| 松散堆积体隧道围岩变形破坏细观特征研究 |
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| 引用本文： | 谢亦朋,杨秀竹,阳军生,张聪,戴勇,梁雄,龚方浩.松散堆积体隧道围岩变形破坏细观特征研究[J].岩土力学,2019,40(12):4925-4934. |
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| 作者姓名： | 谢亦朋 杨秀竹 阳军生 张聪 戴勇 梁雄 龚方浩 |
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| 作者单位： | 1. 中南大学 土木工程学院，湖南 长沙 410075；2. 中南林业科技大学 土木工程学院，湖南 长沙 410004 |
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| 基金项目： | 国家自然科学基金（No.51608539）；湖南省自然科学基金（No.2017JJ2316）；中南大学中央高校基本科研业务费专项资金（No. 2019zzts632）。 |
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| 摘 要： | 隧道穿越复杂松散堆积体地层时，如何确保隧道施工过程的安全是工程人员普遍关心的课题。依托云南省罗打拉隧道，基于Monte Carlo随机原理，结合数字图像处理技术，建立了考虑接触面单元及抗拉强度的堆积体地层隧道开挖细观结构模型，并探讨了隧道开挖引起的堆积体围岩变形、破坏过程以及失稳机制，并在现场进行应用验证。研究结果表明，构建的堆积体地层隧道开挖细观结构模型可有效反映隧道开挖过程中围岩的破坏过程，围岩位移等值线呈波动性与非对称性分布；围岩破坏以剪切破坏为主，局部存在拉裂?剪切复合破坏，且破坏区由边缘块石尖端向深层逐步扩展，形成包裹块石的剪切楔形区及拉剪松动圈，在施工扰动下易发生局部失稳。针对堆积体地层破坏特征，提出了围岩注浆加固措施，地层加固后土石颗粒间胶结良好，开挖轮廓周边形成有效的注浆加固圈，开挖支护过程围岩变形可控，支护结构稳定，效果良好，可为后续类似松散堆积体地层隧道的设计、施工提供新思路。
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| 关 键 词： | 松散堆积体 隧道 数字图像技术 随机模拟 细观结构 注浆加固 |
| 收稿时间： | 2018-10-08 |
Mesoscopic characteristics of deformation and failure on surrounding rocks of tunnel through loose deposits |
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| XIE Yi-peng,YANG Xiu-zhu,YANG Jun-sheng,ZHANG Cong,DAI Yong,LIANG Xiong,GONG Fang-hao.Mesoscopic characteristics of deformation and failure on surrounding rocks of tunnel through loose deposits[J].Rock and Soil Mechanics,2019,40(12):4925-4934. |
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| Authors: | XIE Yi-peng YANG Xiu-zhu YANG Jun-sheng ZHANG Cong DAI Yong LIANG Xiong GONG Fang-hao |
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| Institution: | 1. School of Civil Engineering, Central South University, Changsha, Hunan 410075, China;
2. School of Civil Engineering, Central South University of Forestry and Technology, Changsha, Hunan 410004, China |
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| Abstract: | Safety of tunnel construction is a hot topic for the tunnel passing through complex loose deposits. Based on Monte Carlo stochastic principle and digital image processing technology, a mesostructure model for the excavation of Luodala tunnel is established with considering contact surface element and tensile strength. The deformation, failure process and instability mechanism of loose deposits surrounding rock during excavation are discussed and verified by application of the model in practical engineering. The results show that the model can reflect the failure process of surrounding rock during tunnel excavation, and the displacement contour of surrounding rock presents obvious fluctuation and asymmetry. The failure mode of surrounding rock is mainly shear failure, and tension-shear composite failure is also observed in some part. The failure zone extends from tip of the margin rocks to the deep layers, forming wedge-shaped shear zone and tension-shear loose zone, which are prone to cause local instability under construction disturbance. According to the failure characteristics of loose deposits, the grouting reinforcement measures of surrounding rock are proposed. After the reinforcement, the grouting reinforcement ring has been formed around the tunnel with good soil-rock bond and the deformation of surrounding rock can be controlled and the support structure is stable during the excavation and support process. The resutls can provide new ideas for the design and construction of tunnels in similar loose deposits. |
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| Keywords: | loose deposits tunnel digital imaging technology random simulation mesostructure grouting reinforcement |
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