Effects of Staggered Plates on the Uplift Failure State and Bearing Capacity of NT-CEP Pile Groups

Abstract

Plate position is an important parameter of a New Type Concrete Expanded-Plate (NT-CEP) pile. In this study, two small-scale test models and two, four, six, and nine finite element models were established using a visual small-scale model of half-section piles, an undisturbed soil pull-out test, and the ANSYS finite element software R19.0. The NT-CEP pile groups were studied with the plates set at staggered positions. This study mainly analyzes the displacement contours, stress curves, and load-displacement curves under the action of vertical tension and determines the influence of staggered plate positions on the performance and bearing capacity of the NT-CEP pile group, which provides theoretical support for its application in practical engineering. The bearing plate positions affect the performance of the pile group. The stress distribution in each pile in the pile group is uneven when plate positions are staggered, and the pile with the lower plate position bears a greater force. This has a great influence on the bearing capacity of the NT-CEP pile group. If allowed, the plates can be first set at the same position. If appropriate, the plates can be set in staggered positions; however, a reasonable distance between the upper and lower plates should be considered.