This property was the first building in Christchurch to be releveled located in the Red Zone liquefaction area.
The building required structural stabilisation by means of inserting a K-brace shear wall at the rear of the building. This required the installation of new foundations along the rear wall of the building, in a confined area, in order to transfer shear loads from the building into the ground effectively. Core Civil Solutions is capable of operating within tight spaces to provide such foundation solutions. The client had been presented with a solution using screw piles but sought out an alternative solution due to cost, time, and access restrictions.
Based on building loads, seismic loads and local geotechnical information, an alternative design using groups of raked Ischebeck 40/16 injection piles (32 total), installed to a depth of 14m, and connected using reinforced concrete pile cap, was proposed to and accepted by the client.
The injection piles were installed easily by using a small rig capable of operating in the confined space. Installation produced very little vibration to the damaged building and was completed quickly with an average drilling time of around 25 minutes per pile. No demolition of the building was required and once the piling and pile cap were completed the K-brace structure was successfully installed. The building is now under normal operation.
A faster and less expensive alternative solution was provided for foundation and remedial works by Core Civil. The client chose the alternative solution and the design was installed, tested and signed off successfully without needing to demolish the building.