浅埋黄土隧道不同施工与加固方法的颗粒流数值模拟

发布时间：2018-06-12 16:00

本文选题：黄土隧道 + 加固　；参考：《应用基础与工程科学学报》2016年01期

【摘要】：针对浅埋黄土隧道在开挖过程中发生的拱顶过量沉降问题,采用颗粒离散单元法模拟了不同开挖方法和加固措施对围岩稳定和变形的影响,分析了6种工况的围岩压力分布和位移发展情况,讨论了开挖方法和加固措施对隧道围岩稳定的影响.模拟结果显示,隧道拱肩和拱脚应力集中处水平位移较大,拱部和边墙开挖为黄土隧道留核心开挖施工中的关键工序,施工中宜及早支护避免隧道发生过大变形.浅埋黄土隧道拱顶下沉量远大于周边收敛;对于相同的支护形式,留核心土下部全断面开挖法产生的位移总量约为留核心土下半断面分部开挖法的1.2倍;对于相同的开挖方法,无超前注浆支护产生的位移总量约为有超前支护的1.5倍;而有无系统锚杆的隧道围岩变形量基本相同.研究表明,浅埋黄土隧道可采取超前导管注浆减小隧道开挖变形,而系统锚杆由于支护效果不明显可考虑取消.
[Abstract]:Aiming at the excessive settlement of arch roof in shallow loess tunnel during excavation, the influence of different excavation methods and reinforcement measures on the stability and deformation of surrounding rock is simulated by particle discrete element method. The pressure distribution and displacement development of surrounding rock under six working conditions are analyzed, and the influence of excavation methods and reinforcement measures on the stability of surrounding rock of tunnel is discussed. The simulation results show that the horizontal displacement is large at the stress concentration of the arch shoulder and arch foot, and the excavation of arch and side wall is the key procedure in the construction of loess tunnel with core. It is advisable to protect the tunnel early to avoid the excessive deformation of the tunnel. For the same supporting form, the total displacement produced by the whole section excavation method of the lower part of the retaining core soil is about 1.2 times that of the partial excavation method of the lower half section of the retaining core soil, and for the same excavation method, The total displacement caused by no advance grouting support is about 1.5 times of that of the one with lead support, while the deformation of surrounding rock of tunnel with or without systematic bolt is basically the same. The research shows that shallow loess tunnel can be reduced by grouting with lead pipe, but the system bolt can be cancelled because of the indistinct supporting effect.
【作者单位】：北京科技大学土木与环境工程学院;教育部金属矿山高效开采与安全重点实验室;国家电网江西省电力公司电力经济技术研究院;
【基金】：北京市青年英才计划资助项目(YETP0340) 北京市优秀人才培养资助项目(2013D009006000005) 教育部新世纪优秀人才资助项目(NCET-11-0579) 国家自然科学基金项目(51178044)
【分类号】：U455.4

【相似文献】