黄土隧道中系统锚杆的效用分析

黄土隧道是否应设置系统锚杆,应如何设置锚杆,一直以来是工程界争论的焦点。用隧道稳定性定量计算方法—有限元强度折减法对其进行讨论和分析,结果表明,对于有支护的黄土隧道,可以通过折减材料强度来得到其安全储备大小,并可以用安全系数对安全储备的大小进行定量描述。用强度折减法对某黄土隧道在12种不同支护条件下的安全系数大小进行计算和对比。计算结果对比分析表明,黄土隧道中设置系统锚杆对隧道整体稳定性影响不大,黄土隧道中只有采用拱架支护才能有效提高隧道的稳定性。

Analysis of Effectiveness of System Anchor Rods in Loess Tunnels

Whether loess tunnels need to be equipped with system anchor rods and how to set anchor rods have been the focus of argument in engineering field.This paper discusses and analyzes the quantitative computing method for stability of tunnels—strength reduction FEM（finite element method）,the result shows that the size of safety reserve of loess tunnels with supports can be obtained by reducing material strength and can be described quantitatively by means of safety factors.The paper calculates and compares the size of safety factors of some loess tunnel under the condition of 12 different supports by means of strength reduction method.The result of calculation and comparative analysis show that setup of anchor rods in loess tunnels has minor influence on integral stability of tunnels,and the stability of loess tunnels can be effectively improved only by adopting arcing supports.