Arnavutköy / Istanbul
Site Conditions
- The subsurface profile consisted of uncontrolled spoil material originating from excavation and mining activities.
- A reinforced concrete support structure founded on bored piles had been constructed over the airport southern discharge line.
- A high roadway embankment was required above the existing discharge line.
- If the entire embankment had been constructed using conventional compacted soil fill, the resulting loads would have caused stability problems in the bored-pile-supported reinforced concrete structure.
Designed Solution
- Construction of controlled compacted soil fill above the bored-pile-supported reinforced concrete structure up to the maximum allowable elevation, followed by a trapezoidal geofoam block embankment above this level.
- Design of the roadway embankment using a hybrid solution combining conventional compacted soil fill and geofoam technology, without exceeding the allowable design loads for the existing buried infrastructure.
Advantages of the Applied Geotechnology
- The roadway embankment could be constructed without causing stability problems in the bored-pile-supported reinforced concrete structure.
- Compared with the initially considered alternative of a three-cell reinforced concrete void structure combined with compacted soil fill, the selected solution enabled substantially faster construction and provided a more economical alternative in terms of overall project cost.
- A hybrid solution combining conventional compacted soil fill and geofoam block technology was successfully implemented.
Performance Under Service Loads
- A comprehensive instrumentation program using settlement plates and earth pressure cells was implemented.
- Periodic measurements have been collected since the roadway was opened to traffic in August 2019.
