buildings in old urban centers in Eastern Canada are made of stone masonry reputed to be highly vulnerable to seismic loads.Seismic risk assessment of stone masonry buildings is therefore the first step in the risk mitigation process to provide adequate planning for retrofit and preservation of historical urban centers.This paper focuses on development of analytical displacement-based fragility curves reflecting the characteristics of existing stone masonry buildings in Eastern Canada.The old historic center of Quebec City has been selected as a typical study area.The standard fragility analysis combines the inelastic spectral displacement,a structure-dependent earthquake intensity measure,and the building damage state correlated to the induced building displacement.The proposed procedure consists of a three-step development process:(1) mechanics-based capacity model,(2) displacement-based damage model and(3) seismic demand model.The damage estimation for a uniform hazard scenario of 2% in 50 years probability of exceedance indicates that slight to moderate damage is the most probable damage experienced by these stone masonry buildings.Comparison is also made with fragility curves implicit in the seismic risk assessment tools Hazus and ELER.Hazus shows the highest probability of the occurrence of no to slight damage,whereas the highest probability of extensive and complete damage is predicted with ELER.This comparison shows the importance of the development of fragility curves specific to the generic construction characteristics in the study area and emphasizes the need for critical use of regional risk assessment tools and generated results.