Abstract: Based on cone penetration test (CPT) data of the clay layer in Hefei City, a soil profile random field model was established to explore the influence of linear and nonlinear detrending on the calculated scale of fluctuation of soil properties. Linear and nonlinear detrending methods were used to detrend the original CPT data, and the stationary and ergodic tests were performed on the obtained fluctuation components. Correlation function method and spatial recursion method were used to calculate the scale of fluctuation of soil properties corresponding to the fluctuation components. The sensitivity of calculation methods and sampling spacing to different detrending methods was discussed. The results show that for the data with nonlinear trend, linear detrending will make the stability of the obtained fluctuation components worse, resulting in the increase of the mean value, standard deviation and coefficient of variation of the final calculated scale of fluctuation, and the stability of the calculated results is obviously worse. Compared with linear detrending, nonlinear detrending has better adaptability. In addition, the sensitivity of the correlation function method to different detrending methods is greater than that of the spatial recursion method, and the sampling spacing does not affect the overall trend of the data and the choice of the detrending method.
Keywords: cone penetration test(CPT); detrending; scale of fluctuation; correlation function method; spatial recursion method
合肥工业大学学报自科版