The existing cast in place retaining wall was to be used as a foundation wall for a pedestrian bridge at a subway station upgrade. EBS Geostructural provided a deep foundation solution with micropiles.

THE PROBLEM
Wall required tiebacks to reinforce wall as a result of increased loads based on new use
Limited access available between existing wall and subway track required compact equipment
Additional vertical foundation support for subway station also required
Soil strata was 2 to 2.5 meter (6-8 ft) of fill material to bedrock
Helical piers could not be used due to bedrock embedment requirement

THE SOLUTION
Micropiles were chosen for the project based on several reasons: bedrock embedment required and more cost effective solution than other technologies.
<p class="font_8">EBS equipment able to work within narrow construction envelope without interfering with subway traffic

Depth: 7.5 metres
Total Number of Micropiles: 45