Characterization of timber masonry walls with dynamic tests

Timber-framed wall buildings are seen all over Europe, especially in seismic regions, given its adequacy to resist earthquakes. The “Pombalino” buildings, developed after the great 1755 earthquake that destroyed Lisbon, constitute one of the best examples of historic seismic-resistant structures based on timber-framed masonry walls. The research presented in this article aimed at experimentally evaluating the seismic behavior of the “Pombalino” buildings. The experimental program was based on extensive dynamic testing on sub-structures of typical “Frontal” walls (the timber masonry walls), carried out at the LNEC (the Portuguese National Laboratory of Civil Engineering) shaking table. The tests comprised (a) seismic tests, in which the seismic action was applied with increasing amplitude in one direction; and (b) dynamic identification tests, aiming at evaluating the dynamic properties of the sub-structures and their evolution with damage accumulation.     

Beyond cemetery walls: early medieval funerary topography and Christian salvation

The article examines how the topography of the Christian cemetery in Merovingian Gaul mirrored the status which the souls of individuals were believed to occupy in the sphere of the next world. In practice, moreover, the clergy's treatment of Christian corpses was often perceived as determining their fate. Drawing on both literary and material evidence, the article argues that the boundaries established between the faithful and the damned in the Christian cemetery supported the Church's claims to sacral authority in this life and the next.     

Girlhood,participation and empowerment in Tanzania: climbing material and discursive walls

In this paper I reflect upon encounters with ‘young people’s participation’ during ethnographic research on girlhood and sexual agency with teenage girls in Tanzania. I argue that methodology which centralises participants’ experiences is particularly important in research on issues related to sex and sexuality, where young people’s voices are often disregarded or downplayed. However, such an approach might run up against a number of practical challenges. This paper draws on fieldwork conducted in two sites during 2014 and 2015 to show that attention to the networks of relationships within which young people are embedded and the structural conditions which might generate or obstruct sexual agency is essential for research which seeks to promote their meaningful participation.     

The Berlin wall and the Bastille: Tearing down walls and building myths

This article first discusses the construction, destruction and consumption of the Berlin Wall, noting especially the different meanings of Mauer (the wall as a barrier) and Wand (the surface of a wall). It then compares the end of the Wall with the storming of the Bastille and its transformation into symbolic souvenirs. The fall of the Berlin Wall entered collective memory through mass participation in its destruction, rock concerts held around it, graffiti art and the purchase of Wall fragments. However, sections of the Wall are now being preserved to prevent it from being forgotten by future generations.     

Natural degradation of earthworks,trenches, walls and moats,Northern Thailand

We here investigate the geometry, age, and history of several enigmatic northern Thailand earthwork entrenchments that are mostly located on hills and could not have held water to form moats. The earthworks are either oval or rectangular in plan view and typically encircle 0.3 to 1?sq km areas with no potsherd debris that would indicate former towns. Most trenches are 3–5?m deep with inner walls 4.5–8?m high. Some encircling earthworks are concentric double trenches spaced approximately 10?m apart. Historians have suggested these earthworks enclosed defensible areas where people in outlying villages sought refuge when under attack by neighboring rulers, the Chinese Ho, or the Burmese. We argue that some encircling entrenchments may have been for the capture or containment of elephants. Nearly all of the once near-vertical original walls have degraded to slopes of 32–47°. Fitting calculated curves of the diffusion-based scarp-degradation model to our height-slope data, and assuming most scarps have degraded since the end of La Na Kingdom time a.d. 1558, we derive a diffusion coefficient of 0.002?m² y^?1. Slopes of the rectangular earthwork at Souvannkhomkham, Laos, across the Mekong River from Chiang Saen Noi, are significantly more degraded (approximately 32°), indicating an age of 800–1200 years. Locations of these earthworks are established in hope that they will be preserved as part of the Thai and Lao archaeological legacy.     

北京近代建筑砖石墙体的病害分析

为了尽量减少在修复工作时对历史建筑造成不可预估的破坏,修复前对建筑的病害分析是必不可少的。本文以北京近代建筑砖石墙面为研究对象,针对近代建筑的砖石墙面病害进行了调查研究,结合每类建筑病害特征,对其病害成因进行了简要分析,即病害分析。研究砖石墙面的病害成因,对寻求适宜的砌体病害保护修复方法有着重要的意义。     

Assessment of out-of-plane behavior of rammed earth walls by pull-down tests

This article reports pull-down tests performed on rammed earth construction in Bhutan. The pull–down specimens involved an old rammed earth building component as well as a newly prepared rammed earth wall. Both the wall specimens were tested in out-of-plane direction. Theoretical rigid body formulation and finite element (FE) models were developed to predict the response of the rammed earth structures under out-of-plane loading. The validated FE model was further extended to parametric study of material and physical characteristics of rammed earth construction and their effect on critical response quantities. The change in elastic modulus showed effect in the pre-cracking phase of the wall. Density of rammed earth on the other hand affected the post-peak response of the rammed earth wall. Furthermore, an increase in the physical characteristics, namely, the thickness of wall and the vertical superimposed load on top of the wall, enhanced the rocking resistance capacity of the out-of-plane loaded rammed earth walls.     

城墙命运变迁与遗产保护思考

近五六十年来,人们对古城墙的态度发生了巨大的变化,与之密切相关的城墙命运也是如此,经历了一个从拆除到日渐重视保存、从趋于保护到热衷于修复和重建的历史过程。本文对这一过程及其重要人事进行了梳理,并分析了相关重要影响因素。同时,基于城墙命运巨大变化的历史考察,对快速城市化过程中的城市文化遗产保护进行了多方面的思考。     

Experimental analysis of rubble stone masonry walls strengthened by transverse confinement under compression and compression-shear loadings

Stone masonry walls of ancient buildings have reasonable resistance to vertical loads but lower resistance to shear forces and reduced tensile strength. However, to achieve such compressive strength the masonry must not disaggregate when subjected to loading. This can be achieved if during the construction of the walls larger stones, usually referred as “through stones”, are used, spanning the thickness of the wall, making it possible to improve the transverse confinement of the masonry. For rehabilitation projects and structural reinforcement of such buildings, the transverse confinement can be achieved by fixing steel elements perpendicular to the wall. This confinement technique is often part of a more comprehensive rehabilitation solution, which includes the application of mortar or concrete reinforced layers applied to the wall surface.

This article presents results of an experimental research on material properties and mechanical characterisation of stone masonry specimens strengthened by two transverse confinement solutions (independent steel reinforcing rods and continuous steel ribbons wrapping the specimen). Specimens were tested under compression and compression and shear loadings.

This experimental work is part of a major research project to study the mechanical behavior of URM and strengthened walls, and the characteristics of the building materials of such specimens.     

Design and evaluation of hydraulic lime grouts for the reattachment of lime plasters on earthen walls

Abstract

A laboratory and field testing programme for the formulation and evaluation of hydraulic grouts was developed for the reattachment of lime plasters on earthen (adobe) walls. Formulations utilizing kaolin, hydraulic lime, ceramic microspheres, and fine silica sand, with and without the addition of an acrylic emulsion, were prepared and evaluated in a three-stage testing programme. Standard tests were employed to measure injectability, viscosity, set time, shrinkage, weight, splitting/tensile strength, water vapour transmission rate, and adhesive bond strength. Grout microstructure was comparatively examined using scanning electron microscopy. Of the 18 grout formulations tested, only one mixture composed of (parts by weight) 1 part microspheres, 1 part sand, 2 parts hydraulic lime, 10% part acrylic emulsion was found to meet all the essential performance criteria established.     

A place to remember: scaling the walls of Angel Island immigration station

This paper considers the restoration and presentation of Angel Island Immigration Station, a federal facility in the San Francisco Bay that between 1910 and 1940 worked to prevent the arrival of Chinese laborers to the United States in accordance with the 1882 Chinese Exclusion Act. The production of Angel Island Immigration Station as a national historic landmark is delineated through the social construction of scale. I discuss efforts to achieve a leap in the scale of the site's significance and how this brings forth new management regimes that change the format of the interpretation there. In particular, narrative construction, landscape design, and revised tours, insert a standardized story of Chinese exclusion into the national memory. This paper shows how the imperative to increase the scope of recognition—to petition nationally for status and funds—requires a repackaging of stories to affirm popular American ideals of freedom over those that challenge the nation's persecution of Chinese immigrants.     

Contribution of the resistivity method to characterize mud walls in a very dry region and comparison with GPR

Mud walls are frequent in many archaeological sites, including sites located in semi-desert regions. In cases with buried walls, the geophysical methods can be useful tools for their investigation, since they provide maps of the subsoil in a non-invasive way and in relatively short times. This article deals with the characterization of mud walls in very dry soils through the resistivity method, discussing a methodology to satisfactorily apply the method in this kind of adverse environment and how to interpret the results. The case of the Palo Blanco archaeological site, a pre-Incaic village located in the NW region of Argentina, is analyzed.     

Physical evidence revealed during the cleaning and the excavations of the outer wall of the land walls of Constantinople at the Porta ROmanus

Abstract

During the clearance, excavations and conservation of the Land walls of Constantinople in 1992–93 at the Porta Romanus (Topkapi) some original details of the Theodosian construction techniques and the subsequent repairs were found. It was seen that the structural system of the outer wall which supports the parapet walk and the battlement had been altered during the Late Byzantine era. It was also affirmed that the inner and the outer terrace had been used as a burial ground and ceramic pipes for the water supply system of the moat and stone culverts for the disposal of the ground water of the inner terrace were found.     

Fought under the walls of Bergida: KOCOA analysis of the Roman attack on the Cantabrian oppidum of Monte Bernorio (Spain)

As conflict archaeology has matured as a discipline, there have been calls for more unified analytical techniques. Several researchers advocate the adoption of codified analytical and planning concepts used by the United States Army. One of these concepts, KOCOA Terrain Analysis, shows promise as a locational and analytical aid in archaeological contexts. Defining terrain features are identified and categorized according to well-defined terminology, allowing for a detailed analysis of the effects of terrain on military operations. KOCOA’s structure and codification render the concept transferable between researchers and diachronically across different site types. KOCOA has only rarely been utilized outside the United States and only on historical battlefields. The ongoing archaeological research at the Monte Bernorio oppidum (Palencia, Spain) provides an opportunity to utilize KOCOA in a classical, proto-historical archaeological context.