RU2549789C1 - Method to submerge thin-walled steel shells with deepening into dense waterproof soil - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: thin-walled steel shells 2 are installed into a dense waterproof soil 1 to the bottom of the water area. Vibration engineering means are fixed on the free end of shells 2 by means of connection elements. Vibration engineering means are made in the form of free springless vibratory hammers 4. Connection elements are made in the form of fork guides. Deepening of thin-walled steel shells 2 is carried out in vibration impact low frequency mode with impact mass bounce. Free springless vibratory hammers 4 are suspended via rods 5 with springs 6 onto a stiff crossbeam-surcharge 7 for additional static load against dense waterproof soil 1 and stable mode of operation of free springless vibratory hammers 4.

EFFECT: invention provides for fatigue breakdown of dense waterproof soil and reduced forces of head resistance of soil against deepening of thin-walled steel shells into it.

1 tbl, 3 dwg

Description

The invention relates to the field of construction and can be used in the construction of watertight enclosing waterproof cellular lintels in the waters during the construction of artificial islands, lintels, mooring and enclosing structures, including flood protection structures, etc.

There is a method of erecting a building envelope of thin-walled steel shells on weak soils of the water area, including fastening the conductor to the top of the shell, installing the shell on the bottom and filling its cavity with bulk material, first place pipes in the cavity of the shell, the lower end of which is located above the lower end of the shell, fasten them with the conductor and in the process of filling the cavity with bulk material that squeezes the weak soil of the water area into the pipes, it is simultaneously sucked out of the shell through the pipes using sludge lifting equipment, and after filling the casing with bulk material, the pipes are removed and the casing is pressed into the ground by reactive forces arising from the extraction of the pipes and acting on the casing through the conductor.

In this case, the pipes are placed around the circumference, the coaxial shell, and in the case of installing the shell with a bias, the pipes from the side of their more deepened edge are removed with vibration (see US Pat. RF No. 2032788, E02B 3/06).

The disadvantage of this method is the low reliability of the structures being built in view of the impossibility of ensuring the verticality and water resistance of thin-walled steel shells. This is due to the fact that the reactive forces arising from the extraction of pipes due to the forces of lateral friction on their surface do not fully equalize and overcome the drag forces that occur when submerging thin-walled steel shells, which leads to a violation of the verticality and alignment of the steel shells and reduces their water resistance.

The closest analogue to the claimed object is a method of immersing thin-walled steel shells with deepening in a dense water-resistant soil, including installing thin-walled steel shells at the bottom of the water area, fixing vibronic means on their free end through connecting elements and deepening these shells in dense waterproof soil. In this case, the vibration tools are made in the form of pile vibrators, the placement of which on the free end of thin-walled steel shells depends on the direction of development of their roll, and if necessary, additional deepening of these shells pile vibrators evenly distribute along the entire length of their circumference. In this case, the connecting elements are made in the form of special headrests, and the deepening of thin-walled steel shells is performed in the vibrational mode of longitudinally directed vibrations (RTM 36.44.12.1-90 Design and construction of port hydraulic structures using large-diameter steel shells. - SPb .: VNIIGS. 1992 . - S. 33-34, Fig. 10).

The disadvantage of this method is the low reliability of the constructed enclosing structures in view of the low water resistance of thin-walled steel shells. This is due to the fact that when using pile vibrators in these shells, transverse bends occur, which lead to irreversible deformations of their walls, which leads to an unstable mode of vibration equipment and the formation of a cylindrical deformation of the shells, which, in turn, does not allow a tight joint between adjacent shells.

Under production conditions at real construction sites, it was found that due to the uneven soil density of the bottom of the water area with the following parameters of thin-walled steel shells: diameter 15 m, height 16 m and wall thickness 10 mm, their verticality is not achieved. An analysis of the known design solutions of the junction of the cellular fencing and experimental work showed that an impermeable joint can only be created if thin-walled shells are installed on the ground of the water area with the verticality of their axes. Therefore, when immersing steel thin-walled shells, their alignment is necessary.

The problem to which the invention is directed, is to increase the reliability of erected building envelopes by ensuring the verticality and alignment of the immersed thin-walled steel shells and their high water resistance.

The technical result achieved by the claimed invention is to ensure fatigue fracture of a dense waterproof soil and a decrease in the frontal drag of said soil to the penetration of thin-walled steel shells into it, which eliminates distortions of thin-walled steel shells when immersed in a dense waterproof soil and eliminates lateral bending and deformation walls of these shells.

The problem is solved in that the known method of immersing thin-walled steel shells with deepening in a dense water-resistant soil, including installing thin-walled steel shells on the bottom of the water area, securing vibration tools on their free end through connecting elements and deepening these shells in a dense waterproof soil, according to the change, vibro-technical means are made in the form of free spring-free vibratory hammers, and connecting elements are in the form of fork guides, deep of thin-walled steel shells produce a vibro-impact mode with low frequency impact weight a jump, the availability springless vibromoloty suspended via rods with springs on the rigid cross member-prigruzke for additional static load on the ground and a dense impermeable stable operation free vibromolotov springless.

It is known the use of vibratory hammers, rigidly fixed in caps, for immersing piles of a prismatic or annular cross section by reducing the soil resistance forces along the lateral surface of immersed piles (Vibration technique and technology in pile and drilling works / V.V. Verstov, M.G. Zeitlin , G.G. Azbel. - L .: Stroyizdat, 1987. - 262 pp. Technologies for constructing foundation pit fences in urban areas and water areas / V.V. Verstov, A.N. Gaido, Y.V. Ivanov, St. Petersburg. : SPbGASU, 2014.368 s.). In the known method, alternating hydrodynamic pressures occur under the tip of the immersed piles, leading to liquefaction and reduction of rock resistance, and as a result, the immersion occurs under the own weight of the piles and vibratory hammers.

In the claimed invention, the immersion of thin-walled steel shells is provided by free springless vibratory hammers due to fatigue fracture of the rock under their end, leading to a decrease in the drag forces of dense waterproof soil. In this method, due to the presence of a jump in the shock mass of free springless vibratory hammers, a shock pulse is transmitted to the water-resistant soil, which mainly affects the immersion of the steel shells than the vibration component.

The use of a rigid cross-beam to provide additional static load and a stable mode of operation of vibratory hammers is not known from the prior art.

Based on the foregoing, we can conclude that for a specialist the claimed method of immersing thin-walled steel shells with a deepening in a dense waterproof soil does not follow explicitly from the prior art, and therefore meets the patentability condition "inventive step".

The method of immersion of thin-walled steel shells with deepening in a dense waterproof soil is illustrated by drawings, where:

- in FIG. 1 schematically shows a thin-walled steel shell with free springless vibratory hammers mounted on its free end, suspended through rods with springs on a rigid traverse-load;

- in FIG. 2 schematically shows a section AA in FIG. one;

- in FIG. 3 schematically shows a section bB in FIG. one.

Thin-walled steel shell 2 (Fig. 1-3) is immersed on a dense waterproof soil 1 (Fig. 1). Fork rails 3 (Fig. 1) are installed on its free end, which are rigidly connected to free springless vibratory hammers 4 (Figs. 1, 3). These vibratory hammers 4 through the rods 5 (Fig. 1-2) with springs 6 (Fig. 1) are suspended on a rigid yoke-load 7 (Fig. 1-2). The latter is equipped with sling elements 8 (Fig. 1-2), by means of which it is hung on the hook 9 (Fig. 1) of a hoisting crane (not shown in Fig.).

The inventive method is as follows.

The thin-walled steel shells 2 collected at the assembly stand are transported to the place of their installation on the deck of a floating crane or on a specially equipped barge. These shells 2 are installed by crane to the bottom of the water area in the alignment of the erected structure. Free springless vibratory hammers 4 are fixed on the free end of steel thin-walled shells 2 by means of fork rails 3. The indicated vibratory hammers 4 are suspended through rods 5 with springs 6 on a rigid cross-beam 7. The latter, for the lifting elements 8, is mounted on a hook 9 of a crane. Rigid traverse-load 7 allows you to achieve additional static load on dense waterproof soil 1 and a stable operation of free spring-free vibratory hammers 4. Upon reaching a thin-walled steel shell 2 layers of dense waterproof soil 1, free spring-free vibration hammers 4 are brought into operation in low-frequency vibration mode with a shock frequency of 400 -420 count / min at a height of the jump of the shock mass of 20-40 mm and maintain the ratio of this mass to the driving force of the vibratory hammer 4, equal to 0.4. In this case, in the case of the development of a roll of an immersed thin-walled shell, it is eliminated by the inclusion of free springless vibratory hammers located on the opposite side with respect to the developed roll. Other vibratory hammers do not work. The inventive method provides fatigue destruction of a dense waterproof soil and a decrease in the frontal drag of said soil to the penetration of thin-walled steel shells into it, which eliminates distortions of thin-walled steel shells when immersed in a dense waterproof soil and eliminates lateral bending and deformation of the walls of these shells. This allows us to ensure the verticality and alignment of the immersed thin-walled steel shells and their high water resistance, which helps to increase the reliability of the constructed enclosing structures.

When conducting production experiments, the steel sheet pile was immersed in dense water-resistant soil by means of pile vibrators V-402 in vibration mode and by means of free spring-free vibratory hammers VP-1 in low-frequency vibration shock mode. The results of comparative experiments are shown in the table.

The results in the table show that, in comparison with the prototype of the claimed method allows to increase the immersion depth of the steel sheet pile in a dense waterproof soil.

As a result of production experiments with the immersion of a steel sheet pile in a dense waterproof soil, it was found that for their maximum deepening, a low-frequency vibration-shock mode of operation with a frequency of 400-420 counts / min and a shock mass jump height of 20-40 mm should be used. In this case, it is necessary to maintain the ratio of the mass of the free springless vibratory hammer to its driving force equal to 0.4.

Thus, the claimed invention improves the reliability of the erected fencing structures by ensuring the verticality and alignment of the immersed thin-walled steel shells and their high water resistance in view of the fatigue fracture of dense waterproof soil and a decrease in the drag force of said soil to the penetration of thin-walled steel shells into it, which eliminates distortions thin-walled steel shells when immersed in a dense waterproof soil and the exclusion of transverse and bending and deformation of the walls of said shells. At the same time, the traverse-loading provides an additional static load on a dense waterproof soil and a stable mode of operation of free springless vibratory hammers in the mode of one impact per one revolution of unbalance shafts.

Claims (1)

A method of immersing thin-walled steel shells with deepening in a dense waterproof soil, including installing thin-walled steel shells on the bottom of the water area, securing vibration tools on their free end through connecting elements and deepening said shells in a dense waterproof soil, characterized in that the vibration tools are made in the form of free springless vibratory hammers, and the connecting elements - in the form of fork rails, deepening thin-walled steel shells producing vibro-impact mode in low frequency impact weight with a jump, the availability springless vibromoloty suspended via rods with springs on the rigid cross member-prigruzke for additional static load on the ground and a dense impermeable stable operation free vibromolotov springless.

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