Has highway construction narrowed the urban–rural income gap? Evidence from Chinese cities

Using 2003–2016 panel data of 278 prefecture-level Chinese cities, we analysed the relationship between highway construction, resource flow, and urban–rural income gap using multiple spatial econometric models. Overall highway construction has narrowed the urban–rural income gap owing to better population mobility and goods flow. However, while goods flow has narrowed the gap, population mobility has aggravated it. A regional difference in the impact of highway construction also exists, that is, the effect is negative in central and western cities, but positive for eastern cities. Moreover, China's “4 trillion” fiscal and currency stimulus plan has strengthened highway construction in narrowing the income gap.     

Strengthening techniques tested on masonry structures struck by the Umbria–Marche earthquake of 1997–1998

The results of experiments carried out on structures damaged in the Umbria–Marche earthquake of 1997–1998 are presented. These tests were carried out in situ on masonry panels of various dimensions, which had been strengthened with either traditional or innovative materials and techniques. Concerning traditional methods, panels injected with new limed-based mixes were tested. Other tests were realized by gluing to the wallettes sheets of monodirectional carbon fiber (CFRP) or fiber glass (GFRP) with epoxy resins. In both cases the purpose of the tests was to analyze the effectiveness of the intervention, above all as a technique of seismic-upgrading against in-plane mechanisms of collapse. The results show a significant increase in strength. The experiments carried out allowed to obtain interesting indications for their practical utilization of the studied technique. The injection technique is substantially more efficient when used as a method of repair damaged panels, confirming that a preliminary evaluation of dimension and distribution of voids is necessary before adopting this technique. The experimental work showed that the use of composite materials on double-leaf roughly cut stone masonry is more effective when conducted with other stabilization schemes. The failure of the double leaf roughly cut stone panels strengthened with composite materials resulted from the separation of the two masonry leaves. In both cases the strengthening showed remarkable benefits in terms of increase in strength, providing the masonry with greater shear strength. The increase in stiffness following the intervention, as well as its effect, was also analyzed.     

Exploring the dynamics of the Turkish construction industry using input–output analysis

Construction is commonly regarded as an important industry in economic policy making owing to its strong interactions with other sectors in the economy. Using six national input–output (IO) tables compiled to date and economic data for the period between 1969 and 2006, the behaviour of the Turkish construction sector and its relationships to investment, income and to other sectors in the economy are examined. Analysis reveals that the construction industry is losing its propulsive role and that it tends to exaggerate the fluctuations of the economy. The examination of lead and lag times between changes in GNP, construction activity and investments show that public sector spending cuts, in particular, have significant effects on the amplitude and the timing of slumps of the industry. The analysis of linkage indicators indicates that for the whole period under consideration the construction industry has high linkages with only one other industry. Thus the ‘leading’ role it plays in the economy is questioned.     

The structural behaviour of a pre-stressed column–beam connection as an alternative to the traditional timber joint system

We present a new and alternative proposition for the traditional Asian timber column-and-beam connection, using the Kusabi–Nageshi (K–N) joint system. The mechanical behaviour is complex and relies on the embedment strength of the timber, pre-stress, friction, and elastic energy storage. Using a systematic comparative analysis, the advantages of the K–N joint over more traditional joints can be made clear. The comparison of the hysteresis from cyclic loaded cross-joint tests with varied pre-stress clarifies the enhanced mechanical behaviour of the K–N joint system.     

Assessment of the seismic performance of old riveted steel frame–RC wall buildings

Seismic performance assessment of old dual riveted steel frame–RC wall buildings using the nonlinear dynamic procedure is presented. The study is based on an existing nine-storey building located in Wellington, New Zealand. The building is representative of medium rise steel framed buildings from the first half of the 20th century.A three dimensional numerical model of the building was developed in an inelastic structural analysis program. Nonlinear characterisations necessary for the prediction of the inelastic cyclic behaviours of the structural components were incorporated into the numerical model. Details of the structural configuration and member properties for the analyses were determined from the original engineering drawings, the construction specifications, as-built concrete strength test results and literature on properties of steel sections used around the period the building was constructed. The inelastic time history analyses were conducted using a suite of seven earthquake records relevant to the seismicity of the building's location.Modal properties of the numerical model compare well with results of a physical test conducted on the building. The implemented modelling procedure appeared to have predicted the most probable seismic performance of this type of building, which would not have been captured by other simplified procedures. The assessment also highlighted the adverse effects the characteristics and location of the walls have on the seismic performance of this type of building by introducing significant torsional and vertical irregularities.     

A review of studies on Public–Private Partnership projects in the construction industry

Public–Private Partnership (PPP) in construction is gaining in popularity. Although papers published in major journals have documented real cases of PPP projects, there appears to be a lack of systematically summarizing what they have already provided. Consequently, this paper reviewed PPP studies published in the six top journals in the construction field. The objectives are to compare and contrast the findings of the studies so as to provide insights for directing further PPP research and improving the existing practices of PPP projects. To achieve the review objectives, studies were first classified as either empirical or non-empirical. Empirical studies were further grouped under three themes: risks, relationships, and financing. Non-empirical studies were grouped under five themes: financing, project success factors, risks, and concession period. Suggestions for further research are risks, financing, contractual agreements, development of PPP models, concession periods, and strategies in choosing the right type of PPP.     

CFD Simulations of Pool Fires in a Confined and Ventilated Enclosure Using the Peatross–Beyler Correlation to Calculate the Mass Loss Rate

The aim of this paper is to analyse the application of the Peatross–Beyler (P&B) correlation (Fire and safety science—Proceedings of the fifth international symposium, 1997) to calculate the Mass loss rate (MLR) for a pool fire in a confined and ventilated enclosure for a range of conditions.The experimental references considered are the PRISME-SI-D1, D2 and D6 tests (Prétrel et al. in 9th International seminar on fire safety in nuclear power plants and installations, 2005), conducted by the Institut de Radioprotection et de Sûreté Nucléaire.The dimensions of the enclosure used in the experiment are 5 m in length, 6 m in width and 4 m in height. A pool fire, (0.4,hbox {m}^2) hydrogenated tetrapropylene (TPH, (hbox {C}_{12}hbox {H}_{26})), is located in the center of the room. The compartment is connected to the outside through an inlet and outlet. The P&B correlation is implemented as a boundary condition in computational fluid dynamics calculations. The MLR outcome depends on the average (hbox {O}_2) concentration in a predefined volume and the characteristics of the fuel. The influence of the size and location of the predefined volume, the ventilation branch position (at 1 m and 3.65 m from the floor) and the Renewal Rate ((R_r)) ((4.7,hbox {h}^{-1}) and (8.4,hbox {h}^{-1})) are studied. Two types of (hbox {O}_2) predefined volumes have been tested: layer and ring. The layer volume is located in the low part of the compartment, the base of the volume spanning the compartment floor. The ring is a volume around the pit. It is assumed for both approaches that the measured (hbox {O}_2) is representative of the available oxygen for the flame. The P&B boundary condition predicts the influence of the vitiation on the MLR. Other methods, such as imposing the MLR expected in open condition, overpredict the amount of injected fuel. The results show that the P&B correlation provides good agreement with the experimental data. The deviation between experimental data and numerical prediction for the average MLR in the best case is ?5.0% with absolute values of 0.004 kg/s and 0.0038 kg/s for the experiment and the simulation respectively for case PRS-SI-D1. The MLR calculation is influenced by the position of the ventilation opening and the (R_r). The temperature and (hbox {O}_2) concentration profiles are significantly influenced by the ventilation configuration. These differences are related to the transport of the injected air from the inlet to the floor by density difference.     

对砌体结构类型的分析与抗震设计建议

基于构造柱-圈梁这一特殊形式的约束砌体结构的特点和其在抗震中的显著作用,以及不同配筋砌体构件对配筋率的要求,较好地定义了无筋、配筋及约束砌体构件,并对约束配筋砌体构件在抗震设计中的定位和界定提出了建议,可供修订《建筑抗震设计规范》和《砌体结构设计规范》参考。     

汶川地震作用下约束砌体房屋的抗震能力分析

为验证约束砌体结构的抗震性能,取4栋7层砌体房屋为例进行非线性地震反应分析。4栋房屋中2栋(代号为A1、A2)选自汶川地震影响区的约束砌体房屋,另2栋(代号为B1、B2)为虚拟无筋(或非约束)砌体房屋,除了无任何约束作用的构造措施之外,其他都分别和A1、A2相同。分析中选取汶川地震中基岩和土层场地的共20条地震动作为地震输入。基于分析结果,做了两方面的比较:约束砌体结构房屋地震反应特征和汶川大地震现场调查所见的对比和约束砌体房屋和无筋砌体房屋地震性状的对比。主要结论有:①计算得到的约束砌体房屋在大地震下的震害特征和实际地震相当吻合,结构分析所用的计算模型、恢复力模型和参数取值的可靠性得到验证;②和无筋(或非约束)砌体房屋相比,约束砌体房屋使砌体结构的抗震强度和延性大为改善,具有很好的抗倒塌能力。     

现役砌体结构震害分析与抗震性能评价

在砌体结构震害分析的基础上,以可靠性向量分析理论为基础,介绍了一种砌体结构抗震性能评价方法,通过计算砌体结构墙体的可靠性向量,全面把握结构体系中的薄弱墙体构件,为砌体结构的抗震加固提供必要的决策数据。     

我国砌体结构的发展状况与展望

简要介绍了我国建国以来砌体结构的应用、新型砌体材料、结构的研究和砌体结构理论研究方面取得的成就。并对未来我国砌体结构的发展提出了建议。     

Seismic performance assessment of masonry infill reinforced concrete buildings in Eastern Canada

In Eastern Canada, most of moment resisting reinforced concrete frames with unreinforced masonry infill (MI-MRF) buildings were constructed between 1915 and 1960. These pre-code structures, in terms of seismic requirements, are considered vulnerable to earthquake due to insufficient ductility and resistance. The goal of this study is to provide a quantitative assessment of their seismic performance using fragility functions. Fragility functions represent the probability of damage that corresponds to a specific seismic intensity measure (e.g. peak ground acceleration at the site). Based on a structural characterisation study on existing buildings in Québec region, a case study three storey–three bay MI-MRF was selected as representative for mid-rise buildings. Pushover analyses were conducted on a nonlinear model of the infill frame to obtain the corresponding lateral load-deformation capacity curve. The nonlinear behaviour of the reinforced concrete beams and columns was modelled with concentrated plastic hinges at members’ ends and a modified strut-and-tie model was used for the infill to account for multiple failure modes. A simplified probabilistic nonlinear static procedure was applied to obtain the seismic demand model at increasing levels of seismic intensity. Fragility functions were then developed using an experiment-based damage model that correlate the extent of damage to the displacement demand. Damage assessment using the developed functions was conducted for an earthquake scenario compatible with the design-level seismic hazard in Quebec City with a 2% and 10% probability of exceedance in 50 years. The developed functions and methodology are particularly useful in probability-based seismic loss assessment and in planning mitigation solutions.     

无筋砌体结构多层住宅振动台试验与抗震性能评估

目前,我国城镇大量砌体结构老旧多层住宅面临抗震加固、功能提升等需求.为研究该类结构的抗震性能,进行一个5层无筋砌体结构模型的模拟地震振动台试验,测试分析了 7度多遇地震、设防地震、罕遇地震作用下的裂缝损伤发展状况以及楼层加速度、位移、自振频率、阻尼等变化规律.同时,进行非线性有限元分析,并用基于抗震鉴定标准、基于承载能...     

5.12汶川大地震中砌体结构房屋震害调查与思考

通过对5.12汶川大地震大量砌体结构房屋严重破坏和倒塌的调查分析,发现重灾区地震烈度大于或远大于房屋设防烈度是主要原因,其次还有设计不合理,施工质量较差等原因,总结了砌体结构房屋设计施工的注意事项,可供工程技术人员、施工人员等参考。     

都江堰市钢筋混凝土楼梯的震害分析

楼梯是房屋的出入通道和重要的紧急逃生通道,本文根据对地震现场考察的情况,介绍了汶川地震中都江堰市建筑结构（多层框架结构、多层砌体结构）钢筋混凝土楼梯的破坏情况,分析了破坏原因,并对钢筋混凝土楼梯的抗震设计与施工提出一些建议。     

高延性混凝土加固无筋砖砌体墙抗震性能试验研究

为提高砖砌体墙的抗震性能,采用高延性混凝土（HDC）对其进行加固,对4片HDC加固砖墙和2片作为对比试件的未加固砖墙进行低周水平往复加载试验,主要研究不同加固形式（构造带加固和面层加固）及墙体砂浆强度对加固砖砌体墙的滞回性能、破坏形态、水平承载力及刚度退化等抗震性能的影响。试验结果表明：采用HDC加固可显著提高墙体的承载力和位移延性,延缓墙体开裂和刚度退化,改善墙体的脆性破坏特征;HDC构造带可对砖墙形成有效约束作用,改变墙体的破坏模式。基于试件的破坏形态,提出加固墙体的承载力计算方法,并根据试验结果进行了验证。     

砌体结构建筑的震害及抗震措施

对汶川地震中砌体结构的震害情况进行了分析,总结了砌体结构的震害特征及其原因,从完善砌体结构的抗震设计方面进行了论述,提出了提高砌体结构抗震性能的一些方法,以期保障人民群众的生命财产安全。