西安建筑科技大学学报(自然科学版)

随着城市地铁线路穿越山地环境及交通干线的日益增多,车站基坑邻近边坡以及横跨交通干道作为两种典型的特殊施工环境变得愈发难以避免,而采用顺逆结合施工技术可有效缓解基坑工程与现有交通的矛盾.现有研究对于偏压环境下地铁车站基坑顺逆结合施工过程的系统分析相对欠缺,为分析偏压环境及顺逆结合施工方式对于基坑稳定性的影响,本文依托深圳轨道交通2号线莲塘口岸站工程,基于现场监测数据分及数值模拟方法对偏压环境下顺逆结合施工过程中地层及围护结构的稳定性情况进行了研究.结果显示,施工过程中基坑土体及围护结构均处于稳定状态,施工完成后地表沉降主要影响区分布在0～1.25H之间,次要影响区在1.25～2.0H之间,沉降最大值出现在0.25H区域附近(H为基坑开挖深度),相对于无偏压环境扩大了25%的沉降影响范围.边坡偏压的存在主要影响邻近边坡处围护桩变形,偏压侧拉锚作用可显著减小围护桩的水平变形,相对于无锚索情况可有效缩减10倍的围护桩水平变形.

With the increasing number of subway lines crossing the mountain and transport arteries, it becomes more difficult to avoid the situation of the station adjacent to side slope and the cross-city traffic artery. Through the combination method of bottom-up and top-down technology, contradiction between the foundation pit project and the existing traffic can be well relieved. There is a lack of systematic analysis on the construction process of the subway station foundation pit under the bias environment. Based on the project of Liantangkouan metro station of No. 2 rail line in Shenzhen, deformation characteristics of stratum and supporting structures were analyzed through practical monitor data and numerical simulation method, to obtain the effect of bias pressure of high slope and the construction method. As the results shown, the foundation pit soil mass and the surrounding structure are in a stable state during the construction. Also, the main impact area of surface subsidence is distributed between 0～1.25H, when the secondary impact area is between 1.25～2.0H(“H” refers to the depth of excavated pit). The maximum settlement is distributed around 0.25H. The influence range of settlement is increased by 25% compared with the unbiased environment. Moreover, the existence of slope bias mainly affects the deformation of retaining piles near slope. The anchor tension plays an important role that the maximum horizontal deformation of the support piles can be reduced by approximately 10 times.

引言
1 工程概况
2 基于现场监测的基坑稳定性分析
3 有限差分数值计算
4 结论

图1 莲塘口岸地铁车站站位布置图<br/>Fig.1 Location of the Liantangkouan metro station

图1 莲塘口岸地铁车站站位布置图
Fig.1 Location of the Liantangkouan metro station

图2 地铁车站基坑平面布置<br/>Fig.2 Layout of themetro station

图2 地铁车站基坑平面布置
Fig.2 Layout of themetro station

图3 莲塘口岸站基坑围护结构示意图(单位:mm)<br/>Fig.3 Supporting structure of Liantangkouanmetro station/mm

图3 莲塘口岸站基坑围护结构示意图(单位:mm)
Fig.3 Supporting structure of Liantangkouanmetro station/mm

图4 莲塘口岸站地表沉降监测数据<br/>Fig.4 Monitor data for ground surface settlement of Liantangkouan metro station

图4 莲塘口岸站地表沉降监测数据
Fig.4 Monitor data for ground surface settlement of Liantangkouan metro station

图5 莲塘口岸站水平支撑轴力监测数据<br/>Fig.5 Monitor data for horizontal support axial force of Liantangkouan metro station

图5 莲塘口岸站水平支撑轴力监测数据
Fig.5 Monitor data for horizontal support axial force of Liantangkouan metro station

图6 基坑围护桩及边墙土体水平变形监测数据<br/>Fig.6 Monitor data for horizontal deformation of retaining pile and side wall soil mass

图6 基坑围护桩及边墙土体水平变形监测数据
Fig.6 Monitor data for horizontal deformation of retaining pile and side wall soil mass

图7 莲塘口岸站基坑数值计算模型<br/>Fig.7 Simulation model of Liantangkouan metro station

图7 莲塘口岸站基坑数值计算模型
Fig.7 Simulation model of Liantangkouan metro station

表1 岩土体模型物理力学参数<br/>Tab.1 Physical and mechanical parameters of soil

表1 岩土体模型物理力学参数
Tab.1 Physical and mechanical parameters of soil

表2 支护结构参数<br/>Tab.2 Parameters of support structural elements

表2 支护结构参数
Tab.2 Parameters of support structural elements

图8 地表位移数值模拟与监测对比分析<br/>Fig.8 Comparison of the ground displacement during excavation

图8 地表位移数值模拟与监测对比分析
Fig.8 Comparison of the ground displacement during excavation

图9 围护桩顶水平变形数值模拟与监测对比分析<br/>Fig.9 Comparison of the pile-top horizontal deformation

图9 围护桩顶水平变形数值模拟与监测对比分析
Fig.9 Comparison of the pile-top horizontal deformation

图10 基坑周围地表沉降影响区划分<br/>Fig.10 Area division of ground surface settlement

图10 基坑周围地表沉降影响区划分
Fig.10 Area division of ground surface settlement

图11 基坑开挖区周围地层最大剪应力分布图(单位:Pa)<br/>Fig.11 Contour map of the max shear stress(unit: Pa)

图11 基坑开挖区周围地层最大剪应力分布图(单位:Pa)
Fig.11 Contour map of the max shear stress(unit: Pa)

图12 基坑围护桩水平变形分析<br/>Fig.12 Analysis on the horizontal deformation of piles

图12 基坑围护桩水平变形分析
Fig.12 Analysis on the horizontal deformation of piles

图13 基坑偏压侧围护桩拉锚作用分析<br/>Fig.13 Analysis on the anchor tension on supporting piles

图13 基坑偏压侧围护桩拉锚作用分析
Fig.13 Analysis on the anchor tension on supporting piles

[1] 王志红. 北京地铁平乐园站盖挖逆筑深基坑设计[J]. 岩土工程学报, 2012, 34(S1): 699-704.
[2] 刘继强, 田志强, 林志斌, 等. 高边坡对邻近基坑稳定性的影响研究[J]. 隧道建设, 2011, 31(3): 294-300.
[3] 李大鹏, 唐德高, 闫凤国, 等. 深基坑空间效应机理及考虑其影响的土应力研究[J]. 浙江大学学报(工学版), 2014, 48(9): 1632-1639, 1720.
[4] 刘波, 章定文, 席培胜. 偏压基坑工程设计、施工与受力变形特性研究进展[J]. 中国矿业大学学报, 2018, 47(4): 791-804.
[5] LIU Jie, HENG Hengcao, XIAO Fengjiang. Deformation monitoring and numerical analysis at the top of slope of a foundation pit[J]. Applied Mechanics and Materials. 2013, 353: 640-43.
[6] 石钰锋, 阳军生, 白伟, 等. 紧邻铁路偏压基坑围护结构变形与内力测试分析[J]. 岩石力学与工程学报, 2011, 30(4): 826-833.
[7] 徐烨, 冯仁麟, 吴跃华. 地铁车站偏载深基坑围护结构设计分析[J]. 城市轨道交通研究, 2012, 15(9): 43-48.
[8] 刘波, 席培胜, 章定文. 偏压作用下非等深基坑开挖效应数值分析[J]. 东南大学学报, 2016, 46(4): 853-859.
[9] 王海龙, 方焘, 余小强, 等. 临江下立交匝道偏压基坑开挖方案优化[J]. 铁道科学与工程学报, 2016, 13(6): 1061-1067.
[10]中华人民共和国住房和城乡建设部. 城市轨道交通工程监测技术规范: GB 50911—2013[S]. 北京: 中国建筑工业出版社, 2013.
[11]朱安龙, 张胤, 戴妙林, 等. 基于FLAC3D数值模拟的让压锚索边坡加固机理研究[J]. 岩土工程学报, 2017, 39(4): 713-719.
[12]谢和平, 周宏伟, 王金安, 等. FLAC在煤矿开采沉陷预测中的应用及对比分析[J]. 岩石力学与工程学报, 1999(4): 29-33.
[13]聂淼. 深基坑开挖过程数值模拟及支护对策[D]. 贵州: 贵州大学地质工程, 2009.
[14]HSIEH Piogo, OU Changyu. Shape of ground surface settlement profiles caused by excavation[J]. Canadian Geotechnical Journal, 1998, 35(6): 1004-1017.
[15]郑杰明, 谢玖琪, 杨平, 等. 深基坑开挖支护结构水平变形对地表沉降影响的数值模拟[J]. 现代隧道技术, 2013, 50(2): 102-108.

备注

引言

1 工程概况

2 基于现场监测的基坑稳定性分析

3 有限差分数值计算

4 结论

期刊信息