The Experts below are selected from a list of 108 Experts worldwide ranked by ideXlab platform

R Capozucca - One of the best experts on this subject based on the ideXlab platform.

  • experimental frp srp historic masonry delamination
    Composite Structures, 2010
    Co-Authors: R Capozucca
    Abstract:

    Abstract The preservation of the architectural heritage presents one of the important challenges in civil engineering due to the complexity of the geometry of the structures, the variability of the materials used and the loading history of the buildings. This objective increases for existing constructions in the Seismic Area. External bonding of fiber or, more recently, steel reinforced polymer composites has become a popular technique for strengthening historic monumental masonry buildings. The performance of the interface between composites and masonry is one of the key factors affecting the behaviour of strengthened structures: shear walls, arches and vaults. This paper aims to present the results of an experimental study to evaluate the bond between fiber reinforced polymer (FRP) – glass and carbonFRP – and steel reinforced polymer (SRP) with historic masonry: pull–push shear tests on FRP/SRP-to-historic brick bonded joints specimens were carried out. Modes of failure are discussed in detail and analytical results are compared with experimental data. Experimental strains recorded on FRP/SRP strips were processed to evaluate shear–slip laws of tested specimens; energy fracture and failure load values are compared with theoretical values by simplified models for shear stress–slip. Finally, a simple model of FRP/SRP design suitable for practical application to historic masonry is proposed.

M Zadro - One of the best experts on this subject based on the ideXlab platform.

  • subsurface deformations induced by rainfall and atmospheric pressure tilt strain measurements in the ne italy Seismic Area
    Earth and Planetary Science Letters, 1998
    Co-Authors: Dal G Moro, M Zadro
    Abstract:

    Abstract Tilt and strain measurements are collected in a cave at a depth of 60 m in the Friuli Seismic Area (NE-Italy) where the topography suddenly reaches a height of 600 m a.s.l. The data are analysed to find a possible correlation between crustal deformations on one side and precipitation and barometric pressure variations on the other. Once the significance of the correlation is established, an attempt is made to give a physical explanation of the detected correlation in the frame of the elasticity theory. A significant Areal reduction in strain observations occurs together with a marked rotation of the principal axes in the horizontal plane at the time of rainfall events while no evident signals are revealed in the tilt components. The atmospheric pressure has small influence on the tilt–strain observations, when compared with the effects of rainfall and consequent underground waterflow: referring to large perturbations, atmospheric pressure appears to influence the Areal deformations in terms of about 1 nstrain per mbar, an order of magnitude less then that of the hydrologically induced deformation rate, which reaches up to 600 nstrain (in about 1 day) per 120 mm/day rainfall.

Dr.ing. Habtamu Itefa - One of the best experts on this subject based on the ideXlab platform.

  • EVALUATION OF DYNAMIC STABILITY OF EMBANKMENT DAM: (CASE STUDY OF BILATE EMBANKMENT DAM)
    Addis Ababa Science & Technology University, 2018
    Co-Authors: Habtamu Getachew, Dr.ing. Habtamu Itefa
    Abstract:

    The behavior of the dams has particular complexities against dynamic forces and its assessment requires detailed and scientifically accepted method of analysis depending on the peak ground acceleration amount and suitability of foundation for construction. The thesis included numerical modeling and detailed analysis of embankment dam under three different earthquake conditions. Bilate embankment dam is earth and rock-fill with 42.5 m height and reservoir capacity of 52 million m3. The dam is found in the Seismically active zone with horizontal acceleration of 0.24g and loose alluvium foundation materials. Dynamic stability analysis was not done during the embankment dam design stage and this paper attempted to analyze the dynamic stability of the dam. The thesis used the finite element method, QUAKE/W software modeling in evaluation of liquefiability of Bilate dam which recommendable for dynamic stability analysis of embankment dam constructed on such Area. Consideration is given to evaluate liquefaction potential of embankment dam material and foundation materials. Evaluation of marginal safety factor for both upstream and downstream considering both static and different dynamic loading conditions are done using limit equilibrium method and finite element method (SLOPE/W). Result by QUAKE/W shows almost all foundation materials are liquefied at the end of earthquake. Results from the finite element method show upstream slope marginal safety factor after Maximum credible earthquake and Design base earthquake are 0.893 which are below minimum required. But marginal safety factors determined by pseudo static for upstream, 1.003 and for downstream, 1.225 which are safe. Finally paper concluded finite element method is better than pseudo static method for evaluation of dynamic stability of embankment dam constructed on liquefiable alluvium foundation and highly Seismic Area

John Dalen - One of the best experts on this subject based on the ideXlab platform.

  • acoustic mapping of pelagic fish distribution and abundance in relation to a Seismic shooting Area off the norwegian west coast
    Fisheries Research, 2004
    Co-Authors: Aril Slotte, Kaare A Hansen, John Dalen
    Abstract:

    Abstract In April 1999 Seismic investigations started in an Area off western Norway as part of an ordinary three-dimensional survey, using a vessel with two Seismic sources, each of 20 air guns and 10 hydrophone streamers. The Seismic sources, towed at a depth of 8 m, were alternatively fired every 25 m along 51 transects, each 51 525 m long, separated from adjacent transects by 500 m. The possible influence of this Seismic activity on pelagic fish (herring, blue whiting and mesopelagic species) was investigated in two ways. First, the distribution and abundance within the Seismic Area and the surrounding waters up to 30–50 km away were mapped acoustically three times. In all three surveys the acoustic abundance of pelagic fish was higher outside than inside the Seismic shooting Area, indicating a long-term effect of the Seismic activity. Secondly, the acoustic abundance was recorded directly prior to and after shooting along some of the Seismic transects. In these comparisons no differences were found, indicating that the shooting had insignificant short-term scaring effects. However, both blue whiting and mesopelagic species were found in deeper waters in periods with shooting compared to periods without shooting, indicating that vertical movement rather than horizontal movement could be a short-term reaction to this noise.

M De Stefano - One of the best experts on this subject based on the ideXlab platform.

  • masonry walls with irregular texture of l aquila italy Seismic Area validation of a method for the evaluation of masonry quality
    Materials and Structures, 2016
    Co-Authors: Luisa Rovero, Valerio Alecci, J Mechelli, Ugo Tonietti, M De Stefano
    Abstract:

    The paper presents results of a study on mechanical characterization of the historical masonry walls in L’Aquila region (central Italy), heavily damaged by the 2009 earthquake. Five recurrent types of wall textures are identified and characterized by the stonework sections, and flat-jack tests were carried out on representative walls in order to investigate the mechanical properties. Experimental results showed a good agreement with the estimation determined through a method for the assessment of masonry quality based on a Masonry Quality Index. The study permitted the collection of data useful for designing the Seismic improvement of historical masonry buildings.