Study on Anti-Uplift Effect of Micro-Steel-Pipe Pile on Red-Bedded Soft Rock Subgrade

To investigate the treatment effect of micro-piles on uplift deformation red-bedded soft rock subgrade, an in-situ static load test slurry injected steel pipe with different length was carried out, bearing capacity and characteristics were analyzed, transfer function pile lateral friction resistance modified consideration length. A numerical simulation method considering variable shear stiffness at pile-soil interface established, inversion relevant material parameters out based results. Through simulation, single piles lengths group spacing subgrade investigated. Finally, anti-uplift design in proposed. The results show that increased nonlinearly increase length, variation curve relative displacement showed a hardened type. predicted shows good correlation measured result; all coefficients greater than 0.81. without radially distributed maximum value 5.12 mm as center. micro-pile 7 m or rectangular array 3D could effectively decrease to less 4.0 mm, which can meet requirement specification. Thus, be used for controlling this study provide reference area rock.