High-speed rail roadbed fine-grained soil mixing amount upper limit determining method

The invention discloses a high-speed rail roadbed fine-grained soil mixing amount upper limit determining method. The high-speed rail roadbed fine-grained soil mixing amount upper limit determining method comprises the following steps of (1) preparing filling samples different fine-grained soil content; (2) performing indoor frost heaving test to measure the frost heaving ratio of every filling sample; (3) performing X-ray tomographic scanning on the filling samples, counting and analyzing the area of communication and the box-counting fractal dimension of distribution of the fine-grained soilin every filling sample, and establishing function relations to fine-grained soil content; (4) comprehensively analyzing the change tendency of the fine-grained soil content along with the area of communication and the box-counting fractal dimension as well as the frost heaving ratio corresponding to different fine-grained soil content, determining the maximum mixing amount of fine-grained soil in roadbed filling. The high-speed rail roadbed fine-grained soil mixing amount upper limit determining method takes into consideration the influence of distribution of fine-grained soil filling and microscopic pores, and through a porous structure microscopic analyzing method and an image processing method, can accurately acquire the fine-grained soil mixing amount upper limit meeting the requirements of non-frost heaving filling, thereby being favorable to developing high-speed rail roadbed filling with excellent durability.