DRILLED SHAFT CONSTRUCTION FOR THE BANDRA-WORLI SEA LINK PROJECT

The Bandra Worli Sea Link Project (BWSL) includes a 500 m long cable stayed bridge with two 250 m cable supported main spans on either side of a single central tower with a height of 158 m. Foundations for the project consist of 676 drilled shafts, 72 with a diameter of 2 m and 604 with a diameter of 1.5 m. Working loads on the shafts range from 3.3 MN to 25 MN. The shafts were constructed using a reverse circulation drilling unit and ranged from 4 m to 34 m in length. Rock encountered at the site included highly weathered, fractured and oxidized volcanic material with RQD's of less than 25 percent and unconfined compressive strengths of 1 MPa to massive intact material with unconfined compressive strengths in excess of 100 MPa.