Novel Methodology for Nondestructive Evaluation of Brick Walls: Fuzzy Logic Analysis of MASW Tests

作者：Cascante G^*; Najjaran H; Crespi P

来源：Journal of Infrastructure Systems, 2008, 14(2): 117-128.

DOI：10.1061/(ASCE)1076-0342(2008)14:2(117)

• Rayleigh waves
• Nondestructive tests
• Spectral analysis
• Fuzzy sets
• Walls

This paper presents a novel methodology for the nondestructive evaluation of brick walls using fuzzy logic and summarizes the results of the nondestructive evaluation of the relative condition of a sidewall of a brick masonry channel using the multichannel analysis of surface waves (MASW) test. The new methodology addresses the critical problem of considering the inherent variability of field data in the analysis of seismic tests. Wave propagation measurements were taken on the sidewall at 161 locations; the total length of wall tested was 80 m. Each MASW test consisted of the simultaneous measurement of the impact response of the wall with an array of 15 transducers (accelerometers); each test assessed the relative condition of a wall section 7.5 m long. For one of the sections, measurements were taken before and after a uniform grouting. The relative condition of the wall is evaluated by considering five wave propagation characteristics: group velocity, minimum and maximum phase velocities, predominant frequency, and attenuation coefficient. A fuzzy logic model is developed based on expert knowledge to identify the weaker sections of the sidewalls. The output variable of the model is a condition index that classifies the relative condition of sections in five linguistic categories from "very good" to "damaged" conditions. The effect of each wave propagation characteristics on the condition index is evaluated through a sensitivity analysis.

• 出版日期2008-6