复杂地质条件下隧道燕尾段支护体系现场监测试验分析

In-situ Tests on Support System of Swallow-tailed Tunnel Under Complicated Geological Conditions

开展燕尾式隧道支护体系现场监测试验,研究分析了围岩与初支接触压力、锚杆轴力、钢拱架应力和初喷砼层应力。试验结果表明:大跨断面围岩压力对施工的动态响应明显,连拱断面围岩压力伴随后行洞室开挖产生的空间效应变化显著;锚杆多承受拉力作用,大跨段锚杆支护效果较连拱段明显,锚杆支护参数存在进一步优化的空间;初喷砼层与钢拱架普遍承受压力作用,均发挥了相应的支护作用。研究成果可为类似工程的修建提供参考。

Field tests of support system are carried out to investigate surrounding rock pressure, bolt axial force, steel framework stress and shotcrete stress. The results show that the surrounding rock pressure has dynamic response to constructing in large-span section ; the surrounding rock pressure of the double-arched section changes markedly with excavating of subsequent cavern; bolts are pulled mostly; the practical support effect of bolts is more superior in large-span section ; the parameters of bolt supporting have a further optimized scope ; and the shotcrete and steel arch structure serve the corresponding supporting function. The results are applicable to the other similar engineering projects.