Publication Abstract

Proceedings - Fourth International Conference - Piling and Deep Foundations, 1991, Stresa, Italy, (DFI)

Shape estimation method for cast in-situ piles based on the stress wave theory
M. Honma; Nippon Concrete Industry Co. Ltd, Shimodate, Ibaraki, Japan T. Sakai; Public Works Research Institute, Tsukuba, Ibaraki, Japan H. Murakumi; Asahi Chemical Construction Materials co. Ltd, Japan N. Koyama; Nippon Hume Pipe Co. H. Inaga

Theory and the results of the application of the method to estimate the shape of the cast in-situ piles under low strain condition based on the stress wave theory are presented in this paper. To estimate the pile shape from the vibration response of a pile, both the wave energy attenuation ratio during propagating in the pile and the impedance ratio of the pile components where reflected waves are generating should be determined simultaneously. The characteristic curves method considering the wave attenuation is used for the analysis of the vibration response of the pile to estimate the pile shape. As the results of tests applied this method on cast in-situ piles, if the vibration response which includes the response form the pile toe was carefully analyzed, the pile shapes were estimated with in 10 to 20 percents of error in pile diameter and less than 10 percents for pile length.

 article #523; publication #37 (IC-1991-IT)