Circumferential forces and deformations of shield tunnels due to lateral excavation
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摘要: 针对基坑开挖旁侧盾构隧道结构横向受力和变形规律,提出了一种考虑围护结构变形影响的盾构隧道横向受力理论计算方法,并通过某实际工程三维有限元计算结果和干砂地层隧道旁侧基坑开挖离心模型试验结果,验证了隧道径向附加荷载理论计算方法的可靠性。结合该工程获取的围护桩水平位移、地表沉降、隧道变形和应变现场实测数据,探究了隧道横向受力-变形-内力之间的关联机制。结果表明:①隧道初始径向荷载呈“葫芦形”对称分布,侧方开挖引起隧道近基坑侧和拱顶外荷载减小,而远基坑侧和拱底外荷载增大,这与开挖引起的自由场地层位移和隧道位移相对大小有关,水平和竖向不均衡荷载由隧道纵向差异变形引起的环间剪切力平衡。②隧道椭圆形变形、朝基底方向的顺时针旋转角度和正负弯矩值随开挖不断增大。③隧道环向弯矩分布与螺栓相对位置关系密切相关,研究断面处近基坑侧拱腰附近存在螺栓,其将承担更多的环向拉应力;远基坑侧拱腰附近为混凝土管片,环向拉应力主要由管片承担,从而使得研究断面处隧道管片最大环向弯矩发生在远基坑侧拱腰位置。Abstract: To investigate its transverse forces and deformations subjected to lateral excavation, a theoretical approach for estimating the transverse forces of a shield tunnel considering the influences of deflections of retaining wall proposed. The calculated radial additional loads on the tunnel is compared with the results of three-dimensional finite element analysis of a case history and centrifuge modeling of excavation effects on a nearby existing tunnel in dry sand, which verifies the reliability of this approach. Based on the measured pile deflections, ground settlements, tunnel deformations and structural strains from this case history, the interaction mechanisms of the transverse forces, deformations and internal forces of the tunnel are analyzed. The results show that: (1) The initial radial loads on the tunnel are symmetrically distributed in a "gourd shape". The lateral excavation results in the decrease in the loads on the tunnel crown and right springline near excavation, while the loads on the tunnel invert and left springline away from excavation increase. This phenomenon is related to the relative values of the free-field ground displacements and measured tunnel displacements caused by excavation. The horizontal and vertical unbalanced loads are balanced by the shear force between neighboring rings caused by longitudinal differential deformations of the tunnel. (2) The elliptical deformations, clockwise rotations and bending moments of the tunnel all increase as the excavation proceeds. (3) The distribution of the circumferential bending moment of the tunnel is closely related to the relative position of the bolts. There are bolts near the right tunnel springline closer to the excavation at the investigated cross section, which bear more circumferential tension stress. In comparison, there are no bolts adjacent to the left tunnel away from the excavation, and thus the circumferential tension stress is mainly undertaken by the segments. Hence, the maximum circumferential bending moment of the tunnel at the investigated cross section occurs at the left springline.
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Keywords:
- deep excavation /
- lateral shield tunnel /
- circumferential force /
- deformation /
- bending moment
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表 1 主要土体物理力学参数
Table 1 Physical and mechanical parameters of main soils
土层 w/% γ/(kN·m-3) Es/MPa c/kPa ϕ/(°) ①1杂填土 27.8 17.9 6.0 8 18 ④c碎石 22.2 19.5 11.3 52 32 ⑤1残积土 23.5 19.4 12.5 39 20 ⑩1强风化含
粉砂泥岩— 20.5 46.0 50 18 ⑩2-2中风化
含粉砂泥岩— 22.9 62.0 70 20 注:w为含水率;γ为重度;Es为压缩模量;c为黏聚力(固结快剪);ϕ为内摩擦角(固结快剪)。 表 2 X0+364施工顺序
Table 2 Construction sequence at X0+364
工序 施工时间 开挖或支撑深度/m 第一层土方开挖 07-22—08-18 1.0~8.4 第二道混凝土支撑浇筑 08-19—08-29 7.4~8.4 第二层土方开挖 08-30—10-12 8.4~13.7 第三道钢支撑安装 10-12—10-15 13.1~13.7 第三层土方开挖 10-16—10-31 13.7~17.7 底板浇筑 11-01—11-08 16.0~17.7 表 3 隧道外荷载
Table 3 Magnitudes of external loads on tunnel
单位:kPa 初始荷载 数值 附加荷载 数值 p1 228.1 p7 -21.7 p2 255.1 p8 +7.0 p3 41.1 p9 -3.3 p4 57.5 p10 +13.9 p5 8.6 — — p6 20.7 — — 表 4 有限元计算土体参数
Table 4 Soil parameters for finite element calculations
土层 γ/(kN·m-3) Eoedref/MPa E50ref/MPa Eurref/MPa m c′/kPa φ′/(°) γ0.7/10-4 G0ref/MPa ①1 17.9 6.0 6.0 18.0 0.50 7 15 — — ④c 19.5 11.3 11.3 33.9 0.50 32 15 — — ⑤1 19.4 12.5 12.5 50.0 0.65 32 14 2.1 103.2 ⑩1 20.5 38.3 38.3 114.9 0.50 34 17 1.0 120.5 ⑩2-2 22.9 51.7 51.7 155.1 0.50 48 20 — — 注:Eoedref为参考切线模量;E50ref为参考割线模量;Eurref为参考卸载再加载模量;m为模量应力水平相关幂指数;c′为有效黏聚力;φ′为有效内摩擦角;γ0.7为剪切模量衰减到初始剪切模量70%时所对应的剪应变;G0ref为初始剪切模量。 -
[1] CHEN R P, MENG F Y, LI Z C, et al. Investigation of response of metro tunnels due to adjacent large excavation and protective measures in soft soils[J]. Tunnelling and Underground Space Technology, 2016, 58: 224-235. doi: 10.1016/j.tust.2016.06.002
[2] SHI C H, CAO C Y, LEI M F, et al. Effects of lateral unloading on the mechanical and deformation performance of shield tunnel segment joints[J]. Tunnelling and Underground Space Technology, 2016, 51: 175-188. doi: 10.1016/j.tust.2015.10.033
[3] 张治国, 张孟喜, 王卫东. 基坑开挖对临近地铁隧道影响的两阶段分析方法[J]. 岩土力学, 2011, 32(7): 2085-2092. doi: 10.3969/j.issn.1000-7598.2011.07.028 ZHANG Zhiguo, ZHANG Mengxi, WANG Weidong. Two-stage method for analyzing effects on adjacent metro tunnels due to foundation pit excavation[J]. Rock and Soil Mechanics, 2011, 32(7): 2085-2092. (in Chinese) doi: 10.3969/j.issn.1000-7598.2011.07.028
[4] SAGASETA C. Analysis of undrained soil deformation due to ground loss[J]. Géotechnique, 1987, 37(3): 301-320. doi: 10.1680/geot.1987.37.3.301
[5] CHENG H Z, CHEN R P, WU H N, et al. A simplified method for estimating the longitudinal and circumferential behaviors of the shield-driven tunnel adjacent to a braced excavation[J]. Computers and Geotechnics, 2020, 123: 103595. doi: 10.1016/j.compgeo.2020.103595
[6] 魏纲, 张鑫海, 林心蓓, 等. 基坑开挖引起的旁侧盾构隧道横向受力变化研究[J]. 岩土力学, 2020, 41(2): 635-644, 654. https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202002035.htm WEI Gang, ZHANG Xinhai, LIN Xinbei, et al. Variations of transverse forces on nearby shield tunnel caused by foundation pits excavation[J]. Rock and Soil Mechanics, 2020, 41(2): 635-644, 654. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTLX202002035.htm
[7] MENG F Y, CHEN R P, LIU S L, et al. Centrifuge modeling of ground and tunnel responses to nearby excavation in soft clay[J]. Journal of Geotechnical and Geoenvironmental Engineering, 2021, 147(3): 04020178. doi: 10.1061/(ASCE)GT.1943-5606.0002473
[8] 陈仁朋, ASHRAF A M, 孟凡衍. 基坑开挖对旁侧隧道影响及隔断墙作用离心模型试验研究[J]. 岩土工程学报, 2018, 40(增刊2): 6-11. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2018S2004.htm CHEN Renpeng, ASHRAF A M, MENG Fanyan. Three-dimensional centrifuge modeling of influence of nearby excavations on existing tunnels and effects of cut-off walls[J]. Chinese Journal of Geotechnical Engineering, 2018, 40(S2): 6-11. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2018S2004.htm
[9] MENG F Y, CHEN R P, XU Y, et al. Centrifuge modeling of effectiveness of protective measures on existing tunnel subjected to nearby excavation[J]. Tunnelling and Underground Space Technology, 2021, 112: 103880. doi: 10.1016/j.tust.2021.103880
[10] LIANG R Z, WU J, SUN L W, et al. Performances of adjacent metro structures due to zoned excavation of a large-scale basement in soft ground[J]. Tunnelling and Underground Space Technology, 2021, 117: 104123. doi: 10.1016/j.tust.2021.104123
[11] GONG W P, WANG L, JUANG C H, et al. Robust geotechnical design of shield-driven tunnels[J]. Computers and Geotechnics, 2014, 56: 191-201. doi: 10.1016/j.compgeo.2013.12.006
[12] VESIC A B. Beam on elastic subgrade and the Winkler's hypothesis[C]//Proceedings of the Fifth International Conference of Soil Mechanics and Foundation Engineering. Paris, 1961.
[13] 张陈蓉, 俞剑, 黄茂松. 软黏土中水平循环荷载作用下刚性短桩的p–y曲线分析[J]. 岩土工程学报, 2011, 33(增刊2): 78-82. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2011S2015.htm ZHANG Chenrong, YU Jian, HUANG Maosong. P–y curve analyses of rigid short piles subjected to lateral cyclic load in soft clay[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(S2): 78-82. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2011S2015.htm
[14] WU H N, SHEN S L, LIAO S M, et al. Longitudinal structural modelling of shield tunnels considering shearing dislocation between segmental rings[J]. Tunnelling and Underground Space Technology, 2015, 50: 317-323. doi: 10.1016/j.tust.2015.08.001
[15] NG C W W, HONG Y, LIU G B, et al. Ground deformations and soil-structure interaction of a multi-propped excavation in Shanghai soft clays[J]. Géotechnique, 2012, 62(10): 907-921. doi: 10.1680/geot.10.P.072
[16] LI Z F, LIN W A, YE J N, et al. Soil movement mechanism associated with arching effect in a multi-strutted excavation in soft clay[J]. Tunnelling and Underground Space Technology, 2021, 110: 103816. doi: 10.1016/j.tust.2021.103816
[17] HUANG X, SCHWEIGER H F, HUANG H W. Influence of deep excavations on nearby existing tunnels[J]. International Journal of Geomechanics, 2013, 13(2): 170-180. doi: 10.1061/(ASCE)GM.1943-5622.0000188
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