Slip resistance effect of pile-soil interface inclination angle and moisture content on the anti-sliding pile

To study the slip resistance effect of pile-soil interface with different interface inclination angle and moisture content, the variability of damage modes and shear strengths of assemblies with variable inclination angles under the different conditions of interface inclination angles and water content were compared based on the triaxial unconsolidated undrained test at first. Then, the slip resistance effects of the pile-soil interface with different interface inclination angles and moisture contents were compared by numerical simulation, with consideration to the shear strength parameter of laboratory test. Meanwhile, the critical moisture content w_max was determined based on the plastic deformation theory. Finally, the cross-section of the anti-sliding pile was optimized based on the engineering case. The results show that interface inclination angle and moisture content are the main reasons for the difference in damage mode and shear strength of the assemblies with variable inclination angles. Specifically, an appropriate increase in inclination angle at low moisture content could improve the shear strength of the assembly specimens. In the case of low moisture content in the soil, the slip resistance effect of the pile-soil interface shows a trend of increasing first and then decreasing with the increase of inclination angle on the pile side. At the higher moisture content of the soil on the pile side, the larger the inclination angle of pile-soil interface, the smaller the slip resistance effect of pile-soil interface. Appropriately increasing the triangular section of the back pressure area of the anti-sliding pile could reduce the equivalent concentrated load acting on the friction arch of the pile side by about 33% at maximum when consideration is given to the soil arching effect between piles. Generally, the research results could be used for reference in the design of anti-sliding piles.