| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 269215 | Engineering Structures | 2007 | 19 Pages |
A flexible protection from flooding of lowlands surrounding harbour areas consists of a movable storm surge barrier, such as the Maeslantkering near Rotterdam. It has a curved steel wall that is connected to a pivot element or ball-joint by steel trusses. A critical point in the construction is the rotating ball-joint that controls the movement of the retaining wall into the river. Due to the high forces transmitted between the convex and concave sliding surfaces originating from the hydraulic storm head, waves and wind, a design with thin films consisting of solid lubricants failed. A solution is found by incorporating reinforced polymer bearing elements that offer good dimensional stability and low friction under dry sliding conditions. In present paper, a study is made of the bearing capacity and sliding behaviour of the modified ball-joint in combination with different loading histories during floating, immersion and retaining actions under a full hydraulic head. Loading of the joint by minimum gravity forces and maximum hydraulic forces perpendicular to the gates is the most critical in this respect. Through the application of an elastic bearing layer, the frictional momentum on the ball-joint is influenced by the stiffness, the thickness and the friction coefficient of the sliding material. The dimensional stability and sliding behaviour of the bearing elements is experimentally investigated by large-scale testing, and it is verified by finite element models that both the polymer elements and the steel structure have sufficient strength to carry the loads while retaining a storm. Their reliability is verified by two on-the-field test operations.
