Evaluation of Shield Tunnel Face Stability in Soft Ground
考虑地层变异性的新建隧道下穿引起既有盾构隧道纵向变形的随机分析方法
第 55 卷第 2 期2024 年 2 月中南大学学报(自然科学版)Journal of Central South University (Science and Technology)V ol.55 No.2Feb. 2024考虑地层变异性的新建隧道下穿引起既有盾构隧道纵向变形的随机分析方法施成华1，郑晓悦1，王祖贤1，陈海勇2，孙影杰1(1. 中南大学 土木工程学院，湖南 长沙，410075；2. 中铁开发投资集团有限公司，云南 昆明，650200)摘要：沿盾构隧道纵向的地层变异不可避免，现有对于新建隧道引起既有盾构隧道纵向变形计算的解析模型大多将隧道下卧土体视为均质地基，忽略了地层变异性。
本文针对新建隧道施工引发的既有盾构隧道纵向变形问题，构建考虑地层变异性的盾构隧道纵向力学解析模型，基于随机场理论，结合蒙特卡罗模拟策略提出隧道下穿引起既有盾构隧道纵向变形的随机分析方法。
依托1个工程案例，基于所建立的盾构隧道纵向变形随机分析方法，开展新建隧道下穿施工影响下既有盾构隧道纵向变形随机分析，并与实测结果进行对比。
最后，分析地层刚度变异系数和水平波动距离对既有盾构隧道纵向变形的影响规律。
研究结果表明：地层变异性对盾构隧道纵向变形的影响不可忽略；地层刚度变异系数对既有隧道纵向位移均值和离散程度影响较敏感，地层刚度变异系数对可靠度指标的影响较显著。
关键词：盾构隧道；纵向变形；解析模型；可靠度中图分类号：U455.43 文献标志码：A 文章编号：1672-7207（2024）02-0500-13Random analysis method for longitudinal deformation of existing shield tunnels induced by new tunnelling underpass consideringgeological uncertaintySHI Chenghua 1, ZHENG Xiaoyue 1, WANG Zuxian 1, CHEN Haiyong 2, SUN Yingjie 1(1. School of Civil Engineering, Central South University, Changsha 410075, China;2. China Railway Development and Investment Group Co. Ltd., Kunming 650200, China)Abstract: The strata variation along the longitudinal direction of shield tunnel is inevitable. Most of the existing analytical models for calculating the longitudinal deformation of existing shield tunnels treat the soil underneath收稿日期： 2023 −05 −10； 修回日期： 2023 −07 −12基金项目(Foundation item)：国家自然科学基金资助项目(51778636)；湖南省自然科学基金资助项目(2021JJ30837) (Project(51778636) supported by the National Natural Science Foundation of China; Project(2021JJ30837) supported by the Natural Science Foundation of Hunan Province)通信作者：王祖贤，博士，从事隧道与地下工程研究；E-mail ：**************DOI: 10.11817/j.issn.1672-7207.2024.02.005引用格式： 施成华, 郑晓悦, 王祖贤, 等. 考虑地层变异性的新建隧道下穿引起既有盾构隧道纵向变形的随机分析方法[J]. 中南大学学报(自然科学版), 2024, 55(2): 500−512.Citation: SHI Chenghua, ZHENG Xiaoyue, WANG Zuxian, et al. Random analysis method for longitudinal deformation of existing shield tunnels induced by new tunnelling underpass considering geological uncertainty[J]. Journal of Central South University(Science and Technology), 2024, 55(2): 500−512.第 2 期施成华，等：考虑地层变异性的新建隧道下穿引起既有盾构隧道纵向变形的随机分析方法the tunnel as a homogeneous foundation due to new tunnel construction, ignoring the variability of the stratum. In this paper, to address the longitudinal deformation of existing shield tunnels caused by new tunnel construction, an analytical model of longitudinal mechanics of shield tunnels considering the stratum variability was constructed.Based on the random field theory and Monte Carlo simulation strategy, a random analysis method for the longitudinal deformation of existing shield tunnel caused by tunnel undercrossing was proposed. Based on a project case and the established stochastic analysis method of the longitudinal deformation of shield tunnel, the stochastic analysis of longitudinal deformation of existing shield tunnel under the influence of new tunnel undercrossing construction was made, and the results were compared with the measured results. Finally, the influence of the variation coefficient of stratum stiffness and horizontal fluctuation distance on the longitudinal deformation of the existing shield tunnel was analyzed. The results show that the influence of stratum rariability on the longitudinal deformation of shield tunnel cannot be ignored, the coefficient of variation of stratum stiffness is more sensitive to the mean value and dispersion degree of the longitudinal displacement of existing tunnels, and the coefficient of variation of stratum stiffness has more significant effect on the reliability index.Key words: shield tunnel; longitudinal deformation; analytical model; reliability随着我国城市轨道交通建设的蓬勃发展，新建隧道近接下穿既有盾构隧道已十分普遍。
The Face Stability of Slurry-shield-driven Tunnels
results in excess air pressure and may cause an escape of air to the surface-either by leakage through soil pores or by a heaving of the ground mass above the shield. This phenomenon is partieularly likely to occur when the tunnel is shallow and its diameter large. The problems associated with the use of compressed air have led to the increasing use of slurry-shield tunnelling over the last twenty years (see, e.g., Becker and Sawinski 1982). In a slurry shield, the temporary support of the face is provided by a pressurized mixture of bentonite or clay and water. Because of the high viscosity of the slurry, the risk of an uncontrolled escape of fluid by leakage is generally reduced. As slurry is only slightly heavier than water, the excess fluid pressure in the crown is small. The risk of an upheaval of the ground therefore is eliminated as well. In the last decade, slurry-shield tunnelling has been applied successfully worldwide on several projects. The largest existing tunnel (in Grauholz, Switzerland), excavated by the slurry shield method, has a diameter of 11.65 m (see Fig. 1). However, under extremely unfavourabie geological con-
复杂地面环境盾构区间穿越岩溶段探测及处理技术
0前言城市轨道交通盾构区间,在复杂地面环境条件下,遇到地下岩溶发育的灰岩地层,采用怎样的勘探措施和施工方案,以保证盾构施工期间和后期运营安全,是困扰建设者的一道难题。
本文针对复杂地面环境,确定了加密钻探的范围,采用加密地质钻孔及跨孔地震CT探测法探测熔岩,确定了溶洞处理的原则,并在地面钻孔及隧道内注浆方法施工,确保了施工及后期运营安全。
1工程概况1.1线路概况无锡地铁4号线一期工程四院站~河埒口站区间左线长925.650m;右线长933.863m,设两处平曲线,最小平曲线半径320m,单向下坡,最大纵纵坡26‰,线间距14.00m~ 23.80m,隧道顶埋深约为9.5m~17.90m,设1处联络通道。
区间在DK9+470~DK9+700段,210m长度内穿越岩溶地区,区间采用盾构法施工。
见图1。
1.2周边环境本区间过岩溶段下穿产山新村房屋、上蒋巷房屋、无锡市公安局交通巡警支队滨湖大队房屋,地表环境复杂,房屋密集。
见图2。
1.3工程地质和水文地质本区间岩溶段地层为⑥1黏土、12〇-1层含碎石粉质黏土、12〇-3层残积土、13〇中风化黄龙组灰岩地层等,均为弱透水或不透水层。
地下水类型主要为松散岩类孔隙水的全新统潜水层②、碳酸盐岩类裂隙溶洞水和基岩裂隙水,对隧道掘进影响不大。
[收稿日期]2020⁃01⁃03[作者简介]李迎春,男,无锡地铁集团有限公司,高级工程师,大学本科,主要从事工程管理工作。
复杂地面环境盾构区间穿越岩溶段探测及处理技术李迎春(无锡地铁集团有限公司,江苏无锡214100)[摘要]无锡地铁4号线一期工程四院站~河埒口站区间过溶洞段,地面房屋密集,地表环境复杂,熔岩发育。
在区间一定范围内,采用加密地质钻孔及跨孔地震CT探测法,准确探明溶洞位置和特征,并采用地面钻孔注浆和隧道内盾构超前注浆、管片背后二次注浆方式填充溶洞,确保盾构掘进和后期运营的安全。
[关键词]溶洞;跨孔CT;注浆[中图分类号]U231.3[文献标志码]B[文章编号]1005-6270(2020)03-0061-03Detection and Processing Technology of Shield Tunneling Section Crossing Karst Sectionin Complex Ground EnvironmentLI Ying-chun(Wuxi Metro Group Co.,Ltd,Wuxi Jiangsu214100China)Abstract:In the first phase of the Metro Line4,the limestone cave of the fourth courtyard station to the interval of the No.4section of the subway station is densely built on the ground,and the surface environment is complex,and the lava develops.In a certain range of areas,the location and characteristics of karst caves are accurately identified by means of dense geological boreholes and cross-hole seismic CT detection,and the karst caves are filled by ground borehole grouting,advanced grouting of shield tunnels and secondary grouting behind segments to ensure the safety of shield tunneling and later operation.Key words:karst cave;cross-hole CT;grouting基金项目:江苏省建设系统科技项目(2018ZD254)。
Shield tunneling method using flexible segments, f
专利名称：Shield tunneling method using flexiblesegments, flexible segments for shieldtunneling method, and flexible segments forsecondary application of shield tunnelingmethod发明人：Shintaro Ikeda,Michio Kitawaki申请号：US08/145473申请日：19931028公开号：US05472295A公开日：19951205专利内容由知识产权出版社提供摘要：A general segment 20 which is propelled and set in an excavated hole by a propulsion excavating machine, and a flexible segment where flexible members 4 and rigid ring members are alternately installed and connected inside the skin-plate 7 provided on the outer periphery side of the side rings 5 having the same thickness as the general segment and a thrust- receiving member 9 is provided inside the flexible portion, are propelled and set by the propulsion excavating machine and then secondary coating concrete 30 including a secondary watertight band 15 is applied to said side ring. As a segment for a shield tunneling method, the flexible segment appropriately provides flexibility to quickly cope with earthquakes and uneven settlement. The flexible segment may be handled in the same manner as a standard general segment during excavation work, providing excellent application potential. Furthermore, the elastic and resilient members to provide flexibility are stably secured to connection ring members at both ends, preventing peeling from occurring, and at the same time, generating minimalunreasonable stress, thereby allowing application of excellent durability to be obtained.申请人：THE VICTAULIC COMPANY OF JAPAN LIMITED,MITSUBISHI RUBBER COMPANY LIMITED代理机构：Frishauf, Holtz, Goodman, Langer & Chick更多信息请下载全文后查看。
密实砂土地层盾构隧道开挖面失稳离心模型试验研究_汤旅军
第35卷 第10期 岩 土 工 程 学 报 Vol.35 No.10 2013年10月 Chinese Journal of Geotechnical Engineering Oct. 2013 密实砂土地层盾构隧道开挖面失稳离心模型试验研究汤旅军1，2，陈仁朋1，2*，尹鑫晟1，2，孔令刚1，2，黄 博1，2，陈云敏1，2(1. 浙江大学软弱土与环境土工教育部重点实验室，2. 浙江大学岩土工程研究所，浙江 杭州 310058)摘要：砂土地层中盾构掘进时，开挖面支护力不足极易导致开挖面失稳事故。
通过3种不同隧道埋深比（C/D=0.5，1和2）的离心模型试验对密实砂土地层中盾构隧道开挖面稳定性问题进行了研究。
离心试验研究发现，随着开挖面位移的增大，开挖面支护力先减小为极限值而后逐渐增大并最终趋于残余值；开挖面前方土体总体呈现“楔形体+棱柱体”的失稳区；隧道相对浅埋时（如C/D=0.5），极限状态下失稳区已扩展到地表；隧道相对深埋时（如C/D=1和2），极限状态下失稳区尚处于地基内部；极限支护力随着隧道埋深比的增大先增加而后基本保持不变。
最后，通过现有几种极限支护力理论计算模型对本文试验预测结果的比较分析，评估了上述理论方法的工程适用性。
该研究成果对砂土地层中盾构开挖面稳定性控制具有指导意义。
关键词：离心模型试验；盾构隧道；开挖面稳定；极限支护力；失稳模式中图分类号：TU41 文献标识码：A 文章编号：1000–4548(2013)10–1830–09作者简介：汤旅军(1984–)，男，江苏海门人，博士研究生，主要从事城市地下工程设计与施工方面研究工作。
E-mail: tljzjdx@。
Centrifugal model tests on face stability of shield tunnels in dense sandTANG Lü-jun1, 2, CHEN Ren-peng1, 2, YIN Xin-sheng1, 2, KONG Ling-gang1, 2, HUANG Bo1, 2, CHEN Yun-min1, 2(1. MOE Key Laboratory of Soft Soils and Geoenviromental Engineering, Zhejiang University, Hangzhou 310058, China; 2. Institute ofGeotechnical Engineering, Zhejiang University, Hangzhou 310058, China)Abstract:When tunneling in sand using the shield machine, failure of the tunnel face occurs frequently due to the inadequate support pressure. Centrifugal model tests with different overburden-to-diameter ratios (i.e., C/D= 0.5, 1, 2) are performed to study the problem of tunnel face stability in dense sand. During the tunnel face failure, with the increase of the horizontal displacement of the tunnel face, it is found that the support pressure firstly decreases rapidly to the limit support pressure and then increases gradually to the residual support pressure. A “wedge-prism” failure zone occurs in front of the tunnel face after the face failure. For the relatively shallow buried tunnel (e.g. C/D=0.5), the failure zone has extended to the ground surface in the limit state. While for the relatively deep buried tunnel (e.g. C/D=1 and 2), the failure zone is still in the interior of the ground in the limit state. It is also found that the limit support pressure increases with the increase of relative depth C/D and then remains almost the same. Finally, after comparing the limit support pressures obtained from the existing theoretical methods with those from the centrifugal model tests, the engineering applicability of the existing theoretical models is discussed.The results of this research may help to guarantee the face stability of the shield tunnels in sandy ground.Key words: centrifugal model test; shield tunnel; face stability; limit support pressure; failure pattern0 引 言盾构法广泛应用于城市地下隧道工程。
基于自定义本构模型的盾构隧道开挖面极限支护力研究
基于自定义本构模型的盾构隧道开挖面极限支护力研究黄阜;李在蓝;朱亮;杨欢【摘要】To study the influence of nonlinear failure characteristics on the ultimate support pressure of shield tunnel face,the user-defined constitutive model subjected to nonlinear failure criterion was developedby using the further developing platform in FLAC3 D.By invoking the constitutive model to simulate the excavation of a shield tunnel,the numerical solution of ultimate support pressure subjected to nonlinear failure criterion was ob-tained.Furthermore,the nonlinear failure criterion was introduced into the energy calculation by generalized tan-gential technique,and the upper bound solution of ultimate support pressure for shield tunnel was derived.By comparing the numerical solution and upper bound solution,the validity of ultimate support pressure calculated byuser-defined constitutive model was proved.%为了分析岩土体的非线性破坏特性对盾构隧道的开挖面极限支护力的影响，利用FLAC3 D提供的二次开发平台，开发基于非线性Mohr－Coulomb破坏准则的自定义本构模型。
一种地铁隧道表面裂缝的检测方法
一种地铁隧道表面裂缝的检测方法随着城市化的进程，地铁成为人们生活中不可或缺的一部分。
在地铁车站地下通道中，隧道的安全问题备受关注。
其中，地铁隧道表面的裂缝检测是隧道安全监测中必不可少的一项。
一、隧道表面裂缝的危害隧道表面裂缝对隧道的安全造成很大威胁，尤其是在长时间的风吹雨打、地壳运动等等自然力的侵害下，隧道表面的裂缝数量、大小都会不断增加。
当隧道表面裂缝超过规定的安全值后，就会导致到隧道的长期变形和破坏，最终会威胁到人员生命安全。
二、地铁隧道表面裂缝的检测方法为了防止隧道裂缝对人员造成安全威胁，我们采用一种特殊的基于InSAR遥感技术的方法检测地铁隧道表面裂缝的技术。
InSAR遥感技术是一种利用人造卫星对地面物体进行测量的方法。
这种方法主要通过雷达分析提供的数据，计算不同时间拍摄的影像之间地形的位移量，并且能够通过数据比较、设计成果比较等方法精确的测定地铁隧道表面的裂缝情况。
数据处理也是整个检测过程的关键，处理包含多种操作，如相位解缠、多阶差分处理、时间序列分析等。
最终，可以得到一张隧道表面的裂缝分布图，这张图就是地铁隧道表面裂缝检测的主要成果，对隧道的安全稳定性评估和监控工作都非常重要。
三、该检测方法的优势相比于以往的检测方法，基于InSAR遥感技术的隧道表面裂缝检测方法的优势在于：1. 可在地面杂音和其他因素干扰的情况下，获得高精度的隧道表面形态数据；2. 能够生成隧道地形、直、多个时间较精确的变形、裂缝等信息图，标识裂缝位移等的实时状态并实现长时间监控；3. 可以自动化分析日常遥感数据，检测隧道表面裂缝的产生和扩展，提高监测效率和监测质量。
综上，隧道表面裂缝对隧道安全造成不容忽视的威胁。
采用基于InSAR 遥感技术的隧道表面裂缝检测方法，能够获得高精度的数据，从而及时识别地铁隧道表面裂缝的位置和裂缝的大小等属性，为隧道的维护和管理提供了实时有效的数据支撑。
隧道地表开裂的报告范文
隧道地表开裂的报告范文英文回答：Report on Tunnel Surface Cracking.Introduction:This report aims to provide an analysis of the surface cracking observed in a tunnel. The cracks were identified during a routine inspection and their causes and potential consequences need to be assessed.Description of Cracks:The cracks are primarily located on the surface of the tunnel walls and ceiling. They vary in length, width, and depth. Some cracks are hairline, while others are wider and deeper. The cracks are predominantly found in the middle section of the tunnel, extending approximately 50 meters.Potential Causes:1. Ground Settlement: The cracks could be a result of ground settlement due to geological factors or the presence of underground water sources. This settlement may have caused the tunnel structure to shift and crack.2. Temperature Changes: Fluctuations in temperature can cause expansion and contraction of the tunnel materials, leading to cracks.3. Vibration: Heavy traffic or nearby construction activities may have caused excessive vibration, resulting in cracks on the tunnel surface.4. Age and Wear: The tunnel may have reached its lifespan, and the cracks could be a consequence of natural deterioration over time.Consequences:If left unattended, the surface cracks may lead to moresevere structural damage. Water infiltration through the cracks could weaken the tunnel's integrity and potentially cause collapse. Additionally, the cracks may serve as entry points for corrosive substances, leading to further deterioration.Recommendations:1. Conduct a Detailed Investigation: A comprehensive investigation should be carried out to determine the exact causes of the cracks. This may involve geotechnical surveys, structural analysis, and monitoring of environmental factors.2. Repair and Maintenance: Based on the investigation findings, appropriate repair and maintenance measuresshould be implemented. This may include sealing the cracks, reinforcing the tunnel structure, or even considering a partial or complete renovation if necessary.3. Regular Inspections: Implement a regular inspection schedule to monitor the condition of the tunnel andidentify any new cracks or signs of deterioration. This will help ensure early detection and prompt action to prevent further damage.Conclusion:The surface cracks observed in the tunnel require immediate attention to prevent potential risks to the structure's integrity. By conducting a thorough investigation, implementing appropriate repair measures, and establishing a regular inspection routine, the tunnel can be restored to a safe and functional state.中文回答：隧道地表开裂报告。
盾构隧道下穿河道及侧穿桥桩方案设计
0引言近年来，随着城市地铁的快速发展，地铁隧道下穿河道及侧穿桥桩的风险工程增多。
盾构隧道的施工对土层的扰动容易引起桥梁的沉降、附近管线的沉降和变形，穿越河道更是容易引起隧道渗水及河床沉降；且在不同地区地层性质不同的情况下对于盾构施工的沉降及变形影响程度不同，盾构隧道穿越河道及桥梁的距离把控及风险源加固、施工措施是一个值得深入研究的课题。
本文以北京地铁17清河营站~天通苑东站区间下穿清河及侧穿清河桥桩为例，通过数值分析手段与施工后监测数据相互验证盾构隧道穿越河道及桥桩方案，提出有效的盾构区间下穿河道及侧穿桥桩设计方案。
1工程概况北京地铁17号线清河营站~天通苑东站区间为盾构区间，采用土压平衡盾构机，盾构外径6.4m ，盾构区间于右线里程YK41+091.427~YK41+194.820范围内下穿清河及侧穿清河桥桥桩。
清河的基本概况：根据1999年编制的《清河治理工程规划》，清河在拟建地铁17号线处，规划河道横断面为梯形断面，斜坡采用浆砌石衬砌至50年一遇洪水位，规划河底宽70m ，边坡系数为2，糙率为0.022，纵坡为0.0003，规划河道上口宽为92m 。
该处规划河底高程为25.57m 。
规划河道两侧绿化隔离带宽均为70m ，区间下穿河道最小间距10.977m 。
清河桥的基本概况：清河桥位于北苑东路跨越清河，桥梁中线与北苑东路轴线交角为90°，桥梁中线与清河规划河道斜角角度为89.693°。
桥梁全长4*23.5+10=104m 。
桥面全宽48.5m ，两侧人行步道各宽4.5m ，非机动车道各宽3.5m ，机动车道16m+15m ，中央隔离带1.5m 。
1.1上部结构桥梁上部结构为四孔预制预应力混凝土简支T 梁及一孔预制预应力混凝土简支空心板，桥梁全长4×23.5+10=104m ，桥宽48.5m ，桥梁总面积5044平米。
简支T 梁及简支空心板主梁工厂预制并采用后张法预应力，四孔简支T 梁设置桥面连续。
Evaluation of tunnel face stability by transparent soil models
E-mail addresses: mmahmoud@ (M. Ahmed), iskander@ (M. Iskander).
Tunnelling and Underground Space Technology 27 (2012) 101–110
Contents lists available at SciVerse ScienceDirect
Tunnelling and Underground Space Technology
The SS/HS tunneling method balances existing earth and hydrostatic pressures by applying a pressurized slurry consisting of water, bentonite, and/or polymer conditioners at the tunnel face (Anagnostou and Kovári, 1994). The slurry also prevents the infiltration of groundwater into the tunnel. The EPB method uses the excavated soil to balance the soil and water loads to prevent ground failure at the tunnel face (Clough and Leca, 1993). In both mechanisms an internal pressure is generated to support the cutting face against the existing overburden and hydrostatic pressures. The popularity of pressurized shields has been increased by the effective use of additives and other soil conditioning methods such as foams and polymers which increase the range of soils where SS/HS/EPB methods can be employed (Quebaud et al., 1998; Vinaia et al., 2008).
基于模糊层次和改进灰色关联度耦合算法的隧道爆破风险评价
析法、贝叶斯法、ＢＰ 神经网络法等ꎮ 该类方法更为
科学ꎬ受数据限制程度小ꎬ评价精度更高ꎬ对于学术
研究者比较适用ꎮ
为消除一种模型本身的局限性ꎬ将耦合定性定
量法和数理统计法两种模型( 灰色关联度法、模糊
理论以及多层次分析法) 相结合进行综合评价ꎮ
１. ２ 灰色关联度法
型
灰色 关 联 度 法 的 核 心 是 构 建 ＧＭ ( １ꎬ １ ) 模
定了各风险分级ꎮ 结果表明:各因子的权重由大至小依次为掌子面爆破、爆破管理、地质条件、爆破设计ꎮ 同时ꎬ隧
道爆破风险综合等级为高风险ꎻ各一级指标中ꎬ地质条件为高风险ꎬ掌子面爆破为极高风险ꎬ爆破管理和爆破设计
为中风险ꎮ 基于风险类型和风险评价结果ꎬ可制定分级管控措施及北斗一体化监测系统方案ꎬ实时了解隧道围岩
隧道是高速公路、铁路的重要组成部分之一ꎮ
隧道工程极大地缩短了各省、市、县之间的出行时
间
[１]
ꎮ 在山 区ꎬ 隧 道 施 工 较 为 复 杂ꎮ 当 穿 越 硬 岩
时ꎬ多采用爆破施工ꎮ 但爆破施工存在较大的风险ꎬ
若防控不及时ꎬ容易造成不可挽回的后果 [２] ꎮ
隧道爆 破 越 来 越 成 为 相 关 领 域 的 研 究 热 点ꎮ
产生的危险因素以及产生的后果ꎮ 于丽等 [６] 采用
改进灰色关联度法对超小净距交叉隧道爆破施工进
行研究ꎬ并得出对隧道爆破影响程度最大的因素是
炸药量和净距ꎮ 段军等 [７] 采用模糊评价法对工程
爆破风险进行评价ꎬ并设计了 ４ 组爆破方案ꎬ对各方
案进行风险综合评判ꎬ并最终得出决策方案ꎮ 瞿东
明等 [８] 以恩贡山隧道为研究对象ꎬ研究隧道爆破对
ｔｈｅ ｒｉｓｋ ｏｆ ｔｕｎｎｅｌ ｂｌａｓｔｉｎｇ ｃｏｎｓｔｒｕｃｔｉｏｎꎬ ａｎｄ ｔｈｅ ｃｌａｓｓｉｆｉｃａｔｉｏｎ ｏｆ ｅａｃｈ ｒｉｓｋ ｗａｓ ａｌｓｏ ｄｅｔｅｒｍｉｎｅｄ. Ｔｈｅ ｒｅｓｕｌｔｓ ｓｈｏｗ ｔｈａｔ ｔｈｅ
盾构法 Shield Tunneling Method 盾构法 11
Shield Tunneling MethodModern urban development in Japan had to begin with recovery from the ruins of war. In this small , highly populated country, an enormous amount of urban development work needed to be carried out under far from ideal conditions . With rapid economic growth , socioeconomic activity came to be excessively centralized in urban areas , leading to difficulties in securing space for urban facilities . As a result , they have often had to be built in already developed areas , often heavily built-up areas with dense concentrations of houses on narrow roads . Moreover , most major Japanese cities are situated on soft alluvial ground , through which tunneling is technically difficult .In soft alluvial ground , shield tunneling methods are the obvious choice . This active demand for tunnel construction , boosted by slow development of the urban infrastructure and difficult social and natural conditions , has honed Japan’s shield tunneling technology to a level where it leads the world .Shield tunneling was developed as a method of digging tunnels through the soft ground below rivers . The story of Brunel hitting upon the idea when he saw a shipworm boring holes through the bottom of a ship . He was granted a patent in 1818 , and commenced constructing the Thames Tunnel in London in 1823 . His basic concept was to press a rigid frame shield forward through soft ground with jacks , thus preventing the ground from collapsing , and build the tunnel structure within the frames . By repeating the process of jacking then constructing the support structure , the tunnel would move forward .The shield used for the Thames Tunnel was rectangular in cross section . A later redesign , with a circular cross section , was used by Greathead to construct the Tower Subway in 1869 . Cast steel segments , backfilling , and injection were all used by Greathead in his shield work , so his was the prototype of today’s shield . The use of compressed air was studied for work on the Woolwich Tunnel beneath the River Thames in 1876 , although it was not actually used until the end of the work . Greathead also conceived plans for using water to excavate soil and for the stabilization of the face . As this makes clear the first generation of shield tunneling technology was developed about 150 years ago .Thereafter , no great advances were seen in the technology until the 1960s ; this plateau lasted for about a century until a sudden quantum leap , led mainly by Japan . Having been behind in the early 1960s, Japan was making rapid strides of its own by the latter half of the decade . With increasing demand for tunnels and the need to overcome hostile conditions , research related to shield development became more at Oyodo active .In 1963, a mechanical shield was used to stabilize a tunnel face , although pipe jack excavation method was adopted . In 1969 , a slurry shield 7.3m in diameter was used to complete a tunnel for the Keiyo Line underneath the Morigasaki Canal . This shield diameter was a world record at the time . In 1972, an earth pressure shield was developed , marking Japan’s coming of age in the world of tunneling .The main issue driving innovation in shield tunneling tehno;ogy in the 1960s was the problem that had faced conventional shield work since the early days : how to control the unstable tunnel face . The solution to the problem was to install a bulkhead behind the face and inject into the resulting space a material that could stabilize the cut face . A bentonite slurry , as used for cast-in-situ diaphragm walls and oil wells , offered particular advantages in this role . A shift from open shields to closed designs was the natural result . Once the shield is closed in this way , manual face work becomes impossible , so mechanization of excavation and mick removalbecame a necessity . Further , the hydraulic pressure of the slurry , on the face , acts on the tail void section of the shield . Accordingly , pressure the leakage of pressurized soil and water from the clearance between shield and segment became a driving concern .The device used to prevent such leakage is called a tail seal . In addition , earth seals are needed to protect the rotating parts of machinery from soil intrusion , and these also form an important element in shield technology . As this demonstrates , the most crucial requirements in developing the closed shield were suitable materials for stabilizing the face , mechanical excavation methods , systems for discharging and removing excavated soil , and the tail seal . Face stabilization is possible with slurry or excavated soil , and a shield using the fomer is known as a slurry shield . Slurry was an obvious first choice , as noted above , and its use was pioneered in France , the U.K . , and Germany . In Japan , full use has been made of the slurry shield since 1969 , almost in concert with its use elsewhere . The slurry shield developed in Japan are characterized by the use of fine matter in the excavated soil , with the addition of auxiliary materials such as clay , to obtain a slurry with suitable stabilizing and discharge properties . This achieves very cost-effective slurry with suitable stabilizing and discharge properties . This achieves very cost-effective slurry preparation .This idea of using excavated soil to stabilize the face is unique to Japan ,and is a technology to be proud of . The technology began with the earth-pressure shield , in which a screw conveyor discharges the soil excavated with a cutting head . This is essentially an extension of the mechanized shield , rather than a slurry pressure shield . To make use of the excavated material to stabilize the face , it is necessary to make it plastic so as to exert a controlled pressure on the face , which also ensuring that it is suitably super-plasticized for ease of discharge from the face . Further , it is necessary to incorporate a mechanism for discharging the soil through the bulkhead , across which there is a pressure gap . In practice , the slurry is formed by mixing soil with additives such as bentonite in an agitator . A screw conveyor is used to remove slurry from the face . The conveyor is soil used to control the pressure at the face . A full-scale shield equipped with all of these mechanisms was used for the construction of 2.44m sewer main in Katsushika Ward , Tokyo , in 1976 . This method of tunneling later grew into one of the mainstays of shield tunneling , ranking alongside the conventional slurry shield . In 1981 , a modification involving the use of foam as an additive in the slurry was developed ; This is known as the foam shield .Tail sealing is a key part of closed shield technology . The seal slides over the tunnel segments , and so must exhibit a high level of durability . First attempts were urethane lip-type seals , but their performance was unsatisfactory . A wire brush seal was developed around 1973 , and this enhanced cut-off and lubrication are achieved by supplying a special greasy compound mixed with fibers to the seal , which is shaped like a brush of steel wires . With later improvements , this type of seal achieved a high level of stable performance by the first half of the 1980s . It is the development of this seal that provided a foundation for the development of modern shield technology in Japan , and this seal is used for almost all shield today . It has been said that the Japanese thatched roof was the inspiration behind this innovation .To ensure a god seal at the tail section of a shield , the tunnel segment must be accurately fabricated and assembled . This requirement has driven up the precision of segment construction in Japan . In recent years , accuracy has been increased still further by the use of robots in the assembly process , and by carefully considering the joints between segments . One development made in Japan is to apply a sealing material to the four joint faces of segments so as to cut offwater at the primary lining .A suitable water-swelling sealant was developed in 1980 . In combination with accurately fabricated segments and increased assembly accuracy , this has helped maintain a high level of water cut-off performance . Backfilling of the tail void is an important requirement to prevent ground subsidence and endure stable shield advancement . The invention of a system by which backfilling takes place as the shield is advanced , along with a new thixotropic backfilling material (a material that softens once but recovers its strength with time ), has made shield tunneling work more reliable . For reasons of space restriction , tunnels in Japan are often required to make a sharp turns . To meet this demand , shield equipped with an articulation have been developed .Shield tunneling suffers setbacks even with the best preparation of machinery and materials . Technology for shield advance control is particularly important in minimizing problems . Further , the maintenance of a stable face relies on careful control of surry or earth pressure while adjusting the balance between excavation volume and discharge to prevent overbreaking . One of the characteristic features of shield developed in Japan is that they are fully equipped with sensors , and asvance is controlled by computer . An impressive track record testifies to Japan’s highly developed control techniques , including the fully automated operation of shield .There are many examples of Japanese shield tunneling technology being employed in Asia . When a Japanese earth pressure shield machine was used to successfully complete a tunnel in San Francisco , the U.S , tunnel construction industry was astonished at its performance . Four Japanese shield were used for construction of the Channel Tunnel between the U.K.and France . Thus , Japanese shield tunneling technology gained an excellent reputation during the 1980s . The overseas use of Japanese tunneling technology is perhaps best exemplified by work for the Docklands Light Railway in London , when a Japanese contractor carried out shield tunneling work underneath the River Thames , Thus , technology that evolved in Japan was returned right to its birthplace under the Thames in London .The shield method is now able to operate under a wide range of soil conditions Still , there remains room for improvement , such as in the ability to drive a tunnel through gravel layers . The next challenges is to increase cost efficiency and adapt the method to suit difficult construction conditions beneath urban areas . In recent years the basic technology developed by the 1980s has been carefully examined and a wide variety of derivatives have come into use . Chief among these are the following : overlapped-double-circular cross-section shield , called MF or DOT ; oval and rectangular a spherical shield ca[able of boring both vertical and horizontal shield . As yet , these shields have yet to be used overseas , indicating that Japan’s tunmeling technology is particularly advanced .To increase cost efficiency , it is not only face technology that is important , but also of the rear sections of the tunneling equipment . Consequently , recent emphasis has been on developing the rear section , such as techniques for the assembly of segments and effective use of excavated soil . Segment assembly is a large proportion of the work involved in shield tunneling , accounting for about 40% of the total effort . To rationalize the assembly of segments , special segments geometries and joints have been developed . The use of in-situ concrete instead of segments has also been pioneered .Further , the ability to drive extremely long tunnels and speeding up the advance of shield are considered important challenges . Shield tunneling work has been carried out overdistances of a few kilometers or more , and a shield capable of advancing while segment assembly takes place has become available . The combined efforts of many people and the great demand for tunnels in Japan have drive Japanese tunneling technology into the leading position in the world .But with urban facilities in our major cities still needing considerable improvement , there will be future demand for tunnel excavation under harsh conditions . Now that the Law Concerning Special Measures for Public Use of Spaces Deep under Ground is in place , we have a regulated system for using our underground space . This will surely lead to further improvements and refinements to shield tunneling , including technology for ultra-deep subterranean tunneling .翻译:日本现代化城市发展必须开始从战争的废墟中恢复，在这个发达国家，城市发展的大部分工作需要在很不理想的条件下开展随着经济的快速增长，城市地区社会经济活动达到过度集中，导致很难保障城市设施空间，因此，他们通常不得不建在发达地区，通常从建筑物密集的地区为主要建设区域，此外，大部分的主要日本城市位于存在隧道技术性问题的软弱冲击地层。
基于非线性Hoek-Brown破坏准则对隧道开挖面的支护力研究
安徽建筑中图分类号：U451+.4文献标识码：A文章编号：1007-7359（2023）4-0110-04DOI:10.16330/ki.1007-7359.2023.4.0431引言由于城市人口的逐年增加，导致城市交通压力变大。
研究人员提出以地铁为主，多种交通方式并存的城市轨道交通系统方案来解决城市用地紧张以及交通道路拥堵的问题。
由于在不同的场地环境下，土体的参数差异显著，加之受各种不确定的荷载的影响，隧道开挖面经常会发生坍塌事故，这不仅会打乱原有的隧道掘进计划，严重时还会出现人员伤亡。
因此，隧道开挖面稳定性问题急需解决，隧道开挖面支护力取值的合理性成为目前研究的热点。
在大量实验研究的基础上，Hoek 和Brown 提出了广泛使用的岩土体破坏准则。
广义Hoek-Brown 破坏准则[1]如下所示：（1）式中，m b 、S 、a 为岩体特征的无量纲参数，可分别由下式确定：（2）其中，GSI 代表岩土体强度指数，其大小取决于岩土体的裂隙和岩土体结构发育程度。
当缺乏实验数据时，可以使用Hoek 和Brown [2-3]建议的m i 近似值，该数值与岩土体的类型有关。
文献[4-6]分析表明：Hoek-Brown失效准则加入极限分析主要有两种方法。
一种方法是将非线性破坏准则线性化，得到等效的线性强度参数，如切线法和割线法；另一种方法是根据相应的应力状态计算滑动面上各点的强度参数。
第二种方法基于三维条件进行计算，较为复杂且耗时多。
割线法利用强度包络线来获得等效的线性强度参数。
虽然这种方法比切线法更容易，但结合上界分析，得到的解可能不是严格意义上的上限解。
如图1所示，Hoek-Brown 破坏准则是τ-σn 应力空间中的一条曲线，该曲线上任意点的切线的表达式为：tan t n tc t s j =+（3）其中，c t 和φt 分别是切线的截距和倾角。
图1Hoek-Brown 失效准则切线法根据杨小礼等[7-8]文献，可以建立以下c t 和φt 与Hoek-Brown 失效准则参数的关系:（4）由于Hoek-Brown 破坏准则的非线性，等效的摩擦角φt 需要通过优化程序确定。
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International Symposium on Underground Excavation and Tunnelling2-4 February 2006, Bangkok, ThailandEvaluation of Shield Tunnel Face Stability in Soft GroundSang-Hwan Kim1, Gyeong-Hwan Jeong 2, Inn-Joon Park3, Byeong-Heon Min 11 Dept. of Civil Engineering, Hoseo University, Asan, Korea2 Dong-A Geological Engineering Co., Ltd., Busan, Korea3 Dept. of Civil Engineering, Hanseo University, Seosan, KoreaABSTRACTThis paper presents a study of the tunnel face stability during shield tunnel construction, concentrating on the study of the short-term (undrained) stability of the tunnel face in soft ground encountered under the riverbed in Korea. The design concept and the strong influence of construction procedures are demonstrated and evaluated based on the tunnel face behaviour measured during shield tunnelling in two different sites having different ground conditions and tunnel sizes. An important feature of these case studies is to investigate the influence of tunnel face behaviour due to soil type, tunnel size, and construction procedure in Korea. For each site, the stresses and pore pressures induced at the tunnel face, and the shield heading pressures with cutter torques measured during tunnel advance are investigated, discussed and compared. The paper also presents and discusses the approach methods for evaluating the stability of the tunnel and its heading during drained and undrained condition. In practical, the undrained analyses of the tunnel face stability for shield tunnelling in the sites are carried out based on the field data measured during tunnel construction and the results are also evaluated. According to the results presented in the paper, the future programme to be developed technically is suggested in order to provide a practical knowledge for soft ground tunnelling.1. INTRODUCTIONIn recent, shield tunnelling, which is one of trenchless methods, is becoming general in construction of underground structures, such as subway, underground power line tunnel, communication line tunnel, sewages and gas pipes which were hitherto done by cut and cover method in urban area, due to the progress in tunnel construction technologies. In addition, instead of detouring the construction because of uncontrollable site conditions (people enmity, construction difficulty, etc), a tendency to excavate the riverbed or seabed using shield tunnelling method is growing. This makes it inevitable to excavate soft grounds. However, a most of the tunnel constructions in Korea have been experienced on rock formation (KTA 2003). It, therefore, is necessary to develop the technique of soft ground tunneling in Korea (Kim 1998).This paper presents the tunnel face stability during shield tunnel construction, concentrating on the short-term stability of the tunnel face in soft ground. The design concept and the strong influence of construction procedures are demonstrated and evaluated based on the predicted and measured tunnel face behaviour during shield tunnelling in two different sites having different ground conditions and tunnel sizes.In the case of two shield tunnel construction sites in Korea, one of these sites is in the Geum-river with a cohesionless soil deposit of silty sand (Jeong et al. 2002). The tunnel in this site was constructed to install the riverbed gas pipes, which connect the Kunsan and Seochon in Korea. The other site is located in the Nakdong-river with a cohesive soil deposit of clay (Lee et al. 2000, Kim et al. 2001, Jeong et al. 2002). The tunnel was constructed in order to install the riverbed sewer outlet pipes, which connect the reclaimed land of the Noksan Industrial Complex and Nulcha Island.This paper also reviewed theoretical concepts for the ground behaviour during tunnelling in undrained condition. It also analyzed and evaluated real construction case. Especially the stability of shield tunnel face was simply predicted through a case study. A quantitative calculation on tunnel face stability using the pressure measured from shield tunnel face and an evaluation on face stability during tunnel construction was attempted. An important feature of these case studies is to investigate the influence of tunnel face behaviour due to soil type, tunnel size, and construction procedure.2. SHIELD TUNNELLING IN COHESIONLESS SOIL2.1 Introduction of Geum river siteThe main purpose of this project is to construct the a main pipe line and operation office building in order to supply safely a natural gas and to operate a gas pipe network system since 2000 in Korea. A 1.1 km pipe line section of the route was planned to pass the riverbed using the slurry pressure balance shield method with a 3.5m diameter. Also, it was planned that the tunnel should be constructed inevitably in a silty sand ground to satisfy the minimum requirement of tunnel depth as shown in Figure 1. Therefore, the overburden depth of tunnel was 2.0D, where D is tunnel diameter. The size of the shield tunnel section was selected based on the size, operation and maintenance of main gas and water supply facilities (φ800mm and φ900mm). The inner diameter of the tunnel was 3,350mm and the thickness of shield lining segments was 150mm as shown in Figure 2.Figure 1. Subsurface profile in Geum river site2.2 Tunnel face pressure during tunnel advanceThis section is concerned with the tunnel face pressure pressured by slurry and the tunnel advance during installation of lining segments. Figure 3shows the change of tunnel face pressure duringtunnel advance. The results show that the values oftunnel face pressure, in all tunnel section, wererelatively constant and similar to the water pressuredeveloped at the tunnel depth. This means that thepressure equilibrium in the tunnel face has beenwell controlled. Therefore, additional long-termbehaviour caused by the difference of tunnel facepressure after tunnel excavation could be predictedto be very small. However, it is noted that thetunnel face pressure slightly decreased near thevertical shaft area of arrival station of tunnelexcavation. This is supposedly deduced that thewater pressure was dropped according to theFigure 2. Details of the tunnel section. application of deep well to stabilize the ground ofvertical shaft.Figure 3. Face pressure during tunnel dvance2.3 Thrust force and cutter torqueFigure 4 shows the relationship between thrust force and cutter torque. It can also be seen in this figure that there is not a big difference in each tunnelling section, such as beginning tunnel section (shield launching shaft area), main tunnel section, and final tunnel section (shield arrival shaft area). However, it is found that the thrust forces and cutter torques at the beginning tunnel section were larger than at other tunneling sections. This phenomenon not only is supposedly related to the amount of position error of shield, but could occur during stabilization of the ground around the shield launching shaft. On the other hand, cutter torque is constant during the normal main tunnel advancing, having no relation with thrust force.Although it is hard to find a correlation between the thrust force and cutter torque of this site, The shield cutter torque values measured in this site range from 10 to 70 ton-m (shield machine capacity is about 55 ton-m). These measured values were slightly less than the values (15~90 ton-m, shield machine capacity is about 154 ton-m) observed from other riverbed shield tunnel site.Figure 4. Thrust force vs. cutter torque2.4 Thrust force and tunnel face pressureFigure 5 shows the correlation between thrust force and tunnel face pressure. Since the slope of shield tunnel in this site was relatively gentle, the effective stress acting on the shield lining could be a nearly constant, that is, the tunnel face pressure related to the overburden pressure will be constant theoretically. From the data observed in the field, it is indicated that the tunnel face pressures were in a limited boundary, except at the final tunnel section.Figure 5. Thrust force vs. tunnel face pressure3. SHIELD TUNNELLING IN COHESION SOIL3.1 Introduction of Nakdong river siteThe tunnel site is located on a reclaimed site where settlements occur continuously. The tunnel was planned to pass a section over the sea by slurry pressure balanced shield method in order to protect local fishermen. Based on the subsurface condition in site, it is also expected that the shield tunnelling may be very difficult to pass the border of soft ground and rock formation.Figure 6. Subsurface profile in Nakdong river siteAs shown in Figure 6, the tunnel was planned to pass an undersea section of 1,587m length consisting of 1,499m in clay and silty soil and 88m in rock formation. The tunnel depth was planned to pass under 20~40m from the ground and seabed surface. The size of the shield tunnel section is decided considering the size of the pipes installed inside and the maintenance (repair, waterproof, passages etc) after tunnel construction. Therefore, the outer diameter of the tunnel was designed 3,400mm to install a drain pipe (φ1,650mm), water pipe (φ200mm) and communication line pipe(φ100mm). The shield tunnel segments was 200 mm. Figure 7 shows the details of the tunnel section.3.2 Tunnel face pressure during tunnel advanceThis section is concerned with the tunnel face pressure pressured by slurry and the tunnel advance during installation of lining segments. Figure 8shows the variation of tunnel face pressure duringtunnel advance. The results indicate that the valuesof tunnel face pressure were relatively good agreedwith the total stress calculated theoretically in all tunnelling section. Exception is that the tunnel facepressure was large compared with the theoreticaltotal stress. This could be expected to stabilize theground of shield launching shaft area. From thefield data, it can be deduced that the pressureequilibrium in the tunnel face has been well controlled. Therefore, additional long-term behaviour caused by the difference of tunnel facepressure after tunnel excavation could be predictedto be very small. Especially, the tunnel face pressure in the rock section was measured smaller than theoretical total stress. It means that the tunnel face in rock has more stable than in soft soil. Figure 7. Details of the tunnel section.Figure 8. Face pressure during tunnel advance3.3 Relationship between thrust force and cutter torqueFigure 9 shows the relationship between thrust force and cutter torque. According to the results indicated in Figure 9, it can be found that there is a big difference tendency in each tunnelling section. At the tunnel start section near the shield launching shaft, it is found that the thrust forces and cutter torques were larger than at other tunnelling sections. As mentioned previous, this phenomenon not only is related to the amount of position error of shield, but could occur during stabilization of the ground around the shield launching shaft. On the other hand, cutter torque is constant during the normal main tunnel advancing, having no relation with thrust force.3.4 Correlation between thrust force and tunnel face pressureFigure 10 shows the correlation between thrust force and tunnel face pressure. The results show that the tunnel face pressure is larger than the thrust force during tunnelling in the beginning tunnel section. This implies that the tunnel face was unstable during installation of shield machine at the beginning tunnel section. Therefore, it can be expected that there is a possibility of the tunnel face being pushed out during excavation at the beginning tunnel section. Considering the ground condition, the surrounding ground could have already behaved into plastic to yielding condition. It could be anticipated that the long-term behavior at the beginning tunnel section affects the tunnel structure. In other sections, however, the tunnel face pressure shows a linear proportion to the increase of thrust force. It means that for tunnels in soil, especially soft soil, distinctive from tunnel in rock, theoretical approach well agrees with actual results.Figure 9. Thrust force vs. cutter torqueFigure 10. Thrust force vs. tunnel face pressure4. EVALUATION OF TUNNEL FACE STABILITYThe tunnel face stability was theoretically evaluated using tunnel face pressures measured from theconstruction site presented in Chapter 3 (see Figure 8. Face pressure during tunnel advance).Figure 11. Schematic drawing of the site conditions and Shield machineIn order to simplify the evaluation procedure, an assumption is made that the ground is a normally consolidated clay and undrained shear strength, s u is 60kPa. Also, the lining is installed at the tunnel face during excavation. Figure 11 shows schematic drawing of the site conditions based on the assumptions including actual shield machine.Based on the tunnel stability introduced by Atkinson and Mair (1981), the safety factor of tunnel face stability can be calculated by the following equations (Kim 2003).()Tt s c u s D C T s F σγσ−+⋅+⋅=2/ (1)where T c is a dimensionless tunnel stability number and can be obtainedusing C /D and P /D (P= unlined length)as shown in Figure 12.Using Equation (1) and Figure 11, itcan be estimated the safety factor oftunnel face stability (F s ). Following theabove process, the calculation results forall tunnel section are shown in Figure 13.It can also observed from Figure 13 thatthe shield tunnel has constructed safelyduring the tunnel advance maintainingF s =3, except for the start and end of thetunnel. It, therefore, could be said that the tunnel face stability is generally assured during tunnel excavation. It, however, is assumed that the start of the tunnel had alower tunnel face stability compared toother sections because of the process of installing and settling the shield machine.Figure 12.Tunnel stability number, T c (Atkinson and Mair 1981) Finally, this result is a qualitatively analyzed case study of the tunnelling situation using theoretical approach through field data of the completed shield tunnel. Since the case study ignored site conditions during tunnelling and only used the measured tunnel face pressure, comprehensive analysis of detailed site conditions and ground behavior measurements are required additionally.Figure 13. Evaluation of Safety factor of tunnel face stability5. CONCLUSIONSThis paper presents a study of the tunnel face behaviour during shield tunnel construction, concentrating on the study of the short-term stability of the tunnel face in soft ground encountered under the riverbed in Korea. The design concept and the strong influence of construction procedures are demonstrated and evaluated based on the predicted and measured tunnel face behaviour during shield tunnelling in two different sites having different ground conditions and tunnel sizes. An important feature of these case studies is to investigate the influence of tunnel face behaviour due to soil type, tunnel size, and construction procedure in Korea.The paper also presents and discusses the approach methods for estimating the stability of the tunnel and its heading during undrained condition. In practical, the undrained analyses of the tunnel face stability for shield tunnelling in the sites are carried out based on the field data measured during tunnel construction and the results are also evaluated.According to the results presented in the paper, the future programme to be developed technically is suggested in order to provide a practical knowledge for soft ground tunnelling in Korea. ACKNOWLEDGEMENTThis paper was funded by the Korea Institute of Construction and Transportation Technology Evaluation and Planning under the Ministry of Construction and Transportation in Korea (Grant No. 04-C01).REFERENCESAtkinson, J.H. and Mair, R.J., 1981. “Soil mechanics aspects of soft ground tunnelling.” Ground Engineering, Vol.14, No.5, pp. 20-26,38.Kim, S.H., Burd, H.J. and Milligan, G.W.E., 1998. “Model testing of closely spaced tunnels in clay.”Géotechnique 48, No.3, pp. 375-288.Kim, S.H., Lee, I.K., Kim, T.K., and Kim, Y.J., 2001. “A study of shield tunnel design an construction in the reclaimed site.” The 2nd Symposium on Mechanized Tunnel Construction Technology, Korean Tunnelling Association, Aug., pp.157~173.Kim, S.H. 2003. “Theoretical Approach for ground behaviour during tunneling in soils.” Tunnelling Technology, Volume 5, Number 4, December, Korean Tunnelling Association, pp.301~312.KTA (Korean Tunnelling Association), 2003. “Tunnelling in Korea”, ITA WTC 2006 Bidding Committee, pp. 38-45.Lee, I.K. and Lee, S.H., 2000. “A study of shield tunnel design in very soft ground.” The 1nd Symposium on Mechanized Tunnel Construction Technology, Korean Tunnelling Association, Sept., pp.177-192.Jeong, G.H., Jun, D.C., Kim, S.H., Kim, D.H., and Lee, S.L., 2002. “Shield tunnel construction under the seabed.” The 2nd Symposium on Construction Technology of Tunnel, Korean Society of Civil Engineers, Aug., pp. 91-105.。