大跨度隧道穿越富水浅埋偏压段进洞处理技术

Tunnel Entry TreatmentTechnology for Long-span Tunnel Crossing Water-Rich Shallow Buried Bias Pressure Section

新建佛清从高速石牛岭隧道从化端右洞进洞段为浅埋、偏压、富水流沙地层,洞内净宽15.75m,为大跨度隧道,洞口右侧大型冲沟常年流水,跨越广东省雨季进洞,洞身开挖期间遭遇突泥、股状水、围岩垮塌等情况,出现了冒顶、洞口右侧边坡泥石流、山洪等地质灾害,针对性地调整开挖方法和支护方案,采取处置措施成功进洞,安全贯通球状孤石群堆积体软弱带围岩。

The entrance section of the right tunnel at ConghuaEnd of Shiniuling Tunnel is shallow buried,bias pressure and flow-rich sediment layer.The net width of the tunnel is 15.75m and it is a large-span tunnel.The large gully on the right side of the opening runs year after year.Due to the rainy season in Guangdong Province,mud burst,stranded water,collapse of surrounding rock and other geological disasters occurred during excavation of the tunnel body.At the same time,such geological disasters as roof fall,debris flow on the right side of the opening and mountain torrents occurred.In this paper,according to the characteristic adjustment excavation method and support scheme,the treatment measures are adopted to successfully enter the tunnel and safely penetrate the surrounding rock of weak zone of globular boulder group accumulation.