Calculation Of Load-bearing Capacity Research Articles

Load Bearing Capacity Calculation of the System “Reinforced Concrete Beam – Deformable Base” under Torsion with Bending

It is presented the formulation and solution of the load bearing capacity of statically indeterminable systems “reinforced concrete beam – deformable base” by spatial cross-sections under force and deformation effects. The solution of problem is currently practically absent in general form. It has been established the relationship between stresses and strains of compressed concrete and tensile reinforcement in the form of diagrams. The properties of the base model connections are described based on a variable rigidity coefficient. It is constructed a system of n equations in the form of the initial parameters method with using the modules of the force (strain) action vector. The equations of state are the dependences that establish the relationship between displacements which are acting on the beam with load. Constants of integration are determined by recurrent formulas. It makes possible to obtain the method of initial parameters in the expanded form and, consequently, the method of displacements for calculating statically indefinable systems. The values of the effort obtained could be used to determine the curvature and rigidity of the sections in this way. It is necessary not to set the vector modulusP, the deformation is set in any section (the module is considered as an unknown) during the problem is solving. This allows us to obtain an unambiguous solution even in the case when the dependence M–χ has a downward section, i.e one value of moment can correspond to two values of curvature.

Comparison of experimental research and nonlinear advanced FEM analysis of load capacity and deformability of slender HSC columns in bi-axial bending

The paper compares results of own experimental research of sixteen reinforced concrete columns made of HSC in bi-axial bending with advanced three-dimensional FEM analysis. Computational analysis with application of TNO DIANA v.9.4 system and pre and post processor MIDAS FX+ was conducted. The analysis was used mostly to check a compatibility of the conducted research with the advanced 3D numerical model and to prove a usefulness of applied numerical model in calculation of load-bearing capacity of bi-axially bending columns. Mechanical properties of concrete and reinforcing steel were assumed based on the results of material tests.

Methods of providing failure-free operation in transport infrastructure objects

Abstract This paper is addressing three aspects connected with operation of underground facilities which are providing safety of transport infrastructure in large cities. Calculation of load bearing capacity of steel encasements of shallow underground manifolds was performed with the use of initial parameters method. It was demonstrated that use of steel pipes in extra aggressive environment requires assessment of their load bearing capacity change in the course of time. The paper determines permissible life time for culvert conduits made of steel pipes. It was proposed to use hydrojet cementation technology in order to improve stability of enclosing massif. The authors gave assessment of domestically manufactured measuring devices used for monitoring of manifold and massif structures deformation.

Calculation of load-bearing capacity of prestressed reinforced concrete trusses by the finite element method

The technique of calculation of prestressed reinforced concrete trusses with taking into account geometrical and physical nonlinearity is considered. As a tool for solving the problem, the finite element method has been chosen. Basic design equations and methods for their solution are given. It is assumed that there are both a prestressed and nonprestressed reinforcement in the bars of the trusses. The prestress is modeled by setting the temperature effect on the reinforcement. The ways of taking into account the physical and geometrical nonlinearity for bars of reinforced concrete trusses are considered. An example of the analysis of a flat truss is given and the behavior of the truss on various stages of its loading up to destruction is analyzed. A program for the analysis of flat and spatial concrete trusses taking into account the nonlinear deformation is developed. The program is adapted to the computational complex PRINS. As a part of this complex it is available to a wide range of engineering, scientific and technical workers

Calculation of load-bearing capacity of structural units at processing plants of ALROSA

Calculation of load-bearing capacity of structural units at processing plants of ALROSA

PLASTIC CAPACITY OF BOLTED RHS FLANGE-PLATE JOINTS UNDER AXIAL TENSION

This article considers the calculation of load-bearing capacity of flange-plate joints with bolts along two sides of rectangular hollow sections (RHS) under axial tension. It provides a review and comparison of various calculation methodologies for establishing the load-bearing capacity of RHS flange-plate joints, such as suggested in EN 1993-1-8:2005 and STR 2.05.08:2005 as well as those proposed in different countries and by other authors. Common design principles and derived results for load-bearing capacity of flange-plate joints have been analysed and compared. Following the numerical modelling, which has been done using ANSYS Workbench finite element program, the derived results for load-bearing capacity have been compared with analytical load-bearing capacity results for flange-plate joints of the same structure. The analysis has focused on one type of flange-plate joints with bolts – both preloaded and non-preloaded – along two opposite sides of the tube, with the flange thickness of 15 mm and 25 mm.

Seismic experiment and analysis of rectangular bottom strengthened steel-concrete composite columns

In order to study the working mechanism of rectangular steel-concrete composite columns subjected to compression-bending load and further determine the seismic performance index, a bottom strengthened rectangular steel reinforced concrete (SRC) column with concealed steel plates and a bottom strengthened rectangular concrete filled steel tube (CFST) columns were proposed. Six column models with different configurations were tested under horizontal low cyclic loading. Based on the experiments, the load-bearing capacity, stiffness and degradation process, ductility, hysteretic energy dissipation capacity, and failure characteristics of the models were analyzed. The loadbearing capacity calculation formulas for a normal section and an oblique section of bottom strengthened rectangular steel-concrete composite columns were pesented and a finite element (FE) numerical simulation of the classical specimens was performed. The study shows that the load-bearing capacity, ductility, and seismic energy dissipation capacity of the bottom strengthened rectangular steel-concrete composite columns are significantly improved compared to the conventional rectangular steel-concrete composite columns and the results obtained from the calculation and the FE numerical simulation are in good agreement with those from the experiments. The rectangular steel-concrete composite column with bottom strengthened shows better seismic behavior and higher energy dissipation capacity under suitable constructional requirements and it can be applied to the structure design of highrise buildings.

Highway Bridge Load-Bearing Capacity Assessment Under Chinese and British Methodologies

The purpose of assessment of structures is to check their adequacy for specific loading levels and to identify those bridges that have an unacceptable risk of failure, either in part or complete collapse, under extreme circumstances of loading and material condition [1]. In this study, a comparison was made between new Chinese bridge load-bearing capacity assessment method and The British Highway Agency method. Load-bearing capacity assessment results were generated for bridges super structure and analyzed for moment and shear load effect. Also the study included a comparison of the main component of load-bearing capacity calculation, factored live load, factored dead load, and factored capacity. The comparison shows that the British Method produced lower moment and shear bridges carrying capacity factor than Chinese Method.

Stability of roadways in coalmines alias rock mechanics in practice

This paper describes the procedures for design of supports and stabilization measures in the roadways. The procedures are based on the system developed in Ostrava-Karvina coal basin in Czech Republic. The calculation of load bearing capacity of roadway supports contains the period of roadway construction and mining in the vicinities, based on the size of the natural rock arch. The loading of supports during mining comes from a stress wave in the rock mass in the forefront of coalface and the caving area of mined-out panel. The input data for the calculation method are deduced according to in-situ measurements of convergence and displacement in the roadways.

Medinių Centriškai Gniuždomų Elementų Elgsena Ugnyje

This investigation is intended for an experimental assessment of the fire resistance of the axially loaded timber members aff ected by open flames and for comparing those with design results obtained in accordance wiTheC5-1-2:2005 provisions. Diff erently from metal or reinforced concrete structures, the longitudinal strains of timber at elevated temperature are negligible. A decrease in the bearing resistance of the timber member is associated with diminishing the cross section at the later stages of heat exposure. The process of diminishing the cross section leads to buckling an element or the other mode of fracture. The necessity of special equipment and a great quantity of smoke during an experiment are big problems for researching timber members under fire conditions. Therefore, practically it is impossible to use standard test equipment applied for testing steel or reinforced concrete members at elevated temperature. When researching the behaviour of axially loaded timber members under fire conditions, the furnace was specially designed to use a gas burner to provide the heating of specimen. The furnace was constructed from a special devise for loading the specimen and keeping it at required load level during the test. All timber specimens were of the same cross-section (50mm × 50mm) and length (1.2m). The compression specimens were pin-ended using spherical hinges. Fire resistance and the mode of failure were estimated during the test. The failure of axial compression specimens exposed to fire from one side is based upon diminishing the cross-section, a decrease in compression strength and the modulus of elasticity. In this case, the deflection of specimens follows flame direction. Design value fire resistance for timber elements was calculated using (EC 5-1-2:2005) provisions for the reduced cross-section. The calculation of load-bearing capacity was performed for axially loaded timber elements. The data required for design such as cross-sectional reduction due to charring and timber shrinkage was measured after testing fire.