Application of Dynamic Time Warping to Determine the Shear Wave Velocity from the Down-Hole Test

Abstract

A tailing storage facility (TSF) is a complex hydrotechnical structure that requires continuous monitoring to prevent catastrophic dam damage. One critical issue to control is the soil’s characteristics, which is why many field and laboratory tests are carried out on the dam to determine the relevant soil parameters. Among these tests, down-hole seismic tests, such as SCPT, are performed to determine, e.g., the shear wave velocity. However, accurately calculating the difference in the times of the arrival of the wave at the two geophones is crucial to determining its value. This article proposes a novel method for estimating this variable using the DTW (Dynamic Time Warping) algorithm, which calculates the shift between two signals by determining their optimal match. The article also addresses signal interference and proposes methods for clearing it to obtain more accurate results. Furthermore, the article introduces a method for measuring the signals’ quality based on their similarity, which helps assess whether determining the shear wave velocity is possible for a given sample.

Keywords

• dynamic time warping
• down-hole seismic test
• shear wave speed
• signal quality assessment
• tailing storage facility
• phase shift