Sekolah Citra Berkat

Bored pile foundation for the Sekolah Citra Berkat campus in Citra Raya, Tangerang: 46 piles of 400 mm diameter, built from late February to early May 2025 across the main building, the hall, the STP and the ground water tank.

The ground changes three times: silty clay, soft to firm, in the top ten metres; silty clay, medium to hard, down to about 17 metres; then hard clayey silt below that. The piles fall into two depth groups according to the load they carry — 29 stop at 13–14 metres, 17 go down to 22–23 metres.

Before production started, a trial hole was monitored for more than 14 hours to measure how quickly its walls collapsed. The figure came to 1.2 metres over that period, and it is what set how long a hole could be left open before the cage went in and concreting began.

Four piles were tested: two by PDA and two by PIT, carried out by an independent geotechnical laboratory to ASTM D-4945. The 120-tonne target — twice the 60-tonne design load — was met on both PDA piles, with CAPWAP analysis recording at least 121 and 144 tonnes.