黄土地区挤密桩桩周土体挤密模型的确定

Determination of compaction model of loess surrounding the compaction pile in loess region

研究分析了邓肯-张模型在挤密桩周土体应用中的不足。通过室内试验及对黄土地区挤土桩成孔对桩周土挤密原理的分析,认为桩周挤密黄土变形模量在破坏前符合邓肯-张模型,破坏后可用重塑土室内压缩试验的压缩模量与建议的转换系数β确定,并进一步给出了相应的计算模式,提出了黄土成孔挤密模型并通过一个实例验证了模型的合理性。此模型为以后对桩周土体的应力分析打下了良好的基础,对进一步完善挤密桩设计理论具有参考价值。

The deficiency of Duncan-Chang model in analyzing the stress of the loess surrounding the compaction pile is pointed out. Based on this analysis, the laboratory soil test is conducted and the compaction principle of the loess surrounding the pile in the loess region is analyzed; the above analysis leads to a conclusion that modulus of deformation accords with Duncan-Chang model before the loess surrounding the compaction pile failing and to be determined by modulus of compressibility of remolded sample compression test and suggested coefficient β after failed. Then, a loess compaction model is suggested and verified through an example. The model sets a solid foundation for the future stress analysis of the loess surrounding the pile and has reference value to perfecting design theory of the compaction pile.