Ding Inspection Device (DID)
John Z. Ding, P.E. has recently developed a device for measuring the drilled shaft bottom sediment thickness without human access into the drill hole. As an economical alternative, DID can provide relatively accurate measurement when SID/Mini-SID is not available, especially, in the situation when correlations between SID/Mini-SID and DID have been made at the initial stages of the drilled shaft construction. Under such circumstances, DID can be considered as a reliable tool for the measurement of the bottom cleanliness.