Research on Formation Mechanism and Optimization Control of Segment Crack Damage under Combined Thrust
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摘要: 针对施工过程中千斤顶推力作用下管片损伤问题开展研究。以苏州某地铁线路实际情况为基础，建立多环三维有限元模型，对千斤顶推力过大及推力不均综合作用下管片裂损形成、演化规律及损伤分布等进行分析，并提出相应的工程控制措施。研究结果表明：不同推力作用下，管片损伤主要沿着螺栓孔均匀分布，且内弧面损伤大于外弧面，管片的最大损伤因子呈近似线性增大，损伤面积呈非线性增加。当推力均匀分布时，管片损伤主要集中于第1环管片，当出现不均匀推力时，管片损伤会向推力较大侧转移，并逐渐向第2环和第3环管片发展，推力不均使得相同推力下管片裂缝出现的荷载提前约11%。设计施工中可以通过严格控制千斤顶不均匀推力、优化管片设计、实行分段控制等工程控制措施，减少盾构施工阶段管片裂损的形成。Abstract: The damage of segment under the thrust of jacks during construction was studied. Based on the actual situation of a subway line in Suzhou, a multi-ring three-dimensional finite element model was established to analyze the formation, evolution and distribution of shield segment fracture under the combined action of excessive and uneven thrust of jacks, and the corresponding engineering control measures were put forward. The results show that the segment damage is mainly distributed uniformly along the bolt hole under different thrust, and the damage on the inner cambered surface is larger than that on the outer cambered surface. The maximum damage factor of the segment increases approximately linearly, and the damage area increases nonlinearly. When thrust is evenly distributed, segment damage is mainly concentrated in the first ring segment, while when thrust is not uniform, segment damage will transfer to the side with larger thrust, and gradually develop to the second and third ring segment. The uneven thrust forces advance the loading of segment cracks by about 11% under the same thrust. The formation of segment crack damage during shield construction can be reduced by adopting engineering control measures such as strictly controlling uneven thrust of jacks, optimizing segment design and implementing segment control.
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Key words:
- shield tunnel /
- combined thrust /
- segment crack /
- construction control
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表 2 混凝土拉伸压缩特性
单轴受压 单轴受拉 应力${\sigma _{\rm{c}}}$/Pa 非弹性应变$\tilde \varepsilon _{\rm{c}}^{in}$ 损伤因子${d_{\rm{c}}}$ 应力${\sigma _{\rm{t}}}$/Pa 开裂应变$\tilde \varepsilon _{\rm{t}}^{{\rm{ck}}}$ 损伤因子${d_{\rm{t}}}$ 26620217 0 0 3268020 0 0 38066433 0.000660275 0.211338 3109367 0.000029387 0.133267 34625299 0.001104221 0.312774 2745121 0.000069313 0.271586 28376167 0.001628189 0.423653 2287534 0.000111903 0.392993 22753855 0.002134148 0.516989 1927084 0.000151719 0.484189 18442766 0.002602565 0.589848 1657959 0.000188927 0.552458 15246282 0.003039052 0.646097 1298162 0.000258249 0.645788 12861371 0.003452257 0.689987 921384 0.000387097 0.747787 9641356 0.004234078 0.752972 609247 0.000632153 0.836385 6270598 0.005708696 0.825654 388633 0.001110578 0.900559 3604483 0.008535932 0.890875 244346 0.002058286 0.941891 1803351 0.014837140 0.941205 152767 0.003945412 0.966776 95320 0.007705455 0.981214 59528 0.015181170 0.989422 37369 0.02996564 0.994034 17378 0.09530968 0.997719 
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表 4 千斤顶推力过大和推力不均工况设置表
总推力/kN 工况 分区推力比值 上分区 下分区 左分区 右分区 16000 ① 1∶1∶1∶1 4.00 4.00 4.00 4.00 ② 4∶4∶5∶3 4.00 4.00 5.00 3.00 ③ 2∶2∶3∶1 4.00 4.00 6.00 2.00 18000 ① 1∶1∶1∶1 4.50 4.50 4.50 4.50 ② 4∶4∶5∶3 4.50 4.50 5.625 3.375 ③ 2∶2∶3∶1 4.50 4.50 6.75 2.25 20000 ① 1∶1∶1∶1 5.00 5.00 5.00 5.00 ② 4∶4∶5∶3 5.00 5.00 6.25 3.75 ③ 2∶2∶3∶1 5.00 5.00 7.50 2.50 22000 ① 1∶1∶1∶1 5.50 5.50 5.50 5.50 ② 4∶4∶5∶3 5.50 5.50 6.875 4.125 ③ 2∶2∶3∶1 5.50 5.50 8.25 2.75
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表 5 最大损伤因子统计表
推力/kN 推力分区 工况①
1∶1∶1∶1工况②
4∶4∶5∶3工况③
3∶3∶2∶116000 0.3726 0.5227 0.6284 18000 0.4435 0.6001 0.6879 20000 0.5372 0.6612 0.7595 22000 0.6195 0.7221 0.8708
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[1] 刘建航, 侯学渊. 盾构法隧道[M]. 北京: 中国铁道出版社, 1991. [2] HE C,WANG B. Research progress and development trends of highway tunnels in China[J]. Journal of Modern Transportation,2013,21(4):209-223. doi: 10.1007/s40534-013-0029-4 [3] [日]土木学会编. 隧道标准规范(盾构篇)及解说[M]. 朱 伟译. 北京: 中国建筑工业出版社. 2001. [4] 苏 昂. 千斤顶推力不均对盾构管片裂纹扩展的影响研究[J]. 铁道标准设计,2018,62(11):103-107,113. doi: 10.13238/j.issn.1004-2954.201801020006 [5] 苏 昂. 千斤顶过大荷载作用管片裂纹扩展规律探析[J]. 四川建筑,2018,38(3):108-110. doi: 10.3969/j.issn.1007-8983.2018.03.040 [6] 苏 昂. 千斤顶偏心荷载作用下盾构隧道管片裂纹扩展规律[J]. 铁道建筑,2018,58(5):66-69. doi: 10.3969/j.issn.1003-1995.2018.05.16 [7] 张 鹏. 盾构隧道管片施工力学性能三维数值模拟研究[J]. 铁道工程学报,2012,29(10):63-69. doi: 10.3969/j.issn.1006-2106.2012.10.013 [8] 白廷辉,郑勇波,李晓军,等. 施工阶段盾构衬砌结构受力特性影响因素数值分析[J]. 施工技术,2019,48(7):98-102. [9] 卢岱岳,何 川,王士民. 千斤顶作用下带榫管片的裂纹扩展规律[J]. 西南交通大学学报,2017,52(1):75-82. doi: 10.3969/j.issn.0258-2724.2017.01.011 [10] 李 林. 大直径盾构隧道管片裂缝与施工参数的关系[J]. 公路交通科技(应用技术版),2018,14(10):246-250. [11] 过镇海. 混凝土的强度和本构关系—原理与应用[M]. 北京: 中国建筑工业出版社, 2004. -
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