Earthen architecture has a significant share in the world’s fund of both residential architecture and cultural heritage. It provides a home to more than half of the world’s population and can be found in seismically active areas. Empirically acquired knowledge on building with rammed earth (RE) has usually been passed down from generation to generation by word of mouth, with no written scientific grant for the load-bearing capacity and resistance of structural elements. Today, many countries still do not have standards for the design of RE structures. In the development of new as well as existing design standards, the results of experimental research play a significant role. The focus of this study was on unstabilized RE, which is locally available material with low embodied energy. This paper elaborates experimental campaigns, within which meticulous techniques were employed to provide new knowledge on RE for use in earthquake-prone areas. Furthermore, this paper includes: (i) ranges of values of mechanical properties determined on RE specimens from all over the world; (ii) a comparative summary of experimental research conducted on walls and buildings to assess their seismic performance; (iii) an overview of standards and testing methods used in experiments; and (iv) recommendations for further research.
Historical industrial areas are considered as areas of particular importance in terms of their heritage value and cultural significance. They are usually located in city centers and have great potential for economic, cultural and urban development. At the beginning of the 20th century, Osijek was well known as an industrial city, but the globalization had a ripple effect on the industry, leaving industrial sites of Osijek in ruins. Although comprehensive studies have not yet been made, field research into historical industrial areas of Osijek showed that they are mostly abandoned. A literature review showed that there is not even one document that contains locations and basic information on the historical industrial areas that existed in Osijek from 1824–1945. The aim of this paper is to define exact locations of historical industrial areas that existed in Osijek from 1824–1945 and to analyze their current state, their architectural, urban and identity features. The research resulted in a database containing basic information about 59 historical industrial areas in Osijek. An analysis and comparison of the current state of 13 remaining existing historical industrial areas in Osijek is given. The three case studies present detailed analysis, comparison and evaluation of observed historical industrial areas.
Numerical modelling of the soil in seismic design of structures is always a daunting task. The goal of this article is to develop a simplistic numerical modelling technique for shallow founded buildings on compliant soils. An existing large-scale experimental research (TRISEE) was used for calibration. The physical model comprised of a rigid square foundation placed on a sand bed connected to a rigid column and was subjected to a dynamic sine loading. The results from the TRISEE experiment are well known and commonly used by researchers in this field, yet none of the numerical studies were conducted considering the loose sand case. Nonlinear link elements and linear springs were used for representing the soil. It was determined that the soil behavior is highly influenced by the stiffness, selected hysteresis model, and the p-y curve. Considering the software limitations, numerical models represent the experimental behavior in a good manner. Based on the results obtained from the experiment, a case study on a steel frame building with SSI effects included was conducted. Considering the results from this research, the authors recommend implementation of SSI effects into the building’s design phase since they exhibit unfavorable impacts on the seismic behavior and can lead to underdesigned structural elements. However, it has to be emphasized that certain limitations exist due to simplified modelling approaches that were used for this research.
Rammed earth buildings constitute a large part of the housing stock in rural areas. Although these houses are recognized as a cultural heritage, detailed analyses of their architectural features, geometric parameters crucial for structural stability, and soil properties used for their construction have not yet been carried out in Croatia. The aim of this study is to collect basic data on the architectural features and material properties of rammed earth walls through field research in Croatia. These data are crucial for both numerical and experimental studies to improve the understanding of the structural behavior of rammed earth houses. Data were obtained through field research and a detailed survey of 22 houses. The houses were analyzed, samples of the rammed earth walls were collected, and their properties were tested in the laboratory. This study contributes to a better understanding of regional building practices and provides data that will enable us to identify the causes of damage in future studies and to select rehabilitation measures to preserve the authentic symbols of cultural heritage.
Earthen architecture largely supports the concept of sustainable building. In the seismically active area of eastern Croatia, there is a large number of rammed earth houses, many of which are over 100 years old. All these houses were built using empirical knowledge, i.e., without applying national design standards. In order to support the preservation of ethnic villages and traditional rammed earth houses, a field survey was conducted. Parts of the walls of traditional rammed earth houses were collected, and the material was thoroughly analyzed. Samples of rammed earth were reproduced, and tests were carried out with the aim of determining the shear strength to subsequently determine the seismic behavior of Croatian traditional earthen architecture. This paper presents the results of shear strength tests on samples with different particle size distributions, lime content, the straw of different cereals but also hemp fibers. An increase in shear strength was observed with the addition of natural fibers to the samples.
1 December 2023 in Bulletin of Earthquake Engineering