Drainage northern part of Zug, main canal to the lake & circulago
Go Bau AG exercises the function of the overall project manager and the chief building director in the mandate for BG engineers + consultants AG for the design and implementation of both projects for the realization. Marc Reinhard is the direct contact for both representatives of clients (urban drainage departement of Zug and Wasserwerke Zug AG). He leads the design team at BG engineers and consultants AG and manages the regular planning and building sessions in both projects.
Description of the project:
The City of Zug is located on the shores of the Lake of Zug, 20 miles south of the City of Zurich, Switzerland. With an average growth of about 1.2 % per year, the City’s population increased from 22’300 people in 1995 to 30’000 in 2017. In the mid 90’s, during heavy rainfalls, sewage water was still discharged at 27 locations around the city into the Lake of Zug due to the limited capacity of the combined wastewater sewer and the treatment plant. In 1995, the City Council decided to switch to a separated wastewater and surface water system to minimize the discharge of untreated wastewater into the Lake. Up to date, more than 2/3 of the sewer system has been switched to the new system and now, the main discharge line for the surface water of the northern part of the City is being built (blue line, situation plan in Figure 1).
The main discharge line comprises a total of 3 microtunnels consisting of reinforced concrete pipes of 4 m (13.1 ft) length with an inner diameter of 2’000 mm (78.7 in) and an outer diameter of 2’680 mm (105.5 in). Drive 1, as indicated in Figure 1, has a total length of 357.5 m (1173 ft), drive 3 of 589 m (1932 ft) and drive 5 of 882 m (2894 ft). Since it is a gravity system, the line is being built with a gradient towards the lake. Since drive 5 will be built by mining through the intersection shaft at drive 3, the first portion of drive 5 will be mined downwards to the intersection shaft, where a vertical curve brings it to an ascending slope to account for the changing flow direction (see Figure 2). The water outlet at the end of drive 1 (which is just on the shore of the lake) will be built separately.