Investigation on the 3D Ground Settlement Induced by Shallow Tunneling Considering the Effects of Buildings

Abstract

Complex tunneling process will inevitably result in varying degrees of ground movements. Prediction of ground movements is an essential part of planning, design and construction of a tunneling project. To address the predicting difficulty of ground movement, a correction parameter is introduced to the traditional ground movement solution both under two-dimensional and three-dimensional conditions on basis of the principle of conservation of ground loss. And the surface settlement caused by radial contraction of tunnel under different buried depth and excavation length, and induced by the action of building are studied through a series of model experiments. The experimental results show that the settlement value of any point along the middle line of the tunnel, is only about 50% of the measured value, which verify the necessity for correcting the tradition solutions. In addition, the applicability of the modified solution for different buried depth of tunnel axis under two-dimensional and three-dimensional conditions is also verified. Considering the uneven load distribution in the underlying soil caused by building load, we also introduced a load correction parameter and compared the modified solutions with the elastic analysis solution and the Peck formula. The comparison indicates that the modified solutions of two dimensions and three dimensions are more consistent with the experimental results, especially for the 3D surface settlement solution with large excavation length. And according to the results, the modified solution is more suitable to analyzing the surface settlement under the action of building load than previous modification, which further confirms the correction solutions to be an improvement to a close-form solution for ground surface settlement.