Research of the Stress-Train State of the Span While Constructing by Longitudinal Thrust Method

Abstract

Purpose. The purpose of the given work is to determine the most rational construction schemes during longitudinal thrust such that all of the construction stresses would be allowable. Methodology. As an object of study the work considers common continuous composite reinforced concrete span by the scheme 63+84+63 m made according to the model design of 3.503.9-62 series. For the purpose of research of the span’s stress state using software package “Midas civil” computer finite element models of different schemes of longitudinal thrust were created. Seven construction schemes were accepted for the calculation that include both longitudinal thrust of metal part of the span and the thrust of constructed composite reinforced concrete span. Findings. The calculation of composite reinforced concrete thrust has proved that during the first stages, when the structure reaches the half of the first span, the stress in the concrete slab exceeds designed tensile strength of the concrete. Because of this, given construction schemes can’t be used. On practice it is recommended to thrust the metal part first and then to lay blocks or concrete the solid deck, that is the rational scheme of longitudinal thrust for the given spans. Originality. The results of the stress-strain state research during the longitudinal thrust can be noted as a scientific novelty for the chosen scheme. Practical value. It was shown that the most rational method of construction is the longitudinal thrust when using either launching nose or a temporary support.