九瑞高速岩质隧道钻爆法施工超欠挖控制措施及成本分析

Over-break/shortbreak Control Technology for and Cost Analysis on Rock Tunnels Constructed by Drilling and Blasting Method:Case Study on Tunnels on Jiujiang-Ruichang Highway

为了降低岩溶地质隧道钻爆法施工超欠挖耗费,提高隧道一次性开挖合格率,对目前隧道超欠挖现状进行研究,分析影响隧道超欠挖的因素,介绍超欠挖对工程造价的影响情况。根据实际调查和现场试验,找出了影响超欠挖和造价耗费的主要因素,并制定了有效的控制措施。采用改进后的方案进行隧道开挖施工后,隧道一次性开挖平均合格率由67.4%上升到了83.9%,经济效益提高了49.9%,证明采取的处理措施是成功的,可为以后类似工程提供借鉴。

The state-of-art of overbreak/shortbreak in tunneling is presented, the causes for overbreak/shortbreak are analyzed, and the influences of overbreak/shortbreak on the tunneling cost are described, so as to reduce the cost in- duced by overbreak/shortbreak of rock tunnels constructed by drilling and blasting method and to improve the qualifica- tion rate of tunnel excavation. Effective overbreak/shortbreak control technologies are determined on basis of investiga- tions and trials. After these technologies are applied, the average qualification rate in tunnel excavation has been raised from 67.4% to 83.9% , and the economic efficiency has been improved by 49.9% , which demonstrates that the tech- nologies applied are effective. The paper can provide reference for similar projects in the future.