偏压状态下隧道洞口段明洞暗挖施工

山岭重丘区隧道洞口段存在偏压严重现象,需大范围开挖进洞,存在施工安全性差、环境破坏大等问题.利用重力式混凝土偏压挡墙,通过明暗交界段套拱的施作,平衡隧道的单侧偏压力,做到隧道开挖安全进洞.由浙江省宏途交通建设有限公司承建的黄衢南高速公路蕉坞隧道及83省道兰田张隧道,施工中对明暗交界段采取明洞暗挖技术,阐述了偏压状态下隧道明洞暗挖技术原理和技术流程,该技术既确保了隧道的安全施工,又节约了公路建设用地,避免了高边坡开挖,极大地保护了周边原生态环境,同时降低了工程造价,取得了良好的经济和社会效益.

Undercutting Construction in the Open Tunnel for Portal Section with Unsymmetrical Loadings

The unsymmetrical loading leading-in tunnel portal is especially serious in high mountains heavy.There are problems of poor construction safety and environmental damage.By gravity concrete retaining wall,the unilateral partial pressure of tunnel is balanced through the umbrella arch to insure security excavation into the hole.The JiaoWu and LanTianZhang tunnel,which were constructed by ZheJiang HongTu traffic construction Co.,LTD,take underground cutting technology of cut-and-cover tunnel.With underground cutting technology,the safe construction of tunnel is insured,the highway construction land saved,to avoid the high slope excavation.Furthermore,it greatly protect the surrounding ecological environment,reducing project cost for great economic and social benefits.