SHALLOW TUNNEL FORMED IN PERMAFROST GROUND Russian patent published in 2006 - IPC E02D29/45 

FIELD: building, particularly to erect building structures in permafrost areas and thick snow cover.

SUBSTANCE: tunnel comprises trench in which load-bearing enclosing structure partly submersed in ground below natural ground surface is arranged. The enclosing structure defines space for transport passage structure location. Tunnel built in permafrost ground comprises longitudinal embankment having axis coinciding with longitudinal tunnel axis and defining combination of trapeze and triangle located above trapeze in cross-section. Triangle base coincides with upper trapeze base. Above load-bearing enclosing structure is arranged within the bounds of longitudinal embankment and back-filling ground below natural ground surface and may partly project over the embankment and back-filling ground. Nonfrost-susceptible ground layer is arranged under the passage structure. Total height of the nonfrost-susceptible ground layer between passage structure bottom and lower trench surface is to be not less than season thawing depth. Width B thereof is determined along trench top. Trapeze height h_t, maximal ground embankment height h_e along passage structure axis, upper trapeze base width B_u, total ground embankment width B_e are determined from given correlations.

EFFECT: reduced costs of motor road and rail road erection in permafrost ground and increased ability of ground retaining in permafrost condition.

3 cl, 2 dwg