Reliability enhancement of innovation structures of water culvert pipes
There are considered the results of experimental researches of corrugated metal culvert with a high abrasion resistance. To protect metal pipes of corrugated structures from corrosion damage and ensure normative durability, at the factory shop zinc and sometimes polymer coating are applied on the internal and external surfaces. However, the operating experience has shown that under the conditions of high aggressiveness of the passing flow it is not enough for a safe and reliable operation of the culvert. Design standards specify the necessity of installation of a tray in the bottom area of such pipes which is not always fulfilled in their construction and design. There are found basic factors that determine the depth and speed of the water flow at the outlet of the tubular structures made of corrugated metal. It is established that the availability of the protective concrete tray leads to decreasing of the relative depth on the outlet of such pipes and increasing the speed in the outlet cross-section in comparison with the existing recommendations developed for corrugated pipes without protective concrete tray along the bottom. The values of actual depths on the outlet of the corrugated pipe with a protective tray on the bottom are evidently less than the depths designed according to the existing standard recommendations. It is noted that the absence of a tray in similar innovation tubular crossings on the transport main lines of any category is not permitted and leads to a sharp worsening of the operational reliability and durability of tubular water culvert structures of metal corrugated elements.