Experimental–theoretical analysis of local stresses in box girders of trapezoidal cross section

The paper discusses the effect of local stresses on the carrying capacity of box girders of trapezoidal cross-section. The mathematical model used for identifying the stress–strain state of the local stress is formed based on the principle of decomposing the cross-sectional elements. It was confirmed that trapezoidal box girder has more favourable stress state in comparison with the traditional rectangular box girder under the same conditions of global carrying capacity and mass (cross-sectional area). Relevant parameters of the local stress of the trapezoidal box girder carrier were identified. Behaviour of box girders regarding the local stress is primarily dependent on the width and thickness of the plate which is exposed to the direct loading effect. The criteria to be followed when designing box girders were defined. The study was conducted on two diametrically opposite positions of the same girder, while experimental results were verified on the basis of their consistency with the theoretical and numerical values.