摘要
研究目的:银西高铁上阁村隧道穿越董志塬黄土含水层施工中出现的渗涌水,受地下水渗流影响,引起了洞身黄土含水率增加、围岩自稳性变差等问题。为解决上阁村富水黄土隧道施工难题,论文首先分析了上阁村隧道黄土含水层分布特征,其次介绍了地表降水施工辅助措施及其效果,最后应用MIDAS/GTS建立隧道工程群井降水模型,实现了不同流量以及渗透系数工况下的隧道开挖渗流模拟计算。研究结论:(1)上阁村隧道长大段落通过软塑黄土含水层,通过地表降水梳干隧道洞身范围内地下水,提高了隧道洞身黄土围岩稳定性,确保了隧道施工的安全和进度;(2)不同单井流量(80 m^(3)/d、90 m^(3)/d、100 m^(3)/d)的群井数值模拟结果表明,地下水位降深在短时间内达到了设计要求,验证了降水设计参数及效果;(3)本研究可为黄土等低渗透岩体富水隧道工程施工处置及设计提供依据。
Research purposes:This study addresses the issues of seepage water encountered during the construction of the Shangge Village Tunnel in the Yinchuan-Xi'an High-speed Railway,which traverses through the Dongzhi Loess Aquifer.Influenced by groundwater seepage,the phenomenon has led to the increase of water content in the tunnel's loess walls and deterioration in the stability of surrounding rocks.To resolve the construction challenges posed by the highly water-bearing loess in the Shangge Village Tunnel,this study first analyzed the distribution characteristics of the loess aquifer in the tunnel.Secondly,it introduced surface precipitation as a construction assistance measure and evaluated its effectiveness.Finally,utilizing MIDAS/GTS,the study established a tunnel engineering group well dewatering model to simulate seepage under various flow rates and permeability coefficients during tunnel excavation.Research conclusions:(1)Through the implementation of surface precipitation to drain groundwater within the loess aquifer,particularly in the long sections of the Shangge Village Tunnel,stability of the loess walls within the tunnel cavity was enhanced,ensuring both safety and progress in tunnel construction.(2)Numerical simulation results for different single-well flow rates(80 m^(3)/d,90 m^(3)/d,100 m^(3)/d)in the group wells indicate that groundwater levels reached the design requirements within a short period,validating the effectiveness of the dewatering design parameters.(3)This study can provide a basis for the construction and design of water-rich tunnels in low-permeability rock masses like loess.
作者
张晓宇
赵晓彦
宋浩
ZHANG Xiaoyu;ZHAO Xiaoyan;SONG Hao(Southwet Jiaotong University,Chengdu,Sichuan 611756,China;China Railway First Survey and Design Institute Group Co.Ltd,Xi'an,Shaanxi 710043,China)
出处
《铁道工程学报》
EI
CSCD
北大核心
2024年第4期24-29,34,共7页
Journal of Railway Engineering Society
基金
中铁第一勘察设计集团有限公司科研项目(17-11)。
关键词
银西高铁
黄土隧道
含水层
群井降水
渗流模拟
Yinchuan-Xi'an High-Speed Railway
loess tunnel
aquifer
group well dewatering
seepage simulation
