NON-SUPPORTED CRASH BARRIERS - PROOF OF THE CONCRETE RESISTANCES ACCORDING TO THE CONCRETE-CAPACITY-METHOD

摘要

Crash barriers (see fig. 1.) made of reinforced concrete shall protect the tunnel tube against exceptional effects caused by the traffic. These barriers are in generally fixed additional to the bearing precast concrete tunnel segments by bonded shear bolts. The proofs of the barrier's concrete failure mostly result from the method of Rasmussen according to "Deutscher Ausschuβ fuer Stahlbeton, Heft 346". The proofs of the concrete segment's failure results from the wellknown K - method. The Concrete-Capacity-Method provides a more economic design method and will be applied on the shear bolts of the non-supported crash barriers in the recent Elbtunnel project in Hamburg, Germany. As best possible solution a shear bolt with a diameter of 35mm and an effective anchorage depth of 220mm was designed. The bolt is bonded with hybrid resin mortar and is made of stainless steel A4-70 (316Ti). This paper will present the proofs according to the ETAG of Metal Anchors for use in concrete, Annex C considering all edge and axial influences. The edge influence results from both the external dimension and the screw joint bay's locations of the concrete lining elements. The results of pull-out tests for determining the characteristical resistance to proof the concrete pryout failure will be shown as well as the recommendations for additional reinforcement to transmit the shear force in the crash barriers. The summary compares the results of the CC-Method with those of the Method of Rasmussen and K - method respectively.