引汉济渭工程是解决关中、陕北缺水的重要工程, 其将穿越秦岭主脊段, 主要采用 TBM 法施工。理清 TBM 掘进段的施工环境热害扩散规律, 用以指导 T BM 掘进隧道内的现场施工。以引汉济渭隧洞工程为依托, 主要采用 数值计算方法对不同围岩级别和不同通风条件下 TBM 掘进段的施工环境热害扩散规律进行计算研究。研究结果 表明: 在? 级围岩中施工时, 掘进机段环境空气温度小于 28 e , 满足规范要求。随着围岩级别提高, 掘进面附近区 域温度和高温区范围逐渐扩大, 最高温度达到 50 e , 最大热害扩散范围达到 165 m, 最小的通风有效降温距离仅为 45 m; 随着风管出风口风速的增大和送风温度的降低, 热害扩散范围逐渐减小, 但仍难以使掘进面附近环境温度满 足规范要求, 建议在掘进面附近区域采用局部降温措施。

The H anjiang2to2Weihe riv er w ater transfer pro ject is an im po rtant pro ject to so lv e water sho rtag e in the cent ral Shaanx i plain and northern Shaanxi. It will pass thro ug h the main ridg e section of the Qinling Mo untains and is mainly construc2 ted by the TBM method. T his paper intends to clarify the diffusion rule o f thermal hazard in the constructio n env ir onment of the TBM t unneling sectio n t o guide the co nstr uction of the TBM tunnel. This paper is based on t he t unneling project of the Han2 jiang2to2Weihe river w ater transfer project. Numerical calculatio n w as used to calculate t he thermal hazard diffusion rule in the co nstr uction env iro nment of TBM tunneling sectio ns under different surr ounding r ock g rades and differ ent ventilatio n condi2 tions. Results show ed that in the const ruct ion o f class IV surr ounding ro ck, the ambient air t emperat ur e of the T BM section w as less than 28 e , w hich met the specification r equirements. With the improv ement of the surro unding ro ck gr ade, the temperatur e near the driving surface and the sco pe of hig h2t emperat ur e ar ea w ould g radually increase. The maximum temper ature reached 50 e and the maximum diffusion rang e o f thermal hazard reached 165 m. The minimum effective v ent ilation coo ling distance w as only 45 m. With t he increase o f w ind speed at the o ut let of the air duct and the decrease o f the supply air temperatur e, the diffu2 sio n range of thermal hazard w ould gr adually decrease; but the ambient temper ature near the driv ing surface still could no t meet the specificatio n r equir ements. T her efore, this pa per recommends using lo cal cooling measures in the vicinity of the driv ing sur2 face.

国家自然科学基金( 51678493)