Qian Yongmei, Che Mingyue, Teng Da, Lin Chao, Liu Zunpeng, Zhang Kai
College of Civil Engineering, Jilin Jianzhu University, Changchun, 130118, China.
Changchun Institute of Architecture, Changchun, 130118, China.
Sci Rep. 2024 Jun 12;14(1):13527. doi: 10.1038/s41598-024-64504-8.
The disc overhang diameter can significantly affect the uplift bearing capacity of new concrete expanded-plate pile groups, affecting their design and practical applications. Accordingly, this effect was investigated considering the failure laws of the soil surrounding various pile types and groups. Based on the uplift bearing capacities of single and double piles, a finite element simulation was adopted to establish models for the four-, six-, and nine-pile groups. The relationship between the disc overhang diameter and uplift-bearing capacity of each pile group was explored: as the disk overhang diameter increased, the uplift-bearing capacities of the pile groups increased; however, this relationship is nonlinear. The optimal disc overhang diameter was determined as 1.5-1.75 times the pile diameter. For a constant disc overhang diameter, corner piles have a greater uplift bearing capacity than side piles in the six-pile group, and a greater uplift bearing capacity than the side and center piles in the nine-pile group. Thus, the pile-group effect depends on the pile position. The uplift bearing capacity did not increase linearly with the number of piles, and the average uplift bearing capacity of a pile in a pile group was less than that of a single pile. Therefore, the uplift bearing capacity of the pile groups decreased as the number of piles increased. The reliability of the simulation was verified via visual testing of a small-scale half-cut pile model.
圆盘悬挑直径会显著影响新型混凝土扩盘桩群的抗拔承载力，进而影响其设计和实际应用。因此，结合各类桩型及桩群周围土体的破坏规律，对该影响展开了研究。基于单桩和双桩的抗拔承载力，采用有限元模拟建立了四桩群、六桩群和九桩群的模型。探讨了圆盘悬挑直径与各桩群抗拔承载力之间的关系：随着圆盘悬挑直径的增大，桩群的抗拔承载力增加，但这种关系是非线性的。确定最优圆盘悬挑直径为桩径的1.5 - 1.75倍。对于圆盘悬挑直径恒定的情况，在六桩群中，角桩的抗拔承载力大于边桩；在九桩群中，角桩的抗拔承载力大于边桩和中桩。因此，桩群效应取决于桩的位置。抗拔承载力并非随桩数线性增加，桩群中桩的平均抗拔承载力小于单桩的抗拔承载力。所以，桩群的抗拔承载力随桩数增加而降低。通过对小规模半切桩模型的直观测试，验证了模拟的可靠性。
