Allan Block® Retaining Wall – Richmond Development Stage 4

The Richmond development in its Stage 4 comprises the construction of 25 blocks of townhouses, creating and bringing well built and sustainable designed homes and a suburban way of living to the Mount Wellington area. Although the site was generally flat, the southern end of the site required a retaining wall to support the property boundary and maximise flat yard space for those units. Here is where the Allan Block retaining wall was proposed and agreed as the right product to complete the task.

Design

ENGEO was requested by Wilshire Ryburn Development Limited to design a gravity retaining wall as part of the development. Due to years of successful collaboration, ENGEO contacted our technical team to propose and work on different Allan Block cross sections using the AB® Vertical and No-fines concrete, which would help create a deeper and heavier concrete mass while allowing for a taller gravity wall and the always important space maximisation. Multiple cross sections were prepared to cover different retained heights and even a 3D design was modeled to see how the wall was going to look like beforehand.

Installation

As near vertical cuts were required on the boundary, the project engineers recommended the Allan Block retaining wall to be staged in different lengths, depending on the height of the vertical cut. Bob Hick Earthmoving along with Kingdom Contractors carried out the construction of approximately 98m2 of retaining wall, keeping a clear lines, nice details on the external corner and step downs, and delivering the project on a timely manner despite the COVID restrictions and situation.

To evaluate progress and to ensure client’s satisfaction, the project was visited and inspected twice during construction by one of Bowers Brother’s engineers. Extra support and advice was provided to Bob Hick Earthmoving regarding the use of AB corner units, capping and the adhesive required to fit and secure the AB Capstone in place.