软岩隧洞爆破超挖对施工进度与成本的影响及改进措施

Blasting Overbreak in Soft Rock Tunnel Effected to Construction Schedule and Cost and Improved Measures

以新疆奎屯河引水隧洞项目2标段工程为例,分析了隧道超挖产生的原因,结合工程实际计算了超挖对施工进度和施工成本的影响程度。计算结果表明:V类围岩隧道超挖10 cm时,每延米工时增加29 min,总工期增加69 d;隧道超挖10 cm,每延米平均增加的成本为3 527.987元,总标段增加1 206.6万元。为减少隧道超挖,从钻孔工艺、爆破参数设计和工程管理三个方面,提出了相应的改进措施。实施改进措施后,爆破质量得到大幅提高,经济效益提高49.87%,时间效益提高48.28%。

Based on the second section engineering of the Kuitun River water diversion tunnel in Xinjiang as an example,the cause of the tunnel overbreak was analyzed and in combined with the actual engineering,a calculation was conducted on the overbreak effected to the construction schedule and construction cost.The calculation results showed that when the overbreak of the tunnel with V type surrounding rock was 10 cm,the working hour per meter advanced would be increased by 29 min and the total construction period would be increased by 69 days.When the overbreak of the tunnel was 10 cm,the cost per meter advanced would be averagely increased by RMB 3,527,987 and the cost of the total section would be increased by RMB 12,066,000.In order to reduce the overbreak of the tunnel,from the three aspects of the drilling technology,blasting parameter design and engineering control,the relevant improved measures were provided.After the improved measures implemented,the blasting quality was highly improved,the economic benefits were improved by 49.87% and the time benefit was improved by 48.28%.