Fallacy of Capacity Performance & Innovation Improvement of Jack-In Piling in Malaysia

Abstract

Jack-in piling is gaining rapid acceptance in Malaysia piling industry with its commonly recognised advantages of proof loading every single pile installed, quick installation process and high pile capacity performance. However, this piling system is still subjected to the problem of large soil displacement inducing lateral and vertical movements of earlier installed piles, premature refusal to penetration of pile due to intermittent obstruction and also inadequate pile embedment due to shallow end bearing stratum. Hence, pre-boring technique with or without infill is used to overcome the obstruction problem and to ensure adequate pile embedment. The proof loading pile termination criteria appear to produce favourable pile performance and quality assurance. There is inherent long-term performance deterioration associated with shallow embedment of end bearing piles and incomparable short-term and long-term toe resistances, particularly in meta-sedimentary formation, which is prone to stress relief softening effect. Innovation of improving the installation process using customised recording device to guide the pile installation and pile termination has proven good quality assurance of pile installation and improved productivity. This paper presents the misconceptions of this high capacity jack-in piles, solutions and some proven innovative improvements.