ERECTION OF TUNNELS IN STRUCTURALLY UNSTABLE SOILS WITH KARST PHENOMENA AND/OR BOIL PROCESSES Russian patent published in 2015 - IPC E02D29/00 

FIELD: mining.

SUBSTANCE: proposed method comprises erection of forepoling along shotwall contour. Wells of the first type are drilled along contour of shotwall with said soils, injectors are fitted in every said well to inject solidifying mortar to well bed so that first contour of forepoling is produced from at least one layer of solidifying elements and compacted soil there between. Said first-type wells are arranged so that, at injection, intersecting zones of compacted soil are formed between adjacent wells. Solidifying elements hardened, second-type wells are drilled around forepoling first contour. Solidifying mortar is injected to well walls to make, over the forepoling height, a protective massif of one or several lines of elements intersecting in horizontal. Then, third-type wells are made with their bottoms to be arranged in imaginary cylindrical or elliptic surface above forepoling zone and thereunder. Hear, solidifying mortar in injected into plies of soil located under third-type well bottoms to produce cylindrical or elliptic roof above forepoling zone and thereunder composed by one or more lies of flat-parallel elements intersecting in horizontal to make a geological massif. Soil above said roof plies is additionally compacted by drilling fourth-type wells to inject there through said solidifying mortar into natural cavities and fractures formed in geological massif formation. Mortar can be composed of stock mix containing siliceous component, gas-forming agent, liquid sodium glass and sodium oxide hydrate solution, or simple sand-cement mortar. Said mortar is injected in resilient shells prefilled in said first- and third-type wells in soils with boil processes and second-type wells in extreme lines from forepoling.

EFFECT: forepoling over shotwall contour, higher reliability of soil massif.

6 cl, 4 dwg