大坡度引水隧道无轨运输出渣方式的应用

辽西北供水工程11#支洞，断面小、坡度大，出渣运输方式是决定工期的关键控制因素。采用无轨运输出渣方式，存在以下问题：隧道纵坡坡度较大，运输渣车爬坡困难、存在严重的安全隐患；断面小，自卸车在陡坡上运行和洞内调头困难等。对此采取扩大隧道开挖断面、设置避车洞，改装车辆、确保车辆制动的可靠性；加强安全管理措施等。实践证明，采用无轨运输方式出渣具有节约工期、经济效益显著等特点，可根据实际工况加以选用。

On the Application of the Trackless Transportation Mode to the Slug-Cleanout Construction for Great-Gradient Water Diversion Tunnels

Owing to the 1 1 th branch tunnel of the water supply proj ect in the northwest of Liaoning province being small in cross-section and great in gradient,the slug-cleanout and transport mode becomes the key control factor for the determination of the construction duration of the proj ect.If the trackless slug-cleanout and transport mode were adopted,the following problems would have to be faced：as the longitudinal gradient of the tunnel is comparatively great,it would be very hard for slug-transporting trucks to go up the steep slope,which might result in very serious accidents in safety;as the cross-section is very small,it would be very difficult for tip trucks to run on the steep slope and turn about inside the narrow tunnel.To solve these problems,the cross-section of the face being excavated is enlarged,turn-out caves are provided,tip trucks are transformed to ensure the reliability of their brakes;safety managing measures are strengthened.Practice shows that the use of the trackless slug-cleanout and transport mode has the advantages of shortening the construction duration,achieving very obvious economic benefit,etc.Therefore,the mode may be applied to the construction of certain projects according to the specific construction conditions.