Review of Different Pushover Analysis Methods Applied to Masonry Buildings and Comparison with Nonlinear Dynamic Analysis

This article presents the comparison among different nonlinear seismic analysis methods applied to masonry buildings, i.e., pushover analyses with invariant lateral force distributions, adaptive pushover analysis and nonlinear dynamic analysis. The study focuses on the influence of lateral force distribution on the results of the pushover analysis. Two simple benchmark case studies are considered for the purpose of the research, i.e., a four-wall masonry building prototype without floor rigid diaphragms and a two-wall system with a cross-vault. The comparative study offers a useful review of pushover analysis methods for masonry structures and shows advantages and possible limitations of each approach.     

浙江越窑青瓷标本信息数据库管理系统的设计与实施

对文物标本进行系统分析归纳是传统工艺研究的必要途径,为实现越窑青瓷标本资料的资源共享,提高实验室工作效率,实现分析数据的科学管理,本研究开发设计了“浙江越窑青瓷标本信息数据库管理系统”.该系统基于B/S结构模式,以浙江省博物馆陶瓷标本中心的各类越窑瓷片标本来源、形态、化学成分、物理性能、显微结构、制作工艺等相关信息数据为基础,采用Wi ndows平台,以Visual Studi0 2010为开发环境,结合ASP.NET 4.0框架以及SQL Server数据库技术而构架.经过系统测试和实际运行证明,此管理系统具有良好的应用界面,交互性强,运行稳定,数据处理方便等优势,对实现古陶瓷研究信息资源共享,全面开展越窑青瓷的科学化研究提供了一个良好的数据平台.     

Structural ways to embed a research laboratory into the company: A comparison between Philips and General Electric 1900-1940

This paper compares the Philips Research Department and the Research Laboratory of the American company General Electric (GE). 1 It argues that it is, above all, the issue of the organization of industrial research, appropriate leadership and the embeddedness of a research department in the company as a whole that is important for an historical analysis of an industrial research department. The complex structures that Gilles Holst (the first Philips research director) and Willis Whitney (the GE research director during the first decades of the twentieth century) set up in their organizations enabled scientists to keep in touch with the resources provided by the universities, and made it possible for them to come up with articles, patents and devices for their respective companies. It enabled them also to strengthen their contacts inside and outside the laboratory's walls. However, more than his colleague Whitney at GE, Holst at Philips intended to integrate the research laboratory into the company as a whole. Holst's policy as a research director will be illustrated using the case of Philips' radio research. A comparative discussion of industrial research in the 1930s within both companies shows that the "successful" integration of research activities is context-dependent.     

哈尼梯田文化生态系统研究

本文通过深入哈尼族地区调查,运用系统论及文化生态等方法,提出了哈尼梯田文化生态系统的概念,分析了哈尼梯田文化生态系统的特征、组成、空间结构、物质能量流动及其功能,指出哈尼梯田文化生态系统是一个和谐的人地系统,具有自我维系的功能。     

甘肃出土糟朽木器的形态与结构分析

甘肃出土木器依据形态与结构划分,属于典型的糟朽木器类型,材质外观特征与特性明显。制作材质鉴定表明,基本类型有①松科云杉;②松科冷杉;③柏科圆柏。通过对糟朽木器形态类型、结构属性、影响因素及发生改变原因剖析,指出了糟朽木器材质在经历了第一阶段的转折性根本改变后（含水率远低于纤维饱和点）,即将面临第二阶段的转折性根本变化（含水率略高或接近于平衡含水率）,而这一阶段的改变结果对器物将是毁灭性的;为了避免出土器物在短期内形态发生剧变,运用生物切片、扫描电镜分析技术对木质纤维显微结构进行了观察和研究,研究结果与结构病害腐变结果相吻合。选取与糟朽器物同期考古出土的糟朽棺板木作为分析对象,分别对其化学成分、容积重、含水率以及力学性能进行了实验测试,测得糟朽木器降解损失超过50%,含水率约为10.5%,力学强度指标与正常材质相比,均有明显的下降,且相对差异较大,最大约为正常木材强度的60%。对比分析结果,得出了结论：①糟朽木器的形态与结构状况与实验生物切片分析、电镜显微结构观察和研究结果相吻合,同时材质成分、容积重与力学性能测定结果为上述分析结果提供了有力的数据支撑;②致使糟朽木器形态和结构发生改变的主要因素是胎木含水率,其值是非恒定的并随外部环境而改变,因此含水率可用于反映糟朽木器的材质特性;③纤维饱和点与平衡含水率是影响、衡量和评估糟朽木器形态与结构的两个重要的物理参数;④鉴于糟朽木器的材质特性,后期保存应尽量避免与水分的直接接触,需要严格控制其胎木的含水率,且维持恒定、稳定的保存环境,这点对后期糟朽木器的保存是非常重要的     

Estimating the Higher-Mode Response of Ductile Structures

While the importance of higher-mode actions is appreciated within the engineering community, the affect that ductile nonlinear response has on higher-mode characteristics and the subsequent implications this has for design has received little attention. In this article, the manner in which the higher-mode response of frame-wall structures is affected by inelastic behavior is closely examined and a means of accounting for this in design is proposed. The work focuses firstly on the characteristics of the higher modes present at the development of peak response and then considers how these characteristics would affect the total forces in the building. The study utilizes a series of nonlinear time-history analyses of two different groups of RC frame-wall structures subject to a suite of real records. It is shown that a new modal analysis approach that incorporates transitory inelastic modal characteristics gives significantly improved predictions of peak base shear in frame-wall structures than more traditional modal analysis methods which use elastic higher-mode characteristics. The issues associated with the use of transitory inelastic modal characteristics are discussed and various challenges that would need addressing for the prediction of other response parameters and structural types are identified.     

Shaking Table Model Test of a Steel-Concrete Composite High-Rise Building

Shaking table tests were conducted on a 1/20 scaled-model of a 25-story steel-concrete composite high-rise building, composed of steel frame (SF) and concrete tube (CT). The seismic behavior of the model was investigated with the increasing of table-input acceleration amplitudes. It has been found that the seismic failure of the model concentrated on the shear walls and corner columns at the lowest story of the CT as well as the joints between the SF and the CT. Even subjected to extremely strong earthquakes, due to effective composite action, the composite model was able to support its weight to prevent collapse.     

Reinforced Concrete Exterior Waffle Flat Plate-Column Connections Subjected to Lateral Earthquake Loading

An experimental investigation of an exterior waffle flat plate-column connection subjected to combined gravity and cyclic lateral loading is presented. The test model was designed according to construction practices used over ten years ago in the Mediterranean area. Test results are discussed in conjunction with previous studies on flat-slab connections and ACI 318–05 code idealizations. The specimen exhibited a “strong column-weak plate” mechanism, whose behavior was controlled by the torsion cracks. First yielding and failure occurred at 1% and 5.5% drift-ratios, respectively. The results show that ACI 318–05 code significantly underestimates strength; as an alternative, a simple model is proposed.     

Seismic Damage to Structures in the 2015 Nepal Earthquake Sequences

The 7.8 Mw Gorkha earthquake struck the east of Lamjung in Nepal, followed by a sequence of powerful aftershocks. Chinese Team Six including the authors inspected the seismic damage to civil structures along 10 paths in densely populated areas with a seismic intensity of VII to IX, 40 days after the main shock. The damage was categorized according to structure types and described in detail. Several conclusions are made: powerful aftershocks can significantly affect the failure patterns; geological conditions, structure types, and height have great influence on the level of damage; and the local risky retrofitting technique needs improvement badly.     

Seismic Testing of Critical Lifelines Rehabilitated with Cured in Place Pipeline Lining Technology

Trenchless technology is well accepted for repairing critical underground lifelines with minimal ground surface disruption. The cured in place pipeline (CIPP) lining process is an application of trenchless technology that involves the installation of fiber reinforced composites inside existing pipelines. The uncertain performance of pipelines reinforced with CIPP linings in seismic areas is a barrier to the adoption of this method for seismic retrofit. This article evaluates experimentally the transient seismic response of pressurized pipelines reinforced with fiber reinforced polymer (FRP) linings. The test results show that reinforced pipelines can accommodate very high intensity ground motions and can provide substantial seismic strengthening in addition to efficient rehabilitation of aging underground infrastructure.