heading wall
1.Three-dimensional mechanical performance of primary support under different construction conditions is analyzed by using numerical modeling method. Through four different excavation methods, which are named as curve drift heading, CD, CRD and two-side wall drift heading method, respectively, safety performance of primary support and its effect of confining the wall rock deformation is researched, and the quality of these methods are assessed to recommend proper excavation method for corresponding conditions.
2.to use pre-supporting method by pre-grouting tubes in small diameter; to excavat by the method of double-side pilot heading, to install facilities outside the boreholes to prevent water emerging, and to pour concrete wall and prevent water by grouting. The solution has provideed technical basis for the safety construction of this kind of tunnel.
