The preservation of exposed mudbrick architecture in Karanis (Kom Aushim), Egypt

Excavations in the arid regions of Egypt provide insight into the many types and uses of mudbrick architecture. Upon exposure the inherently unstable building material decays rapidly, resulting in severe loss or complete destruction of once well-preserved buildings. The preservation of mudbrick structures is relatively complicated and expensive. Research has focused on the circumstances that enable preservation and the influence of climate and weather over time. Conservation treatments should address these two processes as soon as possible after exposure of the structures. Our assessment of a range of conservation methods leads to the conclusion that reburial is among the least objectionable method of preservation, despite its drawback of returning the excavated buildings to a situation where they are invisible to both researchers and the public.     

民居中的奇迹——福建的土楼

土楼是福建西南部以永定为中心的客家人的民居。这种民居非常特殊,有方形、园形。多为四层,中间为庭院。居民多属同族、同宗、同姓。它是北方因战乱而南迁的移民带来的。在东汉以后。北方战乱,大姓士绅多聚居建成坞壁,作为保护自己。客家人南迁到福建西南,在少数民族与荒野之中,也采取这种形式建筑以适应防守需要。永居的土楼在当地环境亦有发展,特别是园形土楼,形成独特形式。由于客家人聚族迁移此地,土楼既适应其特殊环境,而且也进一步促进了客家人以耕读为中心的强大内聚力的文化的发展。因此,土楼既是客家文化的一种外在景观,又是其文化内涵的外在条件。     

Mud Brick Metaphysics and the Preservation of Earthen Ruins

In the conservation of built heritage, earthen ruins rank as one of, if not the most, intractable of problems to be confronted. Lacking the very architectural devices originally in place to combat and control weathering, earthen ruins face rapid deterioration without constant remedial and preventive conservation. Often it is the enormous mass of many ancient earthen ruins that explain their persistence; however, even these will collapse over time from differential erosion, or eventually stabilize as formless lumps. The impossible demands of simultaneously preserving architectural form and fabric (materiality) challenge the archaeologist and conservation professional who attempt to manage both for temporary and permanent display.     

Seismic behavior of two Portuguese adobe buildings: part II —numerical modeling and fragility assessment

Considering the likely unfavorable behavior under seismic action of adobe construction, this article aims at providing a seismic fragility characterization of two adobe Portuguese traditional buildings, using numerical models calibrated over experimental results. The study of such two case-study buildings in the region of Aveiro contributes to the understanding of the seismic fragility of adobe construction in the region in general. The buildings were numerically modeled to estimate their structural behavior under seismic loading using adobe material properties that were calibrated based on the experimental results of a cyclic in-plane test of a full-scale double-Tshaped adobe wall. The method chosen to characterize adobe masonry and model its nonlinear behavior followed a total strain crack-based macro-modeling (TSCM) approach, whereas pushover analysis was carried out to reproduce the pseudo-static experimental test in order to enable a refined calibration of adobe masonry mechanical properties. Fragility functions were then derived, based on the above-mentioned numerical models, using nonlinear static analysis, bringing further insight on the seismic fragility of traditional Portuguese adobe construction.     

Seismic performance of historical vaulted adobe constructions: a numerical case study from Yazd,Iran

Past earthquakes have demonstrated that historical vaulted adobe buildings are highly vulnerable to seismic actions. Hence, it is crucial for such building typologies to be evaluated in terms of seismic capacity. To this end, this article deals with the seismic performance of historical vaulted adobe houses from the city of Yazd, Iran as one of the seismically active areas of the world and possessing a very rich adobe heritage. Thus, and based on a detailed geometrical survey, a representative sample of adobe houses from Yazd was studied using a simplified in-plane analysis based on three geometric indexes. Concerning the out-of-plane behavior, a deeper assessment was conducted by performing a numerical study, where the main influential parameters on the seismic behavior of vaulted adobe buildings were considered. The numerical analyses were carried out by adopting the limit analysis theory implemented in the Block2D software. The results obtained indicate the safe in-plane behavior of most of the houses and the safe out-of-plane response of the sample under gravitational loads. However, the sample out-of-plane safety under earthquake-induced loads seems to be a matter of concern.     

Assessment of Construction Techniques and Material Usage in İzmir Rural Houses

The domestic architecture in the rural villages of ?zmir comprises a unique built environment with their masonry wall textures, semi-open sofas, round tiled-hipped roofs, and chimneys, and represents an important part of the cultural and architectural heritage. This assessment is mainly based on field observations that focus on the architectural and structural layout of intact, damaged, and destroyed houses. During field observation and the analysis of data certain plan typologies and relationships between the geological formations of the region and choice of materials and construction techniques were observed. While load-bearing masonry and timber skeleton systems are common, extensive use of timber laces, stone, and fired or adobe brick masonry with mud mortar and timber frames infilled with masonry materials were frequently seen. Generally, round timber elements such as wall plates, laces, lintels, posts, and frames of flooring systems are used. Architectural degenerations in authentic houses, defective details and partially due to the earthquake-prone nature of the region seismicity have been evaluated. An overall approach for the preservation and sustainability of this heritage is suggested.     

The devolution of mudbrick: ethnoarchaeology of abandoned earthen dwellings in the Bolivian Andes

This ethno-geoarchaeological study considers the formation of archaeological deposits through a study of abandoned contemporary mudbrick structures on the Taraco Peninsula, Bolivia. The study site was a domestic compound with rooms for different functions that had been abandoned for over 50 years. Structures were in variable states of decay in terms of roof cover, walling integrity and abandonment fills. Geoarchaeological samples were collected from intact and weathered adobes, earthen hearths, mud plaster, and flooring. Adobes and mud plaster were locally derived from topsoil containing archaeological sediments with added gravel and plant temper. This study found a relatively light anthropogenic signature for decayed earthen houses.Rising damp exfoliated mud plaster despite un-mortared cobble wall foundations. Organic matter from roof fall attracted thriving soil faunal populations, which furthered site destruction through bioturbation, particularly packed earth floors. Sediments derived from weathered mudbrick retained little evidence of prior use as construction materials unless exposed to heat. Sediments exposed to high-temperatures produced the most distinctive rubified features but were structurally compromised. Isolated thermal features from decomposed adobe would not be distinguishable from other hearth types. Adobes exposed to low or moderate heat had few distinctive features in thin section. Intact adobes and floors that were not exposed to heat have fewer pores than natural sediments and distinctive grass inclusions. These adobes disarticulated into loose sediments when exposed to weathering. Adobe fall outside the crumbling structures blended into topsoil.This study sheds light on functional attributes of pre-Columbian construction practices. Thick, fine-textured sterile flooring is commonly encountered in the study region. This would control bioturbation from roof fall in a previous occupation enabling reconstruction in abandoned dwellings. In contrast to the contemporary dwelling, prehistoric mortared cobble foundations would resist rising damp. Cobbles without mortar may relate more to design and construction than durability. These contrasts between contemporary and prehistory construction practices reflect differences in the design, construction costs and functional use-life of adobe structures.     

Soils and Earthen Building Materials Used for the Buddhist Temple Complex

This article presents a comprehensive study of the local soils and historic earthen building materials used in Nako temple complex in Western Himalayas. On-site and laboratory investigations followed a holistic approach to characterize materials and identify historic manufacturing formulas. The interdisciplinary and novel methodology used for analysis of the earthen building materials combine geological, chemical, mineralogical, geotechnical, and mechanical approach. The results presented in this article enable a better understanding of material culture and advance the study of damage and decay processes found in the temple buildings. In addition, a suitable conservation and preservation strategy is presented.     

Seismic behavior of two Portuguese adobe buildings: Part I - in-plane cyclic testing of a full-scale adobe wall

This article addresses the laboratory testing of a full-scale double-T shaped adobe wall, under in-plane horizontal cyclic loading of increasing amplitude, with the aim of contributing to the understanding of the seismic behavior of adobe structures. The wall was built with lime adobes taken from an existing building and mortar with a traditional composition. The behavior of the wall was assessed in terms of: shear stress versus horizontal drift and moment versus rotation relationships; maximum lateral strength; drift and rotation at peak stress; evolution of stiffness, lateral displacements, dissipated energy, and natural frequency; and damage pattern. The wall exhibited brittle behavior and in-plane strength corresponding to 56% of the vertical load. Cracking was observed with an X-shaped pattern whereas no sliding occurred at its base. This research supported the subsequent development of a repair and retrofit solution and also of numerical models to simulate the seismic behavior of two adobe buildings.     

Predictive Tri-Linear Benchmark Curve for In-Plane Behavior of Adobe Walls

In the present study, numerical simulations are conducted to estimate the in-plane response of adobe walls subjected to pseudo-static cyclic loading based on the finite element code ABAQUS. The simplified micro-modeling approach is adopted and an interface model reported in ABAQUS material library is applied as material model for zero-thickness interface elements. The comparison between obtained results and field test data results in good agreement. Parametric studies are carried out to evaluate the effectiveness of independent parameters changes on response of adobe walls. It is noted that mechanical properties of joints and adobe units play an active role on in-plane behavior of walls. A tri-linear benchmark curve is proposed to predict the response of aforementioned walls. In this regard, a statistical study is performed to derive the predictive tri-linear benchmark curve. The regressive analysis on 59 numerical models resulted in proposing predictive models. Finally, by comparing tri-linear curves obtained from the regressive analysis, numerical analysis, and experimental study, appropriate accuracy of theoretical model can be found.