Simulation of Shake Table Tests on Out-of-Plane Masonry Buildings. Part (V): Discrete Element Approach

ABSTRACT

The analysis of the shaking table test of a 3-wall stone masonry structure performed with a discrete element model is presented. The numerical model, created with the code 3DEC, employed a rigid block representation and a Mohr-Coulomb joint model. Joint stiffness calibration to match the experimental natural frequencies is discussed, as well as the boundary conditions to simulate the shake table. Comparisons are made with the measured displacements at key locations, and the modes of deformation and fracture of the walls. The DEM model was able to reproduce important features of the shaking table tests. The experimental deformation and near collapse patterns were clearly identifiable in the numerical simulations, which produced displacements within the observed orders of magnitude, for the various levels of excitation.     

The Diet of Three Medieval Individuals from Caravate (Varese,Italy). Combined Results of ICP‐MS Analysis of Trace Elements and Phytolith Analysis Conducted on Their Dental Calculus

Teeth are in close contact with foodstuffs: phenomena such as caries and wear of the crowns are precious keys to gather information on diet and cooking techniques. Phytoliths are granules of hydrated amorphous silica, which are deposited in the oral cavity while chewing fruit and vegetables and incorporated into dental calculus during its formation. In diet investigation, different plants may therefore be related to specific phytolith shapes. Analysis of chemical trace elements, incorporated in dental calculus from ingested food and replacing small percentages of calcium in normal processes of resorption and redeposition, can further enrich the research on ancient diet. The aim of our work was to set up an analytical protocol, focalised on phytoliths and the inorganic elemental composition of dental calculus, on samples coming from medieval skeletons excavated in Caravate (Varese, Italy). The inductively coupled plasma mass spectrometry analytical technique proved to be particularly suitable for such studies. The results suggested a diet based both on the consumption of carbohydrates (dicotyledons and monocotyledons such as the Poaceae, also known as Gramineae; and Coniferae) and on proteins, mostly derived from fish. Copyright © 2015 John Wiley & Sons, Ltd.     

Mineral soda alumina glass: occurence and meaning

Mineral soda–alumina (m-Na–Al) glass has been found across a vast area stretching from Africa to East Asia. m-Na–Al glass appears around the 5th c. B.C. and is relatively common for periods as late as the 19th c. A.D. It is particularly abundant in South Asia, where raw materials to produce m-Na–Al glass are readily available, and was likely manufactured there; however, the number and the importance of the manufacturing centers is unknown as archaeological information are extremely scarce. The interpretation of data obtained using compositional analysis on a large corpus of artifacts (486) shows that at least five sub-groups of m-Na–Al glass can be identified using the concentrations of calcium, magnesium, uranium, barium, strontium, zirconium and cesium measured with laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS). From this data, it is possible to infer the existence of several m-Na-Al glass making centers, not all of them located in South Asia as previously assumed. They were operating over different time periods and were connected to different exchange networks.     

先秦时期的历政文化

中国古代自尧制新历起形成了实质上与巫史文化对立的历政文化,这标志着中国古人对最基本的自然规律开始有了比较明确的认识,从而对以农业为主的社会生产发生了重大的积极作用,并孕育了中国古代的唯物主义天人哲学,故历政文化是中国古代最重要的优良传统文化之一。在先秦学术中,真正继承历政文化精髓并使之升华的是儒家之学,渊源于历政文化的阴阳五行之学则最终沦为一种“舍人事而任鬼神”的“小数”。     

Combining finite element and finite volume methods for efficient multiphase flow simulations in highly heterogeneous and structurally complex geologic media

The permeability of the Earth's crust commonly varies over many orders of magnitude. Flow velocity can range over several orders of magnitude in structures of interest that vary in scale from centimeters to kilometers. To accurately and efficiently model multiphase flow in geologic media, we introduce a fully conservative node‐centered finite volume method coupled with a Galerkin finite element method on an unstructured triangular grid with a complementary finite volume subgrid. The effectiveness of this approach is demonstrated by comparison with traditional solution methods and by multiphase flow simulations for heterogeneous permeability fields including complex geometries that produce transport parameters and lengths scales varying over four orders of magnitude.     

略论五色审美观在汉代的发展

五色审美观是中国传统审美体系中的重要组成部分。它起源于古老的五色崇拜,到汉代形成五行色彩学体系的雏形,色彩观念转换成一种逻辑推理方式和思想认知图式,并广泛深入民间,形成色彩使用中的形式美规范;发展到唐宋时期,最终形成了五色审美观。在这一审美观念的发展过程中,汉代是一个十分重要的奠基阶段。     

世界城市跨国空间研究的分野与合流

世界城市内部多种跨国要素作用形成的跨国空间已经成为一类新空间类型和客观存在。在跨国经济、跨国社会、跨国文化、跨国主义生活方式等跨国要素的交互作用下,跨国空间的形成发展、演绎逻辑表现出多样化分野。具体表现为：跨国空间在不同历史时期的分化、不同类型的差异以及全球化时代"资本"和"生活"的博弈,地方和空间的割裂与相互渗透等。在此基础上,对跨国空间的研究理念、形成机制和价值体系三方面却存在着合流的趋向,共同指向了全球化时代国家管治模式、自由主义生活方式以及软性制度的改革。     

Sourcing Iron Age softstone artefacts in southeastern Arabia: results from a programme of analysis using Inductively Coupled Plasma-Mass Spectrometry/Optical Emission Spectrometry (ICP-MS/OES)

Iron Age softstone vessels manufactured in southeastern Arabia are widely distributed across that region and in lesser amounts throughout Western Asia. Results from a pilot programme of analysis using Inductively Coupled Plasma Mass Spectrometry/Optical Emission Spectrometry on vessel fragments from two southeast Arabian sites are presented. These results indicate the existence of geochemically distinct groups that are separated by both transition metals and rare earth elements. While this indicates the potential for the application of the provenance postulate in softstone analysis, these promising results need to be further tested by an expanded programme of analysis which includes quarry fragments.     

Seismic Assessment of the Lima Cathedral Bell Towers via Kinematic and Nonlinear Static Pushover Analyses

ABSTRACT

The protection of cultural heritage against earthquake induced actions is one of the main challenges the earthquake engineering science and practice are facing. This article presents a seismic assessment study on one of the most ancient colonial buildings present in Peru, the Cathedral of Lima, focusing on its towers. A historical review highlighted how these structures, together with the whole Cathedral, suffered intense damage and partial collapse during previous earthquakes. In order to identify the structure main deficiencies, both linear kinematic analyses and nonlinear static analyses have been performed. Different nonlinear finite element models have been created to evaluate the influence of the adjacent walls. Different load distributions have been compared to evaluate how simplified patterns could provide results close to load distributions taken from a modal analysis of the complex. A simple retrofit strategy, consisting on the introduction of steel ties, has also been studied as a reference. Results show good correlation between kinematic and pushover analyses. The construction, when compared to the requirements of the national code for new buildings, results significantly vulnerable, pointing out the need to accept some structural damage even after seismic retrofit.     

区域标志性形象:特征、构成与整合开发——以兰州市为例

区域标志性形象具有惟一性、象征性、传承性、资源性特征,其构成要素主要包括文化特色、景观塑造、空间布局、生态背景等。兰州自然环境意象独特,历史文化底蕴深厚,标志性形象的整合开发具有显著的区域优势,但目前存在的问题是,标志性形象的空间分布不均衡,景观形象不突出。鉴于兰州市标志性形象的现状,在综合分析区域差异和比较优势的基础上,提出该区域标志性形象的整合应构建兰州区域本底标志性形象,配置门户和窗口区域标志性,凸显黄河风情线整体标志性,塑造人与环境和谐的标志性。