铁路隧道下综放面覆岩隔离注浆充填开采试验研究

Field study of longwall fully-mechanized caving mining by overburden isolated grouting under a surface railway

针对铁路隧道压煤开采问题,研究了长壁开采条件下铁路隧道的破坏形式及保护要求,提出覆岩隔离注浆充填保护隧道的方法。在采动影响下,铁路隧道保护的核心是变形后的内轮廓满足限界要求,其控制的关键在于减少开采导致的移动量。提出计算采动变形条件下隧道限界富余量的方法,推导出开采变形后隧道内轮廓的坐标方程,并计算其与限界的富余空间。开展长壁综放工作面覆岩注浆充填保护地面铁路隧道试验研究,共施工7个地面钻孔,对覆岩内裂隙进行注浆充填。通过实施注浆充填,隧道减沉率达到88%,限界满足列车通行要求。该方法为开采影响下地面隧道保护提供参考与借鉴。

Aiming at the problem of coal mining under railway tunnels,this study investigated the failure forms and protection requirements of railway tunnels under longwall mining conditions,and proposed a tunnel protection method involving overburden isolated grout injection.As influenced by mining,the core of railway tunnel protection is that the inner contour of a deformed tunnel can meet the gauge requirement,and the key to controlling it is to reduce surface deformation caused by mining.On this basis,a method for calculating the margin of tunnel gauge after mining-induced deformation was established.A coordinate equation for the inner contour of tunnels following deformation was derived,and the marginal space be-tween the contour line and the gauge was calculated.A case study on the protection of a surface railway tunnel was carried out by overburden isolated grout injection during fully-mechanized caving mining.Seven surface boreholes were constructed above the test panel,and fractures formed in the overburden strata were filled during mining.Through the implementation of grout injection,the reduction rate of tunnel subsidence reached 88%and the gauge margin satisfied the requirement for train passage.This study provided a reference for the protection of surface railway tunnels under the influence of longwall mining.