REPLACING TOP LAYER OF SOFT CLAY WITH COMPACTED ENGINEERING FILL TO IMPROVE THE LATERAL CAPACITY OF PILES-PPT Presentation

PPT Presentation

Pdf Summary

The project involved constructing two 89 m-diameter LNG tanks at Dhamra Terminal, supported by 872 bored cast-in-situ piles. The upper soil layers—sandy silt over dredged clay lumps—were considered inadequate for the required lateral pile capacity.<br /><br />Analysis using the existing soil profile predicted 106 mm of pile-head deflection, exceeding the 75 mm criterion. To improve support, the top 3 m of weak soil was replaced with engineered granular fill placed over geotextile. The fill was compacted in 150 mm layers to 98% density.<br /><br />An initial lateral load test on a 1,200 mm pile reached 1,357 kN; maximum deflection was 76 mm, within the tank design limit of 125 mm. Back-analysis of the test informed the engineered-fill parameters used in L-pile modelling. Routine testing of a working pile showed a maximum deflection of 32 mm at 817 kN, below the 75 mm design limit.<br /><br />The presentation concludes that replacing weak surface soil with well-compacted engineered fill substantially improves pile lateral performance. It reports the original lateral capacity as 300 kN against a required 534 kN, and confirms the improvement through load testing.

Keywords

LNG tanks

Dhamra Terminal

bored cast-in-situ piles

lateral pile capacity

engineered granular fill

geotextile

pile-head deflection

lateral load test

L-pile modelling

soil replacement