单线铁路隧道新微台阶带仰拱一次爆破开挖施工技术研究

为解决单线铁路隧道Ⅳ、Ⅴ级石质围岩采取常规微台阶爆破开挖存在的问题,进一步推广运用微台阶法,在总结常规微台阶 爆破开挖所存在的问题基础上,通过实际调研、理论分析等手段,提出台阶尺寸拟定的基本原则,建立维护微台阶稳定的精准爆破 设计体系,开发“W型”爆破网络、研制可缩式轻量化带滑移装置作业平台,形成了新微台阶带仰拱一次爆破开挖技术。 通过中老 铁路友谊隧道工程实践的验证,该工法既可避免常规微台阶爆破开挖存在的缺点,又能大幅提升标准化管理水平和工程进度,可实 现施工管理常态化。

New Construction Technology of One-time Blasting Excavation of Micro-bench with Invert for Single-track Railway Tunnels

Problems exist in blasting excavation of Grade Ⅳ and Ⅴ surrounding rocks of single-track railway tunnel by conventional micro-bench method. Hence, the problems of conventional micro-bench method are summarized; the basic principles for bench size are proposed by investigation and theoretical analysis; a stable precise blasting design system for micro bench maintenance is established; a kind of W-shaped blasting network and a retractable lightweight operational platform with sliding device are developed; and a series of new excavation technology of one-time blasting of micro-bench with invert is obtained. The applicable results of the recommended technology to Youyi Tunnel on China-Laos Railway show that the new construction technology of micro-bench blasting excavation with invert can not only avoid the shortcomings of conventional one, but also greatly improve the standardized management level and project progress to realize normalized construction management.