SU1318641A1 - Method of constructing earth-fill dam - Google Patents

Abstract

The invention relates to the field of hydraulic engineering. The purpose of the invention is to enhance the functionality by providing for the construction of dams from frozen associated soils without compacting them and improving the reliability of the dam. The method includes dumping frozen cohesive soils with their subsequent thawing. To do this, in each floor of the frozen connecting soil a feeding trench (ST) 3 is arranged. Water is fed into the ridge of the tusk and an anti-filtration element 6 is installed in the ST. Water is fed into the ridge of the tusk in two cycles: in the ST. The anti-filtration element 6 is arranged for the period of stabilization of the strength of the dam body by freezing the soil. This sequence of work allows you to adjust the draft of the dam by controlling its temperature and removes restrictions on the rate of water rise in the reservoir, e. 1 hp ff, 1 ill. I SL OO CX O5 4:

Description

The invention relates to hydraulic construction and can be used in the construction of earthen dams, mainly in the northern construction and climate zone.

The purpose of the invention is to enhance the functionality by providing for the construction of dams from frozen associated soils without compacting them and improving the reliability of the dam.

The drawing shows a dam, a transverse section, realizing the proposed method.

The dam contains thrust prisms 1 in each floor of the dumping, the central prism 2, wash down your vault trench 3. The central g prism 2 is divided by the functionally powered trench 3 on the impervious screen 4 and core 5. In addition, the dam has an impervious element 6 .

The method is carried out as follows.

In summer, the base is prepared in known ways. A layer of the dam body is poured over the entire width from thawed soils with compaction to create thermal insulation.

A trench of water 3 forms a closed talik of limited size in the central prism 2 of frozen associated soils. Further heat transfer from the water to the frozen ground is conducted. If there is a thawed filtering layer of soil over the entire width of the dam formed during the first thawing cycle, the efficiency of the second cycle increases to the maximum value (for this method of thawing), since the heat transfer proceeds already convectively, which allows thawing the first Russian to the base.

The thawed soil of the first tier is self-compacted before the onset of frost. During this time, the subsidence of the sedimentary frozen bonded soil is realized. The precipitation of the additional seal occurs in winter. It is protected from frostbite by a layer of thawed soil across the entire width of the dam, filled with summer compaction (ABB A circuit).

In the second winter, the second Russian soil is poured over the entire width, the dam. Frozen unconnected soils are laid with compaction, and frozen communicative materials are laid without compaction. In the summer, the dam is thawed hydraulically in two cycles from a single dam from the cooling effect by the permafrost buildup of the dam. All of the grounds.

In winter, pour the first Rus soil over the entire width of the dam height, for example, 30 m (contour ABCD). Frozen non-bonded soils with compaction are laid into the thrust prisms 1, frozen bonded soils are laid into the central prism 2 without compaction, the feeding trench 3 is filled from non-bonded soils with compaction.

The first cycle of thawing. In summer, the first Rus dams are thawed hydraulically by pouring water into the ridge ridge with overflow of water through the edge of the slopes.

The second cycle of thawing. The defrosting in the first cycle is carried out for a limited time, for example, a month.

thirty

35

The radios of the first year are repeated.

In order to increase the reliability of the dam in the first years of operation, an impervious element 6 is arranged in the feed trench 3 - an ice-earth curtain with a recess in the basement for the calculated depth of thawing. Continuous refrigeration is carried out until the soil of the impervious screen 4 is fully consolidated together with the base, which will take 5-15 years. Upon completion of the formation of the texture of the screen 4, the need for an ice-ground curtain disappears, the freezing system is turned off, but the absence of a prediction of compressibility and filtering in the required volume of the remaining warm time during the double chrome properties of the base under core 5 does not

three months, increasing the dam across the entire width of the thawed ground with compaction (ABB A circuit) and simultaneous water supply to the feeding trench 3.

A portion of the groundwater of the first river of the dam across its entire width thaws during the first hydrotreating cycle, B results in a talix - thawed filter layer E (ABCC E DD contour) providing the necessary conditions for successful thawing of the remaining frozen ground (circuit D EC) in the second cycle of hydro-thawing - during the water supply to the feeding trench 3.

The division of hydro-thawing into two cycles is rational, since the effectiveness of thawing the soil of the soil in the first cycle is small (I) -15 m in depth).

If hydro-thawing is started from the second cycle, then due to the warming effect supplied to the power supply

A trench of water 3 forms a closed talik of limited size in the central prism 2 of frozen associated soils. Further heat transfer from the water to the frozen ground is conducted. If there is a thawed filtering layer of soil over the entire width of the dam formed during the first thawing cycle, the efficiency of the second cycle increases to the maximum value (for this method of thawing), since the heat transfer proceeds already convectively, which allows thawing the first Russian to the base.

The thawed soil of the first tier is self-compacted before the onset of frost. During this time, the subsidence of the sedimentary frozen bonded soil is realized. The precipitation of the additional seal occurs in winter. It is protected from frostbite by a layer of thawed soil across the entire width of the dam, filled with summer compaction (ABB A circuit).

In the second winter, the second Russian soil is poured over the entire width, the dam. Frozen unconnected soils are laid with compaction, and frozen communicative materials are laid without compaction. In the summer, the dam is thawed hydraulically in two cycles with a simultaneous build-up of the dam. All ope30

35

The radios of the first year are repeated.

In order to increase the reliability of the dam in the first years of operation, an impervious element 6 is arranged in the feed trench 3 - an ice-earth curtain with a recess in the basement for the calculated depth of thawing. Continuous refrigeration is carried out until the soil of the impervious screen 4 is fully consolidated together with the base, which will take 5-15 years. Upon completion of the formation of the soil texture of the screen 4, the need for an ice-ground curtain disappears, the freezing system is turned off, but the lack of prediction of compressibility and filtering properties of the base under core 5 in the required amount is not

five

eliminates the possibility of including the freezing system in the next 5-15 years.

The proposed technology allows controlling the draft of the dam by controlling its temperature conditions.

Example. When dumping winter from frozen soil, along the axis of the feeding trench 3, an anti-filtration element 6 is installed - a wooden diaphragm upholstered with a roofing beam that divides the feeding trench 3 into the upper and lower parts capable of supplying BO ;; V, respectively, to the anti-filtration roe 4 and draw 5. In the summer, the ground is thawed on the first cycle. A talik .ABCC ED D is formed. 5 When carrying out the second cycle, thawing (building up the body, and; iepe iinK) fi; 1. aifragms) the anti-filtration -jKpan 4 and draw 5 can already be thawed, with the running; (different

width, degree of ice content, etc.) at different speeds by supplying water with different flow rates and temperatures to the upstream and downstream parts of the feeding trench 3. Such a mode can be achieved by thawing frozen ground 30–40 m high, at which the speed of the vertical deformation of the anti-filtration screen 4 and the core 5 are the same, which ensures the safe operation of the wooden diaphragm (no shear forces) and allows it to be used as an anti-filtration element for the period of additional consolidation a 4.

Claims (2)

1. The method of erection of a soil dam, including dumping of frozen connected ground; and with the help of them thawing. limit; in order to expand the functionality due to the ooeci of the construction of dams on frozen frozen soils without compacting them and improving the reliability of the dam, each floor of the frozen bonded soil is arranged , water is fed into the ridge of the rus in two cycles: with overflowing it through the edges of the slopes and by feeding into the feeding trench and installing an anti-filtration element in the feeding trench. 2. A method according to claim 1, characterized in that the impervious element is set by freezing the soil on a period of stabilization of the strength of the dam body, after which the freezing system is turned off.