地震灾害下城市生命线体系恢复力双维度综合评估

针对现有生命线恢复力研究中单一维度评估的缺陷,引入基础设施网络均衡理论,设计综合考虑生命线网络物理状态和输送能力的体系性能时程响应函数PRF,同时构建包含灾害概率、灾害后果、恢复速率三个主要因素在内的,贯穿技术和组织双维度的生命线体系恢复力评估框架,实现地震灾害下城市生命线体系恢复力双维度综合评估。在以江苏省连云港市区供水网络为例的案例研究中,依据评估框架构建体系恢复力仿真流程,采用场景地震,对环状和网状两种供水体系的震害恢复力进行对比分析,结果显示,尽管网状供水网络的性能水平高于环状网络,但对体系恢复力的提升作用并不明显。而且城市供水体系恢复力随着恢复资源投入量的变化曲线显示,恢复资源的投入量存在最优值,能够以高效费比实现体系恢复力最大化。     

论“奇点建筑”

随着科学技术的不断进步,建筑正逐步显现出“动态化”、“生命化”,建筑状态将发生革命性变化,呈现出奇点建筑的特征。当科学进步到人机合一的状态时,人类必然会经历奇点时刻。本文通过对“奇点建筑”概念的阐述,探讨建筑未来发展的可能趋势。     

装配式混凝土框架节点性能研究进展

随着社会的发展,预制装配式建筑是未来发展方向,而推广的关键是研究预制框架节点连接方式。结合近年来国内外装配式混凝土框架柱干式连接和湿式连接的发展概况,本文综述了节点连接方式、新材料应用以及节点数值模拟分析研究,对多种类型节点连接方式和数值模拟进行总结,分析了各类节点连接方式和现阶段仿真计算模型优缺点及未来发展方向,总结了装配式混凝土框架结构连接的体系形式,有助于全面了解其现状。     

旅游镇慢行系统的规划设计思考

五大连池新镇是依托风景名胜区及自然保护区资源而新建的旅游镇,兼具生态移民镇与游客服务基地的功能,其规模适中,十分适宜发展慢行交通系统。本文综合了该镇贯穿于概念规划、总体规划、控制性详细规划及城市设计等不同阶段的慢行系统规划设计理念与方法,从“慢”格局、“慢”交通、“慢”游赏三个角度,对整体规划格局到局部的设计意向都进行了剖析,较系统的总结了规划组对于旅游镇慢行系统的规划设计思考及其成果。     

含层理构造的非均质片麻岩巴西劈裂试验及离散单元法数值模拟研究

 为了研究岩石各向异性及非均质性对其破坏形式的影响,对含层理构造的非均质片麻岩进行了多组加载角度的巴西劈裂试验,获得不同层理方向片麻岩试件“抗拉强度”。其计算“抗拉强度”随着层理方向与加载方向夹角减小而迅速减小,当层理方向平行于加载方向时,计算“抗拉强度”可认为是片麻岩软弱层理面间的抗拉强度;当层理方向垂直于加载方向时,计算“抗拉强度”可认为是片麻岩岩石矿物基质的等效抗拉强度;当层理方向与加载方向夹角小于90°时,则属于拉–剪复合破坏形式,是片麻岩各向异性和非均质性共同作用的结果,此时对计算“抗拉强度”的应用需要特别谨慎。用UDEC程序建立离散单元数值模型,利用随机分布的条状块体集合,通过设置层理界面和矿物颗粒之间的接触参数,模拟层理构造对片麻岩破坏的影响。数值模拟与试验结果吻合较好,解释了劈裂破坏形式产生的机制,揭示岩石在荷载状态下的破裂过程是裂纹从萌生初期的无序分布,到受微观构造影响而有序集中的自组织过程。     

九寨沟地震灾区调研及重建模式的思考#br#

文中首先从整体上对“88”九寨沟地震灾情进行回顾和总结,并就灾害的损失情况与汶川地震、芦山地震进行了对比分析,对此次地震损失相对较小的原因给出了较为合理的解释。然后在对灾区实地调研的基础上,结合各方有关信息的搜集和梳理,汇总得到九寨沟景区景点受损情况、生态环境受损情况、基础设施受损情况以及房屋建筑受损情况。随后对灾区恢复重建和发展阶段所面临的来自生态环境保护、区域经济发展、旅游资源开发、少数民族文化传承、市场信心等方面的问题进行了深入分析。最后提出了灾后重建的原则、方式和具体路径,以及灾区未来发展的一些建议。     

对“地下连续墙成槽施工对房屋沉降影响的研究”讨论的答复

 首先真诚感谢雷国辉等对“地下连续墙成槽施工对房屋沉降影响的研究”(以下简称“原文”)一文的关注。对于原文中涉及的有关问题,现做以下答复:(1)讨论文中认为成槽作业引起房屋沉降的根本原因在于“开挖引进地基应力释放导致槽壁周围土体的体积变形和剪切变形”,与原文相比可能是理解上的不同。原文基于周围土体向槽壁内位移,必然会引起壁后土体松动产生位移传递(大量实测已发现土体位移传递的滞后规律)或者地基应力变化,从而导致周围土体的变形的理解,从工程应用出发,借用“地层损失”的概念来总结壁后地表沉降的机理;而且,能否直接用变形来判断或揭示地表沉降的机理,原文认为尚需进一步讨论研究。至于“将槽段的稳定系数认定为     

导波在锚固金属杆中传播机理的研究

运用波动的经典理论,提出了导波在金属杆嵌入层“变截面”传播时波速改变的“等效弹性模量”的概念。对导波在锚固金属杆中的传播,尤其是在金属杆与锚固交界面处的传播机理进行理论分析,并提出了在锚固交界面处导波以耦合“低频脉冲”传播的思想。这一概念,可以解释运用导波进行无损检测得到的时域分析图中信号发生的“时滞”与波形拉平现象。     

论中国区域性土的分布和岩土性质的形成

广阔的中国大地上分布着各种具有地区特点的“区域性土”:北部的黄土、南部的红土、中部的老粘土以及东南近海的海洋软土(包括沿海的软土)。它们和一般粘性土的工程特性不同,故而人们有时称之为“特殊土”。笔者曾分别对它们的工程特性和基本性质进行过研究。本文对这些“区域性土”的物理力学、物理化学和微观分析的测试成果作了系统归纳,并对这些“区域性土”的分布规律和工程特性的形成进行了综合研究。研究表明我国“区域性土”地理分布和独特的工程特性的形成,完全取决于我国的气候条件和地理地质环境。     

设置BRB桥梁排架墩基于位移抗震设计方法

基于“保险丝”和“损伤控制”的抗震设计理念,提出在桥梁双柱式排架墩中通过设置屈曲约束支撑(BRB)以提高其横桥向抗震性能的构想。首先从获得“抗震能力”的角度对设置BRB桥梁排架墩的抗震设计参数进行系统性分析,推导出与剪跨比和墩柱间距与直径(边长)比相关的BRB核心段最大和最小长度取值范围|再从求解“地震需求”角度建立了设置保险丝的(SDOF)主结构体系弹塑性反应谱基本方程,分析该体系的非线性地震反应一般规律|然后,基于体系的“抗震能力”和“地震需求”,发展了设置BRB的桥梁排架墩基于位移的抗震设计方法,并结合一个具体桥梁排架墩实例说明建议设计方法的可行性。     

Emergency Preparedness Hub: Designing Decentralized Systems for Disaster Resilience

While advocating for designers as key contributors to disaster resilience, this article proposes an alternative infrastructural model through community-specific design. The design and prototyping of Emergency Preparedness Hubs, or PREPHubs, proposes a new model for disaster infrastructure that is dispersed, off-grid, and locally adapted, while operating as a system. Instead of single-function technocratic objects, they are designed as cultural objects and multi-use systems which provide an alternative to lifeline infrastructures that are often disrupted during natural disasters. As dual-function systems, PREPHubs operate on a daily basis as interactive public space architectures, becoming embedded in the daily lives of local communities.     

A socio-ecological analysis of hospital resilience to extreme weather events

Hospitals play a critical role in helping communities respond effectively to extreme weather events (EWEs). Despite predictions of more EWEs, little is known about the process by which hospital infrastructure resilience to such events can be built. Using Gunderson and Holling’s Adaptive Cycle, a new theoretical perspective based on socio-ecological resilience theory is provided to understand this process. Data were collected using semi-structured interviews, observations of disaster drills and disaster planning meetings, as well as additional documentary analysis of past incident reports. The research findings were then refined and validated in a focus group meeting with respondents. The findings indicate that there are significant organizational barriers which prevent facilities managers improving the resilience of hospital facilities to future EWEs. It was found that the disaster planning process is ad hoc and non-inclusive, focused on man-made disasters and compliance driven, top-down approach, under-resourced and is driven by a general ignorance of the importance of resilient-built facilities to health care delivery during an EWE. It is concluded that to produce more resilient hospital infrastructure, there needs to be a more well-resourced, integrated and collaborative approach to disaster management planning which enables health facilities managers to play a more central role in disaster planning decisions. There also need to be better systems, technologies and training implemented to manage information about health infrastructure performance before, during and after EWEs.     

The Contributions of Blue-Green Infrastructure to Building Urban Climatic Resilience—Bibliometric Analysis Based on Co-citation Networks

Against the backdrop of global climate change and in regards of urban sustainable development, enhancing climate resilience has become a critical strategy in adapting climate change for urban areas, where blue-green infrastructure is considered an important means. Although existing studies mention that blue-green infrastructure (BGI) can promote urban resilience by increasing its own diversity, flexibility, redundancy, modularization, and decentralization, questions like where to promote, by what specific means to promote and to what extent it could promote to are still lack of scientific exploration, leading insufficient support for applying resilience theory into planning and design practice. This research recognizes the role of BGI in building climate resilience in the key fields of functioning–urban floods, sea level rise, and high temperature and heat waves–and summarizes that the common functioning mechanisms include the biophysical properties of BGI, forming modular units with other infrastructures of similar functions, and the reliance on networked structures to help the system restore its physical functions and social connections as quickly as possible after disturbances and attacks. This paper also analyzes possible obstacles that hinder the promotion of BGI solutions–the lack of data support to BGI functioning mechanism, the lack of comprehensive assessment on ecological-social-economic benefits, and the difficulty in gaining confidence from decision-makers and the public. Finally, this paper proposes countermeasures from aspects of theoretical development, planning practice, and implementation and management, in order to offer insights for building urban climate resilience.     

Assessing urban lifeline systems immediately after seismic disaster based on emergency resilience

Resilience is an emerging concept for analyzing the dynamic performance of critical infrastructures during the post-disaster recovery process. Although a number of studies examined how to assess long-term resilience (1 year +), very few have investigated short-term resilience (few days to several weeks following a disaster). This study presents the new concept of ‘emergency resilience’ and the framework for assessing this short-term resilience for urban lifeline systems in the emergency recovery stage. This framework can quantify differences in system performance (pre-disaster vs. post-recovery) using the new ‘recovery degree’ feature. It also integrates a new performance response function which is based on network equilibrium theory to assess emergency resilience in both the technical and organisational dimensions. In the case study of the water pipeline network in Lianyungang, China, the results showed that the levels of the recovery budget b and recovery resource r had different effects on emergency resilience R in seismic disaster. Furthermore, it is demonstrated how the concept and its assessment framework can provide a quick reference tool for optimal decision-making under various scenarios. This study also examined the effects of two anti-seismic reconstruction measures, namely meshed expansion and ductile retrofitting, on the expected emergency resilience of the water pipeline network.     

Continuous and multidimensional assessment of resilience based on functionality analysis for interconnected systems

The increasing number of disruptions to critical infrastructure, like natural disasters, terrorist attacks or internal failure is today a major problem of society. Concern is even greater when considering the interconnected nature of critical infrastructure, which might lead to failure propagation, causing domino and cascade effects. To mitigate such outcomes, critical infrastructure must recover its capacity to function with regard to several criteria. Stakeholders must therefore analyse and improve the resilience of critical infrastructure before any disruption occurs, and base this analysis on different models so as to guarantee society’s vital needs. Current resilience assessment methods are mainly oriented toward the context of a single system, thus narrowing their criteria metrics, limiting flexibility and adaptation to other contexts and overlooking the interconnected nature of systems. This article introduces a new tool-equipped approach that makes it possible to define a model to evaluate the functionalities of interconnected systems. The model is then used to assess the resilience of these systems based on simple and generic criteria that can be extended and adapted. Several assertions related to the concept of resilience and some resilience indicators are also introduced. A case study provides the validation performed by experts from several domains.     

Embedding social inclusiveness and appropriateness in engineering assessment of green infrastructure to enhance urban resilience

ABSTRACT

Urban resilience emerges not only from ‘what’ is done in relation to critical infrastructure systems, but in the ‘how’ of their conception, co-creation and integration into complex socio-ecological-technical systems. For green infrastructure, where ownership and agency may be distributed amongst organisations and diverse communities, inclusiveness and appropriateness require embedding in engineering assessments of green infrastructure and resilience. Through consideration of past, present and future engineering and resilience assessments – from monetising, through greening, to humanising – this paper examines the ways in which GI may be or has already contributed to enhancing urban resilience and types of assessment and indicators that have been or could be used. We suggest that enhancing visibility of the ‘whos’ (individuals, communities) is crucial to fully diversifying assessments. We also suggest some ideas for additional indicators and assert that co-production of future indicators needs to be undertaken with appropriate professionals (e.g. social impact assessment professionals).     

A hierarchy of measures for infrastructure resilience – learning from post-disaster reconstruction in Christchurch,New Zealand

Recent research into the concept of resilience has shown that it helps key players in urban development to assess and set priorities for resistance and recovery for disaster risk management. However, a competing issue within post-disaster recovery is managing the trade-offs between quickly restoring infrastructure services versus taking time to consider and consult on alternative options. Through an examination of the post-earthquake reconstruction in Christchurch, New Zealand, this paper considers infrastructure resilience by using a hierarchy of measures. This hierarchy shows how infrastructure resilience needs to be considered as a series of interventions in response to different levels of damage. It elucidates the varying nature of resilience measures, the decision-making processes required to implement them and constraints, chiefly in funding, that prevent wider application of such measures. This is an important consideration for defining and acting upon the opportunity for change created by a disaster. Furthermore, a broader examination of resilience in disaster risk management highlights that clarification is needed over what constitutes an appropriate response for community involvement in post-disaster infrastructure reconstruction.     

Network structure,complexity, and adaptation in water resource systems

Infrastructure systems are often complex. Many have both natural and built components. For such systems, including water resource networks, resilience is a common policy goal. In the formalised study of complex systems, the structure and function of networks can contribute directly to system resilience. One branch of complex systems studies, network science, describes how connectivity between individual components can explain some system-wide properties of growth and reliability. Water resource systems analysis has only begun to apply techniques from network theory and complexity science to assess adaptability and resilience. We present an analysis of connectivity in a network model of California's water infrastructure system using several network science techniques. Results indicate that nodes in California's water system are clustered but without scale-free properties. The network originates from a mixture of top-down (centralised) and bottom-up (dispersed interactions of parties) planning. This structure provides managers greater flexibility to use local and distant water sources. We use the analysis to illustrate how several disciplinary notions of resilience apply to civil infrastructure planning. We also explore how adaptability, not just complexity, influences resilience in planning. Creating systems that can respond to future changes must be an important policy goal in planning civil infrastructure.     

Efficient Infrastructure Restoration Strategies Using the Recovery Operator

Infrastructure systems are critical for society's resilience, government operation, and overall defense. Thereby, it is imperative to develop informative and computationally efficient analysis methods for infrastructure systems, which reveal system vulnerabilities and recoverability. To capture practical constraints in systems analyses, various layers of complexity play a role, including limited element capacities, restoration resources, and the presence of interdependence among systems. High‐fidelity modeling such as mixed integer programming and physics‐based modeling can often be computationally expensive, making time‐sensitive analyses challenging. Furthermore, the complexity of recovery solutions can reduce analysis transparency. An alternative, presented in this work, is a reduced‐order representation, dubbed a recovery operator, of a high‐fidelity time‐dependent recovery model of a system of interdependent networks. The form of the operator is assumed to be a time‐invariant linear dynamic model apt for infrastructure restoration. The recovery operator is generated by applying system identification techniques to numerous disaster and recovery scenarios. The proposed compact representation provides simple yet powerful information regarding systemic recovery dynamics, and enables generating fast suboptimal recovery policies in time‐critical applications.     

城市应急救援功能抗震韧性研究

城市作为一个复杂系统,不仅包含许多基础设施系统,也拥有众多人口,当灾害发生时,城市系统容易受到影响,一般将导致众多人员伤亡.城市应急救援系统对于降低灾害后续人员伤亡起到关键的作用.采用韧性视角研究城市应急救援系统在灾害发生后的功能变化,可更有效地对城市功能改进提出建议.