The development of the Makassar Wastewater Network is divided into several work Packages based on different catchment area. ArthaGeo is responsible for executing 250mm Diameter PVC Pipe Jacking work for B2 Package under PT. Waskita Karya (Persero) as Main Contractor with a total of 3,338m of 250mm diameter PVC Pipe to be installed.

The main issue of jacking work in loose sand under water table is high risk of water ingress into the tunnel face or shaft entrance. The buoyancy effect during installation of PVC pipe could cause problem where it is difficult to control the direction of microtunneling head. To overcome this situation, we propose the pipe jacking work using full displacement head unit where the cavity is made not by cutting the soil as in current method of tunneling, but by displacing the soil laterally.

The project shows a great success and the new method is found to be satisfactory. The work is completed within the time schedule which earn us credit from both Main-contractor and consultants.