1. A fundamental study of the performance of Xsection castinplace concrete single pilesYu Wang, Yaru Lv, Dongdong Zhang, Jieying Zhou, 2016, izvirni znanstveni članek Opis: Xsection castinplace concrete (XCC) piles are used because they have a higher bearing capacity than circularsection castinplace concrete (CCC) piles of the same crosssectional area. Although the bearing capacity of XCC piles has been studied, the performance of XCC single piles, especially for the stresstransfer mechanism dependent on the geometrical effects, is still not fully understood. This paper reports two comparative field static load tests on an XCC and a CCC single pile of the same crosssectional area. In addition, corresponding threedimensional numerical backanalyses are performed to provide a fundamental understanding. The measured and computed results reveal that the XCC single pile has an approximately 25% higher ultimate bearing capacity than the CCC single pile. This is because the XCC single pile has an approximately 20% larger total side resistance, which is caused by a 60% larger pile perimeter and a slightly smaller unit side resistance. Lateral soil arching effects are developed, causing a nonuniform effective normal stress and a shear stress across the circumference of the XCC single pile. It is suggested that XCC single piles have a higher efficiency in terms of material saving compared with CCC single piles. Ključne besede: Xsection castinplace concrete pile, field static load test, threedimensional numerical backanalysis, stresstransfer mechanism, side resistance, soil arching Objavljeno: 15.06.2018; Ogledov: 657; Prenosov: 31 Celotno besedilo (485,57 KB) Gradivo ima več datotek! Več...

2. Correlation between the point load index, $I_{s(50)}$, and the resistance to unconfined compression in limestone from the comunidad Valenciana, SpainManolo Galván, Jorge Preciado, Jose Serón, 2014, izvirni znanstveni članek Opis: The unconfined compression strength is one of the most important engineering parameters in rock mechanics; it is used to characterize and study the behaviour of solid rocks. A good correlation between the unconfined compression strength test (UCS) and the point load strength (PLS) can be very useful, because it allows for faster and cheaper testing than other methods with the same security to calculate the structures and performances of solid rocks. A preliminary step to implement the correlation is to have a good method to determine the resistance to a point load. This determination is correct if we have a sufficient number of tests on specimens of the same nature, but usually this does not occur, and it is necessary to apply a sizecorrection factor, F = (De/50)α, with α = 0.45. This paper is based on limestone from Comunidad Valenciana, Spain, because it represents a very high percentage of the rocks. The implementation was conducted over 700 field and laboratory tests, of which 255 are PLT tests, 45 are UCS tests, and the rest are other parameters, like porosity and specific weight, Slake Durability, and ultrasonic velocity. Ključne besede: resistance to point load, point load strength, Franklin test, size correction factor, unconfined compression Objavljeno: 14.06.2018; Ogledov: 418; Prenosov: 37 Celotno besedilo (398,58 KB) Gradivo ima več datotek! Več...

3. Lateral resistance of a short rigid pile in a twolayer cohesionless soilErdal Uncuoğlu, Mustafa Laman, 2011, izvirni znanstveni članek Opis: The behavior of a laterally loaded short rigid pile founded in a twolayer sand soil profile has been investigated. For this purpose, a series of model tests were carried out on model piles. The effects of the elasticity modulus, dilatancy and interface behavior of the sand have been explored numerically by performing a series of threedimensional nonlinear finiteelement analyses. The lateral load capacities in the layered sand conditions have been calculated using the methods proposed by Brinch Hansen (1961) and Meyerhof et al. (1981). The results obtained from experimental studies, numerical analyses and a conventional method were compared with each other. The results proved that the parameters investigated had a considerable effect on the behavior of short rigid piles subjected to lateral loads. It was also shown that the value of the ultimate lateral load capacity could vary significantly, depending on the methods used. Ključne besede: lateral load, short pile, twolayered sand, model test, finite element, lateral effective stress Objavljeno: 13.06.2018; Ogledov: 371; Prenosov: 48 Celotno besedilo (612,49 KB) Gradivo ima več datotek! Več...

4. The different methods of displacement monitoring at loading tests of bridges or different structuresBoštjan Kovačič, Rok Kamnik, Andrii Bieliatynskyi, 2016, objavljeni znanstveni prispevek na konferenci Opis: By measuring the displacements and deformations at different structures we deal in the Faculty of Civil Engineering, transportation Engineering and Architecture in University of Maribor for about 20 years. At that time we measured over 600 structures. Most loading tests of bridges and Viaducts were made. The measurements of movements needed to be as precise and accurate as possible. To do that laboratory test of instruments were made to see which instrument gives us reliable results. Displacements can be determined by geodetic and physical methods, depends of the construction. The use of geodetic methods are still preferable. In the paper the measurements with the total station, the level and rotation level, photogrammetry and solutions on the field by physical methods with inductive transducers are presented. We need to measure displacements as quick as possible but efficiently because we can not repeat the measurements under the same conditions. Also the surveying on the bridge and in the lab with the comparison of methods is presented under the different hard terrain conditions  water beneath the construction, big height of the structure, unapproachability, large span structures. Ključne besede: bridges, measurements, strain gauge, load test, deformation, strain, signal processing Objavljeno: 02.08.2017; Ogledov: 633; Prenosov: 242 Celotno besedilo (3,15 MB) Gradivo ima več datotek! Več...

5. Vertical displacements measuring methods during bridge load testsBoštjan Kovačič, Ante Marendić, Rok Kamnik, Mikhail Volkov, Vera Roy, 2016, objavljeni znanstveni prispevek na konferenci Opis: This article introduces the use of the GNSS method for the load testings of bridge structures. We know that there area lot of methods by which you can determine vertical displacement. However, as new bridge constructions are constructed over almost impossible and inaccessible gorges and valleys, the classic measurements method do not allow us to determine vertical displacement so reliably any more or they are very timeconsuming. The GNSS method is well known but there are difficulties when determining the altitude component of this method, which is rather questionable. For this purpose, the methods were tested as practical examples in which some difficulties were encountered, so subsequently another test recording was performed of altitude changes using this method. Ključne besede: bridges, measurements, strain gauge, load test, deformation, strain, signal processing Objavljeno: 29.08.2016; Ogledov: 886; Prenosov: 358 Celotno besedilo (1,55 MB) Gradivo ima več datotek! Več...
