考虑桩基极限沉降深度的荷载传递模型的研究

Research on Load Transfer Model Considering Ultimate Settlement Depth of Pile Foundation

摘要:

荷载传递法广泛运用于基桩承载力和沉降分析。通过理论公式推导，在传统模型上考虑桩径的影响，并引入沉降计算深度概念，建立考虑桩基极限沉降深度的荷载传递模型，以此分析分层厚度（k）和应力比（η）对沉降计算精度的影响。研究发现：当桩端下土层压缩模量变小时，需要采用更小的分层厚度；应力比的设定对极限沉降深度计算有着明显的影响，若在实际工程应用中主要关注点为桩顶沉降，则根据压缩层压缩模量选取合适的应力比参数，若关注点为极限沉降深度，则尽量减小应力比取值。

Abstract:

Load transfer method is widely used in the analysis on the bearing capacity and settlement of foundation pile. The influence of pile diameter is considered in the traditional model through the theoretical formula derivation, and the concept of settlement calculation depth is introduced and the load transfer model considering the ultimate settlement depth of pile foundation is established. On this account, the influence of layered thickness (k) and the stress ratio (η) on the calculation accuracy of settlement is analyzed. The research shows that when the compression modulus of soil layer under the pile tip becomes small, the smaller layered thickness is needed for calculation. The setting of stress ratio has the obvious influence on the calculation of ultimate settlement depth. If the pile top settlement is the main concern in the practical engineering application, the appropriate stress ratio parameters should be selected according to the compression modulus of compressed layer. If the concern is the ultimate settlement depth, the selected value of stress ratio should be minimized.