SU1420095A1 - Regulating jet-guiding structure for bridge overpass of a water duct - Google Patents

Abstract

The invention relates to hydraulic structures, in particular to sloping jets, designed to regulate the internal structure of the flow and organize the movement of sediment at bridge crossings in the foothill areas of the rivers. The purpose of the invention is to improve the operating efficiency of the structure by adjusting the internal flow structure at different levels of water in the watercourse. The jetting structure consists of approach dam I and a jet dam, adjacent a straight section 2 to the end of the approach dam. Through channels 5 are arranged in the jetting dam at a predetermined depth, which are oriented so that their axes intersect the axes of the corresponding half-pile 6 not further than I / 3 of their length, calculated from the head half-pile. The marks of the bottom of the channels 5 are located on the marks of the crests of the heads of the respective half-ponds and decrease towards the bridge section 9. The output sections 10 of the channels 5 are designed as springboards. Because of the slight flooding of the floodplain, when the water level does not reach the bottom of the canals 5, only semi-ponds are involved in the work, working as non-flooding. I can form S (L

Description

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whirlpool zones with reduced flow rates. With an increase in depth on the floodplain, water begins to overflow through the ridges of the semi-pond 6 and channels 5. Over the semi-: dams 6 there will be a vortex rollers as a result of a sharp expansion of the jets flowing over the semi-ponds in the vertical plane. As a result of the active regulating effect of the flooded semispond on the flow, a generally favorable transverse circulation is created at the channel slope of the dam behind the semisplot, with the result that the bottom streams entailing sediment are directed to the deposited dam, where they are deposited. 1 h. the item of f-ly, 4 ill.

one

The invention relates to hydraulic structures, in particular, to back-facing structures that are designed to regulate the internal flow structure and organize the movement of sediment at bridge crossings in the foothill sections of rivers.

The aim of the invention is to increase the efficiency of the facility by adjusting the internal flow structure at different levels of water in the watercourse.

FIG. 1 shows the proposed construction, plan view; in fig. 2 - section A-A isa of FIG. one; in fig. 3 shows a section BB in FIG. I; in fig. 4 shows a section B-B in FIG. one.

The regulatory junction structure for the bridge includes an approaching dam 1 and a diverting dam adjacent a straight section 2 to the end of the approaching dam and ending with curvilinear upper 3 and lower 4 sections. Through channels 5, directed by inwards towards the floodplain flow, are arranged in the jetting dam at a given depth. At the same time, the through channels 5 are oriented so that their axes intersect the axes of the corresponding half-pile 6, adjacent to the channel slope of the dam, no more than 1/3 of their length, counting from the head of the half-pile. In addition, the bottom marks 7 of the channels 5 are located at the ridges of the heads 8 of the corresponding half-piles 6 and decrease towards the bridge cross-section 9. The output sections 10 of the channels 5 are made in the form of springboards 11. The input 12 and output 10 sections of the channels 5 extend beyond the cross section straightening dam from both the upstream and downstream.

The regulatory framework operates as follows.

With a slight flooding of the floodplain, when the water level does not reach the bottom marks of 7 channels 5, only semi-ponds are involved in the work and work as non-flooded, forming whirlpool zones with reduced flow rates. With increasing depth on the flood plain, water begins

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pour over the ridges 8 of the semi-pile 6 and the through channels 5. Behind the semi-pools there are vortex valts as a result of the sharp expansion of the jets flowing over them in a vertical plane. As a result of the active regulating effect of the flooded half-curb 6 on the flow, a generally favorable transverse circulation is created at the channel slope of the diverting dam behind the semi-ponds 6, as a result of which the bottom jets attracting sediments are directed to the protected dam, where they are deposited, strengthened. aiee dam. At the same time, a part of the flood flow enters the bridge channel from the floodplain through the through channels 5. The jets flowing from the through channels 5 fall into the head area of the semi-pond 6 and are deflected by them as oblique weirs to the flow rod. During a collision with the main channel flow, the flow energy is absorbed and a part of the kinetic energy of the jets is converted into the potential energy of the flow. In this case, there is some additional rise of the water level in the head of the semi-pond with the formation of an additional pressure gradient in the direction of the flow dam, under the action of which transverse circulation increases in the flow behind the semi-ponds 6, the transport capacity of the bottom jets and the intensity of water movement in the roller behind the semi-ponds increase. Maximum extra

The S gradient, and hence the effect of the orientation of the through channels, occurs if the axes of the channels intersect the axes of the respective semi-bulkheads at a distance of 1/3 of their length, counting from their heads, since when the heads flow around, maximum curvature of the jet path. Consequently, a maximum pressure gradient arises here. When the jets exit the through channels 5, as a result of their sharp vertical expansion, separated secondary currents with a horizontal axis of rotation are formed, which are located between the output sections I) of the through channels 5 and semi-ponds 6.

At the same time, the speed of movement of the bottom jets is insignificant and they do not threaten the erosion of the bottom and the slopes of the dike. Bottom streams in the detachable flow are directed towards the protected dam and transport to it bottom sediments strengthening the channel part of the dam. The intensity of the rotational movement of the separated flow, its size and transporting capacity enhances the presence of springboards 11 in the outlet sections 10 of the through channels 5 by deflecting the jets from the protected bottom of the watercourse.

The arrangement of channels outside the jet dam from both the upstream and downstream side allows for an increase in the length of the channels within which the flow structure stabilizes more clearly and it acquires a more targeted movement. Due to this, at the exit of channels 5, the stream acquires a more compact form and greater speed, which allows it to move further downstream and have a greater speed on the approach to the semi-dams, which ultimately enhances the favorable transverse circulation behind the semi-ponds. . This eliminates overflow of the flow through the top of the channels in the inlet sections 12, which ensures only an end approach to the channels and reduces the flow resistance at the inlet.

Reducing the heights of the semi-pond and the bottom levels of the corresponding channels towards the alignment of the bridge alignment 9 reduces the concentrated differential in the boundary jet with the slope, spreading it over a longer length, and thus reduces the longitudinal velocity along the diverting dam and the danger of its erosion. In addition, the correspondence between the bottom marks of the channels and the ridges of the semi-pond provides for the transport of jets extending from the channels to the head area of the semi-deep pools to marks not lower than the ridges of the bottom of the bottom of the bottom, as here the maximum pressure gradients are formed. In this case, jets flowing out of the channels and flowing through the ridges of the semi-pile enter into the channel flow along complicated helical trajectories m identical in direction

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with the already existing semi-ponds, which has a positive effect on the increase in the intensity of water movement in the vortex rollers behind the semi-ponds and the general transverse circulation in the semi-semi-ore areas. At the same time, the channels improve the flow behavior of the surface jets. The ridges of the semi-pond, working as slanting weirs, deflect surface jets, which have an increased erosion capacity, towards the bed from the protected dam. The jets emerging from the channels enhance this effect.

Invention mold

Claims (2)

1. Regulatory trickling structure for a bridge crossing through a watercourse, including an approaching dam located in the floodplain and a damming guide adjacent the middle straight line to the end of the approaching dam, ending with curvilinear upstream and downstream sections and having through body channels, which are responsible for the fact that, in order to improve work efficiency by adjusting the internal structure of the flow at different levels of water in the watercourse, to the channel slope of the curvilinear upflow and of the streamline dam sections adjacent adjacent flooded semi-ponds obliquely facing the stream so that the longitudinal axes of the through dam cross channels intersect the axes corresponding to the half-pond not more than 1/3 of their length, counted from the head of the structure; the elevations of the crests of the heads of the corresponding half-seam with their decrease towards the bridge section, and the output sections of the channels are made in the form of springboards. 2. The construction according to claim 1, characterized in that the inlet and outlet sections of the through channels of the diverting dam extend beyond its cross-section both from the upstream and downstream. FIG. 2 12 / / / . FIG. b-b / /// /// eleven