RU1794120C - Method for reinforcing road shoulders, slopes and engineering works - Google Patents

Abstract

Usage: road and hydraulic engineering. SUMMARY OF THE INVENTION: at a distance of 1.5-2.0 m from the roadbed, wells parallel to the bedrock or rock are made parallel to it. Non-explosive vibration sources are placed in them. Vibration vibrations on the soil are carried out in two stages: first, in the range of 60-1500 Hz, softening substances are simultaneously pumped into the soil until the elastic stresses of the soil are redistributed from the compression state to tension, then they transfer to a frequency equal to the natural frequency soil vibrations, with the simultaneous injection of bonding solutions until a strength equal to half of the normative sludge and design value is obtained, 5 cpp, 3 sludge.

Description

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The invention relates to construction, road and hydraulic engineering and can be used to strengthen soils and rocks during engineering works using elastic migration, geo-effect and cavitation effects.

A known method of strengthening roadsides, including removing the upper soil layer, applying rubble, returning the upper soil layer to the old place and double sowing it with perennial grasses.

The known method is laborious, non-technological, associated with the movement of large volumes of soil and gravel and does not use vibration to control the state and properties of the soil in a selected frequency range.

A known method of strengthening roadsides, slopes and engineering structures, including drilling wells, loading

their VV and camouflage blasting followed by hardening of the soil. in the area of the massif adjacent to the blast.

The known method is time-consuming, low-tech, does not allow operating in the selected frequency range, is far from safe, requires stopping the technological process during the production of explosions, requires moving large volumes of soil and crushed stone, as well as drilling large volumes of wells and holes.

The purpose of the invention is to increase the effectiveness of reinforcement.

This goal is achieved by the fact that according to the method, the wells are drilled parallel to the roadbed at a distance of 1.5-2.0 m from it, depth to bedrock or rock, non-explosive sources of vibrations are placed in the wells, and vibrations on the ground are made two stages: first in the range of 60-1500 Hz

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with simultaneous injection of softening solutions into the soil until redistribution of the elastic stresses of the soil from the state of compression to tension, then they switch to a frequency equal to the frequency of natural vibrations of the soil, with simultaneous injection of bonding solutions until a strength is achieved that is half the standard or design value .

Wells are drilled at a distance of 5–9 m from each other.

Softening solutions are injected heated to 80 ° C. . .

Cement mortars are used as hardening solutions.

Surfactants, or sodium hydroxide, or sodium hydroxide with methanol are used as softening solutions.

In order to increase the hydro- and aerodynamic bonds of the soil, the oscillation range is increased to 20 kHz, cavitation processes are initiated along the path of propagation of the elastic wave, and the energy of the cavitating bubble that arises in the rarefaction zone of the elastic wave and collapses in the wave compression zone is distributed from expressions

E l: Po R3 4/3,

where Po is the tensile strength of the soil in the absence of an elastic wave, kg / cm2;

 R is the size of the cavitating bubble, mm ..

In FIG. 1 is a diagram of the implementation of the method, where 1 is a half-road, 2 is a roadside, 3 is a well for accommodating vibration sources, 4 is a vibration source, 5 is an elastic body, 6 is a high-pressure compressor EU-5 or EU-7, 7 electronic control panel for synchronizing the operation of a group of vibration sources; 8 - information and computer complex (IVC); in FIG. 2 shows the cavitation thresholds at different frequencies; in FIG. 3 - experimental data showing the behavior of the radius of the cavitating bubble at a constant pressure at a frequency of 10 kHz:, where 1 - at Po 105 Pa, 2 - at PO 5 -105 Pa, 3 - at Po PoP.

The method is carried out as follows.

At a distance from the roadbed, 1.5-2.0 m and parallel to it, drill holes or wells 3, place vibration sources 4 in them and fill the wells 4 with an elastic viscous body 5, the material of which is used wet quartz sand, fine crushed stone and other mineral additives mixed with water. The value of the acoustic resistance of the material of the elastic viscous body 5 is selected approximately equal to the value of the acoustic resistance of the soil, which

necessary for better transmission of the acoustic impulse into the soil to bring it into an excited state and induce permeability in it when surfactants, sodium hydroxide or sodium hydroxide with methanol are injected into the soil, moreover, wells 3 for placement of vibration sources 4 in them of 200-300 mm drilled and depth to bedrock or rock, which is necessary so that when pumping into the soil into the base

5 of the soil of the bonding solutions, the soils had a monolithic base and formed a single adhesion between the individual inhomogeneities of the soil. The maximum dia. well meter 3 is selected based on

0 optimal conditions for the excitation of elastic vibrations, in the range of 60-1500 Hz, based on the structural features of the soil and conditions of wave similarity, since the wave only then interacts with the

5 on its path by heterogeneity, if it is comparable with it or less than it, At a speed of P-waves in the soil of 1800 m / s and frequencies of 60 and 1500 Hz, the wavelengths, respectively, are: on. 60 Hz wavelength (1800 m / s) / (60

0 Hz) 30 m, at 1500 Hz a wavelength of 1.2 m

and, given that the dimensions of the heterogeneities,

composing the base of the soil are in

range of 1.0-30 m, then the choice of the range of hours. from 60-1500 Hz is due

5. Features of the soil and allows you to bring the soil into an excited state in the selected frequency range in conjunction with the injection into the soil softening solutions, which are used

0 surfactant, sodium hydroxide or sodium hydroxide with methanol, and for clay soils or soils with a low degree of porosity, the solutions are heated to 80 ° C.

5. ,

Vibration effects on the soil are carried out in stages: at first they are produced in the range of 60-1500 Hz in conjunction with the injection of softening solutions and

0 vibrations are carried out during the time at which soil compression deformations are replaced by tensile deformations, which corresponds to optimal soil permeability, then they switch to the vibration frequency 5, different frequencies of natural vibrations of the soil in conjunction with the injection of bonding solutions into the soil, and vibration produced during the time at which the strength of the cementitious mortars, which use fine-grained cement or silicates, reaches about half of the design or regulatory value.

For low-porous soils or soils with significant strength, softening solutions — sodium hydroxide or sodium hydroxide with methanol — are heated to 80 ° C; powerful ultrasonic vibrations in the range of 1–20 kHz initiate cavitating phenomena along the path of the elastic wave, and the energy of the cavitating bubble that forms in the rarefaction zone of the elastic wave and collapsing in the compression zone, the waves are determined from the expression: E 7TP0R3 4/3, where Po is the pressure in the pores and cracks of the soil in the absence of a wave, kg / cmg; R is the size of the cavitating bubble, mm

Micro- and macro-shock fluid flows formed along the wave propagation path contribute to a sharp increase in soil permeability and to improvement of hydro- and aerodynamic bonds of the soil and more complete filling of pores and cracks with fastening solutions.

The amplitude of the sources of oscillation 4 is slowly raised from the minimum to the maximum level, while the synchronization time — the time of joint work of the group of vibration sources 4 — is carried out using an electronic control panel 1, which is connected in feedback with a high-pressure compressor 6 of the type EU-5 or E2 -7, from which a pulse of compressed air is supplied to the source under a pressure of 60 to 300 atmospheres, which is sensed by a strain gauge, converted into an electrical signal and fed to CPI 8, in which, according to a predetermined program, They correct the pulses of pressure waves and synchronize the operation of a group of vibration sources.

During the work of a group of vibration sources, the field of elastic stresses is redistributed along the path of propagation of the compression and extension waves generated by the elastic wave, and partial degassing of the soil takes place. These phenomena occur both during the operation of a group of vibration sources and during the operation of one vibration source.

Thus, the soil is treated with all kinds of compressive and tensile loads, which helps to increase the efficiency of the method, reduce its energy consumption and at the same time reduces the cost of soil consolidation in comparison with the existing traditional methods.

The essence of the method consists in the fact that under the influence of powerful vibrational vibrations in the soil there are compression and tensile waves acting on fluids of liquids and gases contained in the pores and cracks of the soil, like a tectonic pump, that is, migration-migration takes place in the soil mass fluids many times, several orders of magnitude greater than this value under normal conditions, in the absence of an elastic wave.

The authors called this phenomenon an elastic migration geo-effect. It takes place in different frequency ranges Hz - kHz - MHz and is accompanied by:

redistribution of the field of elastic stresses along the path of propagation of the elastic wave and the vibrations of the fluids following it; partial degassing of the soil, that is, the flow of gas components from pores and cracks during vibration x;

cavitating processes in soils subject to the conditions that the direction of wave propagation coincides with the direction of pores and cracks along their strike;

the commensurability of the wavelength and size of pores and cracks along their strike;

if on the wave propagation path there are sections of soil heated above 30 ° C;

if the frequency of the probe pulses is close to the frequency of natural vibrations of fluids containing in the pores and cracks of the soil.

The advantages of the method are. that the placement of vibration sources by the proposed method allows you to:

excite elastic vibrations in the selected frequency range in the accumulation mode, which makes it possible to pump into the soil mass the elastic energy necessary to increase the permeability of the array;

to control the condition and properties of the soil by forcing an array of sizing or hardening solutions onto the array;

to increase the efficiency of the method and its energy intensity.

The use of the claimed method will significantly reduce the cost of strengthening roadsides, slopes and engineering structures through the use of elastic migration geo-effect and cavitation effects in the soil mass with high PT parameters and increase the efficiency of the method compared to existing classical methods soil consolidation: removal of the upper soil layer, sampling of a portion of the soil and backfilling in its place

crushed stone and applying the topsoil to the same place with double sowing of grasses.

Claims (6)

1. A method of reinforcing roadsides, slopes and engineering structures, including drilling wells, loading their explosives and camouflage blasting, characterized in that, in order to increase the effectiveness of reinforcement, the wells are drilled parallel to the roadbed at a distance of 1.5 -2.0 m from it, to the depth of bedrock or rock, are placed in wells non-explosive vibration sources and vibrokreban on the ground are produced in two stages: first - in the range of 60-1500 Hz with the simultaneous injection of de-viscous substances into the ground until redistribution control low stresses of the soil from the state of compression to tension, then they switch to a frequency equal to the frequency of natural vibrations of the soil with the simultaneous injection of bonding solutions until the brine half acquires the strength of the standard or design value. 2. The method of pop. 1, characterized in that the wells are drilled at a distance of 5-9 m from each other. Figure 1 The expected economic effect of the implementation of the claimed method is 34 thousand rubles. in year. 3. The method according to claim 1. characterized in that the softening solutions are pumped heated to 80 ° C. A. The method according to claim 1, with the exception that cement mortars are used as hardening solutions. 5. The method of pop. 1, characterized in that surfactants, or sodium hydroxide, or sodium hydroxide with methanol are used as softening solutions. 6. The method according to claim 1, with the exception that in order to increase the hydro- and aerodynamic bonds of the soil, the oscillation range is increased to 20 kHz and cavitating processes are initiated along the path of propagation of the elastic wave, the energy of a cavitating bubble arising in the discharge zone of the elastic wave and collapsing in the compression zone of the wave is determined from the expression B lgP0 R34 / 3, where Po is the tensile strength of the soil in the absence of an elastic wave, kg / cm2; R is the size of the cavitating bubble.