PERFORMANCE OF INSTRUMENTED BORED PILE IN KENNY HILL FORMATION

Abstract

The Kenny Hill Formation forms part of the various geological formation and extends over a significant part of the Klang Valley of Peninsular Malaysia. Design of cast-in-place bored pile in Malaysia is usually based on empirical correlation with the Standard Penetration Tests (SPT-N). However, the current empirical correlation appears to indicate that the value may not be applicable for material with SPT-N>50. This paper presents the evaluation of measured shaft resistance, fs and end bearing resistance, fb of three instrumented cast-in-place bored piles constructed in the Kenny Hill Formation which were socketed into material with SPT-N value up to 300. The results are examined to validate the existing design method and to establish future guidelines for designing bored piles in this sedimentary formation. The correlation of fsu = 2N as suggested by Chang and Broms (1991) is achievable for material with SPT-N<50 blows/300mm. However, this correlation appeared to be unachievable for material with SPT-N>50 blows/300mm. It is recommended that lower value of Ksu should be considered for SPT-N more than 50. In view of limited data for end bearing resistance, the correlation of fb is almost reach to fbu = 30N.