RU2004708C1 - Method for block excavation of trench ground - Google Patents

Abstract

Use: block trenching in permafrost zones. SUMMARY OF THE INVENTION: cutting slots, removing blocks and tearing off the trench is preceded by summer drilling in the trench strip of a number of wells to the depth of the design marks of the bottom of the trench and pumping water into them for hydroflowing, followed by water withdrawal into the pond along a slope. 1 PLN, 4 il

Description

The invention relates to mining and may find application in the development of trenches in the permafrost zone.

Known methods of block development of the trench.

One of them consists in cutting in frozen ground along the trench strip a pair of longitudinal and a number of transverse slots to a depth up to the design marks of the trench, laying in the next transverse and longitudinal slots of the steel rope, cutting the frozen ground at the bottom of each successive block with a rope and removing the block. However, providing a sufficiently high quality of subsequent reclamation of the upper soil-plant layer of the soil when filling the trench, due to the presence of a smooth sole for each block, the method is very laborious due to the need to form this sole by cutting the permafrost with a rope.

The closest in technical essence to the present invention is a method of block excavation of the soil of the trench, which consists in cutting the slots in the trench strip in winter time to the depth of the average seasonal freezing of the soil, extracting the formed soil blocks and tearing the trench to the design level.

A disadvantage of the known invention is that it is applicable in areas where permafrost is not widespread and where the sole of each block is relatively smooth due to the action of natural forces when the boundary between the upper frozen ground and the lower one, which does not have fortresses with soil that has not been exposed to frost. In the zones of permafrost distribution, this method is not applicable, since in winter seasonally thawing soil merges with permafrost during freezing, as a result of which it is impossible to form any sole of the block, and even more relatively smooth, when removing the block by upward separation, and therefore when the block is returned to the trench, it is impossible to ensure that its upper surface occupies a horizontal position, moreover, at the level of the day surface of the surrounding territory. In other words, this method does not make it possible to ensure the restoration of the soil and plant layer in permafrost propagation zones.

The aim of the invention is to preserve the possibility of reclamation of the soil-vegetation layer in permafrost propagation zones when soil blocks are returned to the trench by providing the formation of the sole of each of them.

To achieve this goal, cutting slots, removing blocks and tearing off the trench is preceded by summer drilling in the trench strip of a number of wells to the depth of design marks for

trenches and injections of water in them to hydrottially soil layer between the marks of the bottom of the trench and above the freezing boundary, and the water coming from the wells simultaneously with injection

5 are diverted into the pond. In addition, the discharged water is distributed over the land cover of the working site by means of deflecting barriers.

0 in FIG. 1 shows a tear-off trench, a longitudinal section; in FIG. 2 - the same, her plan; in FIG. 3 - hydrostatic band of the trench, a longitudinal section; in FIG. 4 - same, her plan.

5 A method for block designing a trench is as follows. In wintertime, a system of longitudinal 2 and transverse 3 slots is cut along a strip of trench 1 to the average depth h ce0 of zone freezing of the soil. The cutting is performed by slitherer 4, operating in the longitudinal and transverse directions. Then, a crane 5 equipped with a grapple is used to extract the formed soil blocks 6 and lay them out in an extended warehouse 7 remote from the trench. Then, the trench 1 is excavated 8 to trench design bottom marks to a depth H with dump 9 dumping near the trench.

0 The winter period of work is preceded by the performance in summer of drilling in the trench strip of a series of boreholes 10 to a depth H of design marks of the bottom of the trench and forcing water into them from the reservoir 11 by pressure

5 to a temporary pipe 12 equipped with vertical hydroneedles 13. Water coming from the wells 10 simultaneously with the injection is diverted into the reservoir 11 along a slope. The discharged water is distributed over the land cover of the working platform 14 by means of deflecting shields 15 of the fence. During the summer time before the onset of frost, the permafrost layer of soil is hydro-thawed to a thickness (H-h) in volumes 16, approaching in shape to the shape of a cylinder.

As a result of summer hydro-thawing under the upper soil layer, which acquires a rather high level during the freezing season

a frosty fortress, there remains a layer of soil of thickness (H-h), unfrozen and therefore lacking a fortress. This makes it possible to remove the formed soil blocks 6 by tearing them up, and to have a relatively smooth surface on the soles of the blocks. To keep this layer unfrozen after cutting the cracks (in the presence of a technological gap between the slimeroz 4 and the crane 5), foam is filled in the cracks or snow is covered. It is also advisable to fill the temporary trench 17 with a depth of h with foam, or fill it with a layer of snow in case of a technological gap between the crane 5 and the excavator 8.

The open trench 1 can be used for various slots: laying household communications, cable systems, etc. In the case of laying a pipeline in it, part of the soil sprinkled into dump 9 does not enter the trench. After the stage of backfilling of the trench 1 (up to the marks of the bottom of the trench 17), the soil is compacted, and then the blocks b are moved onto it, moved from the warehouse 7. Due to the relative smoothness of the soles of these blocks and the accuracy (in the previous stage of backfill) of the size h, the upper one contains soil vegetation cover, the surface of blocks 6 turns out to be horizontal and coincides with the level of the day surface of the surrounding territory. The slots formed at the return of the blocks are neatly filled with soil from the remnants of the blade 9 using a side loader (not shown). The combination of the upper surface of the blocks with the level of the surrounding territory, filling in the slit, and the fact that the blocks on their upper, rather vast surface retained a significant area of the undamaged layer of the soil-plant area, contribute to the rapid restoration of the soil-plant layer after completion of all work .

Claims (1)

Formula 1, METHOD FOR BLOCK DEVELOPMENT OF A Trench of a Trench, which consists of cutting the slit system into the depth of the average seasonal freezing of soil in the winter along the trench strip, extracting the formed soil blocks and re-trenching the trench to the design elevations, characterized in that it is possible to restore the soil to restore -the vegetation layer in permafrost propagation zones when returning soil blocks to the trench by ensuring the formation of the bottom of each of them, before cutting the cracks, from sobo should be noted that the winter operation can begin, without waiting Referring freezing of the surface layer on the full projected above average depth h 1,0-2,0 m talik seasonal freezing ground, normally the north zavershayuschegos in March-April. Thickness sufficient to start work (up to 0.5 m), at which it becomes passable to the place heavy machinery works - a crane and an excavator.It should also be noted that modern science has sufficiently deeply studied the process of permafrost formation and thawing in a seasonally frozen layer of thickness n (Sat. Fundamentals of permafrost forecasting in engineering-geological research, ed. Moscow State University Lomonosov, 1974). From the collection materials it follows that over the winter period of one year, the freezing depth of the surface layer has a finite value that does not exceed the depth H of the trench bottom marks used in the method, for example, the necessary depth (3-1 Ohms) for laying the pipeline with a diameter in it 1420 mm. In other words, the water-thawed layer cannot freeze from above even when exposed to air temperatures of minus 55-60 ° С. From below, the hydrothermal layer can freeze just a few centimeters, because the permafrost temperature is only minus 1-2 ° C. PRI me R. In summer, 60 mm diameter wells are drilled to a depth of 3.5 m in increments of 1.5 m. Water is supplied to the wells for 14 days at a temperature of 18-20 ° C. Subsequently, when trenching the trench in winter time, the presence of the soles of cylindrical volumes is recorded at the bottom of the trench 16 with a diameter of 2.0-2.5 m with soil temperature plus 1 ° C. (56) V.A. Cherkashin. Development of frozen soils. L .: Stroyedat. 1977. attracting soil blocks and tearing off the trench in summertime in non-thawed soil, wells are drilled to the depth of the design marks of the bottom of the trench and water is pumped into them to hydrate the soil layer between the marks of the bottom of the trench and above the seasonal freezing boundary, and the water coming from the wells simultaneously with pumping discharge into the pond deviation. 2, The method according to claim 1. characterized in that the discharged water is distributed over the soil and vegetation cover of the working site by means of deflecting barriers. 5 S;, //. JJJJjJJJJjUJjIJJTT t I A .1 -1-JL.L a J. Leu xff-r t t direction of work. -t tt-tt-gttt-gttt ig. 4.