PS/26/96 - B741 Coal Glen Embankment – Slip Remediation

Description

Repair of existing highways embankment showing signs of slope instability by excavating out failed materials and replacing with engineered fill at a gentler regraded slope of 1V:3H with counterfort drainage; Repair of existing culvert through installation of a CIPP lining (Contractor designed); 10m extension of existing culvert with precast concrete box culvert (Contractor designed) to accommodate regraded slope; Construction of transition unit with manhole access at location where existing and extended culverts meet (Note: Manhole access chamber is to be Contractor designed); Construction of new outfall headwall (Contractor designed) with scour protection through installation of erosion control matting at outfall location; Widening of highway verges to 2m width on both sides of the highway with installation of verge marker posts and post and mesh fencing; Installation of highways surface water drainage system with direct outfalls to Coal Glen watercourse at northern inlet to existing culvert and to the transition unit between existing and extended culvert. Lot 1: Repair of existing highways embankment showing signs of slope instability by excavating out failed materials and replacing with engineered fill at a gentler regraded slope of 1V:3H with counterfort drainage; Repair of existing culvert through installation of a CIPP lining (Contractor designed); 10m extension of existing culvert with precast concrete box culvert (Contractor designed) to accommodate regraded slope; Construction of transition unit with manhole access at location where existing and extended culverts meet (Note: Manhole access chamber is to be Contractor designed); Construction of new outfall headwall (Contractor designed) with scour protection through installation of erosion control matting at outfall location; Widening of highway verges to 2m width on both sides of the highway with installation of verge marker posts and post and mesh fencing; Installation of highways surface water drainage system with direct outfalls to Coal Glen watercourse at northern inlet to existing culvert and to the transition unit between existing and extended culvert.