粉砂质泥岩敞开式TBM掘进及支护参数选择研究

Study on Excavation and Supporting Parameters of Open TBM Tunnels in Silty Mudstone Stratum

国内多数TBM隧道掘进时仅完成初期支护工程,贯通后才会进行二次衬砌,在复杂地质条件下,最优的支护参数可有效减少对岩体扰动、提高隧道安全系数、保障隧道洞室稳定,同时能够有效降低TBM能耗、避免设备异常损坏,进而保证了TBM施工效率。以四川省乐西高速大凉山1号隧道敞开式TBM掘进穿越粉砂质泥岩地层实例,详细分析了洞室稳定和支护参数的关系,建立结构-荷载计算模型,通过对初期支护参数进行计算验证,获得了隧道受力及变形特征,验证了设计支护方案的安全性和合理性;通过分析掘进参数和能耗之间的关系,建立了TBM能耗模型,控制单一掘进参数变量对不同掘进参数条件下TBM能耗曲线进行了对比分析,得出了TBM掘进穿越粉砂质泥岩地层最优掘进参数。

In China, most TBM tunnels complete the initial support works during tunneling, and the secondary lining after penetration. Under complex geological conditions, the optimal support parameters can effectively reduce the disturbance to the rock mass, improve the tunnel safety factor, ensure the stability of the tunnel chamber, effectively reduce TBM energy consumption, avoid abnormal equipment damage so that the TBM construction efficiency can be ensured. Taking the open TBM of Daliangshan No.1 tunnel of Lexi Expressway in Sichuan Province as an example,the relationship between the tunnel stability and the supporting parameters is analyzed in detail. The structure-load calculation model is established. Through the calculation and verification of the initial supporting parameters, the stress and deformation characteristics of the tunnel are obtained to verify the safety and rationality of the designed supporting scheme;By analyzing the relationship between tunneling parameters and energy consumption, a TBM energy consumption model is established. Under different tunneling parameters, the TBM energy consumption curves are compared and analyzed by controlling a single tunneling parameter variable and the optimal parameters of TBM crossing silty mudstone stratum are obtained.