Indah Kiat Pulp & Paper

An earth retaining wall within the Indah Kiat Pulp & Paper Tangerang Mill, Serpong. We built 270 soldier piles with a 7 metre effective length — 266 piles of Ø 500 mm and 4 of Ø 600 mm at the water gate — following a long alignment along the Cisadane River, past warehouses, a pump room, a water pit and pipe racks — all of which stayed in operation.

Drilling used the dry boring method with full casing — steel casing holding the bore wall over the full depth, chosen because the ground here could not be relied on to stand unsupported during drilling and concreting. Reinforcement was graded to the moment profile: on the Ø 500 mm piles, 9D19 with a close D10-100 spiral over the top three metres, then 6D19 and 4D19 with the spiral opening out towards the toe; the Ø 600 mm piles carry 12D19 at the head.

Alongside the soldier piles we carried out Ø 500 mm pre-boring to 9 metres to assist driving at certain points. Pile capacity was verified through three PDA test points spread along the wall alignment.