|
|
|
| Analysis of excavation deformation and bearing characteristics of ultra deep circular shafts for shield tunneling |
| CAO Chengyong1, 2, 3*, ZHANG Xunlong1, CHEN Xiangsheng1, 2, 3, SONG Chengpeng4, HAN Weijie5 |
(1. College of Civil and Transportation Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China; 2. State Key Laboratory of Intelligent Geotechnics and Tunnelling, Shenzhen University, Shenzhen, Guangdong 518060, China; 3. National Engineering Research Center of Deep Shaft Construction, Beijing 100013, China; 4. Shenzhen Municipal Design and Research Institute Co., Ltd., Shenzhen, Guangdong 518029, China; 5. Shenzhen Railway Investment and Construction Group Co., Ltd.,
Shenzhen, Guangdong 518026, China) |
|
|
|
|
Abstract To investigate the excavation deformation and bearing characteristics of ultra-deep circular shafts for shield tunnels in soil-rock composite strata, this study focuses on the circular shaft foundation pits of a shield tunnel section along the Shenzhen Airport-Daya Bay Intercity Railway. By analyzing field measurement data and numerical calculation results from three adjacent shafts—one main shaft with an inner diameter of 36 m and two service shafts with inner diameters of 12.6 m—an in-depth examination of the excavation deformation characteristics and internal force responses of the ultra-deep circular shafts was conducted. The results indicate that: (1) Under the influence of groundwater level fluctuations, soil and rock excavation, and adjacent slopes, the diaphragm walls of the main shaft exhibit a composite deformation pattern characterized by “cantilever” and “bulging,” with a maximum lateral displacement of 0.52‰He (where He denotes the excavation depth). The diaphragm walls of the service shafts demonstrate overall tilting deformation, with a maximum lateral displacement of 0.18‰He, while the maximum surface settlement reached 0.37‰He. (2) During asynchronous excavation of the shafts, the ratios of the maximum circumferential normal stress to the maximum vertical normal stress for the main and service shafts are 4.8 and 4.4, respectively. In addition, the ratios of the maximum vertical bending moment to the maximum circumferential bending moment are 6.9 and 1.9, respectively. Furthermore, the diaphragm walls exhibit compressive bending per unit depth. The axial forces in the ring beam supports of each shaft are relatively high within the groundwater fluctuation zone or near the soil-rock interface due to various factors, including local overloading and uneven soil-water pressure. (3) A simplified calculation method for determining the vertical bending moment of the diaphragm wall based on inclinometer data was proposed and successfully applied in the engineering case. The calculated maximum vertical bending moment of the main shaft is 78% of the design value. This method can effectively and quantitatively assess the bearing capacity of diaphragm walls during shaft construction, particularly in cases where reinforcement meters are not installed. The findings of this research provide valuable insights for similar circular foundation pit engineering in soil-rock composite strata.
|
|
|
|
|
|
[1] 郭 亮,胡瑞青,相 旭. 盾构始发与接收对竖井围护结构的影响研究[J]. 城市轨道交通研究,2024,27(2):141–146.(GUO Liang,HU Ruiqing,XIANG Xu. Influence of shield launching and receiving on working shaft retaining structure[J]. Urban Mass Transit,2024,27(2):141–146.(in Chinese))
[2] 宋越鹏,范晓锋,梁 禹,等. 城际铁路隧道深大圆形竖井开挖阶段变形监测分析[J]. 现代隧道技术,2024,61(5):219–226.(SONG Yuepeng,FAN Xiaofeng,LIANG Yu,et al. Deformation monitoring and analysis during the excavation of deep circular shafts in intercity railway tunnels[J]. Modern Tunnelling Technology,2024,61(5):219–226.(in Chinese))
[3] 占 城,杨国富,尹 超. 城际铁路盾构竖井断面形式比选分析[J]. 广东土木与建筑,2023,30(8):84–88.(ZHAN Cheng,YANG Guofu,YIN Chao. Analysis and selection of cross-section form of shield working well of intercity railway[J]. Guangdong Architecture Civil Engineering,2023,30(8):84–88.(in Chinese))
[4] 马 飞. 基于数值模拟的群洞式圆形深基坑稳定性研究[硕士学位论文][D]. 石家庄:石家庄铁道大学,2022.(MA Fei. Stability study of group-round foundation pits based on numerical simulation[M. S. Thesis][D]. Shijiazhuang:Shijiazhuang Tiedao University,2022.(in Chinese))
[5] 王卫东,徐中华,宗露丹,等. 软土地区56 m深圆形基坑的优化设计与实践[J]. 建筑结构,2022,52(10):1–10.(WANG Weidong,XU Zhonghua,ZONG Ludan,et al. Optimal design and practice of a 56 m ultra-deep circular excavation in soft soils[J]. Building Structure,2022,52(10):1–10.(in Chinese))
[6] QIAO Y F,XIE F,BAI Z W,et al. Deformation characteristics of ultra-deep circular shaft in soft soil:A case study[J]. Underground Space,2024,16:239–260.
[7] 宗露丹,王卫东,徐中华,等. 软土地区56 m超深圆形竖井基坑支护结构力学分析[J]. 隧道建设(中英文),2022,42(7):1 248–1 256. (ZONG Ludan,WANG Weidong,XU Zhonghua,et al. Mechanical properties of a 56 m deep circular shaft foundation pit support structure in soft soils[J]. Tunnel Construction,2022,42(7):1 248–1 256.(in Chinese))
[8] YAN Y,LI M,XU Z. et al. Effect of stratum distribution on deep circular excavation with dewatering above a multi-aquifer system by hydro-mechanical coupled numerical analysis[J]. Journal of Shanghai Jiaotong University (Science),2024,(1):1–11.
[9] 赵一行,詹刚毅,石钰锋,等. 某超深圆形基坑受力变形的尺寸效应分析[J]. 华东交通大学学报,2021,38(5):23–29.(ZHAO Yixing,ZHAN Gangyi,SHI Yufeng,et al. Analysis of the size effect of a ultra-deep circular foundation pit under stress and deformation[J]. Journal of East China Jiaotong University,2021,38(5):23–29.(in Chinese))
[10] 陈小雨,袁 静,胡敏云,等. 相邻深大基坑安全距离理论分析与数值模拟[J]. 地下空间与工程学报,2019,15(5):1 557–1 564.(CHEN Xiaoyu,YUAN Jing,HU Minyun,et al. Theoretical analysis and numerical simulation of safe distance of adjacent deep foundation pits[J]. Chinese Journal of Underground Space and Engineering,2019,15(5):1 557–1 564.(in Chinese))
[11] 岳树桥,左人宇,陆 钊. 相邻基坑有限宽度土条主动土压力的计算[J]. 岩土力学,2016,37(7):2 063–2 069.(YUE Shuqiao,ZUO Renyun,LU Zhao. A method for calculating active earth pressure of soil piece with a finite width between adjacent foundation pits[J]. Rock and Soil Mechanics,2016,37(7):2 063–2 069.(in Chinese))
[12] ZENG F Y,ZHANG Z J,WANG J H,et al. Observed performance of two adjacent and concurrently excavated deep foundation pits in soft clay[J]. Journal of Performance of Constructed Facilities,2018,32(4):04018040.
[13] 丁 智,王金艳,周 勇,等. 邻近基坑同步施工相互影响实测分析[J]. 土木工程学报,2015,48(增2):124–130.(DING Zhi,WANG Jinyan,ZHOU Yong,et al. Monitoring analysis of the interrelationship of synchronous construction in adjacent foundation pit[J]. China Civil Engineering Journal,2015,48(Supp.2):124–130.(in Chinese))
[14] LIN S Q,TAN D Y,LEUNG Y F,et al. Fiber-optic monitoring of a twin circular shaft excavation:Development of circumferential forces and bending moments in diaphragm walls[J]. Journal of Geotechnical and Geoenvironmental Engineering,2023,149(12):04023117.
[15] XU Q W,XIE J L,ZHU H H,et al. Supporting behavior evolution of ultra-deep circular diaphragm walls during excavation:Monitoring and assessment methods comparison[J]. Tunnelling and Underground Space Technology,2024,143:105495.
[16] 邱滟玲,丁文其,赵腾腾,等. 单侧卸荷诱发深基坑的不对称性变形特性与机制[J]. 岩土工程学报,2024,46(1):199–206.(QIU Yanling,DING Wenqi,ZHAO Tengteng,et al. Asymmetrical deformation characteristics and mechanisms of deep excavations induced by one-side unloading[J]. Chinese Journal of Geotechnical Engineering,2024,46(1):199–206.(in Chinese))
[17] 韩伟杰,杨国富,曹成勇,等. 轨道交通深圆形工作井基坑尺寸效应分析[J]. 都市快轨交通,2024,37(6):99–105.(HAN Weijie,YANG Guofu,CAO Chengyong,et al. Size effect of deep circular working shaft excavation for rail transit construction[J]. Urban Rapid Rail Transit,2024,37(6):99–105.(in Chinese))
[18] 王卫东,徐中华,王建华. 上海地区深基坑周边地表变形性状实测统计分析[J]. 岩土工程学报,2011,33(11):1 659–1 666.(WANG Weidong,XU Zhonghua,WANG Jianhua. Statistical analysis of characteristics of ground surface settlement caused by deep excavations in Shanghai soft soils[J]. Chinese Journal of Geotechnical Engineering,2011,33(11):1 659–1 666.(in Chinese))
[19] 崔剑峰,胡建华,贺 炜,等. 圆形地下连续墙的环向刚度折减效应及修正方法研究[J]. 岩土工程学报,2017,39(11):2 132–2 138. (CUI Jianfeng,HU Jianhua,HE Wei,et al. Hoop stiffness and its reduction factor of diaphragm wall panels for circular excavation[J]. Chinese Journal of Geotechnical Engineering,2017,39(11):2 132–2 138.(in Chinese))
[20] 毛朝辉. 基于监测数据的围护墙弯矩反分析及安全评估研究[硕士学位论文][D]. 上海:同济大学,2006.(MAO Zhaohui. Study on back analysis for bending moment of retaining wall and safety evaluation based on monitoring data[M. S. Thesis][D]. Shanghai:Tongji University,2006.(in Chinese))
[21] 顾雷雨,黄宏伟. 基于监测数据的围护墙弯矩计算方法及其与基坑安全相关性研究[C]// 2010力学与工程应用学术研讨会论文集. 上海:[s. n.],2010:202–213.(GU Leiyu,HUANG Hongwei. Method of calculating bending moment of the retaining structure based on themonitoring data and application to the relationship of excavation safety[C]// Proceedings of the 2010 Academic Symposium on Mechanics and Engineering Applications. Shanghai:[s. n.],2010:202–213.(in Chinese))
[22] 中华人民共和国国家标准编写组. GB 50010—2010混凝土结构设计规范[S]. 北京:中国建筑工业出版社,2015.(The National Standards Compilation Group of People′s Republic of China. GB 50010—2010 Code for design of concrete structures[S]. Beijing:China Architecture and Building Press,2015.(in Chinese)) |
| [1] |
LIU Baoguo1, 2*, LAI Haixiang1, 2, SHI Xiaomeng1, 2, CHU Zhaofei3, ZHAO Jinpeng4, YU Mingyuan5. Viscoelastic analytical solution of deep buried circular tunnel considering support creep in non-hydrostatic stress field[J]. , 2026, 45(2): 342-352. |
|
|
|
|