Seismic reinforcement of a R.C. school structure with strength irregularities throughout external bracing walls

The effect of irregularities due to the non-uniform distribution of material properties on structural elements of a significant real case is here investigated. Mechanical tests performed on a typical Italian reinforced concrete (r.c.) school building built in the 1960s showed irregularity in the distribution of compression strength in columns, even though the construction is featured by substantially symmetric distribution of the frames. Extreme scenarios in the distribution of irregularities in compression strength of concrete columns are analyzed, with the hypothesis of rigid or deformable slabs. The seismic analysis showed the influence of the response due to the irregular distributions of concrete strength. A proposal of equivalent "material eccentricity" is shown to account for the mentioned irregularity. Furthermore, the practical solution of reinforcement to mitigate the effects of irregularities is also described. It consists of couple of external r.c. walls stiffened by r.c. buttresses added to the building, connected by transverse slabs. An extensive reduction of material eccentricity is achieved, together with a relevant improvement in seismic capacity

Damage and restoration of historical urban walls: literature review and case of studies

Within this work, the causes of collapses and damages occurred in masonry artefacts have been evaluated to properly identify suitable monitoring and restoration methods. In this regard, a comprehensive literature review has been performed. Based on the results, moisture has been found to be a critical parameter, that affects the structural health of masonry artefacts. Various non-destructive methods were employed to measure moisture and monitor the materials involved, including Infrared Thermography, Electrical Resistivity Tomography, Ground Penetrating Radar, Laser Scanning and Digital Terrestrial Photogrammetry, Global Navigation Satellite Systems, Unilateral Nuclear Magnetic Resonance, Laser-Induced Fluorescence technique, Acoustic Imaging and Acoustic Tomography, Geographic Information System, on-site survey process and computer modeling of the structure with specific FEM software. Finally, the implementation of tie-beams, Fiber Reinforced Polymers layers, ventilation, draining systems, and high-quality materials are proposed as solutions for controlling the moisture effect and retrofitting

Economic vs environmental isocost and isoperformance curves for the seismic and energy improvement of buildings considering Life Cycle Assessment

A methodology to quantitatively assess the improvement of seismic and energy performance of masonry buildings through retrofitting interventions is here proposed. The approach is developed at mesoscale level, considering entire façades with openings and taking into account Life Cycle Assessment (LCA). The costs of retrofitting interventions that couple effects of seismic and thermal improvement (called integrated interventions/approaches) are different whether only the construction phase or the entire life cycle of the building is considered. Therefore, it is necessary to estimate at what extent it is correct to neglect LCA in the analysis of integrated approaches. In this paper, the analysis of three masonry façades is performed with and without LCA. Traditional (insulating panels, diatons, ferro-cement) and more innovative interventions (carbon and glass fiber reinforced polymer composites) are considered. For the comparison, isocost and isoperformance curves, which determine both the economic (Euros) and environmental costs (kg CO2eq) for each intervention, are discussed. The comparison shows the necessity of always considering LCA for a reliable assessment: some retrofitting interventions are the most expensive in the construction phase but they result the most convenient in economic terms and in the amount of CO2eq emissions

Bamboo trusses with low cost and high ductility joints

Innovative solutions of joints for bamboo trusses are presented. Experimental tests show the performances and the high level of ductility of the proposed technique, joined with simplicity in the concept of the joints, low level of technology and low cost of all used materials. It can permit a proper dissemination and a sustainable maintenance in developing countries

Assessment of lightweight concrete properties under cryogenic temperatures: influence on the modulus of elasticity

The current development of Liquid Natural Gas (LNG) storage site requires a thorough analysis of concrete behaviour under cryogenic temperatures. Indeed, this kind of infrastructure is based on a set of tanks that presents several layers. The first one is the cryogenic steel tank that directly contains the LNG. An outer concrete box represents the external layer and usually between these two layers there is a thermal insulating material. A leak from the steel tank can apply a tremendous thermal gradient to the concrete external layer. Thus, the study of concrete behaviour in this situation is important and few studies are available for concrete characterized by lightweight clay aggregate. In this experimental work, the variation of the modulus of elasticity of lightweight clay aggregate concrete, due to temperature gradients have been analyzed and discussed. A set of concrete cubes has been immersed in liquid nitrogen to reach -180°C, then they have been tested under compressive stress measuring both stress and strains. Correlations between elastic properties and temperatures are proposed

Probabilistic models for the erosion rate in embankments and reliability analysis of earth dams

Probabilistic models for the concentrated leak erosion of earthen water retaining structures are presented. The models predict the values of the critical shear stress, the coefficient of erosion and the pipe radius enlargement, starting from other measurable soil properties and the geometrical dimensions of the embankment. The models account for both the non-cohesive and cohesive contributions to the erosion behavior. A Bayesian approach is used for the treatment of the unknown parameters. An importance sampling simulation is adopted to calibrate the models and estimate the posterior distribution of the unknown model parameters using laboratory and in situ experimental data. The new proposed probabilistic model for the pipe radius is then used to develop fragility curves that capture the pipe enlargement as a function of time for a given earth dam

Calibration procedure of regional flow duration curves evaluating water resource withdrawal from diversion dams

In the last decades, climatic changes in Mediterranean regions and frequent events of water resource scarcity in supply systems have required addressing the problem of increasing the inflows in storage reservoirs by connecting them to diversion dams. Usually, diversion dams do not have a large storage volume; consequently, these works are not able to regulate monthly flow, and they can divert to reservoirs only a part of river flow. In this field of research, this study aims to provide a procedure to evaluate water volumes withdrawn from diversion dams considering river flows and transfer flows. The procedure is founded by analysing 36 gauging stations in Sardinia (Italy), where a unique regional flow duration curve (FDC) can be defined. The effectiveness of regional evaluation of volume withdrawn, based on a monthly time scale analysis, has been investigated. The methodology allows finding optimal values of regional FDC parameters in order to better evaluate water resources withdrawn from diversion dams with respect to the current estimation used in the Sardinia Region Water Plan (SRWP). The current SRWP (RAS 2006) uses a fixed and extremely precautionary value of the FDC that underestimates withdrawal volumes. Moreover, a correlation analysis has been carried out in order to extend the evaluation of optimal FDC parameters for ungauged basins that allows to improve application of this procedure. Obtained results could allow to update the SRWP as highlighted in the final application to a real water system

Rocking and kinematic analysis of two masonry church façades

The paper deals with the application of two methods of local analysis on masonry structures. Rocking and kinematic analysis are applied to two cases study: a gable of the Ica Cathedral that survived the 2007 Pisco earthquake and a church façade connected to transverse walls, which collapsed in the 2012 Emilia Romagna earthquake. The critical aspects of both analysis are discussed and the differences in the outputs commented. Being the two rigid blocks at height different from zero, an amplification factor of the seismic record was calculated for performing the rocking analysis. The gable is treated as free-standing block whereas the upper part of the church façade is analyzed in the rocking analysis by accounting for the rebound effect caused by the transverse walls, through the stiffness of a bed spring.The authors wish to thank Ing. Luciano Bellesia for his helpful cooperation. The activity is cosponsored by Consortium RELUIS – Masonry 2014

Fertility preservation in ovarian tumours

A considerable number of patients with a cancer diagnosis are of childbearing age and have not satisfied their desire for a family. Despite ovarian cancer (OC) usually occurring in older patients, 3%–14% are diagnosed at a fertile age with the overall 5-year survival rate being 91.2% in women ≤44 years of age when it is found at 1A–B stage. In this scenario, testing the safety and the efficacy of fertility sparing strategies in OC patients is very important overall in terms of quality of life. Unfortunately, the lack of randomised trials to validate conservative approaches does not guarantee the safety of fertility preservation strategies. However, evidence-based data from descriptive series suggest that in selected cases, the preservation of the uterus and at least one part of the ovary does not lead to a high risk of relapse. This conservative surgery helps to maintain organ function, giving patients of childbearing age the possibility to preserve their fertility. We hereby analysed the main evidence from the international literature on this topic in order to highlight the selected criteria for conservative management of OC patients, including healthy BRCA mutations carriers

Fast falling weight deflectometer method for condition assessment of rc bridges

In this paper, the use of Fast Falling Weight Deflectometer (Fast-FWD) is analyzed as a non-destructive and quick test procedure to evaluate the efficiency of short-span bridges. The FastFWD is an instrument that can produce a broadband dynamic force up to an impact value of 120 KN: The impact is constant and replicable, providing accurate action measures of bridge stiffness in a truly short period (30 ms). In this paper, a single-span reinforced concrete bridge is investigated, using the Fast-FWD. The considered bridge, approximately 12.0 m long and 15.5 m wide, was in critical condition. The bridge is in a suburban principal road near to the City of Cagliari in Sardinia (Italy), with an Annual Average Daily Traffic of 13,500 vehicles/day, and was suddenly closed, creating serious problems for urban mobility. In these conditions, the investigation through other standard techniques is time-consuming and labor intensive. For this reason, it is important to introduce methods that can be rapid, accurate and cost-efficient. In this paper, bridge stiffness values obtained during the in situ experimental campaign were compared with finite element models values. The Fast-FWD has the potential to provide engineering information that can help us to better understand bridge condition, in a rapid and cost-effective procedure