昔格达地层引水隧洞支护施工技术及颗粒离散元模拟

Construction technology and particle flow code modelling of diversion tunnel support in Xigeda stratum

根据攀西地区昔格达地层的基本特性,提出了昔格达地层引水隧洞的施工支护关键技术,并结合攀西地区某铁矿采矿场引水隧洞施工中的塌方治理问题,采用了颗粒离散元(particle flow code,PFC)方法对塌方进行了模拟。结果表明,该类围岩隧洞的施工中,应坚持掘进前先超前支护、掘进中初期支护和二次衬砌紧跟的施工理念,一旦出现塌方,则需要加强初支,并进行全断面径向注浆以加固四周围岩。2006-2019年昔格达地层引水隧洞一系列工程实践表明,该施工技术对于昔格达地层隧洞施工是合理可行的。

This paper provides the key technology of construction support for diversion tunnel in Xigeda stratum according to the basic characteristics of the Xigeda stratum in the Panxi area.In combination of the problem of collapse control in the construction of diversion tunnel in an iron mine in Panxi area,the particle flow code(PFC)method is used to simulate the collapse.The results show that in the construction of this kind of surrounding rock tunnel,it is necessary to always adhere to the construction concepts of advance support before tunneling,initial support followed by secondary lining closely on the tunnel excavation surface.Once a local collapse occurs,it is necessary to strengthen the initial support and carry out full-section radial grouting to reinforce the surrounding rock.The practice of a series of projects from 2006 to 2019 shows that the construction technology introduced in this paper is reliable for the construction of large-sectional tunnels in the Xigeda stratum.