小净距隧道围岩变形特征及施工方法优化

发布时间：2018-03-18 04:10

本文选题：铁路隧道　切入点：合理净距　出处：《铁道建筑》2017年03期 　论文类型：期刊论文

【摘要】：结合湖南省张家界市吴家边隧道工程实例,对隧道净距分别为隧道断面跨度的0.5,0.75,1.0,1.25,1.5倍的双线隧道施工过程进行三维数值分析。结果表明:台阶法和全断面法围岩位移变化曲线均近似呈M形,且随着隧道净距的减小,曲线愈显平滑;若采用台阶法施工,小净距隧道合理净距应取隧道断面跨度的1倍,如对中夹岩及时进行适当支护,间距取隧道断面跨度的0.75倍亦可行;若采用全断面法施工,合理净距应取隧道断面跨度的1.25倍;后行隧道竖向位移值略大于先行隧道,且随净距的增大,后行隧道对先行隧道的影响程度逐渐减弱。
[Abstract]:Combined with the example of Wujiabian Tunnel Project in Zhangjiajie City, Hunan Province, Three-dimensional numerical analysis was carried out on the construction process of double-line tunnel with a net distance of 0.5 / 0.75 / 1 / 1 / 1 / 1. 5 times of tunnel cross-section span respectively. The results show that the displacement variation curves of surrounding rock of step method and full section method are similar to M shape, and with the decrease of net distance of tunnel, the displacement change curve of surrounding rock is similar to M shape, and with the decrease of tunnel net distance, The curve is more smooth; if the step method is used, the reasonable net distance of the tunnel should be 1 times of the span of the tunnel section, if the middle rock is properly supported, the spacing can be taken 0.75 times of the span of the section of the tunnel; if the full section method is used, The reasonable net distance should be 1.25 times of the cross-section span of the tunnel, the vertical displacement of the backward tunnel is slightly larger than that of the advance tunnel, and the influence of the rear tunnel on the advance tunnel is gradually weakened with the increase of the net distance.
【作者单位】：中铁四局集团第一工程有限公司;
【基金】：国家自然科学基金(51509092)
【分类号】：U455.4

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