双线平行地铁隧道盾构同向推进纵向安全间距研究

发布时间：2018-08-17 19:11

【摘要】：为加快双线地铁隧道施工,采用2台盾构机同时开挖,盾构横向间距不变情况下,纵向间距过近会加剧对土体的扰动,影响地表建(构)筑物安全。以武汉地铁三号线为工程背景,选取双线平行隧道盾构同向推进为研究对象,采用现场监测和数值模拟计算方法,综合分析盾构开挖时隧道横向、纵向地表变形特征,揭示双线平行隧道盾构同向推进时的纵向相互影响规律。结果表明:数值计算结果与现场监测数据相吻合;盾构通过后地表形成沉陷槽,隧道拱顶上方地表变形最大,距离隧道轴线越远,地表变形越小;开挖过程中盾首上方隆起值达到最大,盾构穿过后沉降迅速增加,最终趋于稳定;双线地铁隧道盾构同向推进中,盾构的二次扰动加剧了地表最终变形量,盾构纵向间距对地表最终变形量没有影响,随着盾构纵向间距增加,地表总体沉降速率减缓,当盾构纵向距离大于50m时较为安全可靠。研究成果旨在为今后的地铁隧道安全快速的施工提供依据。
[Abstract]:In order to speed up the construction of double-line subway tunnel, if two shield machines are used to excavate simultaneously and the horizontal spacing of shield is invariable, the disturbance to soil mass will be aggravated by the close longitudinal spacing, which will affect the safety of surface construction (construction). Taking Wuhan Metro Line No. 3 as the engineering background, this paper selects the double-line parallel tunnel shield construction as the research object, adopts the field monitoring and numerical simulation calculation method, synthetically analyzes the tunnel transverse and longitudinal surface deformation characteristics when the shield is excavated. The longitudinal interaction law of shield tunneling is revealed. The results show that the numerical results are in good agreement with the field monitoring data, the surface subsidence is formed after shield tunneling passes, the surface deformation above the tunnel arch is the biggest, the farther away from the tunnel axis, the smaller the surface deformation. During the excavation process, the uplift value of the shield head reaches the maximum, the settlement of the shield after passing through the shield increases rapidly, and eventually tends to stabilize; in the same direction of shield driving of the double-line subway tunnel, the secondary disturbance of the shield increases the final deformation of the surface. The longitudinal spacing of shield has no effect on the final deformation of the surface. With the increase of the longitudinal distance of shield, the total subsidence rate of the surface slows down, and it is more safe and reliable when the longitudinal distance of shield is more than 50 m. The purpose of the research is to provide the basis for the safe and fast construction of subway tunnel in the future.
【作者单位】：广东华路交通科技有限公司;中国地质大学(武汉)工程学院;
【基金】：国家自然科学基金项目(41372312) 武汉市“黄鹤英才(科技)计划”资助项目(2015055003)
【分类号】：U455.43;U231.3

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