Description:
-----------------------------------------------------------------------------------------------
The existing Culvert 21 which passes beneath the Worcester and Birmingham canal near Droitwich in Worcesterhsire was in a poor structural condition and in urgent need of repair. Both the upstream and downstream brickwork headwalls were displaying evidence of failure in terms of cracking and significant lateral movement. The upstream headwall had moved significantly and as a result the culvert itself was beginning to fail via missing / loose brickwork / mortar and some deformation.
The works were undertaken whilst maintaining the navigation open. Due to the location of the culvert, in agricultural land and relatively inaccessible to land vehicles the bulk of the necessary resources were to be delivered to site via the waterway.
The upstream headwall was designed such that a new headwall was constructed in a new position further away from the navigation thus reducing the angle of the retained material behind it and thus reducing the lateral force upon the wall. In addition the culvert was to be extended to this new position via the insertion of a weholite pipe which extends into the existing culvert by 2m to prevent any further deformation of the existing brick culvert. The annulus between the culvert and new pipe was pressure grouted.
The downstream headwall was to be repaired in its current position relying on the existing structure and soil anchoring to retain the embankment. Platipus anchors were driven through the wall and anchored into the existing embankment some 6m in length. The existing wall was crack stitched and repointed as required.
On both sides of the navigation the headwalls were furnished with scour portection measures incorporating gabion baskets, gabion mattresses, concrete aprons, rip rap and coir roll and matting. On the upstream side this required quite extensive work as the existing contributory branch stream had to be realigned to accommodate the new headwall in its new position.
The works were delivered on time, to budget and to the required level of workmanship. ----------------------------------------------------------------------------------------------- |
