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Wavelet approach of data analysis for inclinometer measurements Yang Lu , Yanjun Qiu School of Civil Engineering, Southwest Jiaotong University, Chengdu, 610031, P.R. China; Abstract Detection of movement zone and predication of deformation development are two primary applications of inclinometers in slope stability monitoring. But it is often difficult to achieve these goals with great confidence because errors are inevitably involved in the record during casing installation and data collection. To deal with this problem, the wavelet based multi-resolution analysis method is proposed. In this method, inclinometer data are decomposed into different frequency components. Each component is then studied with a resolution matched to its scale so that the useful information can be extracted for further analysis. Applying the wavelet method to a highway slope monitored by inclinometers, a clear profile of subsurface deformations of the slope is obtained and the development of the overall displacement of the slope is predicated. Key Words: wavelet transform, multi-resolution analysis, inclinometer measurement, slope deformation. 1.Introduction Slope failure is an ever present issue for civil engineering works in the mountainous area. But except for earthquake induced slides, most slope failures of large scale occur gradually and are accompanied by measurable displacements, Zavodni and Broadbent (1978). Therefore, deformations are usually primary parameters in the field monitoring for the stability of a cut slope. Depth and extent of sliding zones of the slope can be determined by studying horizontal subsurface displacement detected by an inclinometer. Kutschke et al (2007), for example, implemented a program of field instrumentation with inclinometers to monitor movement of a cut slope in an area of ancient slides. Data collected by the inclinometers proved that the slope was generally in a stable condition. Costly additional measures to stop slope movement were then abandoned. Stevens and Zehrbach (2000) analyzed data collected by inclinometers at the site of a remediated landslide in Northern California. They found that subsurface movements were mainly due to settlement of the fill mass and lateral extension, and not related to movement of the remediated landslide, confirming correctness of the design. In Petley (2004), 12 inclinometers were used to investigate the process of a controlled man-made slope movement. Data collected by the inclinometers provided useful information for the study of mechanisms of the slope failure. The inclinometer probe is the most important component of an inclinometer. The probe contains a gravity-sensing transducer used for inclination measuring. It is connected to a readout device through a cable. By passing along the casings installed in the slope, onset and continuation of deformation normal to the axis of the casing can be detected which provides a profile of subsurface horizontal movements. In the field, horizontal displacement is normally sampled at an interval of 0.3~0.6m. Since a borehole is TRB 2012 Annual Meeting Original paper submittal - not revised by author.
