Evaluating closely spaced twin-tunnelling-induced shear stiffness change by subsurface settlement in clayey ground
Evaluating closely spaced twin-tunnelling-induced shear stiffness change by subsurface settlement in clayey ground
复制标题
评估粘土地层中由地下沉降引起的紧密间隔双隧道剪切刚度变化
DOI：
10.1007/s12665-020-09087-z
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发表时间：
2020-06
影响因子：
2.8
通讯作者：
Cheng Hong-zhan
中科院分区：
文献类型：
--
作者：
Meng Fan-yan;Chen Ren-peng;Wu Huai-na;Cheng Hong-zhan
近距离双洞隧道的实例表明，第二隧道上方的地面沉降，被称为T2后，第一隧道（T1）建造，表现出显着的差异，从以上T1。这种差异可以归因于T1结构引起的干扰。基于卸载圆柱形空腔的闭合形式的塑性解，本研究采用地下沉降槽来确定双隧道掘进过程中的剪切模量变化。根据文献解释了在超固结高岭土中双隧道掘进的1 g模型试验的观测结果。T1施工后，对于不同径向距离但与隧道中心上方垂线成一定角度的位置，径向位移/隧道半径-隧道半径/径向距离曲线呈现良好的线性关系。进一步的分析表明，剪切刚度随着角度的增加而减小。相比之下，在T2施工期间，靠近T1的土壤的剪切模量降低，而另一侧增加。根据轴扭联合试验的观察，剪切模量的变化趋势可以归因于主应力轴的旋转。研究结果可以较好地解释近距离双洞隧道的不均匀沉降现象。
Cases of closely spaced twin tunnels demonstrate that ground settlement above the 2nd tunnel, referred to as T2 constructed after the first tunnel (T1), exhibits pronounced differences from that above T1. The differences can be attributed to the disturbance induced by T1 construction. Based upon closed-form plasticity solutions for an unloading cylindrical cavity, this study employs subsurface settlement troughs to determine the shear modulus change during twin-tunnelling. Observations of 1 g model tests for twin-tunnelling in overconsolidated kaolin clay are interpreted from literature. After T1 construction, for positions with different radial distances but a constant angle with respect to the vertical line above the tunnel center, the graph of radial displacement/tunnel radius versus tunnel radius/radial distance exhibits good linearity. Further analyses demonstrate that the shear stiffness decreases as the angle increases. In comparison, during T2 construction, the shear modulus of soils close to T1 degrades, while the other side increases. In light of the observations of combined axial–torsional tests, the tendency of shear modulus change can be attributed to the rotation of principal stress axes. The findings can explain the differential settlements over closely spaced twin tunnels in clayey ground.
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影响因子：
6.9
作者：
M. Mooney;J. Grasmick;B. Kenneally;Yong Fang
通讯作者：
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DOI：
10.1061/(asce)gt.1943-5606.0000887
发表时间：
2013-09
影响因子：
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DOI：
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发表时间：
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