114.00205 Breaker Bay Rd RW

Details

* Please see attached documents *

The Wellington City Council (WCC) is wishing to construct a retaining wall at the location 70m north of 53 Breaker Bay Road, Breaker Bay, Wellington. The proposed wall is designed as a concrete pile and precast concrete panel lagging wall with anchors. However, alternative tenders are invited to replace the proposed precast panels. The wall will follow a widened alignment and have a concrete return at the northern end to tie into the existing alignment. The temporary work design was completed as part of the permanent design.
An initial assessment of the wall asset was completed between the Pass of Branda and approximately 100m uphill from the Breaker Bay Car Park in relation to reported slope instability. The slope instability consisted of two longitudinal cracks parallel to the wall alignment: approximately 4.1m long 1.0m from the road edge and approximately 5.1m long, 1.7m from the road edge. The movement is believed to have been a result of an ongoing slow-moving landslip within the loose gravelly colluvium/fill supporting the seaward edge of the road.
The seaward edge of the road consists of a steep vegetated slope (average slope angle of approximately 45°) which runs below Breaker Bay Road to a walking path/beach. The base of the steep vegetated slope is over‐steepened and may have been subject to wave erosion during storm events.
South of the crack locations is a concrete block crib wall approximately 12m long (construction date unknown) and an approximately 45m long anchored reinforced concrete pole wall (constructed in 2008 and 2012) to support Breaker Bay Road.
The section of retaining wall to be constructed is approximately 50m long with maximum retained heights up to 3.5m located on Breaker Bay Road between an existing retaining wall to the south and a concrete stormwater outlet (to be retained) to the north.