| 富水黄土隧道施工过程围岩水分迁移规律研究 |
| |
| 引用本文： | 来弘鹏,谭智鹏,孙玉坤,黄鹏志.富水黄土隧道施工过程围岩水分迁移规律研究[J].中国公路学报,2023,36(1):150-161. |
| |
| 作者姓名： | 来弘鹏 谭智鹏 孙玉坤 黄鹏志 |
| |
| 作者单位： | 1. 长安大学 公路学院, 陕西 西安 710064;2. 广州市市政工程设计研究总院有限公司, 广东 广州 510000 |
| |
| 基金项目： | 国家自然科学基金项目（51978064，51908051）；中国铁路总公司科技研究开发计划项目（2017G007-G） |
| |
| 摘 要： | 为了给富水黄土隧道施工提供指导，依托银西高铁上阁村隧道，通过现场监测得到典型断面上覆软塑黄土层隧道水分迁移的基本规律；通过室内试验建立了围岩孔隙比与围岩渗透系数、围岩含水率与围岩强度的关系式，利用FLAC3D内嵌的FISH语言进行相应编程，对土体单元赋予动态渗透系数，实现了流固耦合作用下的隧道开挖模拟，并结合现场监测数据验证了该数值模拟的可靠性，最后基于16种工况的模拟结果，揭示了上覆软塑黄土层距隧道拱顶不同距离下隧道开挖卸载过程中围岩水分迁移规律。结果表明：在开挖扰动下隧道上覆软塑黄土层中水分由黄土层底部向隧道临空面迁移，最终累积于隧道底部，且水分迁移始于掌子面开挖，滞后于初支封闭；当拱顶与软塑黄土层底部距离0 m≤h≤4 m时(h为隧道拱顶与软塑黄土层底部间距),位置水头和压力水头的变化引起洞周水分迁移，水分迁移速度快、迁移量大，隧道仰拱封闭前，水分易侵入临空面；当5 m≤h≤8 m时，位置水头的变化引起洞周水分迁移，水分迁移速度慢、迁移量小；当h>8 m时，无明显水分迁移；当0 m
|
| 关 键 词： | 隧道工程 水分迁移 数值分析 软塑黄土 现场试验 流固耦合 |
| 收稿时间： | 2021-08-13 |
Study on Law of Water Migration in Surrounding Rock During Construction of Water-rich Loess Tunnel |
| |
| LAI Hong-peng,TAN Zhi-peng,SUN Yu-kun,HUANG Peng-zhi.Study on Law of Water Migration in Surrounding Rock During Construction of Water-rich Loess Tunnel[J].China Journal of Highway and Transport,2023,36(1):150-161. |
| |
| Authors: | LAI Hong-peng TAN Zhi-peng SUN Yu-kun HUANG Peng-zhi |
| |
| Affiliation: | 1. School of Highway, Chang'an University, Xi'an 710064, Shaanxi, China;2. Guangzhou Municipal Engineering Design and Research Institute Co. Ltd., Guangzhou 510000, Guangdong, China |
| |
| Abstract: | To provide guidance for the construction of water-rich loess tunnel, and relying on the Shanggecun Tunnel of Yinxi High-speed Railway, the basic law of water migration in a tunnel covered with soft plastic loess layer on the typical section was obtained through field monitoring. The relationship between the porosity ratio and permeability coefficient of the surrounding rock, the water content, and strength of the surrounding rock was established through laboratory tests. The relationship formula was programmed by FISH language in FLAC3D, and the dynamic permeability coefficient was assigned to the soil unit, which realized the simulation of tunnel excavation under the action of fluid-solid coupling. Numerical simulation results were verified by field monitoring data, and the results show that the simulation is reliable. Finally, based on the simulation results of 16 working conditions, the law of moisture migration in the surrounding rock during tunnel excavation and unloading at different distances from the overlying soft plastic loess layer to the tunnel vault is revealed. The results lead to the following conclusions. ① Under disturbance of excavation, the water in the soft plastic loess layer overlying the tunnel migrates from the bottom of the loess layer to the palm surface, and finally accumulates at the bottom of the tunnel. The water migration starts before the excavation of the palm surface and ends after the inverted arch is closed. ② When the distance between the vault and bottom of the soft plastic loess layer is 0 m ≤ h ≤ 4 m, a change in the position and pressure heads causes water migration around the tunnel. The water migration speed is high and the migration volume is large. Before the tunnel invert is closed, water easily invades the excavation surface. When 5 m ≤ h ≤ 8 m, a change in the position head causes water migration around the tunnel. The water migration speed is low and the migration volume is small. When h>8 m, there is no evident water migration during the construction of the tunnel. ③ When 0 m<h ≤ 4 m, the stable value of water content in all parts is higher, approximately 28% in the inverted arch and arch foot, and approximately 25% in the arch waist and arch crown. The upper part is smaller whereas the lower part is larger. When 4 m<h<8 m, the stable value of soil moisture content begins to decrease with the increase of h. When h ≥ 8 m, the stable value of water content in each part is basically the same and remains unchanged with the increase of h. |
| |
| Keywords: | tunnel engineering water migration numerical simulation soft-plastic loess field monitoring fluid-solid coupling |
|
| 点击此处可从《中国公路学报》浏览原始摘要信息 |
|
点击此处可从《中国公路学报》下载全文 |
|
