浅覆土地面出入式盾构开挖引起的土体变形预测

引用本文

魏纲, 黄文. 浅覆土地面出入式盾构开挖引起的土体变形预测[J]. 北京交通大学学报, 2019,43(3): 35-42.
WEI Gang, HUANG Wen. Prediction of soil deformation caused by excavation of ground enetrating shield tunnels under shallow covering[J]. JOURNAL OF BEIJING JIAOTONG UNIVERSITY, 2019,43(3): 35-42.
Doi:10.11860/j.issn.1673-0291.20180142 复制到剪切板

Permissions

北京交通大学学报编辑部所有

浅覆土地面出入式盾构开挖引起的土体变形预测

魏纲, 黄文

浙江大学城市学院工程学院,杭州 310015

通信作者:黄文(1997—),男,浙江温州人.email:1205381014@qq.com.

第一作者:魏纲(1977—),男,浙江杭州人,教授,博士.研究方向为地下隧道施工对周边环境影响及风险评估与控制.email:weig@zucc.edu.cn.

收稿日期: 2018-10-15

基金: 浙江省科技厅公益技术研究项目(2016C33051); 住房和城乡建设部2015年科学技术项目计划(2015-K5-026)

摘要

研究地面出入式盾构隧道施工引起的土体变形计算方法.建立隧道上浮至土体边界顶部的隧道开挖断面收敛模型,基于随机介质理论,推导出浅覆土地面出入式盾构隧道施工时由于土体损失引起的土体变形计算公式.通过实例对所提出的方法进行了验证,并研究了盾构轴线与水平面的夹角α不同对土体变形的影响.研究结果表明:采用本文方法得出的地表沉降预测结果与实测值及有限元模拟值吻合较好,土体水平变形预测结果与实测值基本吻合,证明了方法的可靠性;随着α增大,盾构上仰掘进时,由土体损失引起的纵向地表沉降呈减小趋势,而横向地表沉降曲线影响范围变大;盾构下探掘进时,纵向地表沉降呈增大趋势;本文方法适用于地面出入式盾构法施工中浅覆土段(≤0.5倍的盾构机外直径)的土体变形预测.

关键词: 地面出入式盾构; 土体变形; 随机介质理论; 浅覆土

中图分类号:U455.43 文献标志码:A 文章编号:1673-0291(2019)03-0035-08

Prediction of soil deformation caused by excavation of ground enetrating shield tunnels under shallow covering

WEI Gang, HUANG Wen

School of Engineering, Zhejiang University City College, Hangzhou 310015, China

Fund:Public Technology Project of Science Technology Department of Zhejiang Province (2016C33051); Science and Technology Project of Ministry of Housing and Urban-Rural Development of People’s Republic of China (2015-K5-026)

Abstract

The method to calculate the soil deformation during ground penetrating shield tunnelling is investigated in this paper. Convergence model of tunnel excavation section when tunnel floats on top of soil boundary is established. Based on stochastic medium theory, the ground loss-induced soil deformation formula during construction of ground penetrating shield tunnel is deduced. The results of the proposed method are demonstrated by an example. Besides, the influence of the angle, named α, which is between the shield axis and the horizontal plane on soil deformation is studied. The results show that the predicted surface settlement in this method is consistent with the actual measurements and the finite element simulation values. In addition, the predicted horizontal displacement in this method matches with the actual measurements mostly. As a result, the method is proved reliable. With the increase of α, the longitudinal ground loss-induced surface settlement decreases, and the influence range of the horizontal surface settlement curve widens when the shield is driving upwards. However, the longitudinal surface settlement tends to increase when the shield is driven downwards. The method can be applied to predict soil deformation in the shallow cover section (which means the cover is less than or equal to 0.5 times of outside diameter of the shield) in the construction of ground penetrating shield tunnels.

Keyword: ground penetrating shield; soil deformation; stochastic medium theory; shallow cover

文章图片

为适应地铁地上地下连接段的特殊工况, 新型的地面出入式盾构法产生^[1], 该方法是指盾构从地表始发, 在浅覆土条件下掘进, 最后在目标地点从地表到达.其采用盾构掘进代替过渡段明挖, 地面开挖面积可减小50%~80%, 搬拆迁和对周围环境的影响也可减少; 通过浅埋导坑代替工作井, 可减少开挖土方量, 避免出现施工事故, 缩短工期.由于地面出入式盾构法施工地层埋深较浅, 对覆土浅段土体的扰动较大, 存在引发邻近地下管线和建筑物破坏的隐患.故需对地面出入式盾构浅覆土段施工引起的土体变形进行研究.

地面出入式盾构的研究尚处于起步阶段, 目前主要采用数值模拟^{[2, 3, 4, 5, 6]}、模型试验^{[7, 8, 9, 10, 11, 12]}和解析解^{[13, 14, 15]}等方法对隧道土体扰动、稳定性控制和施工参数等方面进行研究.采用较多的是数值模拟和模型试验.在解析解研究方面, 文献[13]针对超浅埋地面出入式盾构, 考虑衬砌接头处的轴力和弯矩与抗弯刚度的非线性关系, 研究弯矩调整系数和抗弯刚度效率系数的取值; 文献[14]研究掘进坡度对盾构掘进引起的地面隆陷的影响, 得到考虑水平面存在一定坡度时简化的土体垂直变形计算公式; 文献[15]研究了隧道轴线埋深与隧道坡度之间的关系, 提出了仅考虑土体损失的地面出入式盾构竖向土体变形计算方法.文献[14, 15]虽然提出了地面出入式盾构土体变形计算方法, 但没有研究水平位移, 且计算公式考虑因素不全, 特别是没有考虑浅覆土工况下隧道存在上浮的影响, 这与实际覆土较浅时的地面出入式盾构法工况有差异.

本文作者考虑土体损失, 考虑盾构轴线与水平面夹角 $α$ 变化, 以及浅覆土效应即同步注浆后盾构隧道上浮的影响, 基于新建的土体收敛模型, 结合随机介质理论, 得到地面出入式盾构软土地层施工引起土体变形计算方法, 通过实例计算得到的理论值与实测值和有限元模拟值进行比较, 验证本文方法的可靠性.并分析当地面出入式盾构上仰和下探掘进时, $α$ 角度改变对土体变形的影响.

1 计算方法

1.1 计算模型

针对地面出入式盾构法单线施工进行研究, 研究0~0.5D(D为盾构机外直径)覆土的浅覆土、超浅覆土及零覆土工况.考虑到盾构施工中土体损失是主要影响因素, 其他因素主要在开挖面附近有影响.本文在计算时仅考虑土体损失引起的土体变形, 不考虑其他影响因素.理论计算模型示意图见图1, 图中x为离开挖面的水平距离, 掘进为正; y为离轴线的横向水平距离; z为离地面的竖向距离, 向下为正; α 为盾构轴线与水平面的夹角(上仰为正值, 下探为负值).

	Figure Option View Download New Window
	图1 理论计算模型示意图Fig.1 Schematic diagram of theoretical calculation model

针对现有方法不足, 作以下改进:

1)在盾构上仰掘进或下探掘进时, 考虑盾构推进方向与水平面有一定夹角α , 并研究α 角度改变对土体变形规律的影响;

2)考虑覆土较浅时盾构隧道上浮的影响, 提出新的土体收敛模型, 并采用随机介质理论推导出土体变形计算公式;

3)对浅覆土、超浅覆土及零覆土工况下, 实测数据及有限元模拟数据进行验证分析, 验证新建模型及本文方法的可靠性.

传统随机介质理论^[16]在计算土体损失引起地面各点变形时, 土体变形采用等量(均匀)径向移动模式, 如图2(a)所示, 图中 $R$ 为盾构机外半径, $g$ 为等效土体损失参数.改进后的随机介质理论方法^[17]在计算土体损失引起地面各点变形时, 考虑实际隧道周围土体产生的是非等量径向移动, 土体变形采用隧道落到土体边界底部的移动模式, 见图2(b).

	Figure Option View Download New Window
	图2 开挖断面收敛模型Fig.2 Convergence modes of tunnel excavation

图2中的2种模型均没有考虑浅覆土的工况.当隧道上覆土较浅时, 上覆土对盾构隧道向下的压力比正常工况要小很多, 导致地面出入式盾构法隧道施工同步注浆后所产生的浮力不可忽略^{[2, 3, 8, 14]}, 上述2种模型不适用本文研究对象的土体变形计算.

借鉴文献[18]中叠加的各影响因素, 得出新的隧道开挖断面收敛模型的方法, 建立隧道上浮至土体边界顶部的隧道开挖断面收敛模型, 见图3(a).建模依据为:隧道刚开挖时, 开挖断面土体产生等量(均匀)径向收敛, 如图3(b)所示; 隧道开挖后, 由于盾构隧道自重, 隧道下沉, 土体的收敛区域主要集中于隧道上方, 如图3(c)所示; 由于隧道上覆土较浅, 上覆土对盾构隧道向下的压力比正常工况要小很多, 小于地面出入式盾构法隧道施工同步注浆后所产生的浮力, 导致隧道上浮, 隧道上方土体的收敛区域变小, 如图3(d)所示; 实际地面出入式盾构法隧道施工的开挖断面收敛模式, 介于图2(b)和图3(a)之间, 最终取决于图3(b)、图3(c)、图3(d)哪个影响更大, 相互作用后得出实际模型.

	Figure Option View Download New Window
	图3 地面出入式盾构开挖断面收敛模式Fig.3 Convergence modes of ground penetrating shield excavation section

对相关文献进行整理发现:冷建等^[3]基于数值模拟法研究了地面堆载对隧道上浮的影响, 发现工况为 $0.5 R$ 覆土, 无堆载时, 隧道上浮量达到3.74 cm.说明图3(d)的作用影响比较大; 赵辛玮等^[4]通过三维有限元模拟及实测数据分析发现, 原本扰动较大、地表沉降比较明显的浅覆段, 如 $0.5 R$ 覆土工况下, 实测地表沉降不大, 最大值小于6 mm; 滕丽^[6]整理了南京机场线工程的监测数据, 分析覆土为浅、超浅和负时的沉降规律, 发现位于超浅覆土区, 覆土 $0.3 R$ 工况下的分层沉降规律中, 隧道顶部的土体分层沉降只有8 mm, 而中部的土体沉降达到了28 mm, 该工况的土体分层沉降分布规律与图3(a)的土体开挖断面收敛模式比较吻合.

综上, 在浅覆土段考虑图3(b)、图3(c)、图3(d)相互作用时, 图3(d)起到主要作用, 由于隧道上浮是施工中的不利因素, 故根据文献[19]实际工程中的管片上浮量, 本文选取的隧道上浮量为小于15 mm, 采用图3(a)的土体开挖断面收敛模式进行计算.

1.2 理论解计算公式

20世纪50年代, Litwiniszyn^[20]提出随机介质理论, 阳军生等^{[21, 22]}进行了深入研究.该理论从概率统计理论出发, 把整个开挖分解成无限多个微元开挖的总和.因此, 隧道开挖对地表的影响也可以等效为构成这一开挖的许多无限小微元开挖的影响总和.该方法假定:土体不排水、不固结、密度不变化, 开挖引起的岩土体变形为一个不可压缩的过程, 即沉降槽体积等于土体损失体积.该理论适用于22种收敛模型^[17]的积分计算, 同样适用于地面出入式盾构隧道的土体变形计算.

开挖单元示意图见图4, 对应全局坐标 $(x, y, z),$ 在开挖掘进时采用局部坐标 $(ξ, ζ, η),$ 开挖单元被定为 $d ξ, d ζ, d η,$ 对图3(a)进行积分计算.通过积分, 推导出地面出入式盾构隧道施工引起的 $x, y, z$ 三个方向的土体变形计算公式.由于本文收敛模型不同于传统的收敛模型, 故变形计算公式会与传统的收敛模式有区别.

	Figure Option View Download New Window
	图4 开挖单元示意图Fig.4 Schematic diagram of excavation unit

沿隧道掘进方向(纵向)的土体水平变形为

$\begin{array}{l} W_{X} (x, y, z) = \int_{b}^{a} \int_{d}^{c} \int_{-}^{\infty} \frac{(x - ξ) ta n^{2} β}{{(η - z)}^{3}} \times \\ \exp \{- \frac{πta n^{2} β}{{(η - z)}^{2}} [{(x - ξ)}^{2} + {(y - ζ)}^{2}]\} d ξ d ζ d η - \\ \int_{e}^{f} \int_{t}^{u} \int_{-}^{\infty} \frac{(x - ξ) ta n^{2} β}{{(η - z)}^{3}} \times \\ \exp \{- \frac{πta n^{2} β}{{(η - z)}^{2}} [{(x - ξ)}^{2} + {(y - ζ)}^{2}]\} d ξ d ζ d η \end{array}$ (1)

与隧道垂向(横向)的土体水平变形为

$\begin{array}{l} W_{Y} (x, y, z) = \int_{b}^{a} \int_{d}^{c} \int_{-}^{\infty} \frac{(y - ζ) ta n^{2} β}{{(η - z)}^{3}} \times \\ \exp \{- \frac{πta n^{2} β}{{(η - z)}^{2}} [{(x - ξ)}^{2} + {(y - ζ)}^{2}]\} d ξ d ζ d η - \\ \int_{e}^{f} \int_{t}^{u} \int_{\infty}^{0} \frac{(y - ζ) ta n^{2} β}{{(η - z)}^{3}} \times \\ \exp \{- \frac{πta n^{2} β}{{(η - z)}^{2}} [{(x - ξ)}^{2} + {(y - ζ)}^{2}]\} d ξ d ζ d η \end{array}$ (2)

土体竖向变形为

$\begin{array}{l} W_{Z} (x, y, z) = \int_{b}^{a} \int_{d}^{c} \int_{-}^{\infty} \frac{ta n^{2} β}{{(η - z)}^{2}} \times \\ \exp \{- \frac{πta n^{2} β}{{(η - z)}^{2}} [{(x - ξ)}^{2} + {(y - ζ)}^{2}]\} d ξ d ζ d η - \\ \int_{e}^{f} \int_{t}^{u} \int_{-}^{\infty} \frac{ta n^{2} β}{{(η - z)}^{2}} \times \\ \exp \{- \frac{πta n^{2} β}{{(η - z)}^{2}} [{(x - ξ)}^{2} + {(y - ζ)}^{2}]\} d ξ d ζ d η \end{array}$ (3)

式中:β 为隧道周边土层的主要影响角; H为盾构隧道轴线埋深; 三重积分上下限分别为

$a = H + R, b = e = H - R,$

$c = \sqrt[]{R^{2} - {(H - η)}^{2}}$

$d = - \sqrt[]{R^{2} - {(H - η)}^{2}}, f = H + R - g,$

$u = \sqrt[]{{(R - g / 2)}^{2} - {(H - g / 2 - η)}^{2}},$

$t = - \sqrt[]{{(R - \frac{g}{2})}^{2} - {(H - \frac{g}{2} - η)}^{2}} .$

本文方法适用于地面出入式盾构法施工中浅覆土段(覆土≤ 0.5倍盾构外机直径)的土体变形预测.

1.3 计算参数取值

1) $\tan β$ 参数选择^[17].

$\tan β = \frac{H - z}{kH {(1 - z / H)}^{0.3} \sqrt[]{2 π}}$ (4)

式中: $k$ 为地表沉降槽宽度参数.

盾构隧道轴线埋深为

$H = h - x \tan α$ (5)

式中: $h$ 为初始隧道轴线埋深.

联立式(4)和式(5)得到

$\begin{array}{l} \tan β = \\ \frac{h - x \tan α - z}{k (h - x \tan α) {[1 - z / h - x \tan α)]}^{0.3} \sqrt[]{2 π}} \end{array}$ (6)

2) $g$ 参数取值^[23].

$g = 2 R (1 - \sqrt[]{1 - ε})$ (7)

式中: $ε$ 为最大土体损失率.

利用Matlab编程, 可将式(1)~式(3)用于工程实践中, 将土体变形预测结果应用于施工控制优化, 主要流程为:

1)核对工程已知参数, 如盾构几何参数、覆土厚度、盾构轴线与水平面的夹角、土质参数、隧道设计参数等;

2)初步确定计算参数, 例如预测的土体损失率等, 将计算参数输入到Matlab程序中, 计算得到土体变形的预测值;

3)根据土体变形预测值的大小指导现场施工, 控制土体变形.同时, 对施工现场的土体变形进行监测, 得到土体变形的实测值;

4)比较实测值与预测值的大小, 若两者相差不大, 则不作调整; 若实测值较大或较小, 说明对土体损失率的预测偏小或偏大, 应调整相应的计算参数, 重新按照以上流程计算预测值.

2 工程实例验证

由于地面出入式盾构的研究和应用尚处于起步阶段, 目前国内仅有南京机场线秣陵站至将军路站区间的地面出入段工程^[19], 采用单线地面出入式盾构法施工, 工程盾构直径 $R$ =6.2 m, 本文以该工程为背景, 分别对土体竖向变形、沿纵向的土体水平变形及沿横向的土体水平变形进行研究.

2.1 第60环测点

第60环隧道测点的顶部覆土层厚度为 $0.5 R$ =3.1 m.计算参数取值: $h$ =6.2 m, $ε$ =0.096%, 由于本文工况土质均为黏土, 故 $k$ =0.5^[23], $α$ =-2.6° . $ε$ 取值是根据经验及利用Peck公式与实测值拟合得到.

图5为计算得到的第60环测点纵向地表沉降曲线.可见, 盾构下探掘进时, 土体损失主要引起地表沉降, 且集中在开挖面后方, 大约在开挖面后方25 m处沉降值最大(沉降值4.2 mm).本文计算结果与文献[6]有限元模拟计算结果及实测结果吻合较好, 验证了本文方法的可靠性.在开挖面后方30 m附近实测沉降值有明显减小趋势, 由于本文方法没有考虑盾壳摩擦力和附加注浆压力, 与实测数据有一定偏差.

	Figure Option View Download New Window
	图5 第60环测点纵向地表沉降曲线Fig.5 Longitudinal surface subsidence curves of the 60th ring measuring point

图6为 $y$ 分别取0、2、4 m时, 在开挖面后方5 m处计算得到的第60环土体分层沉降曲线, 当 $y$ 分别取0、2 m时仅对盾构隧道顶部上方土体进行计算.可见, 当 $y$ =0 m时, 隧道轴线正上方土体沉降随着垂直深度 $z$ 的变大而变大, 但接近盾构顶部, 即 $z$ =3 m时, 该位置处的沉降又逐渐变小, 这是由于接近盾构顶部的土层受到隧道上浮带来的向上的挤压, 使该位置附近土体沉降影响减小, 沉降值变小, 这与本文考虑隧道上浮的影响而建立的模型相符.当 $y$ =2 m时, 上方土体沉降随着 $z$ 变大而缓慢变大, 但是在隧道顶部以下沉降迅速变大, 这与文献[6]得到的土体分层沉降分布规律相似.当 $y$ =4 m时, 位于盾构一侧, 土体沉降值相对较小, $z$ 从0 m到4.5 m, 沉降值逐渐变小, $z$ 从4.5 m到5.5 m, 沉降值逐渐变大而后又逐渐变小.由于距离隧道轴线较远, 故土体受到的扰动较小, $y$ =4 m时整体沉降值相对于 $y$ =0、2 m时较小, 曲线整体先变小是由于对于半径为3.1 m的盾构机, $y$ =4 m时, 随着垂直深度变大土体和盾构隧道的位置越来越趋近于平行, 故土体沉降会随着垂直深度变大逐渐变小.而后出现一小段变大, 因为接近盾构隧道的中部时, 中下部由于上浮引起的空隙使中部土往下填充, 故出现了一小段土体沉降变大.再往下由于垂直深度较深, 土体扰动越来越小, 土体沉降逐渐变小.

	Figure Option View Download New Window
	图6 第60环测点土体分层沉降曲线Fig.6 Soil stratified sedimentation curves of the 60th ring measuring point

图7为 $z$ 分别取0、1、2、3 m时, 在开挖面后方5 m处计算得到的第60环横向土体分层沉降曲线.可见, 盾构下探掘进时, 随着 $z$ 增大, 横向地表沉降影响范围基本不变; $z$ 从0 m增加到2 m, 土体最大沉降值变大.但是当 $z$ =3 m时(盾构顶部处), 最大沉降值比 $z$ =2 m时减小了, 这是由于隧道上浮, 位于隧道顶部附近土体沉降值变小, 这与图6规律一致.

	Figure Option View Download New Window
	图7 第60环测点横向土体分层沉降曲线Fig.7 Horizontal soil stratified sedimentation curves of the 60th ring measuring point

2.2 第40环测点

第40环隧道测点覆土层厚度为0.3 $R$ =1.86 m.参数取值: $h$ =4.96 m, $ε$ =0.105%, $k$ =0.5, $α$ =-1.2° .计算得第40环测点纵向地表沉降曲线, 见图8.可见, 图8曲线的规律与图5类似.在开挖面后方约10 m处沉降值最大.本文计算结果与文献[4]有限元模拟结果在开挖面后方35 m后规律有所差异, 这是施工工艺的差异造成的, 实测数据中开挖面后方35 m(大约12环的位置)处于刚开始推进阶段, 地表沉降控制相对较差, 沉降值稍大.

	Figure Option View Download New Window
	图8 第40环测点纵向地表沉降曲线Fig.8 Longitudinal surface subsidence curves of the 40th ring measuring point

2.3 第33环测点

第33环隧道测点的覆土层厚度为 $0.3 R$ =1.86 m.计算参数取 $h$ =4.96 m, $ε$ =0.107%, $k = 0.5, α$ =-1.2° .

计算得到第33环测点横向地表沉降曲线, 见图9.可见, 计算结果与文献[4]有限元模拟值及实测数据吻合较好, 本文方法计算得到的理论最大沉降值为4.66 mm, 有限元模拟得出的最大沉降值为4.29 mm, 实测的最大沉降值为4.69 mm, 本文方法得出的理论最大沉降值更加接近实测最大沉降值, 故认为本文方法沉降段曲线比有限元模拟值更接近实测, 表明本文方法具有可靠性.横向地表沉降影响范围在距隧道轴线两侧8 m左右, 最大沉降值在5 mm左右.实测和有限元模拟在距隧道轴线8 m左右的位置均出现了微小的隆起.由于本文方法仅考虑土体损失, 故计算结果没有出现地表隆起, 有些偏差.

	Figure Option View Download New Window
	图9 第33环测点横向地表沉降曲线Fig.9 Horizontal surface subsidence curves of the 33rd ring measuring point

2.4 第22环测点

第22环隧道测点的覆土层厚度为0.计算参数取值: $h$ =3.1 m, $R$ =6.2 m, $ε$ =0.14%, $k = 0.5,$ α =-1.2° .覆土为0处计算的地表沉降是隧道顶部位置的沉降.

计算得第22环测点横向地表沉降曲线见图10.可见:图10曲线的规律与图9类似.该测点横向地表沉降影响范围在距隧道轴线两侧8 m左右, 最大沉降值在4 mm左右, 比图9(0.3R)的最大沉降值略小.相对于有限元模拟结果, 当覆土为0时, 本文计算结果与实测数据更加吻合.覆土为0是指隧道顶部位置无土体.但由于隧道下方有土体损失, 导致隧道下沉, 从而引起地表沉降.

	Figure Option View Download New Window
	图10 第22环测点横向地表沉降曲线Fig.10 Horizontal surface subsidence curves of the 22nd ring measuring point

2.5 第65环测点

第65环隧道测点的覆土层厚度为 $0.5 R$ =3.1 m.计算参数取值: $h$ =6.2 m, $ε$ =0.35%, $k = 0.5, α$ =-2.6° .

在开挖面后方5 m处, 计算得到第65环测点沿纵向的土体水平变形曲线, 见图11, 图中数据正值代表沿着掘进方向的移动.可见, 计算结果与文献[19]的实测数据规律相似, 实测数据基本分布在理论值的两侧, 验证了本文方法的可靠性.沿纵向的土体水平变形为负值, 即向着盾尾方向移动, 这是土体损失造成的.实际工程中最大变形值控制的比较好, 最大值小于3 mm.

	Figure Option View Download New Window
	图11 第65环测点沿纵向的土体水平变形曲线Fig.11 Horizontal deformation curves along the longitudinal soil of the 65th ring measuring point

在距隧道轴线右侧5 m、开挖面后方25 m处, 计算得第65环测点横向土体水平变形曲线, 见图12, 数据正值代表远离隧道轴线的移动.可见, 计算值与文献[19]的实测值基本吻合, 证明了本文方法的可靠性.在4 m深度附近, 土体水平变形方向发生变化, 在0~4 m土体向外侧的移动, 4 m以下则朝向隧道侧移动, 由于考虑隧道上浮影响时, 隧道上半部受到挤压, 产生水平变形以向外为主, 隧道下半部由于上浮, 更多土体往隧道轴线内侧填充, 产生的水平变形以向内为主; 实测变形值的范围在-4 mm到3 mm.

	Figure Option View Download New Window
	图12 第65环测点沿横向的土体水平变形曲线Fig.12 Horizontal deformation curves along the lateral soil of the 65th ring measuring point

3 α 角度变化的影响分析

3.1 上仰掘进

覆土条件同第60环隧道测点, 计算参数取值:h=6.2 m, $ε$ =0.1%, $k$ =0.5.

图13为 $α$ 分别取0.6° 、2.6° 、4.6° 、6.6° 时, 轴线上方纵向地表沉降曲线.可见, 盾构上仰掘进时, 土体损失主要引起地表沉降, 且集中在开挖面后方, 在开挖面后方5 m左右位置出现最大沉降值.随着 $α$ 增大, 开挖面后方的隧道埋深变大, 其对地表沉降的影响在相同土体损失率下会变小, 故地表沉降曲线呈逐渐上移趋势, 开挖面前方则变化很小.

	Figure Option View Download New Window
	图13 上仰掘进时不同α 角取值下纵向地表沉降曲线Fig.13 Longitudinal surface subsidence curves under different values of α when the shield is driven upwards

图14为α分别取0.6° 、2.6° 、4.6° 、6.6° 时, 在开挖面后方40 m处, 横向地表沉降曲线.如图14所示, 盾构上仰掘进时, 随着α 增大, 横向地表沉降影响范围变大.最大沉降值则变小, 这是由于α 越大, 该处的隧道埋深越大, 其对地表沉降的影响在相同土体损失率下越小, 地表沉降曲线变化趋势则逐渐变缓.

	Figure Option View Download New Window
	图14 上仰掘进时不同α 角取值下横向地表沉降曲线Fig.14 Horizontal surface subsidence curves under different values of α when the shield is driven upwards

3.2 下探掘进

计算参数取值:除了 $α$ 取不同值, 其他参数取值同3.1节.

图15为 $α$ 分别取-0.6° 、-1.6° 、-2.6° 时, 计算得到的轴线上方纵向地表沉降曲线.可见, 盾构下探掘进时, 土体损失主要引起地表沉降, 且集中在开挖面后方.随着 $α$ 增大, 开挖面后方隧道的埋深变小, 其对地表沉降的影响在相同土体损失率下会变大, 故地表沉降曲线呈逐渐下移趋势, 开挖面前方则变化很小.

	Figure Option View Download New Window
	图15 下探掘进时不同α 角取值下纵向地表沉降曲线Fig.15 Longitudinal surface subsidence curves under different values of α when the shield is driven downwards

4 结论

1)本文方法适用于0~0.5R厚度的浅覆土及超浅覆土工况.研究隧道周围土体产生的非等量径向移动时, 考虑土体损失, 盾构轴线与水平面夹角α , 以及隧道上浮影响引起的土体变形; 土体变形计算方法采用隧道上浮至土体边界顶部的隧道开挖断面收敛模型结合随机介质理论得到.

2)实际工程案例分析表明:本文方法计算得到的沉降结果与有限元模拟结果和实测数据吻合较好, 土体水平变形计算值与实测值基本吻合, 土体分层沉降规律与理论分析结果相符, 说明本文方法具有可靠性.

3)盾构上仰掘进时, 随着α增大, 纵向地表沉降曲线呈逐渐上移趋势, 开挖面前方变化很小, 横向地表沉降曲线沉降影响范围变大; 盾构下探掘进时, 随着α增大, 纵向地表沉降曲线呈逐渐下移趋势.

4)在研究中作了一些简化, 可在此基础上研究更多施工因素, 如正面附加推力、盾壳摩擦力、附加注浆压力、地层加固等对土体变形的影响; 可建立针对全覆土和收敛模式变化的统一收敛模型; 同时, 可进一步研究不同土体加固控制措施对土体变形的影响.

参考文献

文献列表

[1]	隋涛. 浅覆土下盾构快速穿越法——URUP法[J]. 现代隧道技术, 2012, 49(6): 43-48. SUI Tao. The rapid driving techniques of a shield machine under a section with shallow overburden: URUP method[J]. Modern Tunnelling Technology, 2012, 49(6): 43-48. (in Chinese) [本文引用:1]
[2]	吴惠明, 滕丽, 于亚磊, 等. 地面出入式盾构隧道稳定性控制措施有效性研究[J]. 现代隧道技术, 2014, 51(5): 61-65. WU Huiming, TENG Li, YU Yalei, et al. Analysis of the stability control measures for a ground-penetrating shield tunnel[J]. Modern Tunnelling Technology, 2014, 51(5): 61-65. (in Chinese) [本文引用:2]
[3]	冷建, 叶冠林, 吴惠明, 等. 地面堆载对地面出入式盾构隧道上浮影响规律分析[J]. 现代隧道技术, 2014, 51(增1): 295-299. LENG Jian, YE Guanlin, WU Huiming, et al. Influence of surface loading on floating of ground penetrating shield tunnel[J]. Modern Tunnelling Technology, 2014, 51(S1): 295-299. (in Chinese) [本文引用:3]
[4]	赵辛玮, 马永其, 滕丽. 盾构快速穿越法超浅覆土及负覆土隧道施工预测分析[J]. 上海大学学报(自然科学版), 2015, 21(4): 454-466. ZHAO Xinwei, MA Yongqi, TENG Li. Predictive analysis on shield tunnel using ultra-rapid under pass method[J]. Journal of Shanghai University (Natural Science), 2015, 21(4): 454-466. (in Chinese) [本文引用:4]
[5]	张旭, 叶冠林, 吴惠明, 等. 地面出入式盾构隧道受力变形特性数值分析[J]. 地下空间与工程学报, 2016, 12(2): 436-441. ZHANG Xu, YE Guanlin, WU Huiming, et al. Numerical study on deformation characteristics of ground penetrating shield tunnel[J]. Chinese Journal of Underground Space and Engineering, 2016, 12(2): 436-441. (in Chinese) [本文引用:1]
[6]	滕丽. (GPST)施工变形监测与分析研究[J]. 中国市政工程, 2016(3): 100-103. TENG Li. Monitoring and analysis of construction deformation of ground penetrating shield technology (GPST)[J]. China Municipal Engineering, 2016(3): 100-103. (in Chinese) [本文引用:4]
[7]	OLDENHAVE A H. Starting a large diameter TBM from surface[D]. Delft: Technical University of Delft, 2014. [本文引用:1]
[8]	张子新, 胡文, 刘超, 等. 地面出入式盾构法隧道新技术大型模型试验与工程应用研究[J]. 岩石力学与工程学报, 2013, 32(11): 2161-2169. ZHANG Zixin, HU Wen, LIU Chao, et al. Investigation of ground pass shield tunnelling method based on large-scale model test and its engineering application[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(11): 2161-2169. (in Chinese) [本文引用:2]
[9]	吴惠明, 黄俊, 张冠军, 等. 地面出入式盾构法隧道同步注浆工艺模拟试验[J]. 中国市政工程, 2013(6): 80-82. WU Huiming, HUANG Jun, ZHANG Guanjun, et al. Simulation test of tunnel synchronous grouting process by ground penetrating shield technology (GPST)[J]. China Municipal Engineering, 2013(6): 80-82. (in Chinese) [本文引用:1]
[10]	易路. 地面出入式盾构法隧道施工同步注浆工程应用分析[J]. 低碳世界, 2017(22): 238-239. YI Lu. Investigation of ground pass shield tunnelling method based on engineering application of synchronous grouting technology on tunnel construction[J]. Low Carbon World, 2017(22): 238-239. (in Chinese) [本文引用:1]
[11]	高昂, 张孟喜, 蒋华钦, 等. 地面出入式盾构法隧道施工同步注浆工程应用研究[J]. 岩石力学与工程学报, 2016, 35(9): 1871-1883. GAO Ang, ZHANG Mengxi, JIANG Huaqin, et al. Engineering application of synchronous grouting technology on tunnel construction by ground pass shield tunneling method[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(9): 1871-1883. (in Chinese) [本文引用:1]
[12]	BEIJER A J. The adaptation of the URUP method for the netherland s[D]. Delft: Technical University of Delft, 2010. [本文引用:1]
[13]	张银屏. 地面出入式盾构隧道修正惯用法计算参数研究[J]. 隧道建设, 2014, 34(2): 101-106. ZHANG Yinping. Study on ground penetrating shield-bored tunnel calculation parameters in modified routine method[J]. Tunnel Construction, 2014, 34(2): 101-106. (in Chinese) [本文引用:2]
[14]	林存刚, 刘干斌, 梁荣柱, 等. 隧道坡度对盾构掘进引起地面隆陷的影响[J]. 岩土工程学报, 2014, 36(7): 1203-1212. LIN Cungang, LIU Ganbin, LIANG Rongzhu, et al. Influences of tunnel slope on shield tunnelling-induced heave and subsidence of ground surface[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7): 1203-1212. (in Chinese) [本文引用:4]
[15]	魏纲, 黄文, 姜鑫. 地面出入式盾构开挖对邻近地下管线的影响分析[J]. 铁道科学与工程学报, 2017, 14(9): 1934-1941. WEI Gang, HUANG Wen, JIANG Xin. Analysis of influence of ground penetrating shield tunnel excavation on adjacent underground pipeline[J]. Journal of Railway Science and Engineering, 2017, 14(9): 1934-1941. (in Chinese) [本文引用:3]
[16]	LOGANATHAN N, POULOS H G. Analytical prediction for tunneling-induced ground movement in clays[J]. Journal of Geotechnical and Geoenviromental Engineering, 1998, 124(9): 846-856. [本文引用:1]
[17]	齐静静, 徐日庆, 魏纲. 盾构施工引起土体三维变形的计算方法研究[J]. 岩土力学, 2009, 30(8): 2442-2446. QI Jingjing, XU Riqing, WEI Gang. Research on calculation method of soil 3D displacement due to tunnel construction by shield[J]. Rock and Soil Mechanics, 2009, 30(8): 2442-2446. (in Chinese) [本文引用:3]
[18]	GONZA L C, SAGASETA C. Patterns of soil deformations around tunnels. Application to the extension of Madrid metro[J]. Computers and Geotechnics, 2001, 28(6): 445-468. [本文引用:1]
[19]	吴惠明. 地面出入式盾构隧道结构变形特性及控制研究[D]. 上海: 上海大学, 2014. WU Huiming. Study on characteristic analyse and controlling technogy of structure deformation in GPST[D]. Shanghai: Shanghai University, 2014. (in Chinese) [本文引用:4]
[20]	LITWINISZYN J. The theories and model research of movements of ground masses[C]//Proceedings of the European Congress on Ground Movement. Leeds, 1957: 206-209. [本文引用:1]
[21]	阳军生, 刘宝琛. 挤压式盾构隧道施工引起的地表移动及变形[J]. 岩土力学, 1998, 19(3): 10-13. YANG Junsheng, LIU Baochen. Ground surface movement and deformation due to tunnel construction by squeezing shield[J]. Rock and Soil Mechanics, 1998, 19(3): 10-13. (in Chinese) [本文引用:1]
[22]	阳军生, 刘宝琛. 城市隧道施工引起的地表移动及变形[M]. 北京: 中国铁道出版社, 2002. YANG Junsheng, LIU Baochen. Ground movement and deformation induced by urban tunnel construction[M]. Beijing: China Railway Publishing House, 2002. (in Chinese) [本文引用:1]
[23]	韩煊. 隧道施工引起地层位移及建筑物变形预测的实用方法研究[D]. 西安: 西安理工大学, 2006. HAN Xuan. The analysis and prediction of tunnelling-induced building deformations[D]. Xi’an: Xi’an University of Technology, 2006. (in Chinese) [本文引用:2]

2012

0.0

隋涛. 浅覆土下盾构快速穿越法——URUP法[J]. 现代隧道技术, 2012, 49(6): 43-48.

SUI

Tao

. The rapid driving techniques of a shield machine under a section with shallow overburden: URUP method[J]. Modern Tunnelling Technology, 2012, 49(6): 43-48. (in Chinese)

The rapid driving techniques of a shield machine under a section with shallow overburden, i.e. URUP, is generally used for building underground passageways at crossroads and interchanges, and it is characterized by a short construction period and less impact on the environment and existing architectural structures compared to the conventional shield method. In this paper, the technical features, key steps, shield sections and an application case of this method are introduced in detail.

Shanghai Municipal Engineering Design Institute (Group) Co., Ltd (Design Institute 3)

浅覆土下盾构快速穿越法——URUP法是针对在地面交通十字路口、地面立交路口处建立地下穿越通道而提出的一种施工方法，该方法与传统盾构地下穿越法相比，具有施工周期短、对周围环境和既有建筑结构影响小等优点。鉴于此，文章对该施工工法关键技术、盾构断面，以及应用实例进行了较为详细的论述。

... 为适应地铁地上地下连接段的特殊工况,新型的地面出入式盾构法产生^[1],该方法是指盾构从地表始发,在浅覆土条件下掘进,最后在目标地点从地表到达 ...

2014

0.0

吴惠明, 滕丽, 于亚磊, 等. 地面出入式盾构隧道稳定性控制措施有效性研究[J]. 现代隧道技术, 2014, 51(5): 61-65.

Huiming

, TENG

, YU

Yalei

, et al. Analysis of the stability control measures for a ground-penetrating shield tunnel[J]. Modern Tunnelling Technology, 2014, 51(5): 61-65. (in Chinese)

Based on the Nanjing ground-penetrating shield tunnel project, the finite-element simulation method is adopted to simulate the whole construction process of the ground-penetrating shield. An internal counterweight and surface loading are imposed on the model to analyze their effectiveness at controlling floating and improving stability of the tunnel. The results show that the internal counterweight can significantly improve the stability of the tunnel, while surface loading can reduce tunnel floating to some extent without obvious effects. According to in-situ conditions, the best way to realize the optimum stability of the tunnel is the combination of an internal counterweight and surface loading.

(1 Shanghai University, Shanghai 200072; 2 Shanghai Tunneling Enginnering Co. Ltd.,Shanghai 200082; 3 Shanghai Underground Space Architecture Design & Research Institute, Shanghai 200032; 4 Department of Civil Engineering, Shanghai JiaoTong University, Shanghai 200240)

文章以南京地面出入式盾构工程为背景，采用三维有限元模拟了地面出入式盾构隧道的整个施工过程，通过在模型中施加隧道内部压重与地表堆载，研究了两者对控制隧道上浮量、提高隧道稳定性的有效性。分析计算结果与现场监测数据表明：内部压重能够明显地提高隧道的稳定性，且效果比较明显；地表堆载也能在一定程度上减小隧道的上浮量，但其效果没有内部压重明显；施工中应结合现场实际条件，综合采用两者来实现最佳的稳定隧道效果。

... 地面出入式盾构的研究尚处于起步阶段,目前主要采用数值模拟^[2,3,4,5,6]、模型试验^{[7,8,9,10,11,12]}和解析解^[13,14,15]等方法对隧道土体扰动、稳定性控制和施工参数等方面进行研究 ...

... 当隧道上覆土较浅时,上覆土对盾构隧道向下的压力比正常工况要小很多,导致地面出入式盾构法隧道施工同步注浆后所产生的浮力不可忽略^{[2,3, 8, 14]},上述2种模型不适用本文研究对象的土体变形计算 ...

2014

0.0

... 对相关文献进行整理发现:冷建等^[3]基于数值模拟法研究了地面堆载对隧道上浮的影响,发现工况为 0 ...

2015

0.0

赵辛玮, 马永其, 滕丽. 盾构快速穿越法超浅覆土及负覆土隧道施工预测分析[J]. 上海大学学报(自然科学版), 2015, 21(4): 454-466.

ZHAO

Xinwei

, MA

Yongqi

, TENG

. Predictive analysis on shield tunnel using ultra-rapid under pass method[J]. Journal of Shanghai University (Natural Science), 2015, 21(4): 454-466. (in Chinese)

Ultra-rapid under pass (URUP) is a new shield construction method. The shield machine directly excavate from surface of the beginning section to the surface of the target location. Based on the demonstration project of Nanjing shield tunnel using the URUP method, the whole shield construction process is simulated with a three dimensional nonlinear finite element method (FEM). The ground surface subsidence, the affected area, and the final settlement of ultra-thin ground coverage and partially out of the ground in the shield process are predicted and analyzed. Comparison with the measured data shows that the calculation is reliable. The results provide useful guidance to the project, and may be used as a reference for analysis of similar projects

(1. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China; 2. College of Sciences, Shanghai University, Shanghai 200444, China; 3. Shanghai Urban Construction Co., Ltd., Shanghai 200122, China)

盾构快速穿越(ultra-rapid under pass, URUP)法隧道施工技术是一种盾构机从地表直接始发掘进, 最后在设定目标地点直接掘进到地表的新型施工方法. 以南京机场城轨URUP法隧道示范工程为背景, 利用三维非线性有限元方法(finit element method, FEM), 对URUP 法隧道施工过程进行了数值模拟. 预测分析了隧道施工过程中超浅覆土和负覆土区间的地表变形规律、施工影响范围以及最终沉降值. 分析结果与实测数据比较吻合, 说明了数值模拟的有效性和预测分析的可信性.

... 赵辛玮等^[4]通过三维有限元模拟及实测数据分析发现,原本扰动较大、地表沉降比较明显的浅覆段,如 0 ...

... 本文计算结果与文献[4]有限元模拟结果在开挖面后方35 m后规律有所差异,这是施工工艺的差异造成的,实测数据中开挖面后方35 m(大约12环的位置)处于刚开始推进阶段,地表沉降控制相对较差,沉降值稍大 ...

... 可见,计算结果与文献[4]有限元模拟值及实测数据吻合较好,本文方法计算得到的理论最大沉降值为4 ...

2016

0.0

张旭, 叶冠林, 吴惠明, 等. 地面出入式盾构隧道受力变形特性数值分析[J]. 地下空间与工程学报, 2016, 12(2): 436-441.

ZHANG

, YE

Guanlin

, WU

Huiming

, et al. Numerical study on deformation characteristics of ground penetrating shield tunnel[J]. Chinese Journal of Underground Space and Engineering, 2016, 12(2): 436-441. (in Chinese)

Ground penetrating shield technology (GPST) is a new tunnelling method, which does not require working shaft. It was applied to the Nanjing subway for the first time inChina. Since it starts from the ground directly,the loadings acting upon tunnel are different from the traditional ones. Therefore, it is unknown that whether the traditional design methods can be applied or not. It is necessary to carry out a further study on tunnel deformation characteristics. In order to study the behavior of tunnels under the negative, zero and shallow overburdens, a refined 3D FEM model, including detail of tunnel segments, bolts is built for FEM calculation. The deformation of tunnels under different loading conditions and the coefficient of stiffness reduction of sophisticated tunnels relative to inhomogeneous ring are analyzed carefully. The influence of lateral earth pressure coefficient to deformations of tunnels is also analyzed. It is found that the coefficient of stiffness reduction increases with the increasing of overburden depth, and the critical value of K 0 at which the deformation model swift from “horizontal egg” to “vertical egg” also increases.

1. School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiaotong University, Shanghai 200240, P.R.China; 2. Shanghai Urban Construction Group, Shanghai 200122, P.R.China

地面出入式盾构隧道(GPST)是一种不需要工作井的新型盾构工法,在国内首次应用于南京地铁。盾构机从地面直接出发,隧道所受荷载与一般隧道有很大区别,传统的惯用法是否适用尚存疑问,因此需要进一步研究隧道的受力变形特性。本文以地面出入式盾构施工过程中出现的负覆土—零覆土—浅覆土工况作为研究对象,建立精细化隧道三维模型,分析隧道在不同覆土厚度工况下的受力变形规律,并获得相应的横向刚度折减系数。同时针对土体侧向土压力系数 K 0 进行参数分析,揭示不同地层条件下隧道收敛变形的变化规律。研究表明,横向刚度折减系数随覆土深度增加而增加,而且随着覆土厚度的增加,变形模式由“横鸭蛋”变为“竖鸭蛋”的临界K 0 系数值逐渐增大。

2016

0.0

... 滕丽^[6]整理了南京机场线工程的监测数据,分析覆土为浅、超浅和负时的沉降规律,发现位于超浅覆土区,覆土 0 ...

... 本文计算结果与文献[6]有限元模拟计算结果及实测结果吻合较好,验证了本文方法的可靠性 ...

... 当 y=2 m时,上方土体沉降随着 z变大而缓慢变大,但是在隧道顶部以下沉降迅速变大,这与文献[6]得到的土体分层沉降分布规律相似 ...

2014

0.0

2013

0.0

张子新, 胡文, 刘超, 等. 地面出入式盾构法隧道新技术大型模型试验与工程应用研究[J]. 岩石力学与工程学报, 2013, 32(11): 2161-2169.

ZHANG

Zixin

, HU

Wen

, LIU

Chao

, et al. Investigation of ground pass shield tunnelling method based on large-scale model test and its engineering application[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(11): 2161-2169. (in Chinese)

The creation of ground pass shield tunnelling(GPST) method has conquered the disadvantage of constructing working shaft for shield launching and arrival which is a typical of traditional tunnelling method，and making an innovative turning point on shield tunnelling history. This paper first presents a detail investigation on the key problems of GPST method by adopting large-scale model test，numerical simulation and in-situ monitoring. The surface settlement characteristics of different crossing stages of GPST method have been revealed. In addition，an engineering application of this new method was carried out in Moling-Jiangjun interval of Nanjing intercity fast track；some key tunnelling parameters and effective measures were explored. Comparison was also done between the monitoring data，model test results and numerical results；it is shown a good agreement with each other；and a sound basis is established for the broad application of GPST method.

(1. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education，Tongji University，Shanghai 200092，China；2. Department of Geotechnical Engineering，Tongji University，Shanghai 200092，China；3. Shanghai Urban Construction(Group) Corporation，Shanghai 200023，China)

地面出入式盾构法克服传统盾构法需要在两端修建始发和接收工作井的弊端，实现地表出发和地表接收的全过程盾构施工新技术。采用大型模型试验、数值仿真和工程验证手段，系统研究地面出入式盾构法隧道新技术掘进的关键问题，揭示地面出入式盾构法穿越不同阶段的地表沉降规律；依托地面出入式盾构法首次在我国南京城际快速轨道秣将区间隧道工程的示范应用，探索分析该新方法在工程中主要施工参数的合理选择和有效的控制技术；模型试验、数值仿真结果与工程实测结果获得一致的规律，可为该新方法的进一步推广应用打下坚实基础。

2013

0.0

2017

0.0

2016

0.0

高昂, 张孟喜, 蒋华钦, 等. 地面出入式盾构法隧道施工同步注浆工程应用研究[J]. 岩石力学与工程学报, 2016, 35(9): 1871-1883.

GAO

Ang

, ZHANG

Mengxi

, JIANG

Huaqin

, et al. Engineering application of synchronous grouting technology on tunnel construction by ground pass shield tunneling method[J]. Chinese Journal of Rock Mechanics and Engineering, 2016, 35(9): 1871-1883. (in Chinese)

The traditional methods of shield tunnel construction bring about a large amount of problems such as structure demolition and severe traffic congestion in the process of construction. The construction technique of ground pass shield tunneling(GPST) method applied in the Nanjing airport line was investigated. Soil pressure，pore water pressure，horizontal displacement and vertical settlement were monitored in the construction site. The monitored results were analyzed for three different load cases such as the shallow overburden area，the super shallow overburden area and the negative overburden area. The reasonable and effective grouting parameters were presented. The results show that there is a relationship between the depth of the overburden soil and the soil pressure of the area affected by the shield tunneling. The right area of the negative overburden soil is mildly affected by the synchronous grouting，while the bottom segments are considerably influenced. The pore water pressure under 0.5D overburden condition has a significant effect when the notch to the first three rings，but the pore water pressure under －0.3D overburden is not obviously affected. The horizontal displacements in soil of the three cases are differently distributed. The less the depth is，the more the displacement is. In the negative and super shallow overburden soil area，the settlement of two sides are not evenly distributed and this may be attributed to the unbalanced stress of the two sides when the tunnel is constructed in the curved segment.

(1. Department of Civil Engineering，Shanghai University，Shanghai 200072，China；2. Jiaxing Nanyang Polytechnic Institute，Jiaxing，Zhejiang 314003，China)

传统的盾构隧道施工方法带来了现场附近大量拆迁及路面交通拥堵，施工过程中风险增大等诸多问题。研究新型地面出入式盾构法隧道(GPST)施工技术，结合南京机场线工程，对施工过程中土压力、孔隙水压力、水平位移、分层沉降等数据进行现场监测，并针对浅覆土、超浅覆土、负覆土3种不同工况，分别分析各监测结果变化的原因，并提出合理、有效的注浆参数。结果表明：土压力受盾构推进影响明显的范围与覆土深度有关；盾构到达负覆土右侧底部管片受同步注浆压力影响最大；0.5D覆土下孔隙水压力在切口到达前3环产生明显的影响，而－0.3D覆土下孔隙水压力受影响很不明显；3种工况下土体水平位移规律不明显，当注浆参数合适，可以显著减小因盾构推进引起的纵向位移；在负覆土、超浅覆土施工期间，土体左、右两侧分层沉降并不均匀。实际工程的现场试验监测结果为今后其他类似实际工程的应用提供参考性建议。

2010

0.0

2014

0.0

张银屏. 地面出入式盾构隧道修正惯用法计算参数研究[J]. 隧道建设, 2014, 34(2): 101-106.

ZHANG

Yinping

. Study on ground penetrating shield-bored tunnel calculation parameters in modified routine method[J]. Tunnel Construction, 2014, 34(2): 101-106. (in Chinese)

Modified routine method is widely used in the calculation of the internal force of shieldbored tunnels, and the calculation parameters are generally selected according to the experience. In the paper, the key calculation parameters of ground penetrating shieldbored tunnel in the modified routine method, i.e., the stiffness reduction ratio (η) and the moment release ratio (ξ), are analyzed on basis of shellspring model, considering the nonlinear relationship between the bending stiffness and axial bending moment of the segment joints. Conclusions drawn are as follows: 1) For shieldbored tunnel with supershallow overburden, the minimum value in the specified range of specifications should be adopted for stiffness reduction ratio (η) and the maximum value should be adopted for the moment release ratio (ξ); 2) When the top of the tunnel is above the ground surface, value 1 should be adopted conservatively.

(Shanghai Urban Construction Design & Research Institute, Shanghai 200125, China)

盾构隧道衬砌内力计算常用方法为修正惯用法，其计算参数一般根据经验选取。基于壳-弹簧模型，考虑接头抗弯刚度与接头轴力弯矩的非线性关系，对地面出入式超浅埋盾构隧道修正惯用法的关键计算参数抗弯刚度效率系数η和弯矩调整系数ξ的取值进行分析研究。得到结论：超浅埋盾构隧道η应在规范范围内取最小值，ξ应取最大值，负覆土情况下可偏保守取1。

... 在解析解研究方面,文献[13]针对超浅埋地面出入式盾构,考虑衬砌接头处的轴力和弯矩与抗弯刚度的非线性关系,研究弯矩调整系数和抗弯刚度效率系数的取值 ...

2014

0.0

林存刚, 刘干斌, 梁荣柱, 等. 隧道坡度对盾构掘进引起地面隆陷的影响[J]. 岩土工程学报, 2014, 36(7): 1203-1212.

LIN

Cungang

, LIU

Ganbin

, LIANG

Rongzhu

, et al. Influences of tunnel slope on shield tunnelling-induced heave and subsidence of ground surface[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(7): 1203-1212. (in Chinese)

Based on the Mindlin solution, the vertical movements of ground surface induced by the vertical component of the additional thrust at the excavation face and the friction force imposed on the surrounding soils by the shield skin are calculated through numerical integration. The results are verified by field observations. The analysis indicates that the longitudinal ground surface is expected to be globally heaved due to the vertical component of the additional thrust and the friction force, and the point where the maximum heave observed moves to the cutter-head with the increase of pitch angle of shield tunnelling. Under a fixed pitch angle, the maximum heave of ground surface declines exponentially with the increase of tunnel depth.

1. College of Civil, Construction and Environmental Engineering, Ningbo University, Ningbo 315211, China; 2. College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China

基于Mindlin解,经数值积分计算了盾构以一定坡度掘进时切口附加推力与盾壳摩擦力的竖向分量引起的地面竖向位移,并通过现场实测验证了其合理性。计算表明,随盾构俯仰角的增大,在切口附加推力与盾壳摩擦力竖向分量的作用下,沿隧道纵向地面竖向位移呈现总体上移趋势,且切口前方最大隆起出现的位置更加靠近切口;盾构俯仰角一定时,随隧道埋深的加大,切口附加推力与盾壳摩擦力竖向分量作用下的地面最大隆起呈指数型下降。

... 文献[14]研究掘进坡度对盾构掘进引起的地面隆陷的影响,得到考虑水平面存在一定坡度时简化的土体垂直变形计算公式 ...

... 文献[14,15]虽然提出了地面出入式盾构土体变形计算方法,但没有研究水平位移,且计算公式考虑因素不全,特别是没有考虑浅覆土工况下隧道存在上浮的影响,这与实际覆土较浅时的地面出入式盾构法工况有差异 ...

2017

0.0

... 文献[15]研究了隧道轴线埋深与隧道坡度之间的关系,提出了仅考虑土体损失的地面出入式盾构竖向土体变形计算方法 ...

1998

0.0

... 传统随机介质理论^[16]在计算土体损失引起地面各点变形时,土体变形采用等量(均匀)径向移动模式,如图2(a)所示,图中 R为盾构机外半径, g为等效土体损失参数 ...

2009

0.0

... 改进后的随机介质理论方法^[17]在计算土体损失引起地面各点变形时,考虑实际隧道周围土体产生的是非等量径向移动,土体变形采用隧道落到土体边界底部的移动模式,见图2(b) ...

... 该理论适用于22种收敛模型^[17]的积分计算,同样适用于地面出入式盾构隧道的土体变形计算 ...

... 3 计算参数取值1) tanβ参数选择^[17] ...

2001

0.0

... 借鉴文献[18]中叠加的各影响因素,得出新的隧道开挖断面收敛模型的方法,建立隧道上浮至土体边界顶部的隧道开挖断面收敛模型,见图3(a) ...

2014

0.0

... 综上,在浅覆土段考虑图3(b)、图3(c)、图3(d)相互作用时,图3(d)起到主要作用,由于隧道上浮是施工中的不利因素,故根据文献[19]实际工程中的管片上浮量,本文选取的隧道上浮量为小于15 mm,采用图3(a)的土体开挖断面收敛模式进行计算 ...

... 2 工程实例验证由于地面出入式盾构的研究和应用尚处于起步阶段,目前国内仅有南京机场线秣陵站至将军路站区间的地面出入段工程^[19],采用单线地面出入式盾构法施工,工程盾构直径 R=6 ...

... 可见,计算结果与文献[19]的实测数据规律相似,实测数据基本分布在理论值的两侧,验证了本文方法的可靠性 ...

... 可见,计算值与文献[19]的实测值基本吻合,证明了本文方法的可靠性 ...

1957

0.0

... 2 理论解计算公式20世纪50年代,Litwiniszyn^[20]提出随机介质理论,阳军生等^[21,22]进行了深入研究 ...

1998

0.0

... 2 理论解计算公式20世纪50年代,Litwiniszyn^[20]提出随机介质理论,阳军生等^[21,22]进行了深入研究 ...

2002

0.0

... 2 理论解计算公式20世纪50年代,Litwiniszyn^[20]提出随机介质理论,阳军生等^[21,22]进行了深入研究 ...

2006

0.0

... 2) g参数取值^[23] ...

... 5^[23], α=-2 ...