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.
This paper presents new research in the field of nonlinear static seismic analysis and the N2 method for soil-structure systems. The rationale for this study stems from the inclusion of ...soil-structure systems in simplified displacement-based design methods. The conducted research comprises three parts, including original experimental investigations, the development of numerical models and the validation of results. A new methodology is presented that provides a step-by-step procedure for the implementation of the N2 method on soil-structure systems. Results of a dynamic shake-table test on a simplified scaled structural model founded on compacted dry sand are presented, and a numerical model of the experiment is developed and calibrated with the inclusion of soil-structure interaction effects. This indicates one main significance of this paper, which is the variation between the experimental and the analytical model and how they can be compared. Lastly, a case study was conducted on a numerical model of a 3D steel building. The building was analysed using pushover analysis for a fixed base-case and by considering soil-structure interaction effects. The results of both observed cases were mutually compared and further examined by validating them with nonlinear dynamic analyses. A comparison was conducted considering the inter-story drifts, calculated according to the N2 method and time-history analyses. The results show good agreement when the N2 method is used for buildings on compliant soils. Overall, it was observed that a decrease in the inter-story drifts appears at ground level of the building. This research also provides a framework for future research in the examined field, for instance, on different types of buildings, building typologies and irregularities of the structural system.
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.
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.
Rad obuhvaća parametarsku studiju i primjenu nelinearne metode N2 za ocjenu potresnog ponašanja četverokatne i osmerokatne armiranobetonske okvirne konstrukcije. U istraživanju su korištene tri ...raspodjele horizontalnog opterećivanja konstrukcije potresnim silama: trokutasta (linearna), jednolika i modalna. Također, istražen je utjecaj P-Delta učinka na ponašanje promatranih konstrukcija..
The paper presents a parametric study and the application of the nonlinear N2 method for the evaluation of the seismic behavior of a four-story and an eight-story reinforced concrete frame structure subjected to seismic action. Three distributions of the horizontal loading of the structure by seismic forces were used in the study: triangular (linear), uniform and modal. The influence of the P-delta effects on seismic behavior of the observed structures was also investigated.
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.
U ovom radu izvršeno je dimenzioniranje visoke masivne armiranobetonske braneprema uvjetima opće stabilnosti konstrukcije. Analitičkim postupkom su proračunatevrijednosti normalnih naprezanja u ...tijelu brane. Provedena je usporedba srezultatima vrijednosti naprezanja dobivenih numeričkom analizom u programuSAP2000. Provjerene su tri kombinacije opterećenja za dva tipa temeljne stijene.Bolje poklapanje rezultata analitičkog i numeričkog proračuna uočeno je u slučajutemeljenja brane na krućoj stijeni.
In this paper, the dimensioning of a high massive reinforced concrete dam accordingto the conditions of general structural stability was performed. The values of normalstresses in the dam body were calculated by an analytical procedure. A comparisonwas performed with the results of stress values obtained by numerical analysis inthe SAP2000 software. Three load combinations for two foundation rock types weretested. A stronger correlation of numerical and analytical results was observed in thecase of the foundation on harder rock.
Numerous triaxial tests on sand and sand-like materials have been performed worldwide during the past several decades. Their results provided a development of the advanced soil constitutive models ...and laboratory testing devices, as well as the establishment of a worldwide database of different types of uniform sandy materials. From such research, the critical state and steady state theory has emerged as one of the most useful tool for the modelling of a soil behaviour. This paper presents the results of static drained tests performed on the uniform Drava River sand from the Osijek region in Croatia. The main aim was to determine the shear behaviour and critical state, given that these characteristics are mostly unknown for the tested sand material. A series of detail triaxial tests were performed in drained conditions for three different initial relative densities, DR, and two different loading directions; e.g., axial compression and axial extension. In total, 18 drained tests were performed. The study indicated that the value of 33.75∘ is the critical friction angle for the tested sand. The relative density of 57% is determined as the critical relative density. Additionally, the study confirmed the difference in critical state for compression and extension loading. In addition, the results indicate that the sample preparation procedure has an important impact on the critical state of loosely prepared sandy samples. These results give the first insights into the behaviour of the Drava River sand, which can generally contribute to the worldwide sand behaviour knowledge base.
This paper introduces a discrete simulation model for solving routing and network material flow problems in construction projects. Before the description of the model a detailed literature review is ...provided. The model is verified using a case study of solving the ready-mix concrete network flow and routing problem in metropolitan area in Croatia. Within this study real-time input parameters were taken into account. Simulation model is structured in Enterprise Dynamics simulation software and Microsoft Excel linked with Google Maps. The model is dynamic, easily managed and adjustable, but also provides good estimation for minimization of costs and realization time in solving discrete routing and material network flow problems.
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