抗拔桩实验确定地层变形模量的模拟研究

在地下工程数值模拟计算中,土体变形模量的取值对计算结果影响很大,然而多数数值模拟计算忽视了土体变形模量随着埋深的变化。本文以郑机城际线机场站基坑工程为依托,假定土体变形模量随着埋深呈线性增大趋势,通过模拟现场抗拔桩实验,并对比模拟计算结果与现场实验数据,得出了相应土体摩尔库仑模型的变形模量与埋深之间的近似线性关系。研究所得土体变形模量参数进一步应用于依托工程中的支撑轴力的数值模拟计算,数值模拟计算结果与现场监测数据较为吻合,进一步验证了该参数取值方法的合理性,计算结果能够有效地指导施工。该数值模拟抗拔桩实验获取土层变形模量的方法可为类似工程提供有价值的参考。

A Numerical Study on Determination of the Deformation Modulus of Soil Based on Pull-out Test of Uplift-Pile

In the numerical modelling on the underground projects, the value of soil deformation modulus has great influence on modeling results. However, the change of soil deformation modulus with depth increasing is neglected in most numerical modelling. In this paper, the soil deformation modulus is assumed to be linearly increased with depth increasing based on the project of pit foundation for airport-station of Zhengzhou-airport line. A field experiment on uplift-pile is numerically studied and the relation between soil deformation modulus for Mohr-Coulomb model and depth is obtained through comparisons of modeling results and test data. The parameters of soil deformation modulus obtained are also adopted in the numerical modelling of support axial forces in the based project, the modeling results agree well with those monitored in field, which could be an efficient verification of the rationality of the method for obtaining soil deformation modulus. Therefore, the modeling results could provide valuable guidance for construction of the based project. Therefore, this method of obtaining soil deformation modulus through modeling of uplift-pile could be a useful reference for similar projects.