邻近寺庙群高海拔隧道钻爆施工关键技术研究

Research on Key Construction Technology of Drilling and Blasting in High Altitude Tunnel Near Temple Group

为解决同赛高速隧道施工中振动风险高、作业面不足、洞身超挖的问题,自主研究开发爆破风险识别程序,基于地质背景与施工条件,采用现场试验、数值模拟、工程实测等方式,开展隧道钻爆布孔形式、装药结构、轮廓线等技术参数优化研究。现场实践表明:通过应用研发振动风险识别程序,可大幅度提高现场振动风险识别、动态控制能力,有效避免了敏感人群、建筑群受扰动风险;依据现场有效作业面设大倾角掏槽布孔,辅以扩槽孔、拱顶单排下压孔等措施,在满足掏槽、破岩要求的前提下达到了提升工效的预期;采用优化周边孔装药结构、收紧拱顶轮廓线等措施,有效降低了洞身排险后超挖量,现场初支喷混超方量由200%降低至100%以内,同时每循环节省药量约20kg,经济效益显著。

To solve the problems of high vibration risk,insufficient working surface and over-excavation in the construction of the Tongren-Saierlong Expressway Tunnel,the blasting risk identification program is independently developed.Based on the geological background and construction conditions,field tests,numerical simulation,engineering measurement.were adopted to carry out the optimization of technical parameters such as tunnel drilling and blasting hole layout,charge structure and contour line.The field practice shows that the application of the developed vibration risk identification program can greatly improve the ability of vibration risk identification and dynamic control and effectively avoid the risk of disturbance to sensitive people and buildings.According to the effective working surface of the site,the large inclination angle cutting hole was set up,supplemented by the measures such as the expansion holes and the single row of pressure holes on the vault,which fulfils the expectation of improving the work efficiency under the premise of meeting the requirements of hole cutting and rock breaking.By optimizing the charging structure of the surrounding holes and tightening the contour line of the vault,the amount of over-excavation after the risk removal of the tunnel body is effectively reduced.The amount of over-excavation of the initial support sprayed concrete is reduced from 200%to less than 100%.Meanwhile,the dosage is saved by approximately 20kg per cycle,and the economic benefit is remarkable.