Compressive and flexural behaviour of reinforced concrete permeable piles

Driven piles generate excess pore water pressures in the surrounding soil, where a full dissipation of these pressures may take a very long time. Measures are therefore sought to accelerate soil consolidation. The concept of permeable pile with drainage holes around the circumference of pipe pile could serve this purpose by providing drainage paths. However, the structural integrity of permeable pile may be deteriorated due to these openings. This paper presents the results of uniaxial compression and flexural tests on permeable and normal pile specimens. The influence of concrete strength and pattern of drainage holes in terms of diameter, total number and layers on the ultimate compressive strength is investigated. The crack pattern, deflection profile and concrete strains are measured for both normal and permeable piles. It has been found that drainage holes could cause the reduction in ultimate compressive strength, but the measured values are still far greater than design estimations. Moreover, the permeable piles have higher flexural capacity than the normal piles due to the stress redistribution.