Evaluation of the Base Condition of Drilled Shafts by the Impact-Echo Method
Soo, KD
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Kusong-dong, Yusong-gu, Taejon 305-701, Korea

Woo, KH
KT, Technology Laboratories, Jeonmin-dong 463-1, Yusong-gu, Taejon 305-811, Korea

(Received 19 September 2002; accepted 23 January 2004)

Abstract
Numerical and experimental model studies were carried out to evaluate the base condition of drilled shafts. Base conditions such as free, fixed, rock-socketed, and soft-bottom were considered. To simulate the base conditions, mock-up shaft models made of cement mortar were used. The impact-echo method was applied to evaluate each base condition. Finally, field tests were performed for the rock-socketed shafts. It is found that the rock-socketed condition and socketed length can be evaluated. The soft bottom condition can be identified, only when the side contact between shaft and surrounding rock is poor, whereas it cannot be identified when the side contact is good.

Keywords:
base conditions, drilled shafts, drilling, Impact-Echo method, nondestructive tests, rock-socketed, stress wave propagation

Paper ID: GTJ11696
DOI: 10.1520/GTJ11696

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Author Soo, KD Affiliation Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Kusong-dong, Yusong-gu, Taejon 305-701, Korea Author Woo, KH Affiliation KT, Technology Laboratories, Jeonmin-dong 463-1, Yusong-gu, Taejon 305-811, Korea Author Soo KD, Woo KH Title Evaluation of the Base Condition of Drilled Shafts by the Impact-Echo Method Symposium , Committee on