Application of R/S method for dynamic analysis of additional strain and fracture warning in shaft lining

Abstract

In the past few decades, enormous losses have been induced by hundreds of vertical shafts collapse. This study is based on long-term in situ monitoring data of several mines with overburden soil layers in East China in the past six years. R / S modeling based on fractal theory was used to analyze the development of additional strains in shafts by using Hurst exponent. It can be found that from the monitoring results the Hurst effect is significant ranging from 0.5 to 1.0. Its trend also is in good agreement with forward-biased random distribution. Hence, R / S method can be used to predict the additional strain along the shaft lining. In this paper, Hurst exponent shows an irregular phenomenon before cracking. It is proved that Hurst exponent can be used to predicate the progressive failure of shaft lining from abnormal state to normal state. This paper presents the prediction of shaft lining failures using strains measured by embedded strain gauges in the thick overburden soil layers in east China.