DTCE has been engaged to design a spray and pin retaining wall along the bank underneath the existing concrete driveway. The main reason to install the retaining wall was to protect the existing driveway and retain the exposed bank.
The site presented significant challenges. The slipped bank was approximately 8 metres high and 13 metres wide, with limited access for detailed ground investigation. Construction access from the driveway above was not suitable, so the works were designed to be carried out safely from the base of the slope.

To develop a robust solution, we analysed slope stability under multiple scenarios, including static, seismic, and groundwater conditions. This confirmed the failure mechanism and allowed us to design a retaining system with appropriate safety margins.

The proposed spray and pin wall retains the full 8-metre height of the slipped bank. The nearby house sits well clear of the affected zone and does not impose additional loads on the slope.

To ensure pedestrian safety, a concrete beam and compliant handrail were integrated along the top of the wall.