8 Underground Engineering

8.1 General Requirements

8.1.1 In the underground engineering design of a water-sealed cavern storage project,the surrounding rock's self-stabilizing,load-bearing,and anti-seepage capabilities shall be taken advantage of.

8.1.2 A surrounding rock stability analysis shall be carried out.The stability of the surrounding rocks of the cavern and its major intersections should be verified by using the empirical comparison method and numerical simulation method.It may use the empirical comparison method and block balance method to determine other underground works according to the gedogical conditions.

8.1.3 The smooth blasting method shall be used for underground tunneling.The blasting quality shall comply with the relevant requirements specified in the currently effective national standard Specifications for Bolt-shotcrete Supports(GB 50086).

8.1.4 The underground works of the water-sealed cavern storage shall be dynamically designed.