Fabric transpositions in granite plutons — An insight from non-scaled analogue modelling

Investigations on a set of experimental models of highly viscous intrusions were carried out in order to study the internal strain pattern during vertical ascent and emplacement of granite intrusions. The strain pattern was determined by means of anisotropy of magnetic susceptibility (AMS) resulting from the orientation of magnetite particles in a liquid plaster medium. The modelled intrusions show distinct fabrics reflecting the flow of a rheologically complex, non-Newtonian material. During the vertical growth of the intrusion, constrictional vertical fabrics are transposed into flattening fabrics, and along with the development of low-intensity fabric domains are passively transported upwards. Vertical growth takes place along subvertical thrust shear zones that satisfactorily explain the discordant magmatic fabrics in granites along intrusion sides. The resulting complex fabric patterns suggest that the vertical movement of material in ascending intrusions is accommodated by various flow mechanisms operating simultaneously.     

Higher modes in simplified inelastic seismic analysis of single column bent viaducts

The influence of the higher modes and their consideration in the pushover analysis of reinforced concrete single column bent viaducts with different degree of irregularity is discussed. Typical multimode pushover‐based methods (modal pushover analysis, modal adaptive non‐linear static procedure and incremental response spectrum analysis) are addressed and compared with a single mode procedure (N2) and inelastic time history analysis. If in the transverse direction the substructure of the viaduct is flexible in comparison with the superstructure, the influence of higher modes is small (the structure is regular) and single mode procedure works well. This typically occurs when the columns are high or considerably damaged. Conversely, for the analysis of irregular structures having short and slightly damaged columns, the multimode methods are needed. In most cases, all the analysed multimode pushover‐based methods have given the results comparable with time history analysis, with the exception of cases where torsional sensitivity is varying during the response. All the methods have limitations (discussed in detail in the paper), which should be fully recognized by the user. Copyright © 2005 John Wiley & Sons, Ltd.     

Large wood load and transport in a flood-free period within an inter-dam reach: a decade of monitoring the Dyje River,Czech Republic

This study examined the large wood (LW) load and transport during the non-flood period (2009–2018) following major floods that occurred in 2002 and 2006 within the inter-dam reach of the Dyje River (Czech–Austrian border). The LW load was examined in 36 river corridor segments scattered within the reach in the 2009–2018 period. Two whole-reach surveys (2011 and 2019) on LW frequency and distribution were conducted, and the export of LW to the downstream reservoir was analysed between June 2013 and December 2018. In the period of non-flood discharges, the recruitment and depletion of LW were highly variable processes in space and time, leading to a considerable change in the total LW quantity. Whereas the total number of LW pieces decreased, the total LW volume increased because of the increasing dimensions of newly recruited pieces. The annual variability in the quantity of newly recruited pieces was better explained by the variation in the maximum annual discharges (y = 41.043ln(x) + 3.2737, R² = 0.5352) than by the variability in the number of days with wind gusts >17.2 m/s (y = 1.5004x + 82.096, R² = 0.118). The land use change with the abandonment of human settlements after World War II and the progressive expansion of forest was the major historical factor driving the increased recruitment of LW to the river corridor. While the 2006 (>100-year RI) flood brought approximately 1,250 LW pieces to the reservoir, the 2013 (1.5-year RI) flood delivered 45 pieces. The long-term average monthly input of LW to the reservoir was 7.7 pieces. The exceptional low-magnitude flood of 2013, which occurred at the beginning of the monitoring period, was shown to be a threshold above which the number of LW pieces that floated to the dam significantly increased. © 2020 John Wiley & Sons, Ltd.     

The Stogovce landslide in SW Slovenia triggered during the September 2010 extreme rainfall event

From September 16 to September 20, 2010, a cold weather front went across Slovenia. A heavy 4-day rainfall totaling between 300 and 520 mm caused large floods and triggered numerous rainfall-induced landslides. The damage due to the floods and landslides is estimated over 250 million Euros. One of the largest landslides covering the area of approximately 15 ha was triggered on flysch bedrock, just below a limestone overthrust zone. The sliding material properties, the inclinations of the slope, and the water catchment area indicate that the landslide may transform into a fast moving debris flow. The necessary protective measures were taken to protect inhabitants and the infrastructure against the disaster. The Stogovce landslide is one of the numerous rainfall-induced landslides that have occurred in Slovenia on flysch bedrock in the last 10 years. It proves that landslide risk on flysch territory is increasing. Special program of monitoring and protective measures will have to be developed in near future to protect densely populated areas against landslides as a consequence of weather extremes.     

Cyclic response of slender RC columns typical of precast industrial buildings

The cyclic behaviour of slender cantilever columns in full-scale models of precast industrial buildings, designed by Eurocode 8, was studied experimentally and analytically. The shear span ratio of the columns was 12.5, which is more than allowed by Eurocode 8 for columns in frame structures (10). High deformability and a large deformation capacity (8%~drift) of the columns was observed. A lumped plasticity model was used in the analysis. In the paper the observed behaviour of the models has been compared with the predicted behaviour obtained by several empirically based models and procedures. It was observed that these models, which were developed for much lower shear span ratios (2–6), were not applicable for the analyzed very slender columns without appropriate additional considerations and modifications. In the case of such columns the yield drift is dominated by the flexural mode (it is practically proportional to the height of the column) and the ultimate drift under cyclic loading conditions is only slightly dependent on the shear span (indicating that the ratio of the equivalent length of the plastic hinge to the height of the column decreases with the increasing shear span). An appropriately modified lumped plasticity model incorporating in-cycle and repeated-cycle strength deterioration was chosen for future use in performance-based design and seismic risk studies.     

High-resolution saturated hydraulic conductivity logging of borehole cores using air permeability measurements

Saturated hydraulic conductivity (K _s) is one of the most important parameters determining groundwater flow and contaminant transport in both unsaturated and saturated porous media. The hand-held air permeameter technique was investigated for high-resolution hydraulic conductivity determination on borehole cores using a spatial resolution of ～0.05 m. The suitability of such air permeameter measurements on friable to poorly indurated sediments was tested to improve the spatial prediction of classical laboratory-based K _s measurements obtained at a much lower spatial resolution (～2 m). In total, 368 K _s measurements were made on ～350 m of borehole cores originating from the Campine basin, northern Belgium, while ～5,230 air permeability measurements were performed on the same cores, resulting in a K _s range of seven orders of magnitude. Cross-validation demonstrated that, using air permeameter data as the secondary variable for laboratory based K _s measurements, the performance increased from R ²?=?0.35 for ordinary kriging (laboratory K _s only) to R ²?=?0.61 for co-kriging. The separate treatment of horizontal and vertical hydraulic conductivity revealed considerable anisotropy in certain lithostratigraphical units, while others were clearly isotropic at the sample scale. Air permeameter measurements on borehole cores provide a cost-effective way to improve spatial predictions of traditional laboratory based K _s.     

Results from the first ballast water sampling study in the Mediterranean Sea - the Port of Koper study

The ongoing transfer of harmful organisms by shipping, especially via ballast water transport, may result in a change of biodiversity, alteration of ecosystems, negative impacts on human health and economic loss. Species introductions which cause irreversible consequences to receiving environments and economies call for particular attention. One critical issue is a need to evaluate the quantities and processes of species introductions. Consequently ballast water was sampled on 15 ships calling at the Port of Koper, Slovenia. This was the first ballast water sampling study in the Mediterranean Sea. This paper summarises the sampling results. Samples were analysed for all types of aquatic organisms including bacteria. The results may be considered as background information for an initial risk assessment of future species introductions - an important tool for the implementation of ballast water management measures.