Shaking table tests and numerical analyses of an RC coupled wall structure with replaceable coupling beams          下载免费PDF全文

Xilin Lu  Cong Chen  Huanjun Jiang  Shanshan Wang 《地震工程与结构动力学》2018,47(9):1882-1904

The replaceable coupling beam (RCB) is an innovative structural component developed to increase the seismic resilience of reinforced concrete (RC) shear wall structures. In this study, two 1/5‐scale 5‐story 3‐dimensional RC shear wall structures—one with conventional RC coupling beams and the other with RCBs—were designed, constructed, and tested on a shaking table. The failure pattern, dynamic properties, and structural responses, including the acceleration, displacement, story force, and strain responses, of the 2 structures are compared under earthquake excitations. The test results demonstrate that the seismic performance of the structure with RCBs was improved when RCBs were working compared with the structure with conventional RC coupling beams. In addition, the replaceable devices suffering the severe damage during an earthquake can be conveniently replaced after the earthquake. However, after the sudden failure of RCBs during the severe earthquakes, the inter‐story drift and floor acceleration of the structure with RCBs became larger. The design and manufacture quality of RCBs should be improved to avoid the sudden failure. Then, numerical models for the test structures were established using the commercial software PERFORM‐3D. Numerical simulations of the tests were conducted. The simulation results correspond well with the experimental results, thus verifying the accuracy of the numerical models. The RC shear wall structure installed with RCBs can be applied as a new type of earthquake‐resilient structure in engineering practice.  相似文献   

THE LIVELIHOOD VULNERABILITY OF RURAL HOUSEHOLD IN THE EARTHQUAKE-STRICKEN AREA OF NING'ER,YUNNAN PROVINCE          下载免费PDF全文

WEI Ben-yong  SU Gui-wu  QI Wen-hua  SUN Lei  WU Yang  JIN Yi-fan 《地震地质》2017,39(1):158-171

Strengthening livelihood capacities and making them sustainable is a crucial component of disaster risk reduction. Earthquake disaster not only destroys the whole social production and life system, but also seriously affects the livelihood activities and reduces the livelihood capability of people in the earthquake-hit area. In this paper, taking the stricken area of Ning'erM_S6.4 earthquake in 2007 as an example, we analyzed the livelihood vulnerability of rural household in Yunnan, using the method of questionnaire and on-site interview. The results show that on the whole, the rural household livelihood is much more vulnerable, which would lead to the higher risk of livelihood in Ning'er earthquake-hit area, Yunnan. The main reasons for the higher vulnerability of rural household are the lacks of single or multiple livelihood capitals. Moreover, the livelihood vulnerabilities of rural households with the lacks of human capitals and multiple capitals are the highest. The rural households with the lacks of human capitals and multiple capitals would face much more risk of livelihood. To expand their social capital, raise their cultural quality, increase the ways for living, accelerate household wealth accumulation and improve the level of household buildings are the effective ways of reducing livelihood vulnerability and decreasing the effects of earthquake disaster for local rural households in Ning'er, Yunnan.  相似文献   

River sensitivity: a lost foundation concept in fluvial geomorphology   总被引：1，自引：0，他引：1       下载免费PDF全文

Kirstie A Fryirs 《地球表面变化过程与地形》2017,42(1):55-70

In the twenty‐first century, fluvial geomorphologists are ideally placed to use their science in an applied manner, and provide guidance on environmental issues of concern. Understanding the impact of floods and droughts, land use and climate change, water use, etc. on river forms, processes and evolution requires that we understand interactions between water, sediment and vegetation, and how climate and anthropogenic impacts shape those interactions. More frequently, fluvial geomorphologists are asked to provide answers to a range of river issues, make forecasts about how systems might adjust in the future, and work with managers to implement strategies on‐the‐ground. To some, the field of fluvial geomorphology is underprepared for this task as several principles of landscape form, process and evolution are yet to be fully explored. Others however, see that geomorphologists have a suite of principles and tools at their disposal, and sufficient understanding to make forecasts about future river adjustments with some level of confidence. One concept that has been lost in recent years, but should lie at the heart of such analyses is that of river sensitivity. In this paper I draw on foundation literature to review the concept of river sensitivity. I provide examples that demonstrate how this concept could be reshaped and used for analyses at landform, reach and catchment scales. At the landform scale, morphological sensitivity is a function of textural and geometric sensitivity. At the reach scale, analyses consider inherent behavioural and change sensitivity. At the catchment scale river response and recovery are a function of locational, transmission and filter sensitivity. I then discuss how some temporal concepts can be used to consider how sensitivity in itself adjusts over time. Finally, I discuss future challenges for analysis of river sensitivity and consider how it could be used to improve geomorphological forecasting for use in river management. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Functionality‐fragility surfaces          下载免费PDF全文

Aman Karamlou  Paolo Bocchini 《地震工程与结构动力学》2017,46(10):1687-1709

The evaluation of functionality and its evolution in the aftermath of extreme events and during the restoration phase is a critical step in disaster resilience assessment. To this respect, this paper presents the ‘Functionality‐Fragility Surface’ (FFS), which is a tool for probabilistic functionality and resilience evaluation of damaged structures, infrastructure systems, and communities. FFS integrates two well‐known tools, namely Fragility Curves and Restoration Functions, to present the probability of loss of functionality of a system as a function of the extreme‐event intensity, as well as the elapsed time from the initiation of the restoration process. Because of their versatility, FFSs can be applied to components and systems belonging to different infrastructure sectors (e.g., transportation, power distribution, and telecommunication), so they provide a common rigorous paradigm for integrated resilience analyses of multiple sectors, as well as for studies on interdependencies within and across sectors. While it is shown that FFSs can be developed using available data and simple computations for different types of structures and infrastructure systems, this paper proposes also a sophisticated simulation‐based methodology to develop FFSs for individual bridges, taking into account the uncertainties involved in the response, damage, and restoration scheduling of bridges. A Multi‐Span Simply Supported Steel Girder bridge is used to showcase the application of the proposed methodology. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Impacts of successive wildfire on soil hydraulic properties: Implications for debris flow hazards and system resilience     

Luke A. McGuire  Ann M. Youberg 《地球表面变化过程与地形》2019,44(11):2236-2250

Climate and land use changes have led to recent increases in fire size, severity, and/or frequency in many different geographic regions and ecozones. Most post-wildfire geomorphology studies focus on the impact of a single wildfire but changing wildfire regimes underscore the need to quantify the effects of repeated disturbance by wildfire and the subsequent impacts on system resilience. Here, we examine the impact of two successive wildfires on soil hydraulic properties and debris flow hazards. The 2004 Nuttall-Gibson Complex and the 2017 Frye Fire affected large portions of the Pinaleño Mountains in southern Arizona, creating a mosaic of burn severity patterns that allowed us to quantify differences in wildfire-induced hydrologic changes as a function of burn severity and recent fire history (i.e. burned in only the Frye Fire or burned in both fires). Field observations after the 2017 Frye Fire indicated debris flow activity in areas burned predominantly at low severity. Many of these areas, however, were also affected by the 2004 Nuttall-Gibson Complex, suggesting that the relatively short recovery time between the two wildfires may have played a role in the geomorphic response to the most recent wildfire. Field measurements of soil hydraulic properties suggest that soils burned at moderate severity in 2004 and low severity in 2017 have a lower infiltration capacity relative to those that remained unburned in 2004 and burned at low severity in 2017. Simulations of runoff demonstrate that measured differences in infiltration capacity between once- and twice-burned soils are sufficient in some cases to influence the rainfall intensities needed to initiate runoff generated debris flows. Results quantify the impact of wildfire history and burn severity on runoff and debris flow activity in a landscape affected by successive wildfires and provide insight into how the resilience of geomorphic systems may be affected by successive wildfires. © 2019 John Wiley & Sons, Ltd.  相似文献   

减隔震桥梁设计方法及抗震性能研究综述   总被引：1，自引：1，他引：0       下载免费PDF全文

石岩  李军  秦洪果  钟正午  王玉玲 《地震工程学报》2019,41(5):1121-1132

桥梁作为交通系统中的生命线工程,其抗震性能问题尤为重要。桥梁减隔震技术主要通过减隔震装置来降低结构的地震损伤,目前已发展成为提高强震区桥梁抗震能力的重要措施。为促进减隔震技术在中国桥梁工程领域的进一步发展,首先总结减隔震桥梁的设计方法,归纳其地震反应和震害情况,对采用不同减隔震装置桥梁的非线性动力性能、减隔震效果、地震随机响应、易损性及性能优化方法等研究情况进行梳理;其次,概述减隔震技术在斜交桥、曲线桥及铁路桥梁中的应用情况与研究进展,并介绍新型韧性抗震设计理念在桥梁工程领域中的应用情况和发展前景;最后,总结减隔震桥梁的试验研究情况,指出目前减隔震桥梁研究中的不足和发展趋势。  相似文献   

乡村产业发展对农户生计的影响研究——以宁夏红寺堡区为例   总被引：2，自引：1，他引：1  

马彩虹  袁倩颖  文琦  李学梅 《地理科学进展》2021,40(5):784-797

梳理产业选择与培育的经验,分析产业发展对农户生计的影响,对于促进生态移民区的乡村产业振兴、农户生计恢复与可持续发展具有重要意义.论文以中国最大单体移民迁入区宁夏吴忠市红寺堡区为研究区,针对4大乡村产业各选1个样本村,采用问卷调查法和半结构访谈法获取数据,在比较不同产业投入产出效益的基础上,探究不同产业发展对移民生计产出...  相似文献   

Spatial differentiation and driving factors of economic resilience in the Yangtze River Economic Belt,China北大核心CSCD     

Yuan F.  Xiong X.  Xu Z.  Yu L. 《地理科学进展》2023,(2):249-259

The 2008 global financial crisis had a huge impact on China's real economy, and inspecting the imbalance and differentiation mechanism of the regional economic recovery process after the crisis is conducive to providing a reference for promoting regional high-quality and sustainable development. Based on the multidimensional resilience measurement framework, this study comprehensively investigated the dynamic evolution process of economic resilience in the Yangtze River Economic Belt after the 2008 global financial crisis, and focused on the temporal variation characteristics and spatial differentiation patterns of resistance and resilience. On this basis, the fixed effect panel regression model was used to analyze the role of factors such as industrial development status, regional development foundation, level of opening up, government management level, and innovation environment on economic resilience. The study found that at the overall level, the resistance of the Yangtze River Economic Belt after the impact showed a trend of first rising and then declining and the overall performance was high, but the resilience showed a trend of decline-rise-decline and the overall performance was low. The fluctuations in export resistance and resilience were much greater than the fluctuations in the dimensions of GDP, industry, consumption, and employment. Regression models showed that diversity and related diversity and regional innovation capabilities, although limited in the process of resisting risks in the early stage of the crisis, were conducive to the rapid regional resumption of growth after the crisis, areas with strong government management capabilities may hinder economic recovery to a certain extent, and the ability to open up to the outside world has no significant impact on resistance and resilience. © 2023, Editorial office of PROGRESS IN GEOGRAPHY. All rights reserved.  相似文献