SEISMIC SOIL-STRUCTURE INTERACTION: BENEFICIAL OR DETRIMENTAL?

The role of soil-structure interaction (SSI) in the seismic response of structures is reex-plored using recorded motions and theoretical considerations. Firstly, the way current seismic provisions treat SSI effects is briefly discussed. The idealised design spectra of the codes along with the increased fundamental period and effective damping due to SSI lead invariably to reduced forces in the structure. Reality, however, often differs from this view. It is shown that, in certain seismic and soil environments, an increase in the fundamental natural period of a moderately flexible structure due to SSI may have a detrimental effect on the imposed seismic demand. Secondly, a widely used structural model for assessing SSI effects on inelastic bridge piers is examined. Using theoretical arguments and rigorous numerical analyses it is shown that indiscriminate use of ductility concepts and geometric relations may lead to erroneous conclusions in the assessment of seismic performance. Numerical examples are presented which highlight critical issues of the problem.     

MODELLING OF NONLINEAR DYNAMIC BEHAVIOUR OF A SHALLOW STRIP FOUNDATION WITH MACRO-ELEMENT

A new nonlinear soil-structure interaction macroelement is presented. It models the dynamic behaviour of a shallow strip foundation under seismic action. Based on sub-structured methods, it takes into account the dynamic elastic effect of the infinite far field, and the material and geometrical nonlinear behaviour produced in the near field of the foundation. Effects of soil yielding below the foundation as well as uplift at the interface are considered. Through the concept of macro-element, the overall elastic and plastic behaviour in the soil and at the interface is reduced to its action on the foundation. The macro-element consists of a non linear joint element, expressed in the three degrees of freedom of the strip foundation, reflecting the limited bearing capacity of the foundation. This model provides a practical and efficient tool to study the seismic response of a structure in interaction with the surrounding soil medium. Applications to a bridge pier show the potentialities of this kind of model.     

EFFECT OF SOIL-STRUCTURE INTERACTION ON SEISMICALLY ISOLATED BRIDGES

The objective of this study is two-fold: first, to assess the effects of soil-structure interaction (SSI) on the response of seismically isolated bridge piers and, second, to develop a method that considers SSI and can be easily applied to the preliminary design of bridges. Emphasis is given on pier behaviour, because piers together with the abutments are the most critical components of a bridge with a high potential for concentration of ductility demands during earthquakes. The relative importance that several parameters of the bridge-isolators-soil system play on design is examined. Conclusions and suggestions that can lead to safer and more economical isolated pier design are also presented. Cases in which SSI needs to be incorporated in seismically isolated bridge design are identified and ways to take advantage of SSI in order to enhance safety level and reduce design costs are recommended.     

ORGANIZATION,LEGITIMATION, PARTICIPATION

This article suggests a new interpretation of the state formation process in Early Modern Sweden, focusing on three dimensions: The organization of the state as a way to use limited resources in a rational way, the legitimation of rulers in terms of beliefs and values current in society, and the participation of the subjects in state activities. Our model focuses on institutional change as a result of the intensity of interaction between rulers and subjects. Based on our own research, claims are made for new understanding of state formation in Europe that allows more room for political action from below.     

城市混居地段外来人口社会隔离的空间测度——以广州客村为例

本研究选取广州客村代表典型的城市混居地段,创新性地从空间维度测度本地人与外来人群体的社会隔离程度,包括其社交对象的地域分布差异及空间活动轨迹的差异。基于社会学二模网络理论,建立空间共场性的概念,测度两类人群的社会隔离程度。研究发现:客村外来人群体的社交对象具有鲜明的迁出地指向特征;本地人与外来人两类群体的空间活动轨迹呈现显著分异,体现为使用公共服务设施与公共开敞空间的区隔;通过两类群体之间及各自内部的共场度测度,发现外来人群体过于离散的空间活动轨迹不利于其获取社会网络的支持。     

流动性视角下打工旅游者行为特征研究——以大理古城为例

打工旅游已成为一种新的人口流动现象,本文通过对大理古城32位打工旅游者进行深度访谈和观察,发现他们在"工旅结合"动机和有无薪资的工作特点上存在分异,据此将其划分为3种类型,研究其在大理的行为表现。结果表明,打工旅游的出现促使工作、旅游和休闲之间的界限变得模糊;打工旅游者在大理的日常活动中,一方面表现出类似游客的行为特征,另一方面又在大理过着悠闲懒散但与日常相似的生活,这种行为的双重性表明他们在日常交往中将不断表现出"主"与"客"的身份转换,并据此提出旅游发展的相关政策建议。     

对台湾佛教道场旅游营造的思考

近些年,伴随中国大陆佛教文化旅游热的不断升温,寺院修缮和建设中的粗制滥造、佛教文化旅游产品单一、旅游服务质量不高等问题愈加突出。如何发挥佛教当代积极的社会功能,更好地满足游客对佛教文化的消费需求,促进佛教文化旅游活动的持续、健康发展值得深入思考。借助台湾中华发展基金会资助大陆学者赴台研究项目,笔者通过对台湾地区著名佛教道场的实地考察、调研,梳理有关台湾佛教文化的相关研究成果,与台湾学者广泛、深入地学术交流,在分析、总结、借鉴台湾地区佛教道场旅游营造的成功做法基础上,针对中国大陆佛教文化旅游中存在的主要问题,提出树立精品意识,打造当代的文化遗产;强化服务意识、提高服务水平;加强产品开发,完善旅游服务的建议。     

Maritime interregional interaction in Micronesia: Deciphering multi-group contacts and exchange systems through time

Recent theoretical perspectives focusing on interregional interaction can help explain the evolution of western Micronesian societies. Data from ethnohistoric accounts, oral traditions, and more recently, archaeological investigations, document the interactions between culturally and linguistically distinct island groups in the northwest tropical Pacific. Here, I look at the nature and emergence of these interaction networks between the islands of Yap and Palau in the Western Caroline Islands of Micronesia and the implications they had for transforming indigenous lifeways, exchange systems, and sociopolitics. In particular, I discuss a major facet of these interaction spheres—the Yapese quarrying of their famous stone “money” disks in the Palauan archipelago.     

Recent research in west Mexican archaeology

The last decade has seen the greatest increase in archaeological research in western Mexico since the 1940s. Unlike previously heralded renewals, this one is accompanied by widespread skepticism of the dominant culture-historical paradigm linking west Mexico to the rest of Mesoamerica, to the American Southwest, and to South America. Current research offers substantive new data and interpretations bearing on issues such as the definition of Mesoamerica, the role of South American long distance contacts, the human ecology of highland lakes, the role of river systems in Mesoamerican prehistory, and the nature/role of prehispanic elite exchanges.     

Evidence for Interaction from Recent Hunter-Gatherer Sites in the Caledon Valley

Evidence for contact between hunter-gatherers and agropastoralists from excavated sites in a well-documented frontier zone in the eastern Free State, South Africa, reveals varied intensities of interaction. These interactions range from clientship to relative autonomy. Comparison between recent (eighteenth- to early twentieth-century) hunter-gatherer occupations of rock shelters in the Caledon Valley also suggests that a variety of social relationships between hunter-gatherers and farmers, known ethnographically, occurred simultaneously.