Application of single pass tunnel lining with steel fibre reinforced shotcrete on the ventilation shaft of Mount Motian tunnel

The ventilation shaft of Mount Motian tunnel is an inclined shaft with a dip angle of 24°21'48". Investigations were conducted to evaluate the feasibility of applying single pass tunnel lining (SPTL) of steel fibre reinforced shotcrete (SFRS) to the ventilation shaft as a permanent lining. Concrete mix ratio tests were carried out to find out a proper mix ratio under which the optimum strength and degree of slump can be achieved. Tests were performed on specimens cut from sprayed shotcrete samples for flexural and cleavage tensile strength of the shotcrete. Results of the tests showed that the inclusion of steel fibre largely increased the flexural and tensile behaviour of the shotcrete. The shaft is in construction now and the performance of the completed sections is good