Epping Main Sewer Pipejack – Challenges and Resolutions

Overview

The Epping/Kalkallo Main Sewer project comprises 3.5 km of 1600mm and 1800mm internal diameter sewer at depths ranging from 15m to 42m. Five manholes were installed after the completion of the tunnel drives. The alignment connects the Epping Branch Sewer to the Merri Creek Main Sewer, and services the Northern Growth Corridor removing the need for existing temporary pump stations and allowing for the future growth of Melbourne’s Northern Suburbs. The tunnel alignment crosses under the Hume Freeway and Merri Creek, before crossing near the Merri Creek to connect to the Merri Creek Main Sewer at the downstream end. The alignment predominantly passes through public open space, including the Barry Road Grassland and Whittlesea Gardens, with some sections traversing privately owned land.

The pipejacking/microtunnelling works comprises of 6 straight drives, 400m, 570m, 610m,730m and two 580m in length. Each tunnel drive faced unique challenges on the project including tunnelling through high strength Basalt formation; mixed geology of Melbourne Formation, Paleo Clay and Basalt; creek crossing with shallow overburden and launching and jacking from a 40m shaft.

Speaker – (Aziz) Jiang Aizezi, Senior Project Engineer – Infrastructure Projects, Downer

Aziz has obtained extensive technical knowledge, engineering, finance and management skills in the tunnel and trenchless industry, supporting multiple complex projects from planning phase through to delivery. This includes optioneering, constructability analysis, concept design, tender analysis, design assessments, site/project engineering, forecasting and problem solving.

He has been involved and contributed to successful delivery of trenchless projects involving diverse trenchless techniques including: microtunnelling, pipe jacking, auger boring, pilot boring and horizontal directional drilling.