TY - CONF A1 - Miccoli, Lorenzo A1 - Oliveira, D. V. A1 - Silva, R. A. A1 - Drougkas, A. A1 - Fontana, Patrick T1 - Numerical modelling of rammed earth under different in-plane load conditions N2 - The paper presents a comparison between two different numerical modelling approaches aimed to simulate the in-plain behaviour of rammed earth walls, namely under axial, diagonal and cyclic shearcompression loading. In the first part of the study the mechanical characterisation of wallets tested under uniaxial compression and diagonal compression and walls tested under in-plane cyclic shear-compression loading is presented. The results were used to implement and validate the finite element simulations. The numerical modelling of the rammed earth samples tested is then discussed in the second part. A non-linear constitutive law based on the total strain rotating crack model (TSRCM) was employed as implemented in the DIANA® software. The aim of the numerical analyses presented here is to simulate the behaviour of rammed earth under different inplane loading conditions. For the wallets, tests under static loading both macro- and micro-modelling approaches were considered for the simulation of the experimental tests. For the walls subjected to cyclic loading only the micro-modelling approach was applied for the simulation of the experimental tests. The respective FEM model was calibrated with the experimental results. The rammed earth layers were represented by continuum elements, the contact surfaces between layers by interface elements. This approach allowed assessing the influence of the apparent weakness of the interfaces between layers on the shear behaviour of rammed earth. The goal of the numerical simulation of the cyclic tests was to establish the adequacy of common analytical methods (e. g. used for masonry) applied to the analysis of rammed earth. Rammed earth exhibits brittle characteristics similar to masonry materials and is used in geometrical typologies, such as walls, common in masonry construction. T2 - Lehm 2016 - 7th International Conference on Building with Earth CY - Weimar, Germany DA - 12.11.2016 KW - Building materials KW - FEM analysis KW - Rammed earth KW - Compression and shear testing KW - Cyclinc loading KW - Failure mode KW - Crack pattern PY - 2016 SP - 1 EP - 9 PB - Eigenverlag Dachverband Lehm e. V. CY - Weimar AN - OPUS4-38820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Silva, R.A. A1 - Oliveira, D.V. A1 - Miccoli, Lorenzo A1 - Schueremans, L. ED - Pena, F. ED - Chávez, M. T1 - Modelling of rammed earth under shear loading N2 - The intensive use of earth as a building material since ancient times resulted in an important and significant earthen built heritage currently existing worldwide spread. The rammed earth technique has a significant presence in this heritage, where it served to build from simple dwell-ings to fortresses. However, the high vulnerability of rammed earth constructions to decay agents and to seismic events puts in risk their further existence and the lives of millions of peo-ple. With respect to the seismic behaviour of rammed earth walls, the understanding and mod-elling of their shear behaviour are topics underdeveloped in the bibliography. Nevertheless, these topics are of extreme importance in the preservation and strengthening of rammed earth constructions. Therefore, this paper presents a numerical work aiming at modelling the non-linear behaviour of unstabilised rammed earth under shear loading, resorting to the finite ele-ments method (FEM). The models were used to simulate the behaviour of a set of rammed earth wallets tested under diagonal compression. Both macro- and micro-modelling approach-es were considered, where the objective of this last approach was to evaluate the influence of apparent weakness of the interfaces between layers on the shear behaviour. The total strain ro-tating crack model (TSCRM) was used to simulate the behaviour of the rammed earth material, while the Mohr-Coulomb failure criterion was used to simulate the behaviour of interfaces be-tween layers. Furthermore, uncertainties related to the definition of the input parameters re-quired performing a sensitivity analysis. The numerical models achieved good agreement with the experimental results and the compressive strength, the Poisson’s ratio, the tensile strength and the tensile fracture energy revealed to be the most important parameters in the analyses. T2 - SAHC 2014 - 9th International conference on structural analysis of historical constructions CY - Mexiko City, Mexico DA - 14.10.2014 KW - Rammed earth KW - Diagonal-compression KW - Shear behaviour KW - FEM modelling PY - 2014 SP - Paper-ID 08/015, 1-12 AN - OPUS4-32538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miccoli, Lorenzo A1 - Oliveira, D.V. A1 - Silva, R.A. A1 - Müller, U. A1 - Schueremans, L. T1 - Static behaviour of rammed earth: experimental testing and finite element modelling N2 - The paper presents an experimental program aiming at assessing the mechanical performance of rammed earth walls, namely under compression and shear loading. Axial compression and diagonal compression tests were carried out for this purpose, which allowed determining important mechanical parameters, such as compressive strength, Young's modulus, Poisson's ratio, shear strength and shear modulus. Furthermore, it allowed assessing the level of non-linear behaviour of the respective stress–strain relationships as well as the failure modes. The experimental results were then used in the calibration of numerical models (finite element method) for simulating the non-linear behaviour of rammed earth under shear loading. Both macro- and micro modelling approaches were considered for this purpose. The total strain rotating crack model was used to simulate the behaviour of the rammed earth material, while the Mohr–Coulomb failure criterion was used to simulate the behaviour of interfaces between layers. In general, the numerical models achieved good agreement with the experimental results, but uncertainties related to the definition of the input parameters required to perform a sensitivity analysis. The compressive strength, the Poisson's ratio, the tensile strength and the tensile fracture energy revealed to be the most important parameters in the analyses. KW - Rammed earth KW - Compression behaviour KW - Shear behaviour KW - Finite element analysis PY - 2015 UR - http://link.springer.com/article/10.1617/s11527-014-0411-7/fulltext.html DO - https://doi.org/10.1617/s11527-014-0411-7 SN - 1359-5997 SN - 1871-6873 VL - 48 IS - 10 SP - 3443 EP - 3456 PB - Springer CY - Dordrecht AN - OPUS4-31329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -