摘要
在齐岳山隧道正洞DK363+629掌子面进行超前水平钻探时,揭示出前方存在一个大型腔体,随后实施超前探测,初步判断了腔体形状,对腔体进行了处理。首先对溶腔进行注浆试验,总计注浆1 613 m3,注浆效果不明显,掌子面停止注浆试验;注浆试验失败后,对DK363+629溶腔进行放水试验,放水量为3 000 m3/h,持续放水共计144 h,水量约43万m3,水压持续在0.2 MPa左右,由于受到外界降雨的影响水压持续上扬,证明腔体具有良好的地表联通性和水量补给持续性,为了保证施工安全停止了放水试验。平导贯通后可采用自然流出法排水,并对腔体采取"释能降压"施工。本次泄水总量约63万m3,水压自0.4 MPa降至0.0 MPa,水量稳定在约1 000 m3/h;随后对腔体实施爆破施工,爆破后采用管道引排的方法在不改变原有水流方向和不影响整体地下水系的情况下顺利通过。
A large cavity in karst was detected during exploratory horizontal drilling ahead of the face in the Qiyueshan tunnel at DK363＋629.Exploratory borings were used to determine the shape of the cavity.An injection test was carried out for the karst cavity with a total injection volume of 1613m3,but the test was unsuccessful.A water discharge test was then conducted for the karst cavity with a water release volume of 3000 m3/h continuously for 144h.The water volume was estimated at 430 thousand cubic meters and the water pressure was around 0.2 MPa.The water pressure rose constantly due to rainfall,which showed that the cavity was connected to the ground surface with a continuous water supply.The water discharge test was stopped to ensure construction safety.Natural draining was adopted after breaking through the parallel adit and the principle of ＂energy releasing and pressure reduction＂ was followed.The total volume of discharged water was around 630 thousand cubic meters,and the water pressure was dropped to 0.0 MPa from 0.4 MPa,with a steady rate of water flow around 1000 m3/h.Finally,blasting was employed for the cavity and pipe draining was used without changing the direction of water flow and affecting the whole underground water system.
出处
《现代隧道技术》
EI
北大核心
2011年第4期116-121,共6页
Modern Tunnelling Technology
关键词
铁路隧道
高压充水溶腔
释能降压
放水试验
超前地质预报
High-pressure water-filled karst cavity
Energy release and pressure reduction
Water discharge test
geological forecasting
Railway tunnel
