A High-Performance Quadrilateral Flat Shell Element for Seismic Collapse Simulation of Tall Buildings and Its Implementation in OpenSees

Shear walls are important lateral force-resistant components of tall buildings. Hence, a reliable numerical model that can accurately represent the mechanical characteristics and large deformations of shear walls is critical for realistic collapse simulation of tall buildings. Based on the theory of generalized conforming element, a high-performance quadrilateral flat shell element, NLDKGQ, accounting for the large deformation using the updated Lagrangian formulation, is proposed herein and implemented in OpenSees. The reliability of NLDKGQ is validated using classical benchmark problems and reinforced concrete specimens. In addition, its capability in simulating the collapse of a tall building is also demonstrated.     

Protection of the State of Prehistoric Mounds in Hungary: Law as a Conservation Measure

According to the Act of 1996 on nature protection, mounds (kurgans) are natural monuments protected nationally in Hungary. According to the law, all kurgans in Hungary were to be surveyed by 2002, and 1692 were included in the cadastre. Fewer than half of the kurgans remained intact due to numerous anthropogenic impacts. A high number of disturbing artificial buildings together with soil erosion, soil removal, and afforestation have significantly reduced the landscape value of kurgans. In 2002, 51.5% of the surveyed kurgans still represented some kind of a value and thus their protection became one of the most urgent tasks of nature conservation and archaeology. According to a Hungarian ministerial decree, established on the basis of an EU Council decree, the area of kurgans under cultivation must be removed from cultivation. By 2015, in the area of 90% of the kurgans under cultivation this land use, which caused significant erosion, was terminated.     

江苏淮安王庄村汉墓群发掘简报

2013年淮安市博物馆发掘淮安王庄村汉墓群,共清理汉墓97座。墓葬形制多样,排列有序,共同位于一大型土墩之下,与淮安地区传统族葬墓有明显的区别。墓葬随葬器物丰富多样,器物组合时代特征明确。从出土器物和墓葬形制及排列情况分析,墓葬时代在西汉早期至东汉时期,墓葬之间在年代上有明显的承继关系,是一处大型汉代土墩墓。该墓地的发掘为研究淮安乃至苏北地区汉代墓葬特别是汉代土墩墓类型提供了极其重要的新材料。     

Variability in the lithic and faunal record through 10 reoccupations of a XIX century Yamana Hut

The excavation of Tunel VII, a Yamana site dating to the indigenous/European contact period was part of a long term research project based on the north coast of the Beagle channel (Tierra del Fuego, Argentina). The aim was to evaluate the theory and methodologies and devise an archaeological method that would enable a complete picture of subsistence strategies to be constructed. At Tunel VII (a site with shell middens), we were able to analyse these strategies through 10 successive occupation events on a single location. Archaeozoological analysis of the faunal remains and use-wear analysis of lithic material were used to examine the management of resources. Production and consumption are two very useful concepts, and together they have been used to create a methodology, which, together with spatial analysis using significant variables, has enabled identification of recurrent or significant tendencies in relation to alteration or continuity in subsistence strategies. In the case of Tunel VII, we know that the people who continually occupied the hut were all from the same group.     

寿县李三孤堆楚器的研究与探索

本文介绍了李三孤堆楚墓所出青铜器的流散和收藏慵况,回顾了自20世纪30年代初至今学者们对这批楚器的研究历程及成果,并从铭文释读、器物形制、器群主人及其埋葬环境几方面分别阐述了各家之说,最后通过回顾和分析总结出目前这一研究中存在的问题,提出了深入进行这一研究的重要意义,并指出了今后的研究方向。     

Micromorphological perspectives on the stratigraphical excavation of shell middens: a first approximation from the ethnohistorical site Tunel VII,Tierra del Fuego (Argentina)

Due to their problematic stratigraphy, shell middens have traditionally been excavated by artificial stratigraphical cuts. This approach has often led to the obliteration of the original depositional sequence, removing important information regarding depositional and post-depositional processes, and human frequentation. Since the 1970s, an Argentinian team has been excavating archaeological shell middens in the Beagle Channel with a detailed stratigraphical approach, based on the excavation of actual depositional units (peeling), rather than artificial cuts. In the 1980s, Spanish archaeologists joined the Argentinean team and launched a series of new projects involving the excavation of ethnohistorical Yamana fisher-hunter-gatherer sites. The first excavated midden site was Tunel VII, from which two monolith columns of about 50 cm each (C11 and C12) that spanned the whole stratigraphy were extracted. The two columns were consolidated with resin, and two series of thin sections produced to corroborate stratigraphical observations made in the field, and to verify hypotheses related to the formation of archaeological shell midden sites. We present here the first results obtained from the microscopical observation of seven thin sections from column 11 (West column), extracted from a portion of the profile originally described as corresponding to the hut entrance and associated floor. The observation of microscopical features invisible in the field has provided supplemental information about the depositional and post-depositional processes affecting shell midden sites. We have also preliminarily defined a number of micromorphological characteristics identifying human activities such as discrete shell deposition events, phases of preparation of the hut floor, and compression by repeated trampling. Finally, we have explored the possibility of establishing some guidelines to characterise the length and character of frequentation phases of the site previous to its final abandonment at the beginning of the 20th century.     

Oxygen isotope seasonality in a temperate estuarine shell midden: a case study from CA-ALA-17 on the San Francisco Bay,California

Seasonality determination using stable oxygen isotope (δ¹⁸O) analyses in archaeological mollusk shell has been largely limited to aquatic settings where one of the two factors that control shell δ¹⁸O – water δ¹⁸O (or salinity) and temperature – is assumed to be constant. Open coastal marine environments reflect the former situation, and tropical estuaries constitute the latter. In an effort to expand stable isotope seasonality to an ecological setting where neither variable remains constant, we present a model of annual shell δ¹⁸O cycle of aragonite deposition derived from instrumental data on salinity and temperature from San Francisco Bay, California. The predicted range of modeled shell δ¹⁸O is consistent with observed δ¹⁸O values in prehistoric and modern shells when local conditions are considered. Measurements of δ¹⁸O taken at 0 mm and 2 mm from the terminal growth margin were made on 36 archaeological specimens of Macoma nasuta from a late Holocene hunter-gatherer site CA-ALA-17, and season of collection was inferred using the shell δ¹⁸O model. We conclude that shellfish exploitation occurred through the year with the exception of fall, which may indicate scheduling conflicts with acorn harvesting or other seasonally abundant resources elsewhere. The model supports the feasibility of stable isotope seasonality studies in temperate estuaries, provided that instrumental records are available to quantify the relevant water conditions at appropriate spatial and temporal scales.     

A biometric technique for assessing prehistoric freshwater mussel population dynamics (family: Unionidae) in north Texas

Biometry is useful for a suite of analyses relevant to zooarchaeology, which include analysis of mortality profiles, taphonomy, paleoecology, among other purposes. Here, size-age prediction models are developed for 10 freshwater mussel species found in north Texas to develop a method for studying paleoenvironmental conditions. Shell length is often used to evaluate the structures of modern mussel populations, but its use on paleozoological specimens is not feasible because complete shells rarely preserve. Instead, pallial line-to-lateral teeth length (PLL) and pseudocardinal teeth-to-pallial line length (PSP) are evaluated as proxy measures for shell length. Linear regression models based on PLL and PSP using modern mussels demonstrate that they are accurate proxies of shell length for multiple species from a variety of habitats. In addition, ontogenetic-age structures for a modern sample and for two late Holocene assemblages from north Texas are developed using PLL and PSP. These techniques are useful tools for evaluating past ecological conditions of freshwater mussel populations when large samples are available for study, which expands analytical potential of zooarchaeological studies of prehistoric unionid remains.     

Mapping of subsurface shell midden components through percussion coring: examples from the Dundas Islands

Following earlier examples of mapping the subsurface of shell bearing sites using augering, we employ percussion coring to identify early Holocene shell midden components at two types of sites on the Northwest Coast of North America. We describe a method for mapping subsurface components at shell bearing sites including basal deposits, paleosols and transitions between distinct cultural components. Our research was undertaken for the purpose of identifying early Holocene shell middens above the modern shore, and as components below large shell midden villages. Our results augment the developmental trajectory of shell middens on the Northwest Coast by suggesting that pre-5000 BP forms of these sites may be more common than previously thought. In light of these results, we argue that the Northwest Coast cultural historical sequence, which locates an increase in the number and rate of accumulation of shell middens beginning 5000 years ago, to be premature. However, there are insufficient data from shell middens in the early Holocene, a sampling problem that the percussion coring methods described here can address.     

Boat-based foraging and discontinuous prehistoric red abalone exploitation along the California coast

Temporally and spatially discontinuous pulses of heavy prehistoric exploitation of red abalone (Haliotis rufescens) have been documented along the southern and central California coast. This article examines the very late (post-950 cal BP) appearance of numerous red abalone processing sites on the Monterey Peninsula in central California. We test three prominent explanations offered for the sudden onset of red abalone processing sites: trophic cascades resulting from human predation on sea otters, logistical foraging by inland residents, and changes in sea surface temperature. A trophic cascade appears to have occurred but does not fully explain the nature or timing of the phenomenon in the region.