红层软岩地区隧洞开挖与初期支护方法研究

Study on Tunnel Excavation and Initial Support Method in[HJ63x]Red-Bed Soft Rock Areas

鉴于红层软岩地区隧洞相关围岩特性随时面临高地应力围岩挤压变形问题,其施工难度大,开挖支护方案的确定必须考虑到整个施工过程和工程长期运营的安全稳定性。以亭子口灌区一期工程狮子岩隧洞为例,结合红层软岩地区粉砂质泥岩特性对不同围岩级别的隧洞开挖与支护方案进行了研究,结果表明:施工前有效开展超前地质预报、及早判断地质情况,可以有效应对突发不良地质状况。在隧洞开挖过程中,根据超前地质预报,针对破碎围岩可以及时采取超前支护方式、增加超前小导管或小管棚等措施以加强岩体的稳定性,再逐步进行后续的系统支护施工。

The tunnel in the red-bed soft rock area is faced with the problem of extrusion deformation of high-stress surrounding rock.The excavation construction is extremely difficult.The excavation support scheme must take into account the safety and stability of the whole construction process and long-term operation.Taking the Shiziyan tunnel of the Tingzikou Irrigation Area Project Pase 1 as an example,combined with the characteristics of silty mudstone in red-bed soft rock area,the excavation and support schemes of soft rock tunnel under different surrounding rock levels are discussed.The results show that effective advance geological prediction before construction and early judgment of geological conditions can effectively deal with sudden geological conditions.In the process of excavation,combined with geological forecast,advanced support is carried out in time for broken surrounding rock,and measures such as advanced small pipe or small pipe sheds can be used to enhance the stability of the rock mass,and then subsequent systematic support construction can be gradually carried out.