Search results for " Structural"

New theoretical solution of the outflow process with a weir with complex shape

2016

AbstractIn this paper, the outflow process of a weir with an irregular shape is studied using dimensional analysis and the incomplete self-similarity theory. The new unique stage–discharge relationship, which is deduced theoretically, represents a novel and comprehensive equation to describe the weir outflow process for a full range of flow and different geometric variables of weirs, including finite-crested weirs, broad-crested weirs with positive or negative crest slope, broad-crested weirs with an upstream, downstream, or both upstream and downstream crest ramps, and, triangular weirs with an upstream or downstream ramp. Finally the proposed stage–discharge relationship is calibrated usi…

Discussion of “Simple Flume for Flow Measurement in Open Channel” by Zohrab Samani and Henry Magallanez

2002

This paper is a Discussion of “simple flume for flow measurement in open channel".

Theoretical approaches for modelling buckling effects in rebars of RC members

2017

Buckling of longitudinal bars in reinforced concrete (RC) members is definitely a critical issue in framed structures subjected to seismic loads. Second order effects can affect the compressive stress–strain law of steel bars, influencing ductility calculations of RC structures. Moreover, literature studies show that buckling can occur over a length wider than stirrups’ pitch (global buckling mode), involving more stirrups and inducing large deflections in the bar. If the critical length is not carefully estimated, stirrups’ failure can occur, causing also the sudden loss of confining effects in concrete. This paper presents the results of different approaches for calculating the crit…

Steel and composite tied-arch bridges: a conceptual approach to structural design

2021

The behaviour of tied-arch bridges with composite decks (bowstring bridges) is overly sensitive to the different choices made by the designer in the first phases of the conceptual approach, mainly in the design of the arch and the deck. The geometry of the arch shape, the design of the arch–tie joint and the construction sequence can significantly modify the global behaviour in terms of stress state and deformed configuration. After a general discussion on the different parameters affecting the behaviour of bowstring bridges with steel–concrete composite decks, the consequences of choices made in the conceptual design phases are discussed, analysing the effects of each choice on the global…

Simplified Procedure for Evaluating the Effects of Creep and Shrinkage on Prestressed Concrete Girder Bridges and the Application of European and Nor…

2013

The effects of time-dependent phenomena on concrete prestressed girder bridges are investigated. The study concerns the case of bridges built directly in their final configuration and that of bridges built by a sequence of stages in which geometry, restraints, and loads vary until the final configuration is achieved. An analytical approach based on the principles of aging linear viscoelasticity and the age-adjusted effective modulus method is followed. The paper has two aims: the first is to provide an efficient and simplified tool for the evaluation of the structural response in the early stages of design; the second is to compare the results of the analyses on actual cases of bridges when…

Load-carrying capacity of axially-loaded RC members with circular openings

2012

Abstract Core drilling is today one of the most used technique among the group of partially destructive testing methods in reinforced concrete (RC) members. Even if the engineering practice provided to extract cores only in beams, taking samples from columns could be often necessary. In this case, the presence of the hole introduced a geometrical discontinuity in the member, creating a disturbed region. Consequently, compressive stresses will disperse in lateral direction as they have to avoid the drilled area. A bursting tensile force will develop, in orthogonal direction to the column axis, and if no sufficient reinforcement was arranged, a vertical crack will form, leading to the concret…

Closure to “Experimental Analysis of Local Pressure Losses for Microirrigation Laterals” by Giuseppe Provenzano and Domenico Pumo

2006

Flexural response of external R.C. beam-column joints externally strengthened with steel cages

2015

Abstract An experimental and theoretical research referred to the flexural behavior of external R.C. joints strengthened with steel cages constituted by steel angles and battens is presented. The subassemblage (beam, column and joint) was subjected to a constant vertical load acting on the column and to a monotonically increasing lateral force applied at the tip of the beam. The control specimen is without strengthening system and it was designed with weak column and strong beam and overstrength in the joint region. Strengthening cases here studied refer to steel caging in the column and both in the beam and in the column. Cyclic response in term of load–displacement curves, crack patterns …

Dynamic identification of a reinforced concrete frame in progressive states of damage

2006

Two, full size, reinforced concrete frames were put on a shaking table and underwent seismic excitations with increasing intensities. The aim of the reported experiment was to study changes in their dynamic, modal parameters due to development of cracks in concrete. Dynamic identification of these frames was carried out through diagnostic tests interlaced with the damaging excitations. This paper presents the results of their identification in various states of damage, using low level non-destructive damage estimation methods. A characteristic decrease of natural frequencies and an increase of structural damping was observed. The drop of the natural frequency was fastest for the 1st mode an…

Dimensionless analysis of RC rectangular sections under axial load and biaxial bending

2012

This paper proposes a numerical procedure able to provide ultimate curvature and moment domains of rectangular RC sections subjected to combined axial load and biaxial bending. The formulation is carried out in dimensionless terms in order to give results that are valid for classes of sections characterized by the same values of the geometric and mechanical parameters governing the section response. The role of some of these parameters is investigated here. The results show possible correlations linking the actual values of moment and curvature to the values corresponding to two cases of uniaxial bending to be considered separately. © 2012 Elsevier Ltd.