Behavior of Ground and Response of Existing Foundation Due to Tunneling
Behavior of Ground and Response of Existing Foundation Due to Tunneling
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DOI：
10.3208/sandf.51.395
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发表时间：
2011-06
影响因子：
3.7
通讯作者：
H. Shahin;T. Nakai;Feng Zhang;M. Kikumoto;E. Nakahara
中科院分区：
文献类型：
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作者：
H. Shahin;T. Nakai;Feng Zhang;M. Kikumoto;E. Nakahara
摘要研制了一种模拟隧道开挖的实验装置。利用该装置进行了隧道开挖引起的地表沉降和土压力的二维模型试验。有限元分析，使用弹塑性次加载tij模型进行。通过模型试验和相应的数值分析，阐明了浅埋隧道开挖引起的体积损失对地表沉降和土压力的影响。结果表明，浅埋隧道周围地表沉降槽和土压力分布不仅与隧道体积损失有关，而且与隧道拱顶漂移有关。本文还论证了隧道与邻近既有基础相互作用的影响。对于既有基础，隧道开挖过程中建筑荷载控制地表沉降和变形区。隧道开挖过程中地基的变形机制决定了地基的性状。对桩筏基础中桩的诱导轴力和弯矩进行了数值研究，结果表明，桩筏基础中桩的轴力会因地基的应力松弛而发生变化。由于桩筏的不均匀沉降，在较低的土壤覆盖值下，桩中会产生弯矩。
ABSTRACT An apparatus has been developed to model the excavation of a tunnel in the laboratory. With this apparatus, 2D model tests are carried out to investigate the surface settlement and the earth pressure brought about by the tunneling. Finite element analyses using an elastoplastic subloading tij model are also conducted. The influence of volume loss on the surface settlement and the earth pressure, due to the shallow tunnelling, is illustrated based on the model tests and the corresponding numerical analyses. It is revealed that the surface settlement troughs and the earth pressure distributions around shallow tunnels depend on both the volume loss and the crown drift of the tunnel. The effect of the interaction between the tunneling and existing nearby foundations is also demonstrated in this paper. For existing foundations, the building loads control the surface settlements and the zone of deformation during the tunnel excavation. The behavior of the foundations depends on the deformation mechanism of the ground during the tunnel excavation. The induced axial force and bending moments in the piles of a piled raft are investigated numerically, and it is shown that the axial force changes due to the stress relaxation of the ground. Bending moments are induced in the piles at a lower value of soil cover due to the differential settlement of the piled raft.