P.T. Bauer Pratama Indonesia, the local subsidiary of Bauer Spezialtiefbau, was commissioned by P.T. Hutama Karya as the main contractor of P.T. Angkasa Pura II (Persero) - Indonesia's airport company and the biggest Indonesian airport operator - to carry out the ground improvement work for the construction of the new connection taxiway.
The project - East Connection Taxiway Phase 1 - includes two main tasks: extensive ground improvement for the connection between the north and south runways, and foundation work for taxiway bridges over the airport's main access road. It is a continuation of the previous Secondary Apron project that was completed in May 2017 located at the north side of the airport where Bauer also carried out ground improvement work of 98,300m2 as an initial part of East Cross Taxiway.
Ground improvement work was needed to increase the capacity of in-situ soil prior to pavement work. After improvement, the in-situ soil which is dominantly soft to medium stiff silty clay is expected to reach a CBR value (mechanical strength) of six per cent under the pavement layer and the allowable settlement at a maximum of 100mm in 10 years after construction.
The ground improvement was executed with 5 to 16m deep full displacement columns over a total area of 199,000m2.
For the foundations of the taxiway bridges, a total of 1,072 bored piles with a diameter of 1.2m were drilled to a depth of up to 37m. Three Bauer BG 14 rigs, one BG 22, one BG 28 and its accessories were in operation.