ESTIMATION OF CUT-FILL VOLUMES IN ROCK SLOPE ENGINEERING BASED ON FRACTAL INTERPOLATION
MENG Yongdong1，2，XU Weiya1，TIAN Bin2，LIU Dawen 3
(1. Institute of Geotechnical Research，Hohai University，Nanjing，Jiangsu 210098，China；2. College of Civil and Hydroelectric Engineering，Three Gorges University，Yichang，Hubei 443002，China；3. Chengdu Hydropower Investigation Design and Research Institute，China Hydropower Engineering Consulting Group Co.，Chengdu，Sichuan 610072，China)
Abstract：The traditional interpolation algorithm is mainly based on smoothing mechanism，the result of interpolation cannot truly reflect the natural rock slope surface morphology，and the volume cannot be estimated through these results. In view of the natural terrain of rock slope engineering with random dithering and self- similar characteristics，by acquiring the surface characteristics and using interpolation algorithm based on the fractional Brownian motion(fBm)，more intensive dataset of rock slope with natural terrain can be obtained through the samples of mapping data，and the geomorphic feature of rock slope can be accurately restored. Therefore，the TIN model of excavation mass will be constructed by constraint Delaunay triangulation algorithm according to the dataset points and constraint lines of natural terrain. This method can accurately estimate cut-fill volumes of rock slope engineering. Under the prerequisite that a regional dataset of surface control points is regarded as the actual landscape，and the results of error analysis show that the error percentage of calculating cut-fill volumes with fBm fractal interpolation method is 0.14%，and that using Nurbs interpolation method is 1.5%，and fBm fractal interpolation method has much higher accuracy than traditional methods. In addition，a case study of the left bank high slope excavation of Jinping first stage hydropower station is given. It is shown that this research can provide references for excavation calculation and 3D visualization analysis of slope engineering.
