Sheikh Isa Bin Salman (SIBS) Trunk Sewer Project Bahrain

Challenges

The SIBS project presents several significant engineering and logistical challenges.
Ground conditions across the alignment are complex, requiring close attention to soil transitions and variations in face pressures. High groundwater levels demand robust control measures throughout excavation. Shaft locations must be carefully planned to avoid extensive buried utilities, requiring coordination with multiple stakeholders.

One of the most technically demanding elements is the delivery of a 778m long DN1800 microtunnel drive. Due to the length and the need for absolute accuracy, the excavation requires a gyroscopic guidance system to maintain precise alignment throughout. This ensures the pipeline meets all hydraulic and geometric requirements, despite challenging subsurface conditions.

Delivery Approach

To maintain progress across all drives, we are adopting a collaborative and coordinated delivery strategy with HHG, Stantec Khonji, and SEPPD. The use of five machines operating simultaneously allows us to meet the client’s programme requirements while ensuring safe and controlled working practices.

Each drive is executed using slurry microtunnelling techniques to manage variable ground conditions, support the face, and control groundwater. The guidance system ensures accurate, long‑distance drives, particularly on the DN1800 drive, where precision is paramount. Our teams maintain consistent quality standards and ensure smooth interface management between drives, shafts, and stakeholder requirements.