SU1737064A1 - Dam - Google Patents

Abstract

Use: in hydraulic structures providing overflow of flood waters with ice over the ridge of an unfinished structure. SUMMARY OF THE INVENTION: The dam body is limited to the upper and lower edges. A dam is poured on the ridge of the upper edge. The dam is buried in the body of the dam, made of a large-sized draft, the height is determined according to the calculated thickness of the ice. Through the dam provides consumption for the passage of floating bodies. 2 Il.

Description

FIELD OF THE INVENTION The invention relates to hydraulic construction, in particular, to the discharge of flood costs through unfinished dams made from soil materials.

The purpose of the invention is to reduce the capital costs of the construction of the dam and increase the reliability of its protection from erosion.

Figure 1 schematically shows a dam of ground materials in the period of the passage of the flow of water and ice on top of it, a cross-section; figure 2 - dam, top view.

The dam of soil materials contains the body 1 of the dam with a horse 2 and a bottom 3 edges, with a dam 4 poured on the crest of the dam from a large-size filtering pattern recessed into the body of the dam. Dam 4 is poured along the ridge 2 of the dam ridge with a penetrability of at least 30% and a height of at least 0.5 of the calculated ice thickness.

The values of throughness and height of the dike are determined by the following factors.

The effective pressure H on the dam, determined by the value of the smallest depths at the entrance to the channel and exit from it at the time of the passage of ice, which should not be less than the calculated ice thickness.

Using known dependencies

- MrJ3 / 2 q

5 h

cr

F

(1) and HJ

m JTq

(2)

we obtain the value of H t, 6 6 (3), where 5 is the thickness of the ice; The calf is the critical depth above the dam.

Reliable overflow with minimal flooding, provided by a dam height of at least 1/3 N or (0.5-0.6) d.

Full compensation of filtering losses along the length of the channel by filtration through dabmu, using the known ratio

0.1 q shr V2 g 1/3 N, (4) replacing in it instead of q the expression (2), instead of H - the expression (3) and c 0.7 (coefficient XI

00

Xi about o

one

turbulent flow rate through draft), we get

th 0.14 6, where the y-rate of the dam, i.e. the total area of the holes.

In view of the relationship indicated for the second factor a), it is 30%.

When penetration is less than 30%, the condition of equality of depths above the dam and on the lower edge of the channel is not fulfilled, which results in the formation of gaps in the channel zone and leads to erosion of the dam body.

With an increase in throughput of over 30%, the condition of equality of the depths above the dam and on the lower edge of the channel is fulfilled. Moreover, the exit depths will exceed the depth above the dam, as a result of which the ice passes freely through the dam, without creating gaps and erosion, and thus the reliability of the dam protection is increased.

When passing costs through the earth dam, the load Of from the impact of water, ice is perceived by the filter dam 4. The dam will not let ice pass through the dam until the depth above the hKp reaches the value necessary for ice to overcome the dam crest. the dam provides additional consumption, due to which the critical depth at the lower face 3 increases to a depth that ensures the unimpeded passage of floating bodies that have crossed the dam crest to the lower pool, i.e. the depth of flow at the outlet becomes not less than the depth of flow H above the dam.

The construction of the filtering dam allows you to skip flood expenses over an unfinished dam made of soil materials without using additional materials to prevent erosion, provides reliable protection of the channel of any width from erosion and automatic operation throughout the entire range of upstream.

Claims (1)

Claims of the invention: A dam made of ground materials, working under overflow conditions through a flood ridge with ice, containing a dam body with a lower and an upper edge, with a dam of a large-sized draft buried in the dam body, dumping on the dam so that, in order to reduce the capital expenditures on the construction of the dam and increase the reliability of protecting it from erosion, the dam is poured along the high face of the dam and is made with permeability of permeable holes from the surface area of at least 30% and a height of at least 0.5 of the estimated thickness of the ice passed through the dam, -t 2 + b h Fig 2