Simulations were conducted to assess the performance of anchor bolts used in the steel Department of Public Works (RWS) barrier on various road surface types. The study was commissioned in response to doubts raised during the modelling of these bolts for a previous simulation carried out in 1995. Most of the simulations were carried out using a bus (TB 52). One simulation was carried out using a passenger car (TB 11). During the simulation using the passenger car, the barrier acted as a rigid construction, regardless of the road surface type involved. This raised the ASI value above the permitted safety value of the Acceleration Severity Index (ASI lower than or equal to 1.4). During the simulation using the bus, the barrier was not breached, despite the fact that one or more bolts gave way. When the vertical freedom of movement of the anchor bolts was reduced, this clearly gave a less favourable result. The same thing occurred when the anchor units were fixed at intervals across the barrier element rather than being concentrated at one end. Therefore, the anchoring of an element should be concentrated in a single place. The simulations also showed that a controlled relocation of anchor bolts along the road surface improves their performance.
Samenvatting