降雨入渗及地震作用下边坡稳定性研究

边坡滑坡给社会经济和人民生命安全带来了巨大威胁，降雨和地震是边坡滑坡的两大诱因。以云南省某矿山边坡作为研究对象，取样后在室内进行岩石力学实验，得到后期工作所需的岩石力学参数，利用霍克布朗准则推导出岩体的力学参数，运用理论计算和数值模拟分析降雨和地震对边坡稳定性影响，结果表明：1）在降雨入渗作用下，边坡出现滑坡主要是静水压力造成的；2）在地震作用下，当地震峰值加速度为0.1g时，有效塑性区主要位于边坡中下部，当增大地震峰值加速度，其范围向坡脚移动，当加速度为0.3g时，塑性区出现贯通趋势。     

Experimentelle und analytische Untersuchung des out‐of‐plane‐Verhaltens von unbewehrten Mauerwerkswänden unter Erdbebenbelastung

Experimental and analytical investigation of the seismic out‐of‐plane behavior of unreinforced masonry walls In addition to the vertical and horizontal load‐bearing in‐plane, masonry must also withstand out‐of‐plane loads that occur in earthquake scenarios. The out‐of‐plane behavior of unreinforced masonry walls depends on a variety of parameters and is very complex due to the strong non‐linearity. Current design methods in German codes and various international codes have not been explicitly developed for out‐of‐plane behavior and contain considerable conservatism. In the present work, shaking‐table experiments with heat‐insulating masonry walls have been conducted to investigate the out‐of‐plane behavior of vertical spanning unreinforced masonry walls. As shown in previous numerical investigations, important parameters are neglected in existing design and analysis models and the out‐of‐plane capacity is underestimated significantly. In the conducted experiments the results of these numerical investigations are verified. Furthermore, the development of an analytical design model to determine the force‐displacement relationship and the out‐of‐plane load‐bearing capacity considering all significant parameters is presented.     

基于颗粒阻尼器的曲线桥减震分析与试验

为了将颗粒阻尼器引入到曲线桥减震控制中,设计制作了某典型曲线桥的1/10缩尺试验模型及可用于试验模型桥上的曲型舱颗粒阻尼器(curved-capsule particle damper,简称CPD),基于振动台试验开展了地震波类别和激励方向对该型阻尼器减震效果的影响研究。结果表明:CPD构造简单,可方便快捷地安装于曲线桥上;远场地震波和近断层地震波作用下,CPD沿顺桥向和横桥向均能发挥一定的减震控制效果,对曲线桥动力响应的抑制具有良好的方向适应性;与远场地震波相比,近断层地震波作用下,由于长周期大脉冲的影响,CPD减震控制效果的变异性更大,当在结构自振周期附近存在大脉冲时,CPD的减震控制效果更佳。     

The Spatial Patterning of Alcohol Outlets in Post-Disaster Christchurch,New Zealand: Practical and Policy Implications

Natural disasters greatly impact the environment of affected societies with often unknown consequences. In this study we examine the impact that the Canterbury Earthquakes of 2010–2011 had on the distribution of alcohol outlets in Christchurch, New Zealand. Specifically, we compare the distribution of both on-site and off-site alcohol outlets pre- (December 2009) and post-earthquake (December 2014) and use spatial regression models to identify whether any neighbourhood-level factors predict the observed redistributions. Overall, the number of alcohol outlets decreased by almost 13% after the Canterbury Earthquakes. However, we found a moderate increase in the clustering of both outlet types of outlets in the post-quake period. Increases in rates of both on-site and off-site alcohol outlets in neighbourhoods were positively associated with the percentage of residents who resided in their neighbourhood < 5 years and with neighbourhood crime rate change, while negative associations were found with percentage population aged between 15 and 29 years. The results suggest that the changing spatial distribution of alcohol outlets in Christchurch was not random but driven, in part, by the emergent demographic composition of neighbourhoods. The significant practical and policy implications of a redistribution of alcohol outlets are outlined providing a tangible link between empirical research and practice in an urban environment plagued with post-disaster spatial and social uncertainties.     

阻尼器响应放大技术研究与应用进展

目前，阻尼器在工程结构减隔震控制领域的应用已极为广泛，但存在中小地震作用下阻尼器的位移和速度等较小时，阻尼器难以充分发挥耗能能力的问题。因此近年来阻尼器响应放大技术得到了国内外学者的广泛重视，并利用连杆机构、齿轮机构、杠杆机构、跨层支撑等提出了多种阻尼器响应放大装置。全面综述国内外阻尼器响应放大技术的研究和应用进展，包括装置构造和作用机理等。同时，分析现有阻尼器响应放大技术在遭遇极罕遇地震作用时阻尼器更容易失效等方面的不足，指出响应放大技术的研究和发展方向，以期为阻尼器响应放大技术的发展和极罕遇地震作用下确保工程结构的安全提供有效思路。     

地震落梁两级控制装置的开发与试验

为了增强桥梁抗御地震落梁的能力,减轻交通生命线系统的震害损失,基于耗能减震、多级设防和结构分灾三个抗震性能设计理念,设计了一种具有耗能限位和上部体系连续化两级功能,并能在不同水准地震下自动实现功能转换的地震落梁控制装置。首先,分析了装置的构成、特点和工作机理,对第1级耗能限位组件进行了拟静力试验,测试了耗能滞回曲线;然后,对第2级拉索连梁组件进行了静力拉伸试验,评价了其变形性能、破坏形式和锚固性能;最后,对抗震销栓进行了剪切试验,考察了控制级别的转换,采用试验结果对有限元模拟结果进行了验证。研究表明,地震落梁两级控制装置具有有效的位移约束、合理的耗能机制和明确的分灾保险丝构造,实现了梁-梁连接和墩-梁连接控制模式的优势互补,实现了强震作用下对桥梁落梁失效的控制和对桥墩的安全保护。     

Performance‐based plastic design and collapse assessment of diagrid structure fused with shear link

A diagrid structure fused with shear link (DSSL) is an innovative earthquake resilient structural system. The DSSL combines the steel diagrid structural system with shear links to dissipate the earthquake energy with the goal to minimize structural repair and downtime after strong earthquake shaking. The SLs are placed between diamond‐shaped grid units and decoupled from the gravity system. To facilitate the design of the proposed DSSL system, the performance‐based plastic design (PBPD) procedure is extended to design a prototype building utilizing DSSL. Detailed finite element model is developed to simulate the non‐linear dynamic response of the structure under a range of earthquake shaking intensities. The results of non‐linear dynamic analyses show that the DSSL has excellent seismic performance and can be efficiently designed using PBPD. Lastly, detailed collapse risk assessment of the prototype building is performed using the FEMA‐P695 methodology. The result shows that the PBPD‐designed DSSL has adequate margin against collapse. Hence, it can be used as an effective seismic force resisting system.     

Fuzzy‐sliding mode control of nonlinear smart base‐isolated building under earthquake excitation

In this paper, the effectiveness of the fuzzy sliding mode control strategy on three‐dimensional benchmark building with smart base isolation under seismic excitation has been examined. One of the appropriate control theories for such this nonlinear system is the sliding mode control theory; discontinuous sliding mode theory has weakness such as chattering phenomena. In this paper, we used a combination of fuzzy logic and sliding mode theory for the deletion of this defect. The proposed control theory has been scrutinized by applying on lately developed nonlinear three‐dimensional base‐isolated benchmark building. This building because of the three‐dimensional nature, coalescing of lateral and torsional responses, continuity of responses of the superstructure, and base is modeled with three degrees of freedom on every floor. In this building eight actuators assigned only at the base level and in the two directions (x, y). In other words, 16 actuators are located underneath the structure. Furthermore, the base isolation system has been modeled by considering lateral coupled equations for a better examination of the performance of the system. The results indicate that reduction of control performance is remarkable. Also, utilizing proposed control theory can decrease the responses of building in two main directions and, particularly, in the rotational degree of freedom.     

Coupled shear‐flexural model for dynamic analysis of fixed‐base tall buildings with tuned mass dampers

An equivalent discrete model is developed for time domain dynamic analysis of uniform high‐rise shear wall‐frame buildings with fixed base and carrying any number of tuned mass dampers (TMDs). The equivalent model consists of a flexural cantilever beam and a shear cantilever beam connected in parallel by a finite number of axially rigid members that allow the consideration of intermediate modes of lateral deformation. The proposed model was validated by a building whose lateral resisting system consists of a combination of shear walls and braced frames. The results showed the effectiveness of TMDs to reduce the peak displacements, interstory drift ratio, and accelerations when the building is subjected to a seismic load. The root mean square accelerations due to along‐wind loads also decrease if TMDs are attached to the building.