Diversion tunnel straight pillar plug length design method

Abstract

The invention discloses a diversion tunnel straight pillar plug length design method. The method comprises the steps that (1) a rigid body limit equilibrium method is adopted to calculate the effective length L<0> of a conventional wedge-shaped plug; (2) a three-dimensional finite element method is adopted to perform calculation analysis on a straight pillar plug and the conventional wedge-shapedplug, and safety stock P<0>provided by a wedging effect is obtained; (3) safety stock P<m> provided by surrounding rock supporting anchor rods of the straight pillar plug and safety stock P<c> provided by plug downstream section linings are calculated respectively, and the sum P<1> which is equal to P<m>+P<c> is calculated; (4) P<1> and P<0> are compared; if P<1> is greater than or equal to P<0>,the effective length of the straight pillar plug is L<j> which is equal to L<0>; and if P<1> is smaller than P<0>, the difference is provided by increasing plug length delta(L), and L<j> is equal to L<0>+delta(L); and (5) the design length of the straight pillar plug is L<z> which is greater than or equal to L<j>. The method overcomes the defect that the water-retaining extra safety stock of an existing straight pillar plug is lowered compared with the conventional wedge-shaped plug, and the method is a supplement to an existing plug length design method and is beneficial for promoting application of the straight pillar plug in a diversion tunnel and particularly a large diversion tunnel plugging project.

Description

technical field [0001] The invention relates to the technical field of water conservancy and hydropower engineering construction diversion, and more specifically relates to a method for designing the length of a straight cylindrical plug in a diversion tunnel. Background technique [0002] After the diversion tunnel of water conservancy and hydropower projects completes the diversion task, it needs to be blocked with concrete plugs, and it will run together with the dam to retain water. Its design level is the same as that of the dam. "Code for Design of Hydraulic Tunnels" (DL5195-2004) stipulates that "the type of sealing body is selected according to the cross-sectional shape of the hydraulic tunnel, construction conditions, engineering geological conditions and other factors. The type of longitudinal section of the sealing body should preferably be wedge-shaped .” See Table 1 for the characteristics of the permanent plugs in the diversion tunnels of some large-scale hydro...

AI Technical Summary

Problems solved by technology

[0016] In view of the additional overload capacity of the wedge-shaped plug, if the straight cylindrical plug is directly used instead of the wedge-shaped plug, the additional safety reserve of the plug will be reduced.

Images