Performance-based seismic design of nonstructural building components:The next frontier of earthquake engineering

With the development and implementation of performance-based earthquake engineering,harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event,failure of architectural,mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover,nonstructural damage has limited the functionality of critical facilities,such as hospitals,following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore,it is not surprising that in many past earthquakes,losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore,the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings,or of rescue workers entering buildings. In comparison to structural components and systems,there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse,and the available codes and guidelines are usually,for the most part,based on past experiences,engineering judgment and intuition,rather than on objective experimental and analytical results. Often,design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components,identifying major knowledge gaps that will need to be filled by future research. Furthermore,considering recent trends in earthquake engineering,the paper explores how performance-based seismic design might be conceived for nonstructural components,drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components.

Additive Manufacture of Ceramics Components by Inkjet Printing

In order to build a ceramic component by inkjet printing, the object must be fabricated through the interaction and solidification of drops, typically in the range of 10–100 p L. In order to achieve this goal, stable ceramic inks must be developed. These inks should satisfy specific rheological conditions that can be illustrated within a parameter space defined by the Reynolds and Weber numbers. Printed drops initially deform on impact with a surface by dynamic dissipative processes, but then spread to an equilibrium shape defined by capillarity. We can identify the processes by which these drops interact to form linear features during printing, but there is a poorer level of understanding as to how 2D and 3D structures form. The stability of 2D sheets of ink appears to be possible over a more limited range of process conditions that is seen with the formation of lines. In most cases, the ink solidifies through evaporation and there is a need to control the drying process to eliminate the "coffee ring" defect. Despite these uncertainties, there have been a large number of reports on the successful use of inkjet printing for the manufacture of small ceramic components from a number of different ceramics. This technique offers good prospects as a future manufacturing technique. This review identifies potential areas for future research to improve our understanding of this manufacturing method.

Treatment of Heavy Metal Pollution in Sediment and Its Resource Utilization in Building Ceramics

With the rapid development of China's social economy and the acceleration of urbanization,a large quantity of production and domestic sewage is discharged into rivers and lakes,and the concentration of pollutants leads to serious excessive heavy metals in sediment,which affects the ecological environment.In this paper,the treatment technology of heavy metal pollution in sediment and its resource utilization in building ceramics in China are systematically analyzed and summarized,in order to provide a reference for the treatment of sediment in rivers and lakes and the sustainable development of building ceramics industry.

Shandong Hualuoli Building Ceramics General Co. (Group)

The Shandong Hualuoli Building Ceramics General Co. (Group) is a large comprehensive building materials enterprise established with approval from the Provincial Structure Reform Commission in March 1993. The company was first founded in 1979 with seven subsidiary enterprises, including the Linyi Hualuoli Building Ceramics Co. Ltd., Linyi Tianren Building

Research on Measurement and Calculation of Carbon Emission from the Production of Prefabricated Building Components

The measurement and calculation of the carbon emission from the production of prefabricated building components were studied.Based on the carbon emission factor method,a carbon emission calculation model of the components in the production phase was established.Besides,the actual measurement method and calculated at rated power method were proposed for the measurement and calculation of carbon emission,and several measurements were carried out in a component factory located in a coastal area of south China and a component factory located in Beijing,respectively.The results of the study show that the carbon emission factors of laminates and wallboards produced by factories located in coastal areas of southern China under natural curing conditions were 7.61 kg CO2/m3 and 5.84 kg CO2/m3 respectively.The carbon emissions conversion coefficients of concrete mixer,reinforcing bar production line and travelling crane between actual operation and with per the rated power were approximately 0.44,0.34 and 0.34 respectively.When the actual measurement cannot be performed,the conversion coefficient can be used to correct the data of the calculated at rated power to make it closer to the true value.The carbon emission factor of the laminated panels produced by the component factory in Beijing under steam curing concrete conditions was 132.15 kg CO2/m3,and the factory is used as a prototype,a complementary steam generation system model of solar energy and boiler was established,and it was calculated that the system can reduce CO2 emissions by about 300 tons throughout the year.

Preliminary investigation of building damage in Hatay under February 6,2023 Turkey earthquakes

On February 6,2023,an M_(w)7.8 earthquake hit the south of Kahramanmaras prefecture,Turkey,followed by another M_(w)7.5 earthquake after nine hours in the middle region of the Kahramanmaras prefecture.More than 84,000 buildings collapsed or were severely damaged,and more than 50,000 lives were lost in Turkey and Syria.Some of the authors,as members of Chinese rescue team,entered Antakya,Hatay prefecture,and investigated the damaged buildings.This paper first summarizes the damage patterns of buildings and provides three reasons for the massive number of collapsed buildings;i.e.,the lack of seismic measures for better ductility,site effects such as liquefaction and surface rupture,and pronounced low-frequency components of the ground motions.Next,the seismic responses of two typical buildings are calculated based on the geometric data estimated by visual inspection.The results imply that the resonance of the whole structure and the poorer ductility of key members resulted in the collapse of buildings.Finally,some conclusions are drawn.Note that although a large number of buildings were seriously damaged to collapse,the majority of buildings in the areas of extreme shaking were lightly or moderately damaged,which implies that well designed and constructed buildings were able to survive and protect human lives even in over-design earthquakes.

Assessment of the long-term possible radiological risk from the use of ceramic tiles in Malaysia

This study investigated the level of natural radioactivity and radiological risks of 40 different ceramic tiles through gamma-ray spectroscopy using a high-purity germanium detector. The calculated activity concentrations were evaluated to determine their potential radiological risks to human health. Furthermore, the activity concentrations were subjected to the RESRAD-BUILD computer code to assess the effect of ventilation rate, dweller position, and room size and direction on the total effective dose(TED). The simulated TED received by a receptor when changing the ventilation rate in a room ranged from0.26 ± 0.01 to 0.61 ± 0.01 mSv/y; however,the percentage variations in the TED due to dweller position and room size are 34, 31,and 35% and 33, 27, and 40% for the x-,y-,and z-directions, respectively. The overall TED received by the dweller based on room size and direction is 0.75 mSv/y. The calculated radiological risk parameters were all below the recommended maximum limit. However, the TED received by the dweller is significantly affected by the directions of the measurement, position,room size,and ventilation. Therefore,estimating the TED from one direction would underestimate the total dose received by the dweller.

Review of Conventional and Innovative Technologies for Fire Retrofitting of Existing Buildings

Fire effects can be one of the most harmful conditions that any building may experience throughout its service life. Developing practical protection methods and concepts against potential fire disasters in buildings has been an important consideration in design of buildings in recent decades. Rapid developments in technology have heightened the demand for new and innovative fire protection systems in comparison with conventional and traditional methods. Such a need for new technologies is in particular of greater importance when it comes to existing buildings. Retrofitting an existing building for fire safety is a greater challenge compared with designing a new building using materials and components that have more desirable and superior fire rating to begin with. Furthermore, strategies to design a new building that includes state-of-the-art fire safety features are also different from solutions that may be more suitable for retrofitting an existing building. This paper presents a review of the literature concerning conventional and new or innovative retrofitting methods for fire safety of buildings. Advantages and disadvantages of different fire protection devices and methods as available and understood from the literature are mentioned. Study of fire safety systems shows that each has its drawbacks. Comparison of the results shows that disadvantages of a solitary system for retrofitting against fire can be improved by using a combination of several fire safety concepts or methods simultaneously.

甘肃积石山6.2级地震村镇建筑震害调查与分析

积石山地震对甘肃和青海部分地区房屋建筑造成了严重破坏。调查了地震烈度7度和8度地区的11个调查点的村镇建筑震害。震害调查表明:地震灾区主要为乡镇和农村地区,房屋结构类型主要为土木、砖木和未设防砖混结构;在烈度8度地区,土木结构房屋主要表现为严重破坏或倒塌破坏,砖木结构和未设防砖混结构房屋主要表现为中等破坏和严重破坏,设防砖混和钢筋混凝土框架结构房屋主要表现为轻微破坏和中等破坏;在烈度7度地区,土木结构房屋以中等破坏为主,砖木结构和未设防砖混结构房屋以轻微破坏和中等破坏为主,设防砖混和钢筋混凝土框架结构房屋以轻微破坏和基本完好为主。此次地震震害较同级别地震偏重,与震区复杂地形、地震动峰值放大效应、建筑砌筑质量差和结构受力不合理等因素相关。建议进一步开展复杂地形场地放大效应及频谱影响研究,重视建筑非结构构件抗震宣传与实用技术研发。

微波介质陶瓷产业体系发展研究

微波介质陶瓷作为微波电路中的电介质,是现代通信技术中的关键基础材料,广泛应用于通信、导航、雷达、卫星等领域。本文在分析国内外微波介质陶瓷及产业发展现状的基础上,剖析了当前我国微波介质陶瓷发展面临的问题,提出了涵盖发展目标、发展思路、重点发展方向以及发展路线图的微波介质陶瓷产业体系自立自强发展战略。为促进微波介质陶瓷的发展,实现我国微波介质陶瓷产品由中低端为主向高端型升级转变,突破高性能微波介质陶瓷制备技术及上游高纯原材料的自主化生产技术,建议加强微波介质陶瓷的基础研究和应用研究、强化重点微波通信领域的创新研发、积极布局第六代移动通信用介质陶瓷和加强产业生态建设。

航空发动机陶瓷基复合材料无损表征技术研究进展

随着陶瓷基复合材料在先进航空发动机热端部件中的推广应用,对其在工艺研发、制备加工、试验考核以及使用服役等阶段形成的缺陷/损伤进行高效准确的无损表征尤为重要。由于陶瓷基复合材料复杂的制备成型工艺及多相复合引起的高度非均质和各向异性,导致传统基于整体均质化假设的无损检测技术面临诸多挑战。本文结合陶瓷基复合材料在航空发动机领域的应用情况,分析了其在制备、加工及服役等阶段的典型缺陷/损伤类型及特征,重点回顾了近年来陶瓷基复合材料无损表征技术的研究进展及应用情况,总结了现有无损表征技术面临的主要挑战,并对未来的发展趋势进行了展望。

建筑陶瓷产业现代化治理体系探析

在国家治理体系现代化建设的大背景下,建筑陶瓷产业治理体系作为产业治理体系的一部分,其现代化建设在国家治理体系现代化进程中必不可少。同时,建筑陶瓷产业现代化治理体系也是建筑陶瓷产业实现现代化的重要前提和手段。本文主要分析了建筑陶瓷产业现代化治理体系建设的必要性,并初步探讨了建筑陶瓷产业现代化治理体系的内涵、基本要素和实施路径。

提钒尾矿综合回收利用研究现状

从有价组分回收、新型功能材料合成和多用途建筑材料制备三个方面阐述了目前提钒尾矿资源的综合回收利用途径,可为提钒尾矿综合回收技术应用提供参考。

基于EMI-CNN的建筑施工模板支撑体系节点健康监测

为预防模板坍塌引发建筑施工安全事故风险,提出一种基于压电阻抗法(EMI)和卷积神经网络(CNN)的模板支撑体系节点智能监测方法。首先,利用压电陶瓷传感器(PZT)的机电耦合特性及其集驱动-传感于一体的特点,建立PZT-节点耦合系统的机电阻抗传感机制模型;其次,基于EMI法,以与待测结构耦合的PZT片电导信号为监测指标,确定模板支撑体系节点松动的发生;然后,以敏感频段内PZT片的801个原始电导信号为模型输入,9个节点松动程度为模型输出,构建162组学习样本和27组测试样本,建立EMI-CNN模型,确定节点松动程度;最后,以一个实际工程中的建筑施工模板体系节点为例,验证EMI-CNN模型的有效性,并对比分析EMI-BP模型。研究结果表明:EMI-CNN模型经过85次迭代达到收敛,预测准确率达到100%,相较于EMI-BP模型提高29.63%。该监测方法可实现对建筑施工模板支撑体系节点健康状态实时、准确、无损监测。

高层建筑竖向构件分离顶升纠偏关键技术研究

为了揭示高层建筑竖向构件分离顶升纠偏工艺的内在机理,给出了顶升系统的理论模拟方法,分别从千斤顶布置、顶升控制模式和顶升误差三个因素对结构内力的影响展开研究。通过对比各因素影响下结构的内力计算结果,总结了墙柱分离顶升纠偏设计、施工过程中的关键技术。结果表明:分离顶升过程中,单向双千斤顶布置形式不可取;“力为主、位移为辅”的双控顶升模式更适用于实际工程;顶升时的微小误差,可能会引起极大的结构附加内力,应通过理论分析和施工控制加以避免。

东北地区教育建筑天然采光设计机制和优化策略研究

本文针对东北地区教育建筑冬季严重眩光和照度不足的双重问题,从探索典型教室空间天然光分布特点入手,分析采光设计机制,通过实地观察监测和静态、动态模拟比较分析,提出了界面柔光、构件导光和腔体补光三种采光优化设计策略,并结合实际工程进行了设计应用和建成后的监测评估,形成了对教育建筑设计实践具有参考借鉴价值的方法探索和理念创新。

基于BIM的PC构件排样优化设计

针对PC构件排样与上游装配式建筑设计模型的协同效用问题,进行了基于BIM的PC构件排样优化设计研究。分析了装配式BIM中PC构件的组成元素,完成PC构件信息的提取;结合改进蚁群算法与动态剩余矩形算法对PC构件排样进行优化,采用遗传变异策略与路径选择机制改进算法后期易陷入局部最优的不足,经过多次优化迭代得出最优排样。某PC构件企业的生产排样实例验证了基于BIM的PC构件排样优化方案可实现上游装配式建筑设计模型与PC构件排样的协同效用,提高了排样效率。

预埋吊件的拉剪耦合力学性能试验研究

在预制构件吊装施工过程中,预埋吊件起到了举足轻重的作用。随着对预埋吊件需求量的迅速增大,需对正在生产使用的预埋吊件的安全性能问题进行深入的研究,为了深入研究预埋吊件的拉剪耦合力学性能,选取了三类三种共18个预埋吊件,并将其设计成三组共9个混凝土试件进行拉剪耦合试验。通过对试验现象的分析可知,9个混凝土试件均发生了混凝土破坏,通过对试验数据和荷载-位移曲线进行处理分析,可计算出每个预埋吊件的极限承载力,验证了该试验方案的可行性;将试验数据代入三个规范中关于拉剪耦合的计算公式进行验算,结果表明美国规范ACI 318规定的计算方式在计算拉剪耦合作用力时更为安全。

国内外建筑围护结构风荷载规范对比研究

针对围护结构设计风荷载,分析了如下风荷载规范中的相关规定:中国GB 50009—2012、中国JGJ/T 481—2019、美国ASCE/SEI 7⁃16、日本AIJ⁃2015、澳大利亚/新西兰AS/NZS 1170.2:2021、欧洲BS EN 1991⁃1⁃4:2005、加拿大NBCC 2015。分析结果表明,国内外围护结构风荷载规范的理论基础主要包括准定常理论和风压极值理论,均将设计风荷载表示成设计风速与设计风压系数的乘积;设计风速的确定需要考虑地貌、局部地形、季节、风向、相邻建筑干扰等因素的影响,各国规范对这些因素考虑的详尽程度不一;设计风压系数则需要考虑来流湍流和特征湍流共同作用下风压的时间随机性和空间分布不均匀性、不同方向来流时建筑表面风压的差异性、建筑表面风压相关性等因素,各国规范均通过风压分区和面积折减较好地考虑了这些因素,不同之处在于不同规范所涵盖的建筑体型、考虑建筑几何参数影响的风压分区结果及面积折减的特征有所区别。

装配式建筑用预制构件碳排放研究

基于碳排放系数法,建立了装配式建筑用预制构件碳排放核算方法,研究了单位预制实心墙板、柱、梁、楼梯、叠合楼板、女儿墙、凸窗、空调板等预制构件从生产到运输过程的碳排放情况。结果表明:预制构件碳排放在528~1008 kgCO_(2)/m^(3);梁、柱碳排放高于其他预制构件,为685~1008 kgCO_(2)/m^(3);各环节的碳排放从大到小依次为原材料隐含碳排放C_(Y)>原材料运输碳排放C_(T)>能耗碳排放C_(S);钢筋和水泥在原材料隐含碳排放中占比较大。