PCC群桩变形特性数值模拟研究

摘要

铁路路基沉降对于铁路的安全与路基稳定性具有重要意义，尤其当铁路工程穿越软土地区时，避免路基出现不均匀沉降。依托连盐铁路工程，采用现浇大直径管桩（简称PCC桩）进行软土地基处理，运用有限元软件ABAQUS，建立了连盐铁路PCC群桩数值分析模型，考虑了PCC桩的桩长、桩径和弹性模量对PCC群桩变形特性的影响，研究了PCC群桩的桩顶沉降变化规律。研究结果表明：在相同的荷载作用下，PCC桩越靠近路基的中心，桩顶沉降就越大，PCC群桩桩顶沉降随着桩长的增加而减小，且随着桩径的增加而减小，而弹性模量对桩顶沉降影响较小。%The railway subgrade settlement is very important to the railway safety and stability of subgrade, especially when the railway project is crossing through the soft soil area, it should avoid the uneven settlement of subgrade. The cast⁃in⁃situ large diameter pile ( PCC pile) is used in soft soil foundation treatment based on the Lianyungang⁃Yancheng Railway pro⁃ject, the PCC piles numerical analysis model of Lianyungang⁃Yancheng Railway is established by using the finite element software ABAQUS. The pile length, diameter and elasticity modulus of PCC pile are considered to affect the deformation characteristics of PCC pile foundation, the behavior of PCC pile top settlement variation is studied. The results show that PCC pile is closer to the roadbed center, the settlement of pile top is greater under the same load, the settlement of pile top decreases with the increasing of the pile length and pile diameter, and the influence of elastic modulus on the pile top set⁃tlement is less affected.