Liquefaction-Induced Lateral Load on Pile in a Medium Dr Sand Layer

One-g shake-table experiments are conducted to explore the response of single piles due to liquefaction-induced lateral soil flow. The piles are embedded in saturated Medium Relative Density (Dr) sand strata 1.7–5.0 m in thickness. Peak lateral pile displacements and bending moments are recorded and analyzed by uniform and triangular pressure distributions. On this basis, the observed levels of pile bending moment upon liquefaction suggest a hydrostatic lateral pressure approximately equal to that due to the total overburden stress. Using the experimental data, comparisons with current recommendations are made, and the Showa Bridge case history is briefly assessed.     

山东地区商文化聚落形态演变初探

本文考察了山东地区商文化的聚落形态演变过程及其历史背景。商文化聚落形态在山东地区经历了四个阶段的变化:早商时期仅济南大辛庄一处遗址;中商时期遗址数量增加并在泰沂山脉两侧形成了规模较大的聚落群;晚商早期遗址数量保持稳定但等级较高的遗址处于衰落状态;晚商晚期不但遗址总数而且等级较高的遗址数量都明显增加,还出现了像苏埠屯这样的高规格墓地。这一聚落形态的演变反映了商文化在山东地区东扩的连续性与阶段性。     

“汉代城市和聚落考古与汉文化国际学术研讨会”纪要

城市是一个国家或地区的政治、文化中心和经济管理、军事指挥中心,是人类文明的集中体现,对古代城址进行发掘和研究历来是考古学的基本内容及重要任务之一。聚落一般指人们聚居的地方,是生产、生活等各种活动的空间及场所。广义的聚落包括城市,     

大运河宁波段聚落文化遗产保护措施研究

聚落文化遗产是大运河遗产的重要组成部分,与运河兴衰息息相关。宁波段运河聚落文化遗产历史久远,保存类型丰富,历史价值突出。宁波运河的开凿和变迁对运河聚落整体格局的形成、演变和发展关系紧密;同时运河聚落的产生和发展也促进了运河功能的不断完善和运河经济的发展。如何保护好运河聚落文化遗产已经成为重要的研究课题。本文意在梳理宁波段运河聚落文化遗产的构成情况,并对宁波段运河聚落文化遗产的科学保护提出了可行性建议。     

A Multi-Mode Method for Estimation of Floor Response Spectra

A new simplified procedure for estimation of floor response spectra (FRS) is proposed. This methodology enriches the most common procedures using nonlinear response-history analysis to predict FRS by including a direct multi-mode technique to estimate FRS. A novel feature of the procedure is that the coupling effect is considered to establish equivalent modal systems and the FRS are developed by incorporating capacity spectrum method in conjunction with ductility-based FRS for each modal system. Both the proposed method and the traditional method are applied to three steel moment frame structures, and a reasonable accuracy is demonstrated.     

A Simplified Procedure to Select a Suitable Retrofit Strategy for Existing RC Buildings Using Pushover Analysis

Over the past ten years, the development of analytical procedures to accurately evaluate the seismic performance of existing buildings has gathered the attention of researchers. This has resulted in the publication of several standards, which, however, inadequately cover the issue of retrofit strategy selection. In the present article, a procedure that allows a comparison of available strategies in order to select the optimum solution for an existing deficient building is proposed. The procedure is based on calculating the pushover curve for the unstrengthened structure. A capacity spectrum is then estimated assuming different retrofit scenarios, which is then used for the evaluation of the strategies. The latter is based on criteria that assess the main structural system characteristics and how each solution benefits them. The final step of the procedure introduces simplified rules that allow the approximate design of each retrofit solution, which allows the evaluation of their applicability. The proposed procedure was applied to two idealized buildings with different structural systems. Results obtained indicate that less effective or inapplicable rehabilitation strategies were properly detected. Thus, the results were considered acceptable in terms of identifying the possible optimum strategy, which, however, should be verified with a detailed design of the retrofit system.     

Foundation Degrees in Geography and Tourism: A Critical Reflection on Student Experiences and the Implications for Undergraduate Degree Courses

Over the last decade, some UK Geography Departments have diversified their range of courses to offer Foundation degrees (Fds), providing students with alternative routes through higher education (HE). These courses are delivered either offsite at further education colleges (FECs), embedded within an undergraduate programme at higher education institutions (HEIs), or by work-based learning. These pathways present students, staff and institutions with new opportunities, issues and challenges. This study examines contrasting pathways of offsite and onsite Fds in Tourism Management and Development Geography offered by two HEIs and two FECs in southwest England. The needs and experiences of Fd students are varied, related to the individual's personal and academic background, the course pathway taken, institution-specific issues and the degree of support and preparedness for HE. The contrasting academic cultures, teaching methods and assessments encountered in FECs and HEIs, and the availability of resources, raise generic and specific issues, such as confidence building and learning to become independent and autonomous learners, which challenge Geography and Tourism students during their academic careers. This study concludes that closer collaboration between the HEI and the partner FEC is necessary for Geography and Tourism courses, and highlights the need for better alignment and reinforcement of HE systems in FECs, for instance through fieldwork, and the offering effective induction and support in study skills. Finally, it is important to facilitate the smooth transitions of students ‘topping-up’ to Year 3 of an Honours degree at the parent HEI. Managers of undergraduate courses in Geography and associated subjects can also learn from the vocational and contextualized learning promoted by Fd courses and direct entry students to undergraduate courses.     

Numerical Analyses of the Effectiveness of Soft Barriers into the Soil for the Mitigation of Seismic Risk

An approach to mitigate the seismic risk of existing structures by means of the creation of a continuous thin layer of grouted soil at a convenient depth is presented. A parametric numerical analysis is reported using different constitutive models with reference to two geometrical schemes. It is shown that if the grouted layer has a stiffness significantly lower than that of the surrounding soil, it may be effective in reducing the seismic demand. In the parametric analyses, the positive role of yielding is also observed, which indicates that the barrier is more effective with larger input amplitudes.     

A comprehensive numerical chronology for the pre-Columbian cultures of the Palpa valleys,south coast of Peru

Before the arrival of the Spaniards in Peru in 1532, many different societies flourished in the coastal desert of southern Peru. Of these, one of the best known is the Nasca culture (living in the area between about 260 cal BC and 640 cal BC.), which created the famous geoglyphs on the desert floor. In this paper we present a numerical chronology for the cultural development in the valleys of Palpa, in the northern part of the Nazca region, which spans the time from the Archaic Period (starting there around 3760 cal BC) to the Late Intermediate Period (terminating with the arrival of the Spaniards in 1532 AD). The chronology is based on more than 150 ¹⁴C samples collected by our project from well-documented archaeological excavations of 17 different sites in and around Palpa. Thanks to the advanced AMS-¹⁴C dating technique, demanding only few milligrams of organic material, we could focus on samples of plants, like beans, corn, or reed, representing single years of growth or use, and also on delicate materials like straw from clay bricks (adobe) and textiles. All single ¹⁴C dates were combined to cultural phases using a Bayesian statistical model, implementing the a priori information of the archaeological contexts, and adopting the relative ceramic chronologies available for this area.     

An ethnoarchaeological inductive model for predicting archaeological site location: A case-study of pastoral settlement patterns in the Val di Fiemme and Val di Sole (Trentino,Italian Alps)

In this paper I propose a novel integration of inductive predictive modelling and ethnoarchaeology. The case study concerns seasonal upland pastoral settlement patterns in the eastern Italian Alps. A sample of modern pastoral sites has been selected, and their relationships with environmental variables have been analyzed in order to create a model to predict the location of archaeological upland pastoral sites. The model has been tested with modern and archaeological control samples. It has proved to be useful for predicting the location of specific site categories. Ethnoarchaeological fieldwork has been carried out in the same alpine sample area, which has enhanced the interpretative potential of the proposed model, suggesting that the spatial of the analyzed sites could well be related to their dairying function. The creation of ethnoarchaeological locational models with a predictive potential may be very important not only in helping to tackle some theoretical and methodological problems in predictive modelling, but also in enhancing the importance of ethnoarchaeology in landscape archaeology projects.     

Applying the H/V Method to Dense Cities. A Case Study of Valencia City

The aim of this study was to apply Nakamura's technique to Valencia city center, after some preliminary tests in Barcelona. Previous studies of Barcelona had measured periods in restrictive conditions and in various types of material ranging from very soft soil (with a predominant period of approximately 2 s) to rock (0.3 s), and under different measurement conditions. The Valencia city center measurements were taken by using the distance from buildings and car and pedestrian traffic to construct a measurement grid that was as regular as possible. We also estimated possible soil-structure interaction to detect potential vulnerability.     

A Microscale Approach for the Seismic Response of MDOF Structures Including Soil-Foundation-Structure Interaction

In this article, a three-dimensional microscale computational framework utilizing the discrete element method is presented to analyze the seismic response of soil-foundation- MDOF structure systems. The proposed approach is used to explore the response of MDOF structures on a square embedded footing founded on a dry granular deposit. Computational simulations were conducted to investigate the response of the system to several base excitations. The impact of replacing a MDOF structure with its equivalent single degree of freedom (ESDOF) structure while accounting for soil-foundation-structure interaction (SFSI) is investigated. Detrimental or beneficial effect of SFSI on the response is also examined.     

A Minimum-Impact Method for Measuring Corrosion Rate of Steel-Hulled Shipwrecks in Seawater

Current research on USS Arizona is focused on a minimum-impact technique for calculating corrosion rate of the battleship's steel hull by analysing physical and chemical properties of marine encrustation covering the exposed hull. An equation is derived that allows concretion thickness, density, and total iron content to be used to calculate corrosion rate of steel hull plate.
© 2006 The Authors     

A Static Nonlinear Procedure for the Evaluation of the Elastic Buckling of Anchored Steel Tanks Due to Earthquakes

Ground-supported steel tanks experienced extensive damage in past earthquakes. The failure of tanks in earthquakes may cause severe environmental damage and economic losses. This study deals with the evaluation of the elastic buckling of above-ground steel tanks anchored to the foundation due to seismic shaking. The proposed nonlinear static procedure is based on the capacity spectrum method (CSM) utilized for the seismic evaluation of buildings. Different from the standard CSM, the results are not the base shear and the maximum displacement of a characteristic point of the structure but the minimum value of the horizontal peak ground acceleration (PGA) that produces buckling in the tank shell. Three detailed finite element models of tank-liquid systems with height to diameter ratios H/D of 0.40, 0.63, and 0.95 are used to verify the methodology. The 1997 UBC design spectrum and response spectra of records of the 1986 El Salvador and 1966 Parkfield earthquakes are used as seismic demand. The estimates of the PGA for the occurrence of first elastic buckling obtained with the proposed nonlinear static procedure were quite accurate compared with those calculated with more elaborate dynamic buckling studies. For all the cases considered, the proposed methodology yielded slightly smaller values of the critical PGA for the first elastic buckling compared to the dynamic buckling results.     

Collaborative Networks for Effective Ecosystem‐Based Management: A Set of Working Hypotheses

Ecosystem‐based management (EBM) represents a comprehensive approach to better govern the environment that also illustrates the collaborative trend in policy and public administration. The need for stakeholder involvement and collaboration is strongly articulated, yet how and for what purposes collaboration would be effective remains largely untested. We address this gap by developing and evaluating a set of hypotheses specifying how certain patterns of collaborations among actors affect their joint ability to accomplish EBM. Content analyses of management plans drawn from five EBM planning processes in Sweden are combined with analyses of the collaborative networks through which these plans have been developed. Our results indicate that system thinking and the ability to integrate across different management phases are favored by collaborations between different kinds of actors, and by project leaders being centrally located in the networks. We also find that dense substructures of collaboration increase the level of specificity in the plans in regards to explicating constraints on human activities. Having many collaborative ties does however not enhance the overall level of specificity. Our results also show that different network characteristics can give rise to similar EBM outcomes. This observed equifinality suggests there is no single blueprint for well‐performing collaborative networks.     

A Two‐Tiered Method for Identifying Trends in Media Framing of Policy Issues: The Case of the War on Terror

Research on media framing of policy issues has flourished. Yet the varied approaches to conceptualizing and operationalizing issue frames that make this literature rich also hinder its advancement. Here, we document the benefits of a two‐tiered method: the first level accounts for issue‐specific frames, while the second level tracks frames that generalize across issues. For this study, we draw on generalizable frames from prospect theory (loss vs. gain frames) and social identity theory (self‐referential vs. other‐referential frames). We discuss the theoretical merits of a two‐tiered approach, arguing that it should yield compound insights greater than the sum of its parts. Applying this method to newspaper coverage of the war on terror, we find a strong trend at the generalizable level: media framing of the war shifted over time from a predominant use of “fear” (self‐referential loss) frames to an increasing use of “charity” (other‐referential gain) frames. Our approach further reveals that the fear frames used in the lead‐up to the Iraq War were not driven by issue‐specific frames related to terrorism or weapons of mass destruction as we might have thought, but rather by frames related to the anticipated threats to U.S. troops. This study sharpens our understanding of how framing of the war evolved, but more broadly it suggests that a two‐tiered approach could be applied both within and across policy issues to advance our understanding of the framing process.