Simulation of Shake Table Tests on Out-of-Plane Masonry Buildings. Part (III): Two-Step FEM Approach

ABSTRACT

This article presents numerical simulations of two full-scale masonry structures which were tested on the shaking table within the scope of the workshop “Methods and challenges on the out-of-plane assessment of existing masonry buildings”. The numerical models have been developed on the basis of the blind-prediction models which have been improved after the publication of the test results. The solution procedure is divided into two steps with separate numerical simulations for each one. In the first step the collapse mechanism of the structure is determined by means of pushover analysis using a continuum, plasticity-based model. In the second step the dynamic response of the structure is simulated using a multibody model approach and frictional contacts. Results of the tests show reasonable, yet far from perfect predictive capabilities of the used numerical methods.     

Mineralogical and Chemical Characterization of Roman Slag from the Archaeological Site of Castra (Ajdovščina,Slovenia)

This study deals with the mineralogical and chemical characterization of archaeometallurgical material from the Roman archaeological site of Castra (Ajdov??ina, western Slovenia). Samples were initially analysed via optical microscopy and X‐ray powder diffraction, with the composition of individual phases then determined using scanning electron microscopy coupled with electron‐dispersive spectroscopy, and Raman microspectroscopy. Chemical investigation was carried out by using inductively coupled plasma atomic emission spectroscopy to measure the major element content. The results showed that the slag originated from iron smithing operations, with calcium‐rich olivines, as well as wuestite and leucite, the most abundant phases. The investigated slags were also found to be characterized by significantly high lime levels, which probably promoted the formation of the calcium‐rich olivines.     

Variety of Black and White Limestone Tesserae Used in Ancient Mosaics in Slovenia

This study concerns the microfacies characterization of white and black limestone tesserae from selected Roman floor mosaics in Slovenia, with the aim of defining their provenance. We investigated 42 tesserae from 15 different mosaics from the archaeological sites of Ljubljana, Izola, Mo?nje, Ptuj, ?rnomelj and ?entpavel, dated from the first century bc to the fifth century ad . Among the studied tesserae, 13 different microfacies were identified: eight black and five white. The most common were mudstones with ostracods (65% of black tesserae) and wacke‐packstones with miliolids (85% of white tesserae). The majority of the identified facies can be found in the Cretaceous successions of the Dinaric Carbonate Platform in south‐western Slovenia, north‐eastern Italy and south‐eastern Croatia, suggesting a regional or imported origin of the tesserae.     

Wall Paintings from the Roman Emona (Ljubljana,Slovenia): Characterization of Mortar Layers and Pigments

This study concerns the investigation of mortar layers and pigments of wall paintings from the Roman town of Emona (Ljubljana, Slovenia). Fragments of wall paintings consist of up to three preserved mortar layers. The mineralogical–petrographic compositions of the mortars were determined by means of optical microscopy and FT–IR spectroscopy. The investigated samples were divided into several groups based on similar thicknesses of the mortar layer, the binder colour and the composition of an aggregate. Furthermore, the results of mercury intrusion porosimetry showed that mortar layers consisting of carbonate grains exhibited lower porosity with respect to layers with mainly silicate grains, which is attributed to the angular shapes of carbonate aggregate. This is in accordance with the drilling resistance measurement system test (DRMS), confirming that layers with angular carbonate grains are harder than those with addition of rounded silicate ones, due to the good packing effect. The wall paintings were mainly executed using the fresco technique, while for some details secco was used. The identified pigments were red and yellow ochre, green earth, Egyptian blue, carbon black and lime white; all of them belonged to the so‐called austere pigment, which is quite common in Roman wall paintings.