超高层建筑结构优化过程中的环境成本计算

近年来中国大陆掀起了超高层建筑的兴建热潮。超高层建筑体量巨大,其碳排放和能源消耗对环境有显著影响。在评估和优化超高层建筑的全生命周期环境成本时,提出了一个全新的全生命周期模型。新模型有两大特征：首先,同时考虑了建筑材料的空间分布与时间特征;其次,把单尺度生命周期概念拓展到多尺度生命周期概念,以从更多角度来研究碳排放情况。建立了一个基准超高层建筑模型来阐释对新模型的应用。根据初步研究结果,应用新方法可以选择出更优化的结构设计方法,以最大程度减少碳排放量。     

基于EBS的水利枢纽工程全生命周期费用结构体系研究

全生命周期费用结构体系是工程项目全生命周期费用管理的重要方法之一。在建立面向元素或构成部位的水利枢纽工程系统分解结构的基础上,提出了由二维费用结构矩阵和成本映射模型构成的水利枢纽工程全生命周期费用结构体系。应用此方法,可以在不同的层次组织汇总项目费用信息,对项目费用进行层次分析和控制,可以在项目不同阶段对任意层次的费用控制单元的费用要素进行管理,实现全生命周期费用的优化管理。     

建筑热设计优化经济性分析及案例研究

针对建筑早期设计阶段的建筑热设计优化方案的经济性评价,从全生命周期的角度提出了基于费用年值及追加投资回收期的经济性评价方法。结合工程实例,采用上述经济性评价方法选择确定了经济性最佳的建筑热设计优化方案,并运用能耗分析软件对该方案及原有热设计方案的建筑能耗进行模拟,同时对上述2个方案的全生命周期内的经济性进行对比。对比结果表明,前者相对于后者更有利于建筑项目获得较高的经济效益和环境效益。     

450m以上超高层商业建筑工程造价确定与控制

随着我国市场经济的快速增长,我国各地对超高层商业建筑项目的施工要求也在相应提高,其中施工标高为400～600m或以上的商业超高层工程项目正具有全面发展的趋势。根据这些形式,本文将对450m以上超高层商业建筑施工技术以及造价管理方面的主要特征加以分析。同时通过列举一些案例,指出项目的前期收费评估,并着重对建筑结构、幕墙、机械设备、措施等工程的四类子项造价预估做出详尽说明。然后指出设计成本费用调整的重点领域,来了解工程顾问模型在建设项目工程造价管理中的使用方式和关键含义。     

国贸三期B阶段基于BIM的现场施工管理信息技术

针对国贸三期B阶段超高层建筑施工场地狭小、结构复杂多变、体量大、专业多、工期短等特点,对深化设计、制造加工、施工管理、竣工交付各阶段进行基于BIM全生命周期施工管理信息技术应用,并对包括土建、钢结构、机电、幕墙、装饰装修在内的全专业实现BIM三维模型深化设计,探索BIM技术在超高层建筑全专业、全生命周期中的应用,提高项目精细化、信息化、协同化管理水平。     

德国DGNB认证体系的建筑生命周期评估(LCA)方法简介及国内项目案例分析

德国DGNB认证体系对建筑生命周期评估(LCA)提出了要求,并在国际通用的生命周期评估原则及框架下对建筑碳排放以及其他重要的环境排放指标提出了明确的计算方法。建筑生命周期评估包括了建筑全生命周期的碳排放以及其他重要的环境排放指标。针对国内某DGNB项目案例,对建筑生命周期评估方法进行了介绍并对结果做了简要分析。     

基于全生命期的既有建筑节能改造项目的费用预测研究

参考建筑节能和建筑能耗的定义,并结合现有建筑节能改造的具体内容,首先,以预测理论为基础对全生命周期费用预测的基本方法和步骤进行了系统的阐述,在此基础上提出了既有建筑节能改造项目费用估算的概念和费用组成;其次,对既有建筑节能改造项目的费用影响因素分阶段进行了系统的阐述和分析,从内部影响因素与各阶段费用相关性的角度为项目特征的提取提供理论依据;最后,针对既有建筑节能改造项目全生命周期费用的组成特点,构建了具有阶段特色的费用估算方法.     

某超高层住宅项目结构设计

本文结合某超高层住宅项目结构体系布置,对超高层建筑结构设计进行了分析与研究。通过对SATWE和PMSAP程序计算结果进行对比分析,知该超高层建筑抗震设计是合理的。     

谈超高层建筑造价控制的主要因素

阐述了超高层建筑的主要建筑特征和施工特点,对比分析了超高层建筑与高层建筑工程造价中的费用投入比例,探讨了影响超高层建筑工程造价的各项因素,并提出了合理控制工程造价的措施,从而提高超高层项目建设过程中的综合效益。     

超高层结构动力弹塑性分析方法研究

基于现有的研究理论,对超高层结构各主要受力构件的弹塑性参数设置进行探讨。在对超高层结构进行动力弹塑性时程分析时,采用"直接法"和"间接法"两种方法对结构"大震不倒"进行判断,并对两种方法按包络取值。对结构损伤提出了一种新的基于《建筑抗震设计规范》(GB 50011—2010)的判别方法,并与美国FEMA 356规范判别方法进行对比。以苏州绿地中央广场项目办公楼为工程背景,采用PERFORM-3D软件对其进行7度大震下动力弹塑性时程分析,从宏观上评价该结构体系的抗震性能。通过对比发现,《建筑抗震设计规范》(GB 50011—2010)对结构抗震性能评估与美国FEMA 356规范相比更加偏于安全。     

网壳结构寿命周期总费用的计算方法研究

现代结构系统在灾害中产生巨大经济损失的特点,使人们意识到在结构设计之初就对结构的寿命周期总费用进行有效评估、并反过来指导工程设计具有重要意义。对网壳结构寿命周期总费用的计算方法进行研究,分别提出初始造价、维护费用和失效损失的计算公式,并考虑寿命周期内网壳结构可能受到的荷载发生的概率,建立寿命周期总费用的计算方法,编制网壳结构寿命周期总费用的计算程序。通过一具体的网壳结构工程算例验证上述方法和程序的有效性。研究结果表明,网壳结构初始造价的追加投资会由于结构使用过程中失效损失费用的减小而得到补偿,而寿命周期总费用最小正是结构设计的最优状态,按照现行规范设计方法得到的结构配置方案不一定是寿命周期总费用最小的方案。     

Stochastic dependency in life-cycle cost analysis of multi-component structures

It is crucial to assure that civil engineering structures can operate properly and safely, as damages during the service life may lead to catastrophic loss of property, fatalities and long-term consequences. The approaches for structural management through a life-cycle cost analysis need to address explicitly the dependencies between elements. The evaluation of the life-cycle maintenance cost of structures in this article considers stochastic, degradation and economic dependencies. A new approach to include stochastic and degradation dependencies, structural redundancy and load redistribution in structural management is developed herein. The proposed model uses the fault tree analysis and the conditional probabilities to take into account stochastic dependencies between the structural elements. The degradation consequences are evaluated and a method is proposed to account for load redistribution. Also, a practical formulation to approximate the reliability of systems formed by interrelated components is proposed, by the mean of a redundancy factor that can be computed by structural analysis. The proposed approach provides effective optimal maintenance decisions for civil engineering structures by considering the interaction between elements.     

高性能结构抗多次多种灾害全寿命性能分析与设计理论研究进展

为促进高性能结构抗多次多种灾害全寿命性能设计理论研究在我国的发展,详细介绍了该领域的国内外研究现状并建立了其基本研究框架。对高性能结构在全寿命周期内可能遭受的多种灾害单独作用和联合作用的发生概率模型的研究成果进行了阐述,以碳化腐蚀作用和风致疲劳作用为例,论述了在结构全寿命周期内由环境作用引起材料及构件退化的时变模型研究现状,为开展多次多种灾害作用下高性能结构的全寿命性能分析研究提供了方向,并系统介绍了多种灾害作用下结构易损性分析方法和考虑灾害损失成本的结构全寿命抗灾性能优化设计方法的研究进展。基于全寿命周期的结构抗多次多种灾害性能设计方法,能够合理地解决传统设计方法中未考虑多种灾害联合作用和结构性能退化问题,对于建筑结构设计领域的发展具有重要意义。     

基于时变可靠度的锈蚀混凝土结构全寿命成本模型

为了分析混凝土结构在氯盐环境下的全寿命周期成本,基于现有氯离子扩散模型和裂缝宽度预测模型,采用MATLAB软件进行Monte-Carlo抽样模拟,建立结构失效概率与可靠度指标的拟合公式。通过研究维护-加固措施对可靠度指标的影响,建立全寿命周期内维护-加固费用计算评估方法,并以混凝土桥梁结构为例计算了全寿命周期维护-加固成本。结果表明:失效概率与可靠度指标可用以失效概率等于0.1为界的分段函数进行描述;维护-加固效果持续时间对结构构件服役年限延长的影响最显著;当保护层厚度取60 mm时,维护-加固阶段费用有明显下降,较保护层厚度取40 mm时减少25%~50%。     

绿色建筑全寿命周期成本控制管理研究

本文对绿色建筑全寿命周期的影响因素进行了全面分析,探讨了绿色建筑全寿命周期成本控制管理的方法,提出了加强绿色建筑全寿命周期成本控制管理的政策建议,为全面推广绿色建筑全寿命周期成本控制管理奠定了基础。     

Reliability-based service life assessment for deteriorating reinforced concrete buildings considering the effect of cumulative damage

Most engineering systems used in maintenance strategies must consider deterioration and seismic structural damage. To identify the effects of deterioration and earthquakes simultaneously on structural performance, this study applies an integral simulation method. Compared with that of previous studies, the feature of the proposed method is its analysis of the time-dependent structural capacity of a deteriorating reinforced concrete (RC) building and the simulation of life-cycle earthquake events within a specified service period, while considering cumulative damage induced by deterioration and earthquakes. In addition, the proposed assessment method is applied to derive the reliability-based service life of a deteriorating RC building located in a region with high seismic hazard. Briefly, for deteriorating RC buildings, the proposed reliability-based service life assessment method provides useful information related to maintenance based on both serviceability and safety.     

Inventory analysis of LCA on steel- and concrete-construction office buildings

A life-cycle inventory model for the office buildings is developed in this paper. The environmental effects of two different building structures, steel and concrete, are intercompared. The results show that the steel-framed building is superior to the concrete-framed building on the following two indexes, the life-cycle energy consumption and environmental emissions of building materials. It is found that the life-cycle energy consumption of building materials per area in the steel-framed building is 24.9% as that in the concrete-framed building, whereas, on use phase, the energy consumption and emissions of steel-framed building are both larger than those of concrete-framed building. As a result, lower energy consumption and environmental emissions are achieved by the concrete-framed building compared with the steel-framed building on the whole life cycle of building. The present study also provides a good method of assessing the performance of energy saving and environmental protection of different building structures based on a whole life cycle.     

A model for earthquake risk management based on the life-cycle performance of structures

Over 50 years of design life, buildings are exposed to different magnitudes and frequencies of earthquakes that require consideration of life-cycle cost (LCC). The LCC entails quantifying the building performance under seismic hazard and investments throughout the life of the structures. Traditional LCC utilises probabilities of being in different damage states. However, for buildings with inherent irregularities (e.g. vertical irregularity and plan irregularity), these probabilities are not readily available. In this paper, a system-based approach, utilising fuzzy set theory, is used to quantify the possibility of being in different damage states. The analysis is limited to study the effect of seismic exposure on the building LCC. The proposed method is illustrated with two case studies, a six-storey reinforced concrete (RC) building located in Vancouver, Canada, and vulnerability of an urban centre with 1000 RC buildings. Furthermore, sensitivity analysis is carried out to highlight the impact of different building performance modifiers on the LCC.     

超高层建筑结构经济性探讨

超高层建筑投资巨大,结构造价占较大比例。基于超高层建筑结构的受力特点,对影响超高层建筑结构造价的若干因素进行探讨,如建筑体型、结构体系、结构材料等。此外,施工方案和施工周期也间接影响结构造价。最后,对部分已建或在建的高度300m以上超高层建筑的结构用钢量进行初步统计和分析,以期找到一些规律。结构造价受多因素影响,需要相互平衡,合理优化的结构设计是降低结构造价的必由之路。     

Life-cycle of structural systems: recent achievements and future directions

Structural systems are under deterioration due to ageing, mechanical stressors, and harsh environment, among other threats. Corrosion and fatigue can cause gradual structural deterioration. Moreover, natural and man-made hazards may lead to a sudden drop in the structural performance. Inspection and maintenance actions are performed to monitor the structural safety and maintain the performance over certain thresholds. However, these actions must be effectively planned throughout the life-cycle of a system to ensure the optimum budget allocation and maximum possible service life without adverse effects on the structural system safety. Life-cycle engineering provides rational means to optimise life-cycle aspects, starting from the initial design and construction to dismantling and replacing the system at the end of its service life. This paper presents a brief overview of the recent research achievements in the field of life-cycle engineering for civil and marine structural systems and indicates future directions in this research field. Several aspects of life-cycle engineering are presented, including the performance prediction under uncertainty and optimisation of life-cycle cost and intervention activities, as well as the role of structural health monitoring and non-destructive testing techniques in supporting the life-cycle management decisions. Risk, resilience, sustainability, and their integration into the life-cycle management are also discussed.