Contribution of Earthquake-Resistant Design for Reinforced Concrete Buildings when Coping with External Explosions

Fanaticism, as well as social and economic crises, has provoked a significant increase in the frequency of terrorist attacks during the last two decades and, when considered together with possible accidental explosions, has lead to a higher awareness among involved staff (owners, designers, constructors, government entities). Additionally, the fact that some buildings or targets are in seismic areas while others are not leads to a blast-loading behavior comparison. This article examines the contribution of earthquake-resistant design when coping with ground-surface explosions through nonlinear seismic assessment static analyses and nonlinear time-history analyses of blast resistance assessment using finite elements.     

Impact of Modification on Ground Motion Characteristics and Geotechnical Seismic Analyses for a California Site

The impact of different modification techniques on ground motion characteristics and results of seismic geotechnical analyses is investigated for a site in California. Twenty-eight motions were selected and scaled and also modified using both time domain (TD) and frequency domain (FD) techniques. PGV and PGD of the TD-modified motions are found to be larger than their FD-modified counterparts, but slightly less than the scaled ground motion characteristics. Cyclic stress ratios and amplification factors are similar for all sets of motions. Newmark-type slope displacements caused by the scaled and modified ground motions are similar (within 25%) for a variety of sliding masses.     

文物政策研究的意义现状与问题分析

文物政策科学研究,又称文物软科学研究,是为促进文物事业宏观管理和决策的专业化、科学化和民生化提供支持、咨询、评价和反馈的综合性研究。文物事业是保护和管理国家不可再生宝贵文物资源的特殊文化行业,其政策研究具有特殊性和重大现实意义。但目前文物政策研究成果分散、水平不高,缺乏研究机构和组织规划。     

Seismic Behavior of L-Shaped RC Squat Walls under Various Lateral Loading Directions

Considerable progress has been made on the research of non-rectangular reinforced concrete (RC) squat walls over the past decades. However, the experimental data of L-shaped RC squat walls remain limited, especially for their seismic behaviors under non-principal bending actions. This paper presents an experimental and numerical investigation on L-shaped RC squat structural walls with an emphasis on how varying the directions of lateral cyclic loading influences the seismic responses of these walls. Four L-shaped specimens are tested under lateral cyclic displacements and low levels of axial compression The variables are axial loads and lateral loading directions. The performance of specimens is discussed in terms of cracking patterns, failure mechanisms, hysteretic responses, deformation components and strain profiles. Furthermore, three-dimensional finite element models are developed to supplement the experimental results. The direction of lateral loading is found to have a significant effect on the peak shear strength of L-shaped RC squat walls.     

Ground Motion Parameters for the 2011 Great Japan Tohoku Earthquake

The 2011 great Japan Tohoku earthquake is not only the most devastating but also, one of the best recorded earthquakes in the history of seismology. A thorough study of strong motion characteristics of this earthquake is conducted using 20 well established ground motion parameters (GMPs). The behaviour of these parameters with fault distance and average shear wave velocity is examined and attenuation relationships are developed using the 1172 surface level strong motion records. In addition, all GMPs are categorized on a statistical basis using principal component analysis, which is further used to rate the damage potential of ground motion records.     

晚清民国乌鲁木齐地区村落类型与社会治理——以个案分析为中心

晚清民国乌鲁木齐地区的村落,根据人口结构不同,可以分为宗族、地理相近与地理相错三种类型。由于三种类型村落的自治程度不同,造成了政府对其治理方式上存在区别,也突出了国家对其控制力上存在差别。文章主要以村落个案分析为中心,针对每种类型的村落,以个案的形式说明村落类型与治理之间的关系及反映出的乡村社会治理的空间差异性。     

《馆藏文物防震规范》关键技术——防震安全设计研究

《馆藏文物防震规范》WW/T 0069-2015,基于馆藏文物防震安全提出馆舍、展陈和文物全系统防震安全理念、设计方法和具体措施。本研究针对馆藏文物防震设计方法、适用范围、展柜及文物安全性判别等关键技术问题展开研究。首先,提出了"地震波+馆舍+展柜+文物"的全过程全系统防震设计理念;其次,针对浮放展柜及文物,进行地震作用下安全性分析研究;第三,与Getty博物馆研究成果对比,验证本研究理论的正确性与可靠性。分析得出:文物防震安全与文物高宽比、支撑接触面摩擦系数、安放处加速度峰值等因素有关;引入了抗滑动安全系数和抗倾覆安全系数进行设计,可充分保证文物安全性。     

Identification of Pottery‐Forming Techniques using Quantitative Analysis of the Orientation of Inclusions and Voids in Thin Sections

The relationship between forming techniques and orientation of the components of ceramic materials in the context of pottery technology has long been recognized and used for identification of the techniques employed to create archaeological ceramics. The alignment of inclusions is usually characterized by qualitative categories or ordinal scales. This paper evaluates the potential of quantitative orientation analysis for identification of pottery‐forming techniques. A collection of experimental pottery formed using five forming techniques and combined techniques was analysed. The forming techniques were characterized by the intervals of the mean direction and the circular standard deviations of the orientation of the major axes of the ellipses equivalent to the objects representing random sections of inclusions and voids. The most informative criteria for the identification of pottery techniques are the circular standard deviation of the inclusion/void orientations in the core area of the vessel wall in a perpendicular thin section and the mean direction in a tangential section.     

Ground‐Penetrating Radar Velocity Determination and Precision Estimates Using Common‐Midpoint (CMP) Collection with Hand‐Picking,Semblance Analysis and Cross‐Correlation Analysis: A Case Study and Tutorial for Archaeologists

The most crucial parameter to be determined in an archaeological ground‐penetrating radar (GPR) survey is the velocity of the subsurface material. Precision velocity estimates comprise the basis for depth estimation, topographic correction and migration, and can therefore be the difference between spurious interpretations and/or efficient GPR‐guided excavation with sound archaeological interpretation of the GPR results. Here, we examine the options available for determining the GPR velocity and for assessing the precision of velocity estimates from GPR data, using data collected at a small‐scale iron‐working site in Rhode Island, United States. In the case study, the initial velocity analysis of common‐offset GPR profile data, using the popular method of hyperbola fitting, produced some unexpectedly high subsurface signal velocity estimates, while analysis of common midpoint (CMP) GPR data yielded a more reasonable subsurface signal velocity estimate. Several reflection analysis procedures for CMP data, including hand and automated signal picking using cross‐correlation and semblance analysis, are used and discussed here in terms of efficiency of processing and yielded results. The case study demonstrates that CMP data may offer more accurate and precise velocity estimates than hyperbola fitting under certain field conditions, and that semblance analysis, though faster than hand‐picking or cross‐correlation, offers less precision.