Osman Gazi Bridge
Turkey

The Osman Gazi Bridge (referred to as the Izmit Bay Crossing during design and construction) was the world’s fourth largest suspension bridge when it opened in 2016, with a span of 1,550m.  The bridge spans the Sea of Marmara and crosses the northern splay of the North Anatolian Fault, which marks the boundary between the Eurasian and Anatolian tectonic plate boundaries.

Geo-Design undertook a specialist review of ground conditions for the north anchorage blocks and provided on site design verification for the south anchorage block:

• Site supervision
  Design, supervision and interpretation of targeted ground investigation to allow geological and hydrogeological evaluation of rock and soil conditions.
• Laboratory testing
  Specification and interpretation of discontinuity shear strength testing.
• Reporting
  Geological and geotechnical interpretative reporting and a review of rock mass failure mechanisms.