Instrumented full scale test and numerical analysis to investigate performance of bamboo pile-mattress system as soil reinforcement for coastal embankment on soft clay

Bamboo pile-mattress is a system that combines both bamboo piles and bamboo mattress for reinforcement embankment on soft clay. This system utilizes bamboo piles to act as friction piles and bamboo mattress to distribute embankment load uniformly, to alter critical failure surface, and to provide upward buoyancy pressure. The system has been utilized in several projects for coastal embankment on soft clay in Indonesia and has been proven reliable and durable.f. To investigate the performance of the system, instrumented full scale test was conducted at near shore area at Tambak Oso, Surabaya. At the area, very soft to medium clay layer was found until 3 0 in below ground surface. Stability analysis and settlement prediction was performed using analytical and numerical methods. The numerical method analysis was conducted using finite element method utilizing a commercial program package. Trial embankment was performed in several fill stages followed by observation of embankment stability and ground settlement. Field observation indicated that embankment using bamboo pile-mattress system showed adequate stability against slope failure and bearing capacity failure and actual settlement was also close to predicted settlement. Hence, bamboo pile-mattress system is proven to be reliable as ground reinforcement and to distribute settlement more uniformly and the calculation method was fit with actual condition.