Seismic loss assessment of RC high-rise buildings designed according to Eurocode 8

A probabilistic seismic loss assessment of RC high-rise(RCHR)buildings designed according to Eurocode 8 and located in the Southern Euro-Mediterranean zone is presented herein.The loss assessment methodology is based on a comprehensive simulation approach which takes into account ground motion(GM)uncertainty,and the random effects in seismic demand,as well as in predicting the damage states(DSs).The methodology is implemented on three RCHR buildings of 20-story,30-story and 40-story with a core wall structural system.The loss functions described by a cumulative lognormal probability distribution are obtained for two intensity levels for a large set of simulations(NLTHAs)based on 60 GM records with a wide range of magnitude(M),distance to source(R)and different site soil conditions(SS).The losses expressed in percent of building replacement cost for RCHR buildings are obtained.In the estimation of losses,both structural(S)and nonstructural(NS)damage for four DSs are considered.The effect of different GM characteristics(M,R and SS)on the obtained losses are investigated.Finally,the estimated performance of the RCHR buildings are checked to ensure that they fulfill limit state requirements according to Eurocode 8.

Verification of Depth Adjustment Factor in Eurocode 5 for Tropical Hardwood Timbers

The depth adjustment factor for bending strength stated in Eurocode 5(EC5)is only applicable to timbers having a characteristic density below 700 kg/m^(3).However,most Malaysian timbers are hardwood,some with a characteristic density reaching above 700 kg/m^(3).Therefore,the objective of this study was to examine whether the depth adjustment factor stipulated in EC5 is valid for Malaysian hardwood timbers.Six timber species were selected for this study,namely Kapur(Dryobalanops C.F.Gaertn.),Kempas(Koompassia Maingay ex Benth.),Keruing(Dipterocarpus C.F.Gaertn.),Light red meranti(Shorea Roxb.ex C.F.Gaertn.),Geronggang(Cratoxylum Blume)and Balau(Shorea Roxb.ex C.F.Gaertn.).The determination of bending strength and characteristic density was conducted according to BS EN 408:2010 and BS EN 384:2016,respectively.A graph for mean bending strength vs.(150/h)was plotted for each timber species.The power function was selected to analyze the relationship between the two variables.The power of the regression equations varied depending on the characteristic density of the timber species.For species with a characteristic density below 700 kg/m^(3),such as Kapur,Keruing,and Light red meranti,the power was between 0.16 to 0.17.In contrast,for species having a characteristic density above 700 kg/m^(3),namely Kempas and Balau,the power was higher at 0.23 and 0.24,respectively.Geronggang was an exception to this pattern.These values are close to the depth adjustment factor given in EC5,which is 0.2.Based on the results,it can be suggested that the adjustment factor of 0.2 is also applicable to Malaysian hardwood timbers with a characteristic density above 700 kg/m^(3).

Experimental Research of Impact Toughness of the Kazakhstani Construction Steel— Assessment of Compliance with the Provisions of 1993 Eurocode

Since 2015, the Republic of Kazakhstan has a new regulatory framework for construction on the basis of Eurocode. Many new steel quality requirements have been introduced for steel structures. As a result, Kazakhstan’s steel production almost ceased to be used in construction. Therefore, a series of studies is being carried out to determine the quality of local steel for compliance with the requirements of Eurocode 1993. Impact toughness testing was carried out on 126 samples of 8, 10, 20 mm thick structural steel produced by the “Arcelor-Mittal” company. The experimental study of impact toughness of KCV and KCU at a temperature of +20˚, -20˚, -40˚ degrees were conducted for seven types of structural steel, the most common in the Republic of Kazakhstan, on the experimental experimentation facility of the KazRDICA JSC. The ST RK STB EN 10045-1-2012 techniques were used. In each series of tests, 3 specimens were used. It has been established that in all cases the temperature requirements of Eurocode 1993 (National Annex to SP RK EN1993-1-1: 2005/2011*, Table НП.2*) are met. A regression relationship between the values of impact toughness and temperature was constructed. It has been established that construction steel produced in the Republic of Kazakhstan fully complies with the requirements of 1993 Eurocode. The studies on the dependence of Brinell hardness of steel on the impact toughness of steel at specified temperatures are performed. The correlation dependencies between the values of impact toughness and BH Brinell hardness have been obtained.

基于Eurocode规范的混凝土桥梁设计分析

伴随国家“一带一路”倡议的逐步推进,中国工程企业的业务范围逐渐遍布全球各地。尽管国家正大力推进中国规范走出去,但限于意识形态、技术优势、工程习惯等诸多因素,欧洲、非洲、东南亚等许多国家坚持必须采用Eurocode规范。因此,要想在激烈的国际竞争中脱颖而出,志在走出国门的中国设计咨询企业必须熟悉国外规范和设计习惯。基于此,文章结合笔者多个海外工程项目的设计经验,系统介绍Eurocode规范在混凝土桥梁设计方面的荷载及混凝土结构设计指标,同时结合一个实际工程案例,详细阐述Eurocode规范的设计方法和主要原则,希望对同行在今后的设计工作中有一定借鉴价值。

基于Eurocode3方法的不锈钢地铁车体疲劳强度评估

为了确保地铁车辆的长期安全可靠运行,采用EN12663-1:2010标准对某不锈钢地铁车辆车体结构进行了疲劳强度仿真计算,并采用Eurocode 3方法对焊缝进行了评估,分析计算结果表明该车体结构满足2×106循环周次疲劳寿命的要求。

基于Eurocode 3标准的某塔设备稳定性分析

有限元方法较高的计算能力为其在实际应用中提供了更多可能,介绍了Eurocode 3标准中公式法和数值模拟LBA-MNA方法。通过真实案例,根据Eurocode 3标准中的公式法对轴向弯矩作用下的塔设备进行稳定性分析,并与LBA-MNA法分析结果进行比较。结果表明,通过延长单筒节来进行多筒节的失稳分析是偏保守的。

Structural Eurocodes Systems (China) Forum Held in Beijing——Construction Standards in China

The Structural Eurocodes Systems, which are developed by the European Committee for Standardization (CEN), have come into trial use in the 28 countries of European Union (EU), and will lay a significant influence on the development of the construction industry and on the international market of construction.

Eurocode7直接法中极限状态三种分项系数组合的选择

欧洲岩土工程规范Eurocode7直接法中验证地基和结构构件的破坏或过度变形时,给出了不同情况下作用力、岩土参数和反力的分项系数,不同的分项系数组合得到了三种设计方法。案例分析表明,这三种设计方法的结果有较大离散。在偏心受压条形基础和悬臂式挡土墙的设计中,活载的分布决定其分项系数的选择,同时偏心的大小也影响着恒载分项系数的选择;再者,荷载分布的不同,影响着岩土结构设计是对荷载还是对岩土参数更为敏感,因此也就决定了相应的分项系数和更合适的分项系数组合。

Impact of Earthquake Action on the Design and Sizing of Jointed Masonry Structures in South Kivu, DRC

This article deals with the investigation of the effects of seismic impacts on the design and dimensioning of structures in South Kivu. The starting point is the observation of an ambivalence that can be observed in the province, namely the non-consideration of seismic action in the study of structures by both professionals and researchers. The main objective of the study is to show the importance of dynamic analysis of structures in South Kivu. It adopts a meta-analytical approach referring to previous researches on South Kivu and proposes an efficient and optimal method. To arrive at the results, we use Eurocode 7 and 8. In addition, we conducted static analysis using the Coulomb method and dynamic analysis using the Mononobe-Okabe method and compared the results. At Nyabibwe, the results showed that we have a deviation of 24.47% for slip stability, 12.038% for overturning stability and 9.677% for stability against punching through a weight wall.

Assessment of Deviation in Quality of Steel Reinforcing Bars Used in Some Building Sites in Cameroon

The present work evaluated the deviations in the quality of steel reinforcing bars in terms of markings, diameter, yield strength and ductility in order to facilitate the drawing up of a yield strength value for the Cameroon National Annex to Eurocode 2. The methodology of the work started with the collection of steel samples from various active building project sites in four different towns viz: Bamenda, Douala, Maroua and Yaoundé and testing their tensile strength and elongation using a Universal Testing Machine and also carrying out the bending test. Results show that bars without marked manufacturer’s name fell all the tests. Other results show that 52% of all the steel had yield stresses below 400 Mpa and the highest deviation in the yield strengths was 22.50%. The study recommends that properly marked grade 500 steel bars should be adopted in the Cameroon national annex to Eurocode 2.

Weld Joint Efficiency of the Kazakhstani Constructional Steel

In the Republic of Kazakhstan, the regulatory framework in construction based on Eurocodes has been in force since 2015. However, Kazakhstani produced steel has not been studied for compliance with the requirements of Eurocode 1993. This has resulted in limited use of Kazakhstani structural steel in construction. The feasibility of using structural steel in welded joints has been experimentally investigated. To verify the application of such joints in construction, including earthquake engineering, experimental studies of welded joints made of structural steel produced by Arcelor-Mittal in Temirtau have been carried out. In total, 7 types of structural steel of various thicknesses were selected. Five specimens have been used in each series of tests. The Brinell hardness values of the weld joint, yield strength of steel and tensile strength, relative rupture strain were determined. It was found that for all types of structural steel, the quality of weld joints complied with the requirements of Eurocode 1993—a sample rupture appeared along the plates (main body of the metal), not along the weld joints. It has been established that structural steel produced in the Republic of Kazakhstan fully complies with the requirements of Eurocode 1993. The studies on the dependence of Brinell hardness values of weld joint steel on the yield strength, tensile strength and relative rupture strain have been carried out. The correlation dependences between the values of yield strength of steel and tensile strength, relative rupture strain and BH Brinell hardness were studied. The results of work will allow for significantly increasing the use of Kazakhstani structural steel in seismic and conventional areas of the Republic of Kazakhstan.

Comparative Evaluation of the Chemical Composition and Physical Properties of Reinforced Concrete Steel Bars Used in Construction in Senegal

This article presents, the study of a comparative evaluation of the chemical composition and physical properties, linear mass deviations, of four (04) types of steel used in the construction sector in Senegal. Type 1 (E1), Type 2 (E2) and Type 3 (E3) steels are produced by locally established companies and Type 4 (E4) witness bars are imported from the France. The chemical analyses of the different types of steel were carried out by combustion, infrared (IR) detection for carbon and sulfur, by reducing fusion for nitrogen and by optical emission spectrometer (SEO) for the rest of the elements. The composition was determined on bars with a diameter of 10 mm. Linear mass deviations were evaluated for steels with a diameter of 8 mm, 10 mm and 12 mm. The results of the chemical analyses showed that the limit value for the percentage of carbon was exceeded by 29.16% for the steel, type 3. For the other types (1, 2 and 4), the limit values set out in the French standard NF EN 10,080 are not exceeded. As regards the relative differences in mass, the results showed that for steels of local manufacture, all the samples of bars with diameters 10 and 12 mm and 33% of steels with diameters 8 mm do not comply with the standard. The results also indicate that the chemical composition and relative linear mass deviations of the steels, type 4 comply with the standard. Thus, locally manufactured steels are not always suitable for use in reinforced concrete constructions.

欧美规范中公路桥梁正交异性钢桥面板抗疲劳设计对比分析

为给我国公路桥梁正交异性钢桥面板抗疲劳设计提供参考,从疲劳荷载、疲劳细部分类及疲劳验算公式等方面对比AASHTO、Eurocode 3规范,并分别应用2本规范对我国一座公路桥梁的正交异性钢桥面板进行疲劳验算。结果表明:针对公路桥梁正交异性钢桥面板的抗疲劳设计,AASHTO、Eurocode 3两本规范在设计思路、细部分类、验算公式等方面基本一致,参考其对我国公路桥梁正交异性钢桥面板进行抗疲劳设计是可靠的,鉴于Eurocode 3对正交异性钢桥面板的疲劳细部规定更全面,参考Eurocode 3对公路桥梁正交异性钢桥面板进行抗疲劳设计较为合适。

中欧(法)挡土墙设计规范对比研究

研究目的:为明确中欧(法)挡土墙设计规范差异,为开展海外工程设计提供参考,本文结合算例对中欧(法)挡土墙设计规范进行了对比研究。研究结论:(1) Eurocode 7只介绍了岩土工程设计原理和设计中要考虑的主要因素,但较少涉及具体计算方法,难以直接指导实际设计,需要结合各成员国制定的补充规范使用;(2)中法挡土墙设计规范所涉及的抗滑移、抗倾覆、基底承载力、偏心距等验算内容所对应的安全度基本一致;(3)法国规范基底摩擦系数取值较高,依据法国规范进行设计时挡墙底部尺寸可适当减小;(4)在进行结构强度验算时法国规范规定的荷载分项系数取值小于铁路支挡规范,在进行裂缝宽度检算时欧洲规范规定的裂缝宽度限值高于混规,从而导致依据法国规范设计的挡墙配筋量大幅减少;(5)本文得出的结论可应用于海外岩土工程设计。

国内外铁路桥梁规范抗疲劳设计方法分析

回顾中国铁路钢桥设计规范的抗疲劳设计方法,阐述英国BS5400规范和欧洲规范Eurocode3的抗疲劳设计条文,分析比较这些规范抗疲劳设计方法。英国规范和欧洲规范采用了无限疲劳寿命方法和有限疲劳寿命相结合的方法,中国铁路桥规使用的是无限疲劳寿命方法,各国规范均不同程度地使用了概率的方法来处理影响结构疲劳的因素。在特殊结构细节分类和构造细节热点名义应力的计算方法上,英国BS5400及欧洲规范都进行了详细的规定,并且对于剪应力疲劳在欧洲规范中有了较为详尽的计算方法。

中欧美拉伸锚固长度比较研究

对中欧美规范中拉伸锚固长度的定义和计算公式进行了比较,并选取不同工况,重点考虑了钢筋间距和直径、混凝土强度和保护层厚度的影响,用规范公式对梁和板中的锚固长度进行了计算分析。通过对比发现,在几种主要因素影响下,Eurocode 2锚固长度曲线变化趋势和极限锚固长度曲线变化趋势整体上比较接近。当考虑钢筋间距和直径的影响时,在梁中和板中,GB 50010—2002的变化趋势和Eurocode 2比较相似,值也比较接近。在考虑混凝土强度和保护层厚度时,GB 50010—2002精细方法计算值在影响因素取值较大时,对于板来说偏保守,建议取个适当的折减系数。ACI318-05多数因素影响下均偏保守,建议考虑相应因素的影响时取合适的折减系数。

中、欧、美岩土勘察布置的比较

针对中外标准有关岩土勘察布置要求的差异化问题,进行了中标(GB 50021-2001《岩土工程勘察规范》、JTS133-2013《水运工程岩土勘察规范》)、欧标(Eurocode 7《岩土工程设计规范》)和美标(《ASTM岩土勘察类标准》)有关岩土勘察布置要求的对比分析研究。研究发现,中外勘察标准在阶段划分、内容、方法、勘探点间距与深度、试验数量、勘察过程中的优化、施工阶段控制与监测等各个环节均存在明显差异,并在此基础上提出了海外勘察标准应用要点。这些研究成果有助于行业同仁对海外勘察标准的了解和使用,也利于中国勘察标准的国际接轨。

欧洲结构规范与欧洲土建标准体系

欧洲结构规范Eurocodes是工程建设领域中极具影响力和权威性的一套区域性国际标准,自2010年4月1日起作为欧盟的法定标准在各成员国及其殖民地地区得到了广泛的应用。该文简要介绍了欧洲土建标准的体系架构,列举了与Eurocodes相关的土建领域常用的欧洲标准及ISO国际标准,以便于从事国外土建工程设计与施工的专业人员更好地理解、掌握和运用欧洲结构规范。

欧美标准砂土液化判别方法解读和优化

多数海外项目执行欧美标准,欧美砂土液化判别方法跟中国标准存在较大差异而且比较复杂,国内大多勘察技术人员对欧美标准砂土液化判别方法尚掌握不全面、不会正确应用。对照中国水运行业抗震标准,对欧标Eurocode 8和美国Seed简化法砂土液化判别方法进行了解读。结合工程案例对3种判别方法进行对比分析,揭示了与中标的差异,并系统展示了欧美判别标准全貌,包括其原理、判别条件、判别程序、相关特点等。在此基础上,针对欧美判别方法存在的缺陷和问题,在符合标准和误差允许前提下进行简化,使利用欧美标准判别液化更加简单易行。

基于欧标的支挡结构设计验算方法探讨

目前国内尚缺乏支挡结构方面统一的设计及验算标准，以致相关设计工作缺乏针对性、统一性和系统性，同时也给不同行业之间技术交流带来困难。以符合欧标的《德国土工结构与基础安全验算标准》（DINl054．2005）为例，介绍和探讨了欧标中支挡结构设计相关概念及验算方法，以期增进对欧标相关方面的理解，为我国岩土工程设计规范的今后发展提供一定的参考。