BRIDGE CONSTRUCTION IN BERDIANSK COUNTY OF TAURIDA GOVERNORATE IN THE SECOND HALF OF THE ХІХ CENTURY

The purpose of the article is to cover the local range of problems of bridge construction in Berdiansk county of Taurida Governorate in the second half of the XIX century. The article analyses mechanisms of emergence of infrastructure facilities in Ukraine which was under Russian rule. Moreover, the article reveals prioritization of infrastructure facility emergence in a certain locality, the construction process itself and difficulties in implementation of projects, cost estimation, technical characteristics. In addition, the article investigates the role of zemstvo in development of transport system infrastructure and its influence on county development. It was found out that bridges were facilities of vital importance for a locality: possibility of conducting trading operations, receiving correspondence, rural-urban communication, but on the technological side bridge construction still wasn't at a very high level. Investigation analysis showed significant contribution of zemstvo into development of transport infrastructure, although counter-reforms slowed down the pace of development of communication routes of the county.

Shear live load analysis of NEXT beam bridges for accelerated bridge construction

Using precast concrete elements in bridge structures has emerged as an economic and durable solution to enhance the sustainability of bridges. The northeast extreme tee (NEXT) beams were recently developed for accelerated bridge construction by the Precast/Prestressed Concrete Institute (PCI). To date, several studies on the live load distribution factor (LLDF) for moment in NEXT F beam bridges have been reported. However, the LLDFs for shear in NEXT F beam bridges are still unclear. In this paper, the lateral distributions of live load shear in NEXT F beam bridges were examined through a comprehensive parametric study. The parameters covered in this study included bridge section, span length, beam section, number of beams, and number of lanes loaded. A validated finite element (FE) modeling technique was employed to analyze the shear behavior of NEXT F beam bridges under the AASHTO HL-93 loading and to determine the LLDFs for shear in NEXT beam bridges. A method for computing the FE-LLDF for shear was proposed for NEXT beam bridges. Results from this study showed that the FE-LLDFs have a similar trend as the AASHTO LFRD-LLDFs. However, it was observed that some LRFD-LLDFs are lower than the FE-LLDFs by up to 14.1%, which implied using the LRFD-LLDFs for shear could result in an unsafe shear design for NEXT beam bridges. It is recommended that a factor of 1.2 be applied to the LRFD-LLDF for shear in NEXT F beam bridges for structural safety and design simplicity.