| 砂土层中盾构掘进实测数据及数值模拟分析 |
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| 引用本文： | 骆冠勇,钟淼,曹洪,潘泓.砂土层中盾构掘进实测数据及数值模拟分析[J].岩土力学,2022,43(Z2):563-574. |
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| 作者姓名： | 骆冠勇 钟淼 曹洪 潘泓 |
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| 作者单位： | 1. 华南理工大学 土木与交通学院，广东 广州 510640；2. 华南理工大学 亚热带建筑科学国家重点实验室，广东 广州 510640 |
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| 基金项目： | 国家自然科学基金项目（No.51978282）；广东省自然科学基金项目（No.2020A1515010583）；华南理工大学亚热带建筑科学国家重点实验室开放研究项目（No.2022ZB21）；广东省现代土木工程技术重点实验室（No.2021B1212040003）。 |
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| 摘 要： | 相对于其他土层，盾构在富水砂层中掘进的风险更大，但目前盾构掘进引起砂层变形的机制并不清楚。依托广州某电力隧道项目，选取一典型富水砂性地层断面对盾构隧道施工引起的地层变形进行高频率、近距离的监测，得到以下几点认识可供类似的工程参考：（1）富水环境下，相对于均质砂层，隧道处于粉砂+粗砂地层组合更容易发生渗透破坏。此情况下，粉砂层在承受更大渗透力同时，又受粗砂层强烈补给供水，非常容易被侵蚀甚至掏空。（2）地层均匀损失与局部集中损失引起地层扰动规律有较大的不同。地层均匀损失时由于拱效应没集中局部损失的强，其扰动范围、地表沉降及水平位移均更大。水平位移最大值的位置与地层损失的非均匀化也密切相关。地层均匀损失时，隧道两边最大水平位移发生在隧道高程范围内；但地层非均匀损失（隧道顶部局部塌落）时，发生最大的水平位移的位置会明显上移。（3）渗透力的作用使得地层扰动范围扩大。（4）地层损失率受注浆影响严重，隧道附近大，地表最小，隧道上方土体呈松散化趋势。
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| 关 键 词： | 盾构施工 地层变形 砂层 实测 数值模拟 |
| 收稿时间： | 2021-09-21 |
| 修稿时间： | 2022-07-20 |
Measured data and numerical simulation analysis of shield tunneling in sand |
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| LUO Guan-yong,ZHONG Miao,CAO Hong,PAN Hong.Measured data and numerical simulation analysis of shield tunneling in sand[J].Rock and Soil Mechanics,2022,43(Z2):563-574. |
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| Authors: | LUO Guan-yong ZHONG Miao CAO Hong PAN Hong |
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| Institution: | 1. School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong 510640, China;
2. The State Key Laboratory of Subtropical Building Science, South China University of Technology, Guangzhou, Guangdong 510640, China |
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| Abstract: | Compared with other soil layers, the risk of shield tunneling in water-rich sand is greater, but the mechanism of sand deformation caused by shield tunneling is currently unclear. Relying on an electric power tunnel project in Guangzhou, this paper selects a typical water-rich sandy stratum section for high-frequency, close-range monitoring of stratum deformation caused by shield tunnel construction. The following understandings are obtained, which can be used as reference for similar projects. 1) In a water-rich environment, compared to in a homogeneous sand layer, in a combination of fine and coarse sands, the tunnel is more prone to seepage failure. Under this circumstance, the fine sand layer bears greater seepage force while being strongly supplied with water from the coarse sand layer, and the fine sand layer is thus very easy to be eroded or even hollowed out. 2) The ground deformation caused by uniform volume loss and local concentrated loss is quite different. In the case of uniform loss, because the arching effect is not as strong as the local loss, the disturbance range, surface settlement and horizontal displacement are all larger. The location of the maximum horizontal displacement is also closely related to the heterogeneity of the formation loss. When the formation loss is uniform, the maximum horizontal displacement on both sides of the tunnel occurs within the tunnel elevation range; but when the uneven loss (partial collapse of the tunnel top) occurs, the location of the maximum horizontal displacement will move up significantly. 3) The seepage force expands the range of stratum disturbance. 4) The stratum loss rate is severely affected by grouting. The vicinity of the tunnel is large, the ground surface is the smallest, and the soil above the tunnel tends to loosen. |
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| Keywords: | shield construction soil deformation sand stratum field monitor numerical simulation |
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