Başakşehir / Istanbul
Site Conditions
- A roadway embankment up to 3 m high was planned to be constructed over an existing piled retaining structure, although this additional load had not been considered as a service load in the original retaining system design.
- A reinforced concrete retaining wall had been constructed on top of the pile cap beam to accommodate the roadway embankment.
- The stress increases induced by construction of the roadway embankment would have adversely affected the stability of the existing retaining structure.
- Prior to construction of the reinforced concrete metro shaft structure, the spaces between the waler beams of the temporary shoring system had to be filled to obtain a level surface and reduce concrete consumption.
Designed Solution
- Construction of the roadway embankment using geofoam block technology.
Advantages of the Applied Geotechnology
- The roadway embankment could be constructed without causing stability problems in the existing piled retaining structure.
- The geofoam block layout was designed according to a zero lateral earth pressure concept, preventing lateral loads from being transferred to the reinforced concrete retaining wall constructed above the pile cap beam.
Performance Under Service Loads
- A comprehensive instrumentation program was implemented using settlement plates and earth pressure cells.
- Periodic measurements have been collected since the roadway was opened to traffic on November 1, 2017.
