摘要
以圆梁山隧道毛坝向斜高水压地段为工程背景,自行研制高水压隧道渗流场试验装置系统,通过室内模型试验,分析隧道修建过程中渗流场的变化规律及作用在二衬背后的水压力作用系数。结果表明:围岩边界不透水时,初始渗流场为静水场,围岩边界透水时,初始渗流场为非静水场;隧道开挖后,水压力等值线是以隧道为中心的圆环形状,无注浆圈时在围岩内的分布较均匀,有5m注浆圈时,等值线在注浆圈内密度较大,在注浆圈外较稀疏;注浆的施作,明显减小了隧道内的排水量,增加了注浆圈外表面的水压力作用系数,注浆圈承担了较大的地下水压力;衬砌施作后,有注浆圈时,衬砌背后的水压力有明显的折减现象,在排水孔断面上的分布呈'葫芦'状,衬砌背后水压力作用系数最小,围岩内和注浆圈外表面的水压力作用系数几乎相同,衬砌背后的水压力在排水系统与水沟连通的位置处最小,在仰拱处较大,在其他位置分布较均匀;隧道排水比越大,衬砌背后的水压力作用系数越小。
The variation laws of the seepage field during tunnel construction process and the effect coeffi- cient of water pressure acting on the secondary lining were studied through indoor model test by self-made test device system of high water pressure tunnel seepage field with Yuanliangshan tunnel Maoba syncline high water pressure region as engineering background. The results show that, when the surrounding rock boundary is impermeable, the initial seepage field is a hydrostatic pressure field. When the surrounding rock boundary is permeable, the initial seepage field is a non-hydrostatic pressure field. The water-pres- sure isoline is orbicular with the tunnel as center after tunnel excavation, and it is more evenly distributed in the surrounding rock without grouting circle. The density of isoline is larger inside the grouting circle and sparser outside the grouting circle when the grouting circle is 5 m. The amount of draining in the tun- nel has been significantly reduced after grouting, but the water pressure effect coefficient on the outside surface of the grouting circle has been increased. Most of ground water pressure is undertaken by the grou- ting circle. The seepage field after tunnel excavation has changed a lot after the lining structure being con- structed and with the presence of grouting circle. The reduction phenomenon of water pressure behind the lining is very obvious. The contour line of the water pressure is a ＇gourd＇ shape in a section with drainage holes and at this time the effect coefficient of water pressure behind the lining is minimum. The effect coef- ficients of water pressure inside the surrounding rock and on the outside surface of the grouting circle are almost the same. The water pressure behind the lining is smaller in the connected position between the drainage system and the ditch and larger in the inverted arch. In other position, it is more evenly distribu- ted. The greater the drainage fraction of tunnel, the smaller the water pressure behind the lining and its effect coefficient.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2013年第1期50-58,共9页
China Railway Science
基金
国家自然科学基金资助项目(51078243)
河北省自然科学基金资助项目(2010001060)
铁道部科技研究开发计划项目(2001G009-2)
关键词
高水压隧道
模型试验
试验装置系统
渗流场
水压力
作用系数
High water pressure tunnel
Model test
Test device system
Seepage field
Water pressure
Effect coefficient
