Rock Deformation under Various Degrees of Karst Development

Karst development and the deformation response of erosive rocks significantly influence the stability of cutting slopes. In this research, cutting slopes for high-speed railways was investigated in karst areas, and four representative points with various degrees of karst development were chosen to examine the rock response by applying rectangular rigid bearing plate tests. The displacement distribution of the rock under the plate was analyzed using elastic half space model theory. Results corroborate that, although the erosive rock experienced loading-unloading cyclic loading, the envelope diagram was upward convex. When a relatively lower load was applied, the slope of the P-w curve was steep, and the rock deformation was smaller. As the load increased, the slope of the P-w curve became moderate; under the same load condition, rocks with a high degree of karst development had high deformation and deformation modulus values. However, rocks that were less influenced or unaffected by karst development had minimal deformation. At the same point under the bearing plate, increasing the load enhanced the displacement of the point, and the deformation value became high as the degree of karst development strengthened.