Performance of high-rise pile group adjacent slope

Abstract

For the consideration of required elevation, pile shafts are partially buried in the soil stratum and partially exposed above the ground surface, known as high-rise pile group (HRPG). The HRPG is extensively used in the construction of infrastructures and is usually adjacent the slope. It is frequently subjected to high lateral loads from the superstructure, leading to considerable displacement and bending moment. To alleviate the deformation and internal force of HRPG, a batter pile is employed, forming the high-rise batter pile group (HRBPG). A numerical simulation is conducted to observe the response of HRPG foundation subjected to downwards lateral load adjacent slope. The effects of slope angle, cap elevation, and lateral loading magnitude are determined. Results of HRBPG are compared with traditional high-rise vertical pile group (HRVPG). Conclusions can be drawn as follows. (1) The slope has significant effect on the displacement and bending moment of HRPG, so it should be considered in the design process. The displacement and bending moment of pile shaft increase gradually with the slope angle (0°–30°) and then they have a sharp growth (45°–60°). (2) With the rise of cap elevation, the displacement increases dramatically, whereas the bending moment rises and then falls. The displacement is highly sensitive under lateral loading with a high cap elevation; the higher the elevation is, the greater the displacement will be. Special attention should be paid when a high pile cap is adopted under large lateral loading. The displacement and bending moment of HRBPG are considerably smaller than those of HRVPG at a high pile cap elevation. (3) The displacement and bending moment are relatively small when a diminutive lateral loading is performed; however, they have a sharp growth under large lateral loading. The larger the load is, the greater the bending moment and displacement will be. (4) The displacement of the leading pile is slightly larger than that of the trailing pile, whereas the bending moment of the rear pile is larger than that of the leading pile. The pile shaft displacement above the ground surface is considerably larger than that below. The maximum bending moment occurs at the pile head, and the pile toe has minuscule bending moment. (5) The use of batter pile is beneficial for reducing the displacement and bending moment, whereas the slope and lateral loading are detrimental.