Use of Physical Modelling and Building Information Modelling For Mangere Wastewater Pump Station

The Mangere wastewater pump station is part of Central Interceptor (CI) Project and will be located at Mangere Wastewater Treatment Plant (WWTP) in Auckland. It will lift wastewater from the end of a 13 km long tunnel to the Mangere WWTP. The pump station is an essential component of the project, required to control the delivery of flow from the tunnel into the WWTP. The pump station has been designed so that the rate of pumping enables the plant to operate within the consented flow limits. It has been designed to pump a peak flow of 6 m3/s, however it will be capable of pumping 7.2 m3/s with the high wet well levels during tunnel surcharge events. The shaft of pump station is approximately 40 m deep and consists of diaphragm wall construction. The paper will discuss the use of the following two valuable tools to deliver the design:

• a Froude scale physical model of the inlet and wet well with the geometric scale of 1:8.6 to maintain dynamic similarity to simulate the full-scale flow conditions. Physical modelling was carried out to understand the hydraulic conditions and evaluate the performance of the proposed design. It proved significantly useful in identifying sub optimal conditions that were resolved in the design phase.
• 3D and 6D Building Information Model (BIM) of the pump station to assist in visualization. This BIM is a digital representation of the physical and functional characteristics of the pump station. The BIM proved extremely useful by improving collaboration within the design team, and during Safety in Design and operability reviews with Watercare staff, and identifying service clashes.