Rational Method for Selecting Seismic Waves for Pavement Evaluation

Abstract

The precision of pavement moduli values is affected by the selection process of the signals from the seismic pavement analyzer (SPA). If improper signals were selected, moduli values from the SPA were lower than those obtained from the falling weight deflectometer (FWD). The precision was determined using a 95% confidence interval. The discrepancies in the seismic testing results were attributed to the wide range of irregularities in some of the SPA signals. Based on the crossing analysis of a narrow-band process, the irregularity factor α was introduced in this study to evaluate the degree of distortions in the seismic signals. A threshold of 0.8 was determined to be the minimum acceptable limit for α. Lower values of α associated with irregular signals caused drastic increases in the ratios of the confidence intervals between the SPA and FWD results. The need for having a rigorous calibration protocol for the SPA has been emphasized. Using the proposed method enhanced the quality of the seismic analysis for pavement evaluation.