SU1548318A1 - Method of joining cylindrical shells of water-development works - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to hydraulic engineering. The purpose of the invention is to increase reliability by creating a uniform deformation along the height of the intermediate shell. The method is as follows. A pre-deformed intermediate shell 2 is lowered into the gap between the cylindrical shells 1. When the shell 2 is lowered, under its own weight, beginning with the position of its lower slice at the bottom level, a pulsed bubbling of the water volume in it at the bottom of the water area is performed. By stopping the bubbling, water is added as the level of the bubbling water is lowered. The water level in the shell 2 is gradually made 0.15-0.2 m above the water level of the water area to create an overpressure in the intermediate shell 2. Simultaneously with the bubbling off, the shell 2 is further submerged to the design value with the help of tackle blocks. Then the internal volume of the shell 2 covered with sand. 1 hp f-ly, 7 ill.

Description

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The invention relates to the construction of hydraulic structures and can be used in the construction of dams, lintels, as well as mooring facilities.

The purpose of the invention is to increase reliability by creating a uniform deformation along the height of the intermediate

SHELLS.

FIG. 1 shows cylindrical shells connected by an intermediate shell, top view; in fig. 2 is a section A-A in FIG. one; in fig. 3 shows a section BB in FIG. 1 (sparging device installed in the intermediate shell) —Fig. .4 is a plot of the pressure distribution on the wall of the intermediate shell at the height at the time of bubbling; in fig. 5 - the same, in the process of filling it with an additional volume of water; in fig. 6 is a section of a BIS in FIG. 1 (immersion scheme of the intermediate shell using pulleys mounted on cylindrical adjacent shells); in fig. 7 — equipment for sparging the internal volume of the intermediate shell.

The method is carried out as follows.

Having installed cylindrical shells 1 at the bottom of the water area, which under their own weight sink into the underwater base to a depth of not less than 2 m, and having filled their internal volume with soil, intermediate cylindrical shells pull the cable along the transverse axis to the center on the coastal mounting platform on both sides. - a dumbbell-shaped form in plan “Each dumbbell-shaped intermediate shell 2 is delivered with the help of a floating crane to the place of their installation, set between the shells 1 and lowered to the bottom surface of the water area Thoroughly sn cable straps. By installing intermediate sheath 2 between cylindrical adjacent

SHELLS 1 AND REMOVED TIE, SHELL

2, maintaining a dumbbell-shaped form in terms of its own weight, being in sliding contact with the shells 1, is lowered. The straps are removed before the shell is lowered in order to carry out this crucial operation in an accessible (and not submerged) position, in order to eliminate the possibility of gaps between shells 1 and 2. The lower shell is suspended at the moment when the bottom edge is at the bottom of the water area. . The intermediate casing 2 is equipped with bubblers 3, which are placed at the level of its lower cut, at the bottom level. The bubblers 3 are connected by a piping system 4 to a gas generator, which is connected to a storage tank 5 of compressed air. Impulsive bubbling of water into the internal volume of the intermediate casing is carried out to raise the water in it by 0.2 m in order to create an overpressure, the value of which is sufficient to form a circular shape of the casing outside its contact zone with adjacent cylindrical shells 1. Simultaneously - the shell is immersed under its own weight to a depth of 0.5-1 m. Having stopped bubbling, water is added from the storage tank 5 to the shell 2 as the level of bubbling water inside the shells is lowered. The water level in the shell 2 is gradually made 0.15-0.2 m above the water level of the water area to create excessive pressure in the intermediate shell 2. At the same time as the barbotis is turned off, the shell 2 is further immersed in the base soil. To do this, with the help of the polyspits 6, the shell 2 is fastened on four sides to the shells 1 and, including the winches, lowered to the design mark.

Having deepened the intermediate shell 2 into the bottom, its internal volume is covered with sand, keeping the excess pressure from the additional volume of water in it until the shell 2 is filled with sand for at least a third of the height of the shell 2.

The excess internal pressure in accordance with plot 7 (Fig. 4) is the pressure difference between the inside and outside of the water acting on the wall of the casing 2. With intensive bubbling in a short period of 5-7 seconds, the foamed water does not have time to rise from the bottom one third of the internal volume of the shell 2. The water pressure in the bottom level with air supply does not change; above one third of the height the value of the excess pressure is constant. Thus, the normal slope of the plot in the lower third is rounded and corresponds to the plot 7 in the shape of a curvilinear rectangle. On

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In the second stage, when water is poured in a lowered soil sheath, an overpressure occurs in accordance with the diagram 8 in the shape of a rectangular quadrilateral.

If two fixed points are connected by a flexible element (whose flexural rigidity is small or absent), which is to be loaded with a uniform load, normal at each point to the flexible element, then the flexible element will take the form of a part of a circle. The solution of the problem is unique for a given length of the element and fixed fastening of the ends of the element. This shell, loaded over its entire height with an excess pressure, has a circular shape in a horizontal section in a sufficient approximation to it already at a pressure of 0.2 m of water column.

According to the proposed method, the diameter of the intermediate shell is 23 m, the diameter of the protruding dumbbell-shaped part is 8 m (after immersion), the thickness of the shell wall is 6 mm. The volume of two storage tanks 5 of no more than 2 m with compressed air at pressures up to 15 MPa.

The bubblers 3 are directly mounted on the tanks of the storage tanks 5 and are lowered fully assembled into the working position (Fig. 7). The discharge time for all air is 3-5 seconds, and the ballasts 9 are reliably fixed for the bubblers to be fixed. It can achieve close contact between adjacent cylindrical and intermediate shells. The contact area does not change as the bulk material fills the intermediate shell. This is due to the water level raised by pulsed bubbling in the bottom of the water area before the intermediate shell is immersed, the weight of the entire water column remains the same, and consequently, the excess pressure at the bottom level is zero. The base is thus not subjected to a destructive flow of water from inside.

However, at all other points along the height of the intermediate shell, the pressure is higher than outside the shell. Outside the contact zone, the intermediate shell assumes a circular outline in the plan, i.e. exactly the same as it will be after strutting her ground. Naturally, the magnitude of the thrust during barbing is an order of magnitude smaller than with backfilling, but at a ratio of shell thickness of 0.5–1 cm to its diameter of 15 m, even a slight internal pressure leads it to a circular outline in the plan.

Claims (2)

1. A method of joining cylindrical shells of a hydraulic structure, consisting in lowering into the gap between cylindrical shells arranged in a row pre-deformed to the center on both sides along the transverse axis of the intermediate sheath with subsequent release from pre-deformation and filling with bulk material, characterized by that, in order to increase the reliability of the connection of the shells by creating a uniform deformation along the height of the intermediate sheath, while lowering the latter under a tweeter of its own weight creates an overpressure in the intermediate shell by bubbling up the volume of water in it, which starts from the position of its lower section at the bottom level, pours the internal volume of the intermediate shell into additional volume of water and dredges it into the ground by the design value, bubbling is carried out with a single pulse. 2. A method according to claim 1, characterized in that the intermediate shell is sunk into the ground by a design value by means of pulley blocks. go , ъ ABOUT $ ig.Z go with g sh J g-ohhe AT (pi / g. 6 SZSSE - SI eri 2.7