A new concept of micropile was proposed for the purpose of obtainingbetter skin friction and cost efficiency compared to the conventionaltype. The new concept was called waveform micropile since shear keyswere formed during the drilling and grouting process. Jet groutingmethod was applied for making the shear key shape in order to createhigher skin frictional resistance. The shear keys of waveform micropilewere expected not only to increase bearing capacity, but also to decreasesettlement. Especially, the shear key length and separation distancebetween them were considered as a crucial factor in achievingimprovements of bearing capacity. In this study, a series of centrifugetest was conducted using different shapes of waveform micropilesincluding conventional and a jet grouted piles. With the obtained data, acomparative study was done to evaluated load-settlement relationshipbetween different micropile models. Then, the ultimate loads of all pileswere compared by a well-known estimation method. The analysis resultfrom the load-settlement curve showed that the waveform micropileachieved higher resistance compared to the micropile without shear keys.During the ultimate load analysis, FHWA mannual, which is known asmicropile design guideline, was considered not suitable to accountultimate load for the waveform micropile.
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