Structural Assessment of Companhia Aurífícia,a 19th Century Industrial Building Located in Northern Portugal

Companhia Aurifícia is located in Porto, Portugal, and was founded in 1864. It was a pioneer factory in the industrial production, casting, rolling, and stamping of metallic objects and laboured for about 150 years, in areas as jewelry, manufacture of parts in silver and gold or the production, and casting of various metals. In 1866, it began laboring in Rua dos Bragas, its present location, and in 2003 ceased all activities.Companhia Aurifícia is an industrial complex including several buildings, all located in the same block. It is a precious example of the industrial architecture in Porto, where the still existent retaining walls, structures, machinery, and decorative elements make it one of the last examples of 19^th century industrial life of the city.This article aims to evaluate the safety condition of one of the buildings included in this industrial complex, in order to propose the necessary strengthening interventions.     

The red-stained flint crescent from Gesher: new insights into PPNA hafting technology

A red-stained flint crescent found in the Pre-Pottery Neolithic A (ca. 9000 BC) site of Gesher, Israel, provides us with a unique opportunity to study the hafting technology of a particular tool type in the Levant. We present here a reconstruction, based on chemical and mineralogical analyses, of the hafting technologies and materials employed in the process. Use will also be made of relevant studies of the archaeological record. Local material was used for the production of an elastic adhesive paste, mud plaster, which was then hardened to hold the crescent securely in the haft. The study contributes insight into the hafting technology that was most probably implemented in the production and maintenance of composite tools during the Early Neolithic period.     

春秋郢都无城说

楚郢都故址所在,至今尚未解决,被学界认为有可能为楚郢都故址的江陵纪南城、当阳季家湖古城和宜城楚皇城,作为春秋早期楚始都之郢的可能性都不大。春秋郢都故址至今未能找到,应是被"城"所蔽。结合文献分析及考古实证,可知春秋郢都并没有城,没有城垣遗迹,只是一个大遗址。     

A DAMAGE MODEL FOR THE ANALYSIS OF THE SEISMIC RESPONSE OF MONUMENTAL BUILDINGS

In this paper the Author proposes a damage model for the analysis of masonry plates and shells, which is based on an improvement of a previous constitutive model. The modifications introduced, connected to the head joint damage, allow us to study the influence of masonry texture on the damage modes once the mechanical characteristics of the elements constituting the masonry and the results of tests on simple assemblages are known. Having a nonlinear constitutive model is certainly one of the basic elements for understanding the damage mechanisms in masonry buildings. If, in fact, an elastic-linear constitutive model may be used under normal loading conditions, in critical situations it is necessary to model the damage and the dissipation mechanisms that occur between the elements, stone (brick) and mortar, in correlation with their characteristics and kind of masonry. To validate the model a comparison is made between the numerical and experimental results, in the case of tests available in the literature in masonry panels subjected to out-of plane loading and in a real structure through the observation of the damage in Umbria (Italy) surveyed after the 1997 earthquake.     

Simple Homogenization-Topology Optimization Approach for the Pushover Analysis of Masonry Walls

ABSTRACT

A topology optimized rigid triangular FE macro-model with non-linear homogenized interfaces for the pushover analysis of in plane loaded masonry is presented. The shape of the mesh and the position of the interfaces is evaluated through a topology optimization approach that detects the main compressive stress fluxes in the structure. Different values of the horizontal action are considered to derive an adaptive mesh or an optimal discretization that is suitable for multiple loads. Masonry properties are calibrated by means of a homogenization approach in the nonlinear range. To tackle elastic and inelastic deformations, interfaces are assumed to behave as elasto-plastic with softening in both tension and compression, with orthotropic behavior. The two-step procedure competes favorably with classic equivalent frame approaches because it does not require a-priori assumptions on the mesh and on the length of the rigid offsets. An example of technical relevance is discussed, relying into a multi-story masonry wall loaded up to failure.     

古代彩塑和壁画中植物纤维种类鉴别

针对古代彩塑泥层和壁画地仗中植物纤维种类鉴定技术欠缺的现状,开发出一套以纤维横截面细胞形貌识别为基础的植物纤维种类鉴别方法。从秸秆类植物的化学脱胶技术、提取单根纤维、纤维横截面切片,以及纤维截面细胞形貌对比等开展了系列研究。将该方法应用于彩塑泥层和壁画地仗中常见的9种植物纤维：麦秸秆、稻秸秆、玉米秸秆、高粱秸、黄麻、亚麻、苎麻、剑麻和棉花,并以宁夏须弥山石窟以及甘肃麦积山石窟的彩塑文物样品中取出的纤维标本为例进行了鉴定。结果表明：须弥山石窟彩塑粗泥层中的植物纤维为小麦与黄麻,细泥层中的为苎麻,彩塑佛像手指中的为棉花;麦积山彩塑泥层中含有麦秸秆。研究结果证明本方法可以应用于文物样品中植物纤维种类鉴别。     

Degradation of mud brick houses in an arid environment: a geoarchaeological model

A common assumption in Near Eastern tell archaeology is that the majority of sediments originate from degraded mud bricks. Little is known about the mechanism of mud brick wall degradation. Here we present a detailed macro- and microscopic ethnoarchaeological study of the degradation of a mud brick house and propose a comprehensive mechanism for tell formation processes in arid environments. The study took place in southern Israel by trenching a ca. 60 year old abandoned mud brick house, followed by extensive sediment sampling. Macroscopic observations showed that mud brick walls degrade by collapse of single bricks and/or collapse of intact wall parts, either inwards or outwards. In addition, infill sediments within the house and outside it, in close proximity to its walls, form alternating sedimentary layers of various colors and textures. The degraded mud brick material lost its distinctive macroscopic structure, which makes it impossible to accurately identify this material by field observations alone. Mineralogical and elemental analyses established the sources of the house infill sediments, namely mud bricks and wind blown sediments. Alternating layers mostly originate from mixing between degraded mud brick material and wind blown sediments. Micromorphological observations revealed microscopic mechanisms of mud brick degradation and include processes of mud slurry gravity flows, sediment coatings and infillings, wind abrasion of walls, small-scale puddling, and bioturbation. This study provides a working scheme for site formation of abandoned mud brick structures in arid environments. It provides a set of criteria by which it is possible to differentiate floors from post-abandonment sedimentary features and thus improves the reliability of activity area research.     

The ‘Triple R’ Approach on the Restoration of Archaeological Dry Stone City Walls: Procedures and Application to a UNESCO World Heritage Site in Oman

The ‘Triple R’ approach on the restoration of dry stone walls, using recognizable, reversible and respectful constructive techniques is here illustrated. A set of restoration procedures are explained and applied to a UNESCO World Heritage site in Al-Baleed (Salalah, Sultanate of Oman) in the ‘Land of Frankincense’. The procedures were adapted in an innovative way to take into account the climate features of the Indian Ocean area (specifically, the effects of the monsoon season). All the restoration procedures aimed at conserving the site’s original architectural features by using only suitable stones and materials found on-site. Specific procedures have been adopted to consolidate walls, gates, foundations and sloping surfaces. Simple on-site mechanical tests and evaluation methods have been developed for a quick assessment of the safety level of the restored walls to ease future archaeological excavations. The application is related to a waterfront side of the ancient city built around the ninth century and added to over the next five centuries. These restoration procedures allowed for further archaeological excavations with new findings is here described.     

SOME DESIGN PRINCIPLES RELEVANT TO TORSIONAL PHENOMENA IN DUCTILE BUILDINGS

Recent studies provided opportunities to review some of the principles, which have been used in the formulations of internationally accepted code-recommendations relevant to the seismic design of ductile buildings also subjected to torsional phenomena. With the progress of this study, features emerged which are considered to have contributed to a better understanding of structural behaviour. Moreover, the identification of deeply embedded fallacies, relevant to ductile response, suggested the introduction of some changes in seismic design strategies, yet not widely known or appreciated. Reasons for necessary re-interpretations of traditional structural properties, together with illustrative examples, demonstrating applications, rather than set code-type rules, are offered.     

BEHAVIOUR OF REHABILITATED STRUCTURAL WALLS

An experimental program for identifying the causes of failures in structural walls under earthquake loading and investigating potential rehabilitation schemes was undertaken. Large-scale models of the plastic hinge region of the walls were tested. An innovative test setup that provides the possibility of controlling the ratio of the shear force to both bending moment and axial load was constructed. A control wall was tested and failed prematurely in shear reproducing the failure observed in the field. Two different rehabilitation schemes to improve the behaviour of the wall using biaxial fibre reinforced polymer (FRP) sheets were designed to prevent the shear failure. To improve the ductility, the end column elements of the walls were confined using anchored FRP. The two schemes were tested and proved to be effective in increasing shear strength, ductility, and energy dissipation capacity of the walls.