Abstract: In complex geological environments,deep-buried tunnel linings are prone to cracking,which in turn affects
their seepage behavior. This study,based on the water conveyance tunnel of the Jiangxi Yanshan Pumped Storage Power Station,
employs a three-dimensional numerical seepage simulation method to systematically analyze the influence of lining crack
development length,depth,spatial distribution,and permeability on the seepage field of the water conveyance tunnel. The results
indicate that the water pressure around the tunnel and the overflow volume are significantly affected by the length and permeability
of lining cracks. An increase in crack development length and permeability weakens the anti-seepage capacity of the
lining structure,leading to a notable increase in leakage at the cracked sections. The presence of cracks in the tunnel lining
causes a rapid attenuation of water pressure in the surrounding rock near the affected area. The larger the development length
and depth of the cracks,the more pronounced the decrease in water pressure around the tunnel,with the attenuation being more
severe closer to the cracked regions. The increase in seepage flow diminishes as the permeability coefficient rises. When cracks
are dispersed,the overflow volume of the tunnel increases by 11% compared to when cracks are concentrated,with the middle
section experiencing an increase of up to 31. 8%. Tunnels with dispersed lining cracks exhibit a higher overall risk of seepage,
while those with concentrated cracks show a greater decrease in water pressure. As the circumferential development range of
lining cracks expands,both the unit-length overflow volume and the decrease in water pressure around the tunnel increase.
Compared to the scenario where cracks develop only at the vault,when the crack development range extends to the spandrel,
haunch,and invert the decreases in water pressure in the surrounding rock at the vault are 7. 9%,14. 2%,and 19. 3%,respec
tively. At a distance of 40 meters from the tunnel cracks,the decreases in tunnel water pressure are 20. 5%,24. 5%,26. 1%,
and 28. 1%,respectively. The water pressure in the surrounding rock at the vault of the cracked tunnel decreases significantly,
whereas that of adjacent intact tunnels shows only a slight decrease,approximately 26. 2% of the decrease observed in the
cracked tunnel.