基于CFRP加固的钢混排架厂房全寿命周期地震成本研究

采用增量动力分析(incremental dynamic analysis,IDA)对坐落于我国西部具体地区的单层钢混排架工业厂房基于碳纤维布(carbon fiber reinforced polymer,CFRP)加固前后的地震损伤和全寿命周期地震成本进行对比计算分析,研究中参考了中国抗震规范和美国太平洋地震工程研究中心(PEER)强震数据库后拟合建立了与分析地区地质场地条件接近的当地地震风险度概率模型。采用多参数混合加权推导计算出CFRP加固钢混排架柱厂房结构全寿命周期地震损失成本统计值,计算过程中的结构尺寸、材料强度、地震荷载等相关参数变量采用蒙特卡洛(Monte CarloSampling,MCS)随机样本法予以考虑,研究结果显示该地区CFRP加固单层钢混排架厂房结构全寿命周期地震成本统计中位值在5.75元/(年·m2),扣除加固材料成本及加工费用后较同类型未加固普通厂房全寿命期地震成本费用综合节省约16.5%,显示厂房采用CFRP加固技术后具有良好的全寿命周期地震成本经济性,同时CFRP加固后的厂房结构地震年平均成本直接费Co V统计偏差在1.35%～1.36%。

基于随机模拟的单层工业厂房全寿命期地震成本研究

依据中国建筑抗震设计规范(GB50011-2010)建立了我国西部具体地区的地震风险概率模型,基于IDA增量动力分析对该地区典型单层钢筋混凝土排架工业厂房结构承载力和地震易损性进行了分析计算,采用三参数分别表征排架厂房结构性和非结构性构件地震损伤并进一步加权计算了单层工业厂房全寿命期地震损失成本,计算中包括结构荷载、材料特征值、外加地震荷载等有关参数变量不确定性采用蒙特卡洛(Monte Carlo Sampling,MCS)随机样本予以考虑,研究得到了该地区单层排架工业厂房结构的地震巨灾保险费用统计值在12.78元~12.86元/年·m^2,验证了技术分析路径的可行性,通过对统计结果值的特征分析,单层钢混排架结构厂房的地震年均成本直接费用CoV偏差在1.11-1.12%之间。

基于增量动力分析的多层隔震结构全寿命期地震成本研究

基于中国建筑抗震设计规范(GB50011—2010)建立了中国西部工程结构全寿命期地震成本概率模型,以中国西部具体地区(宁夏银川)为样本选择地区,以该地区简化多层基础隔震框架结构为样本进行结构全寿命期地震成本计算,基于IDA增量动力分析对该地区简化多层隔震结构全寿命期地震成本采用拉丁超立方样本(Latin Hypercube Sampling,LHS)法随机分析研究,结果显示对于多层结构采用隔震技术后地震巨灾保险费率从长期来看低于常规框架结构,通过对统计结果值进行的特征分析,隔震结构的Co V值显著地低于常规框架结构。研究结果对于已有城镇多层隔震建筑与多层钢筋混凝土框架结构地震巨灾保险未来推广具有指导意义。

新疆油田地震成本变化规律及影响因素分析

在系统收集和统计新疆油田2001—2010年地震勘探投资、工作量和成果的基础上,总结出了新疆油田2001—2010年地震成本的变化规律,并将各类因素对地震成本的影响进行了系统的分析,提出了优化和降低新疆油田地震成本的基本对策。指出:从2001—2010年新疆油田地震成本基本呈现出逐年增高的趋势,物价上涨是造成地震成本增高的主要社会原因,地震技术的更新和参数强化是造成地震成本增高的技术原因,地震地质目标的转变是地震成本增高的地质因素,而地理地貌环境差异是造成地震成本差异变化的地域原因。因此,新疆油田优化和降低地震成本的关键,只有在技术和管理上下功夫。

土木工程结构全寿命期地震损失成本进展研究

近年来在西太平洋地区发生的一系列重大自然灾害如地震、飓风等给人类社会敲响了警钟,为了应对重大自然灾害的不利影响,世界各国政府都在研究或已经出台了防灾减灾保险法律如地震保险法加以应对,这应该说是防灾减灾研究的一个必然的趋势。而完善的地震保险政策的出台必须建立在工程结构全寿命期地震损失成本研究的基础上。由于我国目前工程结构全寿命期地震损失成本研究等基础应用研究的缺乏导致我国巨灾保险政策迟迟难以推出,基于此,总结和回顾了工程结构全寿命期地震损失成本研究的理论内涵和研究现状,分析了以往工程结构地震易损性研究和全寿命期地震损失成本研究所面临的理论缺陷和应用局限,重点阐述了基于组合的地震易损性研究的理论优势、具体实施步骤和关键技术特点,最后展望了基于此建立我国工程结构全寿命期地震损失成本研究框架体系的重大意义。

Design and implementation of low-cost geomagnetic field monitoring equipment for high-density deployment

The observation of geomagnetic field variations is an important approach to studying earthquake precursors.Since 1987,the China Earthquake Administration has explored this seismomagnetic relationship.In particular,they studied local magnetic field anomalies over the Chinese mainland for earthquake prediction.Owing to the years of research on the seismomagnetic relationship,earthquake prediction experts have concluded that the compressive magnetic effect,tectonic magnetic effect,electric magnetic fluid effect,and other factors contribute to preearthquake magnetic anomalies.However,this involves a small magnitude of magnetic field changes.It is difficult to relate them to the abnormal changes of the extremely large magnetic field in regions with extreme earthquakes owing to the high cost of professional geomagnetic equipment,thereby limiting large-scale deployment.Moreover,it is difficult to obtain strong magnetic field changes before an earthquake.The Tianjin Earthquake Agency has developed low-cost geomagnetic field observation equipment through the Beijing–Tianjin–Hebei geomagnetic equipment test project.The new system was used to test the availability of equipment and determine the findings based on big data..

LCCA方法在桥梁工程中应用的研究综述

从寿命周期成本构成、成本计算模型和结构性能指标3方面介绍了桥梁全寿命周期成本分析(Life Cycle Cost Analysis,LCCA)方法,重点阐述、分析了腐蚀作用下桥梁结构和构件的时变可靠度。将LCCA方法在桥梁工程中的应用分为规划设计阶段、运营阶段和抗震设计3部分,目前LCCA方法在规划设计阶段应用仍处于理论的初步研究阶段,在运营阶段应用以桥梁维修方案优化研究为主,在抗震设计中应用主要为地震作用下各级破坏概率和损伤成本的计算。最后,对LCCA方法在桥梁工程中应用的发展趋势进行了展望。

Performance-based system seismic assessment for long-span suspension bridges under two-level seismic hazard

Since there are few studies on the performance-based seismic evaluation of the long-span suspension bridge system under two-level earthquake hazard in Chinese code,the developed procedure of this study can be regarded as a general program to assess the seismic performance of the overall system for long-span suspension bridges.In the procedure,the probabilistic seismic demand models of multiple bridge components were developed by nonlinear time-history analyses incorporating the related uncertainties,and the component-level fragility curves were calculated by the reasonable definition of limit states of the corresponding components in combination with seismic hazard analysis.The bridge repair cost ratios used to evaluate the system seismic performance were derived through the performance-based methodology and the damage probability of critical components.Furthermore,the repair cost ratios of the overall bridge system that was retrofitted with fluid viscous dampers for the main bridge and changed restraint systems for the approach bridges were compared.The results show that peak ground velocity and peak ground acceleration can be selected as the optimal intensity measurements of long-span suspension bridges using the TOPSIS(technique for order preference by similarity to an ideal solution).The bridge repair cost ratios can serve as accurate evaluation indicators to provide an efficient evaluation of retrofit measures.The seismic evaluation of long-span bridges is misled when ignoring the interaction of adjacent structures.However,the repair cost ratios of a bridge system that has optimum seismic performance are less sensitive to the relative importance of adjacent structures.

Potentials of community-based tourism in transformations towards green economies after the 2008 Wenchuan earthquake in West China

This study investigates the contrasting sceneries of community-based tourism after the 2008 Wenchuan earthquake and focuses on the potentials of tourism in transformations towards green economies. How are tourism and environment linked in a sustainable relationship? And how can potentials of community-based tourism be directed in transformations towards green economies? A qualitative research design is used to examine contrasting sceneries and specific green elements of community-based tourism in a Qiang people's fortress village in Mao County, Sichuan Province, West China and further discuss how tourism can be compatible with human wellbeing through demonstrating a commitment to sustainable development. The study argues that potential economic, social and environmental costs of tourism need to be considered when evaluating the loss of community benefits toward sustainability. The green elements suggest the potential of community-based tourism in transformations towards green economies, involving green agricultural, green building, and green energy, green governance, green service and green consumption. This study will contribute to the debate about the relationship between tourism and environment sustainability in the green economies, as well as the critique of what can be learned for community development from green tourism in mountainous regions after the inevitable natural disasters.