EMPIRICAL EVALUATION OF SITE EFFECTS BY MEANS OF H/V SPECTRAL RATIOS AT THE LOCATIONS OF STRONG MOTION ACCELEROMETERS IN ISRAEL

Acceleration data from local and regional earthquakes is of prime importance in evaluating the seismic hazard. Consequently, strong motion accelerometers are currently installed at more than 60 locations in Israel. We have explored the possibility of site amplification effects at 10 sites where local earthquakes triggered strong motion accelerometers by integrating empirical and analytical estimations. Implementing H/V spectral ratio techniques using 15 accelerograms from nine earthquakes, 105 seismograms shear-wave records of 35 local and regional earthquakes and seismograms of microtremors were used in the empirical evaluations. The subsurface models were constructed by integrating available geological and geophysical information at the analysed site with empirically evaluated site response functions. Amplification effects of factor 3-6 are observed at various frequencies in the 0.8-6.0 Hz band. Through the analysis process it became evident that the instant availability of many useful time windows of microtremors provides systematic estimations of the fundamental resonance frequency of each site and their associated amplification levels, which are similar to those obtained from H/V spectral ratios of seismograms and accelerograms and to those inferred from the subsurface geology. Analytical transfer functions should be reviewed with respect to empirical site response evaluations. Estimations that are based on only one approach may be totally misleading.     

VERTICAL EARTHQUAKE GROUND MOTION RECORDS: AN OVERVIEW

Recent research clearly shows the importance of including the vertical component of earthquake ground motion in seismic analysis and design. In addition, pioneering studies [e.g., Elnashai and Papazoglou (1997)] have explored and documented the characteristics of available near-field vertical ground motion records. As a follow-up, this paper complements earlier studies, and investigates additional far-field records and available downhole array vertical motion records. A total of 111 free-field strong motion records (from California) and available downhole array records are employed. Compared to near-field records, far-field records generally contain more energy at longer periods. Based on the available data, response spectra are presented for near-field and far-field records respectively. The currently scarce downhole-array vertical motion records show that significant amplification may occur within the top 10-20 m soil layers. A simple one-dimensional (ID) vertical wave propagation model did not appear adequate for modelling the observed downhole array response. In using such a simplified model, very high viscous damping in the range of 15-25% was needed to match the recorded downhole vertical response, even for small tremors. Additional data and research are required [Beresnev et al., 2002] towards the development of a rational vertical motion site response analysis procedure.     

A NON-PARAMETRIC APPROACH TO ATTENUATION RELATIONS

Abstract

A non-parametric multidimensional regression method is proposed for the prediction of seismic ground motion parameters. The main features which distinguish the method from standard regression procedures are: (1) The relationship between the input and output variables is not selected a priori by a prediction law, (2) an arbitrary number of input variables Can be taken into account, provided that an appropriate data base exists, and (3) the computational procedure is very simple. The results can be easily updated when new information becomes available. The method has been applied for the derivation of attenuation relations by using a combination of databases compiled by other researchers. In the majority of the cases discussed in this paper, the method was used for the prediction of horizontal peak ground acceleration as a function of magnitude and distance. In some cases, ground conditions were also taken into account. Some results on the attenuation relations of peak ground velocity and displacement, as well as Arias intensity, are also presented.     

墓葬壁画地仗层加固修复技术研究

任何形式的古代壁画,其结构主要都是由基础支撑体、地仗层、颜料层三部分组成。但各种类型壁画的制作工艺不同,所使用的材料也不同。壁画的地仗层下与支撑体黏接,上又是颜料层的载体,地仗层性质的优劣直接关系到壁画能否长期保存,许多壁画的毁坏都是因地仗层的毁坏而引发的。本文针对陕西唐昭陵长乐公主墓壁画,河北湾漳北齐墓壁画、河南洛阳唐安国相王孺人崔氏墓壁画地仗层的保护修复,从壁画制作材料与工艺、修复工艺、外观等方面详细介绍三种不同的墓葬壁画原地仗层加固方法,并进行了比较。     

近世浙江丧葬习俗的区域特征及地域差异

本文以历代地方志及现代民俗学调查报告为基础,并结合其它相关历史文献资料,对近世时期流行于浙江地区的土葬、火葬、二次葬、潮魂葬等丧葬习俗的区域特征及地域差异,作了简要的介绍及总结,在此基础上对制约浙江地区丧葬习俗地域差异的因素进行了分析、阐述。     

Cover it! The Protection of a Merovingian Burial Ground in Borgharen (Municipality of Maastricht), the Netherlands

A Merovingian burial ground in Borgharen was threatened by development. Plans however could be changed so the site could be preserved. The initial research however showed the bone material was at risk of severe degradation in the near future. In order to determine whether in situ preservation was feasible three campaigns were carried out. This led to the conclusion that the burial conditions were excellent and there was little risk that severe degradation will reduce archaeological information of the site over the coming decades. The remaining threat concerned illegal excavators with metal detectors and spades. To protect the site it was covered with a series of different materials to prevent the site from being looted.     

Identifying stone tools used in mining,smelting, and casting in Middle Bronze Age Cyprus

Abstract

Metallurgical production sites are often difficult to identify in the archaeological record because ore beneficiation and slag processing in the past involved the use of ground stone tools that were similar to those used in other contexts to prepare cereals and foods. Analysis of the ground stone assemblage from a Middle Bronze Age copper mining and production site at Ambelikou Aletri in Cyprus provided an opportunity to distinguish industrial and domestic ground stone tools and to identify the types of tools used in different stages of metal production. A comparison of tool morphologies, raw materials, and wear and breakage patterns from Ambelikou Aletri with those from contemporary domestic contexts, suggests that distinctions in the nature and structure of industrial and domestic tool kits do exist and those distinctions have an important role to play in identifying mining, smelting, and casting sites in the future.     

Seismic Reconnaissance and Observed Damage after the Mw 6.8, 24 August 2016 Chauk (Central Myanmar) Earthquake

On 24 August 2016, Mw 6.8 earthquake occurred near Chauk, Central Myanmar. This earthquake caused a significant amount of damage over a very large number of historical monuments. After providing a general summary of the regional tectonic settings and seismicity, the observed ground motion has been discussed, and performance of structures in the epicentral area is addressed, focusing on the damage observed in both historical and recent constructions. The observed damage patterns and their extent are analyzed and interpreted in light of observed damage that was found. Lastly, seismic fragility curves of local buildings have been derived.     

从和平共处、求同存异到维护世界的多样性——中国外交对国际社会认识与反应的演进

从中共第一代领导集体首先倡导和平共处、求同存异的外交思想到第二代领导集体对和平共处、求同存异外交思想的继承和发展,再到第三代领导集体强调尊重并维护世界多样性,反映的是中国外交正确认识国际社会、充分尊重客观现实、合理应对时代变化的历史进程。实践证明,和平共处、求同存异与维护世界多样性的主张,不仅反映了国际社会的本质,而且代表了国际社会发展的趋势,它们既是中国推行独立自主和平外交政策的指导思想,也是中国外交对当代国际关系理论的重大贡献。