西安建筑科技大学学报(自然科学版)

黄土地区地铁竖井转横通暗挖施工稳定性分析

卫守峰^1,2

(1.中国铁建大桥工程局集团有限公司,天津 300300; 2.西安建筑科技大学陕西省岩土与地下空间工程重点实验室,陕西西安 710055)

Optimization analysis of tunnel construction methods through cross aisle from subway shaft based on numerical test analysis in loess stratum

WEI Shoufeng^1,2

(1.Chinese Railway Bridge Engineering Bureau Group Co.Ltd., Tianjin 300300, China; 2.Key Laboratory of Geotechnical and Underground Space Engineering of Shaanxi Province, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China )

Keywords： subway engineering; cross aisle from subway shaft; construction method; loess strata; numerical simulation

DOI: 10.15986/j.1006-7930.2020.03.009

备注

摘要

全文

图/表

参考文献

针对地铁暗挖采用的竖井转横通道施工中采用的先竖井封底,再通过井内临时搭设的施工平台进行竖井转横通道施工的“先竖井后横通”施工方案存在的施工周期长、安全隐患大的问题,依托在建的西安地铁五号线区间黄土隧道工程的施工,进行了竖井转横通道施工方案的数值试验研究,分析了黄土地层中“先竖井后横通”施工和竖井施工到横通道高程后先转入横通道施工,在横通道具备作业空间后进行竖井下部开挖的“竖井-横通并行”施工时竖井-横通道结构及地层的变形、受力特点,对比研究两种施工方案引起的地表沉降及围岩塑性区的变化.数值分析表明,“竖井-横通并行”施工时,马头门横向收敛位移和竖井靠近马头门一侧井壁的支护结构应力较“先竖井后横通”施工方案小约14%以上,因此对稳定性较好的黄土地层,建议采用“竖井-横通并行”施工方案.

The safety control of excavation through cross aisle from subway shaft is the key technology in building urban metro.The old method applied is to excavate the shaft to design elevation position and then to excavate the cross aisle.Owing to the long excavating time and too much space taken,the paper takes finite element analysis software to analyze a new method,i.e. to excavate the shaft to the temporary inverted arch elevation position in superior step of the cross aisle and then to excavate the shaft based on successfully using the last method in the construction through cross aisle from subway shaft of Xian rail traffic line 5 in the first phase.The paper analyzes the consolidation safety in two different ways by large finite element analysis Software.Results show that the surface and construction about the cross aisle show the same results after the whole excavation in loess stratum.And the new way can get a better result,about 30%, at controlling the crosswise strain of the horsehead and the mechanical conditions of sidewall, so that the tunnels were more stable.Comparative analysis of field monitoring results prove economic, security and feasibility of “cross-channel parallel shaft construction” program.

引言
1 竖井转横通道施工方案比选分析
2 竖井转横通道施工稳定性数值试验
3 竖井转横通道施工及现场监测
4 结论

图1 区间隧道施工竖井剖面图(单位:cm)<br/>Fig.1 Geological conditions of shafts(unit: cm)

图1 区间隧道施工竖井剖面图(单位:cm)
Fig.1 Geological conditions of shafts(unit: cm)

表1 竖井支护参数表<br/>Tab.1 Shaft supporting parameter

表1 竖井支护参数表
Tab.1 Shaft supporting parameter

表2 横通道支护参数表<br/>Tab.2 Cross passage supporting parameter

表2 横通道支护参数表
Tab.2 Cross passage supporting parameter

图2 方案一施工工序图<br/>Fig.2 Construction sequence of the first plan

图2 方案一施工工序图
Fig.2 Construction sequence of the first plan

图3 方案二施工工序图<br/>Fig.3 Construction sequence of the second plan

图3 方案二施工工序图
Fig.3 Construction sequence of the second plan

图4 竖井转横通道施工模拟数值模型<br/>Fig.4 Location of shaft and cross passage

图4 竖井转横通道施工模拟数值模型
Fig.4 Location of shaft and cross passage

表3 模型物理力学参数表<br/>Tab.3 Physico-mechanical parameters of model

表3 模型物理力学参数表
Tab.3 Physico-mechanical parameters of model

图5 先竖井后横通施工时竖井转横通施工工序(方案一)<br/>Fig.5 Construction of the first plan shaft and cross passage

图5 先竖井后横通施工时竖井转横通施工工序(方案一)
Fig.5 Construction of the first plan shaft and cross passage

图6 并行方案时竖井转横通道施工工序(方案二)<br/>Fig.6 Shaft construction and cross passage of second plan

图6 并行方案时竖井转横通道施工工序(方案二)
Fig.6 Shaft construction and cross passage of second plan

表4 竖井转横通道施工中竖井最大变形对比表(单位:mm)<br/>Tab.4 Maximum deformation of shaft(unit: mm)

表4 竖井转横通道施工中竖井最大变形对比表(单位:mm)
Tab.4 Maximum deformation of shaft(unit: mm)

图7 地表沉降(单位:mm)<br/>Fig.7 Ground surface settlement(unit: mm)

图7 地表沉降(单位:mm)
Fig.7 Ground surface settlement(unit: mm)

图8 竖井井壁随深度变化曲线<br/>Fig.8 Deformation of shaft under different depth

图8 竖井井壁随深度变化曲线
Fig.8 Deformation of shaft under different depth

表5 竖井最大受力对比表(单位:kPa)<br/>Tab.5 Maximum force of shaft(unit: kPa)

表5 竖井最大受力对比表(单位:kPa)
Tab.5 Maximum force of shaft(unit: kPa)

图9 竖井围岩塑性分布<br/>Fig.9 Plastic zone of horizontal distribution surrounding rock

图9 竖井围岩塑性分布
Fig.9 Plastic zone of horizontal distribution surrounding rock

表6 竖井转横通道施工时横通道变形对比表(单位:mm)<br/>Tab.6 Maximum deformation of cross passage(unit: mm)

表6 竖井转横通道施工时横通道变形对比表(单位:mm)
Tab.6 Maximum deformation of cross passage(unit: mm)

表7 横通道最大受力对比表(单位:kPa)<br/>Tab.7 Maximum force of cross passage(unit: kPa)

表7 横通道最大受力对比表(单位:kPa)
Tab.7 Maximum force of cross passage(unit: kPa)

图10 横通道不同位置的变形对比曲线<br/>Fig.10 Deformation of cross passage arch hance

图10 横通道不同位置的变形对比曲线
Fig.10 Deformation of cross passage arch hance

图11 横通道马头门处围岩塑性对比分布<br/>Fig.11 plastic zone of horse head

图11 横通道马头门处围岩塑性对比分布
Fig.11 plastic zone of horse head

图12 最大收敛值随施工变化曲线<br/>Fig.12 Variation process of maximum deformation of cross passage arch hance

图12 最大收敛值随施工变化曲线
Fig.12 Variation process of maximum deformation of cross passage arch hance

图13 最大隆起位置随施工对比变化曲线<br/>Fig.13 Variation process of maximum deformation of cross passage invert

图13 最大隆起位置随施工对比变化曲线
Fig.13 Variation process of maximum deformation of cross passage invert

图14 竖井马头门大主应力分布云图<br/>Fig.14 Maximum principal stress distribution of horse head

图14 竖井马头门大主应力分布云图
Fig.14 Maximum principal stress distribution of horse head

图15 竖井马头门段剪应力分布云图<br/>Fig.15 Maximum shear stress distribution of horse head

图15 竖井马头门段剪应力分布云图
Fig.15 Maximum shear stress distribution of horse head

图16 竖井开挖、支护顺序(1、3、5、7为开挖顺序,Ⅱ、Ⅳ、Ⅵ为格栅钢架施工顺序)<br/>Fig.16 Excavation and support sequence of shaft(1、3、5、7 are excavation sequence, Ⅱ、Ⅳ、Ⅵ are support sequence)

图16 竖井开挖、支护顺序(1、3、5、7为开挖顺序,Ⅱ、Ⅳ、Ⅵ为格栅钢架施工顺序)
Fig.16 Excavation and support sequence of shaft(1、3、5、7 are excavation sequence, Ⅱ、Ⅳ、Ⅵ are support sequence)