Structural bearings and expansion joints for bridges

Abstract

<p>Bridge superstructures have to be designed to permit thermal and live load strains to occur without unintended restraints. Bridge bearings have to transfer forces from the superstructure to the substructure, allowing all movements in directions defined by the designer. The two functions -transfer the loads and allow movements only in the required directions for a long service time with little maintenance - are not so easy to fulfil. Differ­ent bearings for different purposes and requirements have been developed so, that the bridge designer can choose the most suitable bearing. <p> By the movement of a bridge, gaps are necessary between superstructure and substructure. Expansion joints fill the gaps, allowing traffic loads tobe carried and allowing all expected displacements with low resistance. Ex­pansion joints should provide a smooth transition, avoid noise emission as far as possible and withstand all mechanical actions and chemical attacks (de-icing) for a long time. A simple exchange of all wearing parts and of the entire expansion joint should be possible. <p> The present volume provides a comprehensive survey of arrangement, construction and installation of bearings and expansion joints for bridges including calculation of bearing reactions and movements, analysis and design, inspection and maintenance. A long list of references deals with the subjects but also with aspects in the vicinity of bearings and expansion joints. <p> This book is aimed at both students and practising engineers, working in the field of bridge design, construction, analysis, inspection, maintenance and repair.

Szabad-e közúti hídjainkon műgumi szőnyegszerű dilatációt építeni?

“…A hasznos terhelés okozta mozgások amplitúdója lényegesen kisebb a hőmozgásnál, azonban gyors ismétlődés miatt ezek összegzett elmozdulása egy nagyságrenddel nagyobb, mint a hőmozgás esetében (Hakenjos et al 1985). Németországi kísérlet során mérték egy 185 m hosszú városi híd hosszmozgásait, amelyen naponta 60 000 közúti egységjármű és 500 villamos haladt át.…”

“…. ábra: Íves felszerkezet saruzása: a) kéttámaszú, dilatációra merőleges saruzás (fent balra); b) többnyílású, dilatációra merőleges saruzás (fent jobbra); c) egyirányú mozgósaruk beállítása azonos szögre (lent balra); d) többnyílású híd α=0 saruzással (lent jobbra)(Ramberger, 2002).…”

Providing Serviceability of Structural Bearing Types for Roadway Bridges

“…Відповідно до діючих норм [4], розрахунковий термін служби опорних частин повинен становити не менше ніж 30 років. Проте в разі складних конструкцій слід надавати перевагу конструкціям, прогнозований термін експлуатації яких близький до терміну експлуатації транспортної споруди в цілому [5]. В Україні на даний час промисловістю виробляються тільки гумові опорні частини.…”

Investigations into Nonlinear Effects of Normal Pressures on Dynamic Cyclic Responses of Novel 3D-Printed TPMS Bridge Bearings

“…The practical use of a bearing type is based on several factors, including geometry, deflection, predicted loading, maintenance, displacement and rotation demands, existing clearance, strategies, designer preference, and availability, as well as cost [11]. Accordingly, standard bridge bearings can be classified into two groups: either elastomeric bearings or high-load multirotational (HLMR) bearings (spherical, pot, and disc) [12]. An elastomeric bearing is a combination of elastomeric pads (rubber layers) without/with any reinforcement (steel shims or fibre fabric), called plain and reinforced elastomeric bearings, respectively.…”