Common method of valuation of strain-stress state of bearing resistance of prestressed concrete elements of round cross-section through strain model
A. N. Bambura, Ye. V. Dorogova
State Enterprise «State Research Institute of Building Constructions»
Annotation: Purpose, tasks and actuality of research deals with assessment of stress-strain state and bearing capacity of the usual and pre-stressed reinforced-concrete elements with round section are presented there. The basic premises and assumptions for deformation model of concrete are stated there. The engineer method for designing of stress-strain state and bearing capacity of elements with round section are proposed on basis of these premises and assumptions. In accordance with accepted assumptions, the averaged section corresponding to average concrete and reinforcement deformations along block length between cracks (if they have place, but not the section with crack) is accepted as design value when elaboration of calculation apparatus. In the process, the hypothesis of plat sections is considering as truth for design section. The correlation between stresses and deformations of compressed concrete is accepted as curvilinear diagram in accordance with equation 3.14 EN 1992-1-1; the deformations of usual reinforcement or increment of deformations in pre-stressed reinforcement are equal to deformations of surrounding concrete. The limit values εсul of fiberdeformations of compressed concrete or rupture of all strained reinforcement rods or loss of bearing capacity of design section due to loss of stability of deformation or loss of equilibrium between internal and external forces are accepted as criterion of bearing capacity loss by design section. Numerical integration (in quadrature) of the non-linear equations set of equilibrium is carrying out there. In process, the compresses area of reinforced concrete element with round section is dividing by m layers perpendicular to axis of moment action. The solution of the gotten non-linear equations sets is carrying out by matching on parameters of deformed state εс(1) and ℵ (or εс(2)) in accordance with deformation methodology. Comparison of the results of the reinforced concrete round sections elements bearing capacity determination (when diving of compressed by m = 40 layers) gotten on «exact» method (direct integration of equilibrium equations) with calculation results on engineer method has shown following: the maximal calculation error does not exceed 1 %. It is acceptable from point of practice.
Keywords: bearing capacity, stress-strain state, round section, equilibrium equation, solution error.
Pages: 209-216.
Link for citation: Bambura, A. N.; Dorogova, Ye. V. Common method of valuation of strain-stress state of bearing resistance of prestressed concrete elements of round cross-section through strain model. – Text : electronic. – In: Modern Industrial and Civil Construction. – 2014. – Vol. 10, N 4. – Р. 209-216. – URL: https://donnasa.ru/publish_house/journals/spgs/2014-4/01_bambura_dorogova.pdf (date of access: 16.09.2024). (in Russian)
Vol. 10, N 4 (2014)Journal: Modern Industrial and Civil Construction
Publish house: Donbas National Academy of Civil Engineering and Architecture