论文部分内容阅读
现浇X形桩基础广泛应用于高速公路、市政道路等工程软土地基处理,但对于其群桩相互作用特性研究尚不多见。文中应用有限差分软件FLAC3D建立了X形桩和圆形桩的群桩三维模型,并采用现场数据验证了该模型的合理性。引入双桩相互作用系数来定量计算受荷桩和被动桩的相互作用,并且研究了被动桩位置、桩数、桩土模量比和桩间距对群桩相互作用的影响,从而揭示了现浇X形桩的群桩效应。结果表明:桩位和桩间距对现浇X形桩群桩相互作用影响较大;桩数对X形桩群桩相互作用系数影响较小。荷载较小时,桩土模量比和桩距对X形桩群桩相互作用系数有较大影响;随荷载增大,桩土模量比变化对X形桩群桩相互作用系数的影响减弱。现浇X形桩群桩的相互作用远大于等截面积圆形桩,且与等外包圆形桩相似,这对考虑群桩效应进行X形桩基础设计时有参考意义。
Cast-in-place X-shaped pile foundation is widely used in soft soil foundation treatment of expressways, municipal roads and other projects, but the study of the interaction characteristics of pile groups is still rare. In this paper, the finite element software FLAC3D is used to establish the three-dimensional pile group model of X-shaped pile and circular pile, and the rationality of the model is verified by field data. The interaction between piles and passive piles is quantified by the interaction coefficient of double piles. The effects of passive piles’ position, number of piles, pile-soil modulus ratio and pile spacing on the interaction of pile groups are revealed, Pile group effect of X-shaped pile. The results show that the interaction between pile and pile spacing has a great effect on the interaction of cast-in-situ X-shaped piles. The pile number has little effect on the interaction coefficient of X-shaped pile groups. When the load is small, the pile-soil modulus ratio and the pile distance have a great influence on the interaction coefficient of X-shaped pile group pile. With the increase of load, the influence of pile-soil modulus ratio on the interaction coefficient of X-shaped pile group pile is weakened. The interaction of cast-in-situ X-shaped pile group pile is much larger than the circular pile with equivalent cross-sectional area, which is similar to the equivalent circular pile, which is of significance for the design of X-shaped pile foundation considering group pile effect.