CN116791558A

CN116791558A - Vibroflotation method capable of realizing effective pile diameter of gravel pile

Info

Publication number: CN116791558A
Application number: CN202210254281.8A
Authority: CN
Inventors: 石峰; 郭万红; 韩伟; 孙亮
Original assignee: Sinohydro Foundation Engineering Co Ltd
Current assignee: Sinohydro Foundation Engineering Co Ltd
Priority date: 2022-03-15
Filing date: 2022-03-15
Publication date: 2023-09-22

Abstract

The invention discloses a vibroflotation method capable of realizing the effective pile diameter of a gravel pile, which comprises the following steps: the method comprises the following steps of controlling the sewage of a vibroflotation gravel pile machine comprising a telescopic guide rod and a vibroflotation device, and rapidly completing vibroflotation construction of a gravel pile hole; placing the gravel filler into the gravel pile hole, and enabling a vibroflotation device to vibroflotate and encrypt the surrounding gravel filler; during the vibration-impact encryption of the surrounding crushed stone filler by the vibration-impact device, a flow velocity sensor arranged in the vibration-impact device generates a real-time electric signal corresponding to the vibration amplitude of the vibration-impact device; and controlling the vibroflotation encryption of the vibroflotation device according to the real-time electric signals generated by the flow velocity sensor arranged in the vibroflotation device, so that the pile diameter of the gravel pile formed by the gravels filled in the gravel pile holes is equal to the effective pile diameter.

Description

Vibroflotation method capable of realizing effective pile diameter of gravel pile

Technical Field

The invention relates to the technical field of vibroflotation gravel piles, in particular to a vibroflotation method capable of ensuring effective pile diameter of a gravel pile.

Background

The vibroflotation method is a foundation treatment method, and the loose foundation soil layer is vibrated and sealed under the combined action of horizontal vibration of a vibroflotation device and high-pressure water or high-pressure air; or after the holes are formed in the foundation layer, backfilling hard coarse particle materials with stable performance, and forming a composite foundation by a reinforcement (vibroflotation pile) formed by vibration compaction and surrounding foundation soil.

In the construction process by using the vibroflotation method, if a special stratum with large hardness of undisturbed soil of a foundation and complex soil layer composition structure is encountered, when the construction effect cannot be guaranteed under the horizontal vibration action of the vibroflotation device, the stratum is subjected to water-flushing pre-destruction by high-pressure water, so that the penetration and pore-forming capacity of the vibroflotation device can be improved.

Technical Specification for Foundation treatment by the vibroflotation method of Water and electricity Hydraulic engineering (DL/T524-2016) stipulates that: the water pump is used for pressurizing water in the water storage facility and delivering the water to the vibroflotation device for supplying water. The multi-stage pump or the single-stage pump can be selected according to construction requirements so as to meet the principle of construction water pressure and water quantity. In general, a water pump having a water supply pressure of 0.3MPa to 1.0MPa and a water supply amount of not less than 15m3/h (250L/min) is selected.

The above-mentioned regulations are summarized based on the experience of engineering practice (the existing construction level of the domestic vibroflotation gravel pile is within 35m, and the stratum is relatively single shallow Kong Zhenchong), and only a general range of water supply pressure and water supply amount of the water pump is given, and no specific regulations are provided as to what water pressure should be adopted for what stratum. For deep coverage above 50m, there are often weak interlayers (e.g., lake deposited muddy clay) and relatively dense hard layers (e.g., sand layers or sand layers with gravel), which are quite different from the problems encountered in pore-forming, and therefore the above specifications have not been applicable to deep coverage formations above 50 m.

In addition, the vibroflotation encryption of the existing vibroflotation device is controlled according to the encryption current, but the encryption current cannot be accurately determined, so that the gravel pile obtained by carrying out the encryption control on the vibroflotation device according to the encryption current cannot be tightly combined with the soil layer.

Disclosure of Invention

The invention aims to overcome the problems in the prior art, and provides a vibroflotation method capable of realizing the effective pile diameter of the gravel pile, which can accurately control the supply of the drainage pressure according to different formation compactedness, so that the vibroflotation construction of the deep-thick cover layer formation with the thickness of more than 50m is accelerated, and the gravel pile formed by vibroflotation gravel filler is tightly combined with the soil layer.

In order to achieve the above object of the present invention, the present invention provides the following technical solutions:

an vibroflotation method capable of ensuring effective pile diameter of gravel pile comprises the following steps:

the method comprises the following steps of controlling the sewage of a vibroflotation gravel pile machine comprising a telescopic guide rod and a vibroflotation device, and rapidly completing vibroflotation construction of a gravel pile hole;

placing the gravel filler into the gravel pile hole, and enabling the vibroflotation device to vibroflotate and encrypt the surrounding gravel filler;

during the vibration-impact encryption of the surrounding crushed stone filler by the vibration-impact device, a flow velocity sensor arranged in the vibration-impact device generates a real-time electric signal corresponding to the amplitude of the vibration-impact device;

and controlling the vibroflotation encryption of the vibroflotation device according to the real-time electric signals generated by the flow rate sensor arranged in the vibroflotation device, so that the pile diameter of the gravel pile formed by the gravel filler filled in the gravel pile hole is equal to the effective pile diameter.

In one example of the present invention, a flow rate sensor disposed within a vibroflotator includes:

a support bar with one end mounted to the housing of the vibroflotation motor;

a cylinder body which is arranged at the other end of the supporting rod and is filled with liquid;

a piston mounted inside the vibroflotation housing and extending into the cylinder, the piston comprising a piston rod and a piston head, the piston head dividing the cylinder interior into a first cavity and a second cavity;

a conduit connecting the first cavity and the second cavity;

a flow rate detector mounted on the pipe;

wherein, during the movement of the piston within the cylinder as the vibroflotator housing vibrates, the liquid within the cylinder flows through the flow rate detector via the pipe line, causing the flow rate detector to generate an electrical signal corresponding to the amplitude of vibration of the vibroflotator housing.

In another example of the present invention, a flow rate sensor disposed within a vibroflotator includes:

a cylinder body which is arranged on the inner side of the vibrator shell and is filled with liquid;

a support bar with one end mounted to the housing of the vibroflotation motor;

the piston is arranged at the other end of the supporting rod and comprises a piston rod and a piston head, and the piston head stretches into the cylinder body to divide the inner cavity of the cylinder body into a first cavity and a second cavity;

a conduit connecting the first cavity and the second cavity;

a flow rate detector mounted on the pipe;

wherein, during the movement of the cylinder body relative to the piston as the vibroflotation housing vibrates, the liquid in the cylinder body flows through the flow velocity detector via the pipeline, so that the flow velocity detector generates an electric signal corresponding to the vibration amplitude of the vibroflotation housing.

Preferably, controlling the vibroflotation encryption of the vibroflotation device according to the real-time electric signal generated by the flow rate sensor arranged in the vibroflotation device comprises:

comparing the amplitude of the real-time electric signal with a preset amplitude;

when the amplitude of the electric signal is smaller than or equal to the preset amplitude, judging that the pile diameter of the crushed stone pile to be formed is equal to the effective pile diameter, and lifting the vibroflotation device upwards to vibroflotate crushed stone in the middle part of the crushed stone pile to be formed, so that the crushed stone pile with the pile diameter equal to the effective pile diameter is finally formed;

when the amplitude of the electric signal is larger than the preset amplitude, controlling the vibroflotation device to continuously vibroflotate the gravels embedded in the soil layer around the gravel pile hole.

Preferably, the preset amplitude is an amplitude at which the vibrator amplitude obtained in advance is reduced to the minimum.

analyzing the amplitude of the preceding electric signal and the amplitude of the following electric signal obtained by the flow sensor in the vibroflotation period;

when the amplitude of the subsequent electric signal is smaller than that of the preceding electric signal and is kept for a period of time, judging that the pile diameter of the gravel pile to be formed is equal to the effective pile diameter, and lifting the vibroflotation device upwards to vibroflotate broken stones in the middle part of the gravel pile to be formed, so that the gravel pile with the pile diameter equal to the effective pile diameter is finally formed.

Preferably, by controlling the sewage of the vibroflotation gravel pile machine including the telescopic guide rod and the vibroflotation device, the vibroflotation construction of the gravel pile hole is rapidly completed, which comprises:

the pipeline for supplying the sewage passes through the telescopic guide rod and the vibroflotation device and then extends out of the bottom end of the vibroflotation device, so that the sewage is sprayed out of the bottom end of the vibroflotation device to perform water flushing pre-damage on the stratum;

acquiring the current stratum compactness in the vibroflotation construction process;

acquiring an instantaneous downwater pressure of the supplied downwater, and determining the acquired instantaneous downwater pressure as a current downwater pressure;

searching a target launching pressure corresponding to the current formation compactness according to the corresponding relation between the preset launching pressure and the formation compactness;

and controlling the flow rate of the sewage supplied to the sewage, so that the current sewage pressure reaches the target sewage pressure, and completing the vibroflotation construction by using the vibroflotation device vibroflotation and the target sewage pressure.

Wherein the obtaining the current formation compactness comprises: acquiring the current vibroflotation current of a vibroflotation device; searching the formation compactness corresponding to the current vibroflotation current according to the preset corresponding relation between the vibroflotation current and the formation compactness; and determining the found formation compactness as the current formation compactness.

Preferably, the obtaining the current vibroflotation current of the vibroflotation device includes: acquiring an instantaneous value of the vibroflotation current of the vibroflotation device; and determining the obtained instantaneous value of the vibroflotation current as the current vibroflotation current.

Alternatively, the obtaining the current vibroflotation current of the vibroflotation device includes: acquiring a plurality of instantaneous values of vibroflotation current of a vibroflotation device; carrying out average treatment on the obtained instantaneous values of the plurality of vibroflotation currents to obtain average vibroflotation currents; the average vibroflotation current is determined as the present vibroflotation current.

Preferably, the interval time for acquiring the two adjacent instantaneous values of the vibroflotation current is equal.

Preferably, the averaging processing of the obtained plurality of instantaneous values of the vibroflotation current includes: and (3) continuously acquired n (n is more than or equal to 2) instantaneous values of the vibroflotation current are compiled into a queue, and the n instantaneous values of the vibroflotation current in the queue are added and then averaged.

Preferably, adding one newly obtained instantaneous value of the vibroflotation current into the tail of the queue, removing one instantaneous value of the vibroflotation current at the same time, forming a new queue, adding n instantaneous values of the vibroflotation current in the new queue, and taking an average value.

Preferably, said controlling the flow of the supplied sewage to bring the current sewage pressure to the target sewage pressure comprises: comparing the current sewage pressure with the target sewage pressure to obtain a difference value between the current sewage pressure and the target sewage pressure; and controlling the water discharge flow of the water pump supply sewage according to the difference value between the current sewage pressure and the target sewage pressure, so that the current sewage pressure reaches the target sewage pressure.

Preferably, the controlling the discharge flow rate of the water pump to supply the discharge water according to the difference between the current discharge pressure and the target discharge pressure comprises: when the current sewage pressure is greater than the upper limit of the target sewage pressure, controlling the water pump to reduce the sewage flow; when the current sewage pressure is smaller than the lower limit of the target sewage pressure, controlling the water pump to increase the sewage flow; when the current sewage pressure is within the target sewage pressure range, the water pump is controlled to maintain the sewage flow.

The vibroflotation construction comprises vibroflotation pore-forming and vibroflotation encryption.

The beneficial effects of the invention are as follows:

1) According to the deep-hole vibroflotation device, for a deep-covered complex stratum, the supply quantity of the downwater pressure is accurately controlled according to the compactness of different strata, so that the vibroflotation device and the proper downwater pressure act together to smoothly finish deep-hole vibroflotation construction of the complex stratum, and the difficult problem of deep-thickness coverage stratum vibroflotation construction of more than 50m is solved;

2) According to the invention, the instantaneous value of the vibroflotation current obtained by the stratum with uneven local distribution is subjected to average treatment, so that the problem that the supply sewage pressure is frequently regulated due to frequent abrupt change of the vibroflotation current is avoided, the water supply stability of the water pump is ensured, and the service life of the water pump is prolonged;

3) Can tightly combine the gravel pile with surrounding soil layers, and the pile diameter of the gravel pile really meets the design requirement.

Drawings

FIG. 1 is a schematic view of a construction method for realizing the effective pile diameter of a gravel pile according to the present invention;

FIG. 2 is a schematic view of an vibroflotation gravel pile machine used in the present invention;

FIG. 3 is a schematic block diagram of a launch control system of an vibroflotation gravel pile machine of the present invention;

FIG. 4 is a flow chart of a method of obtaining current formation compaction according to an embodiment of the present invention;

FIG. 5 is a flow chart of a method of controlling sewage according to an embodiment of the present invention;

FIG. 6 is a schematic view of a flow rate sensor of the present invention disposed within a vibroflotator;

FIG. 7a is an enlarged schematic view of a first example of portion A of FIG. 6;

FIG. 7b is an enlarged schematic view of a second example of portion A of FIG. 6;

FIG. 8 is a schematic diagram of an encryption control section of the present invention for controlling the encryption control of the ballast filler by the vibroflotation device;

fig. 9 is a flowchart of a first embodiment of vibroflotation encryption control performed by the encryption control section in fig. 8;

fig. 10 is a flowchart of a second embodiment of vibration encryption control by the encryption control section in fig. 8.

Detailed Description

Fig. 1 shows a construction method for realizing effective pile diameter of gravel pile, which comprises the following steps:

during the vibroflotation encryption of the surrounding crushed stone filler by the vibroflotation device, a flow velocity sensor arranged in the vibroflotation device generates a real-time electric signal corresponding to the amplitude of the vibroflotation device;

and controlling the vibroflotation encryption of the vibroflotation device according to the real-time electric signals generated by the flow velocity sensor arranged in the vibroflotation device, so that the pile diameter of the gravel pile formed by the gravels filled in the gravel pile holes is equal to the effective pile diameter.

The effective pile diameter of the gravel pile is the pile diameter of the gravel pile formed in the gravel pile hole and tightly combined with soil layers around the hole. The effective pile diameter of the gravel pile has the following significance:

firstly, tightly combining gravel piles formed in gravel pile holes with soil layers around the holes;

secondly, the effective pile diameter of the gravel pile is the pile diameter of the gravel pile meeting the vibroflotation encryption requirement, so that the actual pile diameter is not required to be calculated in the vibroflotation construction process, and the vibroflotation construction process is quickened.

According to the real-time electric signal generated by a flow velocity sensor arranged in the vibroflotation device, the vibroflotation encryption of the vibroflotation device is controlled, and the method comprises the following steps:

The preset amplitude of the present invention is an amplitude at which the vibrator amplitude obtained in advance is reduced to the minimum.

Fig. 2 shows an vibroflotation gravel pile machine 1000 used in the gravel pile construction process of the present invention. As shown in fig. 2, the vibroflotation gravel pile machine 1000 includes a lifting device, a guide rod 10, a vibroflotation device 13 and an automatic feeding device.

Specifically, the hoisting device comprises a host machine of the vibroflotation gravel pile machine, a mast 11 connected with the host machine, and a main hoisting device arranged at the rear end of the host machine, wherein a guide rod 10 is hoisted through a steel wire rope of the main hoisting device and the mast 11, so that the guide rod is vertically arranged under the action of dead weight.

In addition, an automatic feeding device is arranged on the main machine, is arranged at the rear part of the main machine of the hoisting device and can be used as a counterweight of the main machine. The automatic feeding device comprises an air pipe winding device, a cable winding device and a water pipe winding device, and the three devices and the main winding device are arranged to synchronously feed.

The guide bar 10 has a connection section at the upper part for connection with the wire rope of the main winding device, a support section at the middle and a working section at the lower part for connection with the vibrator 13. The guide rod 10 is a telescopic guide rod, so that the axial length of the guide rod 10 can be adjusted to change the lowering or lifting position of the vibroflotation system relative to the ground. That is, the guide bar 10 has a plurality of layers of sleeves sequentially sleeved from inside to outside, the connecting section is a top layer sleeve, the working section is a bottom layer sleeve, and the supporting section comprises one or more layers of middle sleeves. Wherein, adjacent two-layer sleeve pipe can adopt prior art's connection structure to link together, can make adjacent two-layer sleeve pipe axial slip smooth, can prevent again that torsion from taking place each other. When the guide rod is in operation, the number and the length of the multi-layer sleeves in the guide rod can be determined according to the use requirement, for example, more than 4 layers of sleeves can be adopted, and the length of each layer of sleeve can be 18-25 meters (the length of the sleeve on the top layer can be longer). When the pile is used, the length of the multi-layer sleeve of the guide rod can be prolonged or shortened, and when the multi-layer sleeve of the telescopic guide rod is fully extended, the total length of the telescopic guide rod can reach 100 meters or even longer, so that the vibroflotation gravel pile machine can be used for vibroflotation and hole making of a stratum with the depth of more than 50 meters.

The lower water is sprayed out from the lowest end of the vibroflotation device to pre-destroy the stratum by water flushing, and the vibroflotation device and the lower water jointly act to finish vibroflotation construction. The vibroflotation construction generally comprises 1) vibroflotation to form a gravel pile hole, and 2) vibroflotation to form a gravel pile by using a vibroflotation device to vibroflotate the gravel filled in the gravel pile hole.

The invention forms a gravel pile hole by a control method for the launching of a vibroflotation gravel pile machine, which comprises the following steps: acquiring the current stratum compactness in the vibroflotation construction process; and controlling the flow rate of the water supplied by the water pump to drain in real time according to the current stratum compactness, so that the combined action of the vibroflotation device and the drain is used for rapid vibroflotation broken stone pile hole construction.

The invention automatically controls the supply quantity of the sewage according to the current stratum compactness, is suitable for shallow Kong Zhenchong with a single stratum and deep hole vibroflotation with complex stratum, and ensures smooth execution of shallow hole or deep hole vibroflotation construction.

As shown in fig. 5, the present embodiment provides a method for controlling the drainage of an vibroflotation gravel pile machine, including:

s100, enabling a pipeline for supplying the sewage to pass through a telescopic guide rod and a vibroflotation device and then extend out of the bottom end of the vibroflotation device, so that the sewage is sprayed out of the bottom end of the vibroflotation device to perform water flushing pre-damage on a stratum;

s101, acquiring the current stratum compactness in the vibroflotation construction process;

s102, acquiring the instantaneous water pressure of the supplied water, and determining the acquired instantaneous water pressure as the current water pressure;

s103, searching a target launching pressure corresponding to the current formation compactness according to the corresponding relation between the preset launching pressure and the formation compactness;

s104, controlling the flow of the sewage supplied to the sewage, so that the current sewage pressure reaches the target sewage pressure, and completing vibroflotation construction by using vibroflotation and the target sewage pressure.

As shown in fig. 4, S101 includes, during the vibroflotation construction process, acquiring the current formation compactness:

s201, acquiring the current vibroflotation current of a vibroflotation device;

s202, searching the formation compactness corresponding to the current vibroflotation current according to the preset corresponding relation between the vibroflotation current and the formation compactness;

and S203, determining the found formation compactness as the current formation compactness.

As shown in fig. 2, the vibroflotation device 3 is connected with the controller 1 through the vibroflotation device frequency conversion cabinet 2, and the vibroflotation device frequency conversion cabinet 2 and the controller 1 are in wireless connection, or can be in wired connection.

In one implementation of this embodiment, when a stratum with a locally uniform distribution is encountered, the obtained instantaneous value of the vibroflotation current is stable, and S201 obtaining the current vibroflotation current of the vibroflotation device is achieved by: acquiring an instantaneous value of the vibroflotation current of the vibroflotation device; and determining the obtained instantaneous value of the vibroflotation current as the current vibroflotation current.

When the embodiment is implemented, the controller 1 acquires the vibroflotation current signal of the vibroflotation device 3 from the vibroflotation device frequency conversion cabinet 2, and determines the acquired vibroflotation current as the current vibroflotation current. Or, a current detection sensor (not shown in the figure) is arranged on a vibroflotation line of the vibroflotation frequency conversion cabinet 2 connected with the vibroflotation 3; when the vibroflotation device 3 is started, a vibroflotation current signal is generated by the current detection sensor, and the vibroflotation current signal is transmitted to the controller 1 in real time in a wired or wireless mode. The controller 1 determines the vibroflotation current transmitted from the current detection sensor in real time as the present vibroflotation current. The current detection sensor may be any sensor capable of detecting current in the prior art. Such as a current transformer.

In another implementation of this embodiment, when a formation with a locally unevenly distributed is encountered, the instantaneous value of the obtained vibroflotation current jumps greatly, and S201 obtains the current vibroflotation current of the vibroflotation device by: acquiring a plurality of instantaneous values of vibroflotation current of a vibroflotation device; carrying out average treatment on the obtained instantaneous values of the plurality of vibroflotation currents to obtain average vibroflotation currents; the average vibroflotation current is determined as the present vibroflotation current. And the interval time for acquiring the adjacent two instantaneous values of the vibroflotation current is equal. The method for carrying out average treatment on the obtained instantaneous values of the plurality of vibroflotation currents comprises the following steps: continuously obtaining n (n is more than or equal to 2) instantaneous values of the vibroflotation current, braiding the n instantaneous values of the vibroflotation current into a queue, adding the n instantaneous values of the vibroflotation current in the queue, and taking an average value; adding one instantaneous value of the vibroflotation current newly obtained each time into the tail of the queue, removing one instantaneous value of the vibroflotation current at the same time, forming a new queue, adding n instantaneous values of the vibroflotation current in the new queue, and taking an arithmetic average value.

In the embodiment, the method of obtaining the instantaneous value of the vibroflotation current is the same as that of the previous embodiment. Specifically, a current average processing module is arranged in the controller, the controller obtains instantaneous values of the vibroflotation current from the vibroflotation frequency conversion cabinet 2 or the current detection sensor, and n (n is more than or equal to 2) instantaneous values of the vibroflotation current in the queue are subjected to average processing through the current average processing module, so that average vibroflotation current is obtained; the controller determines the average vibroflotation current as the present vibroflotation current.

S202, searching the formation compactness corresponding to the current vibroflotation current according to the preset corresponding relation between the vibroflotation current and the formation compactness; and S203, determining the found formation compactness as the current formation compactness. The specific implementation mode is as follows:

the corresponding relation between the vibroflotation current and the formation compactness is preset in the controller. The corresponding relation between the vibroflotation current and the formation compactness is obtained through a test, namely, before the formal construction, a test pile is firstly made on site, and the controller analyzes and determines the corresponding relation between the vibroflotation current and the formation compactness through a large amount of data obtained by the test pile.

In one implementation of this example, the correspondence between vibroflotation current and formation compaction is shown in table 1. The formation compactness is divided into three grades of soft, medium and hard, and the corresponding relation between the formation compactness and the vibroflotation current of different grades is obtained through field test data.

TABLE 1 correspondence between vibroflotation current and formation compaction

Vibroflotation current I	Formation solidity Dr
		I<0.3Ie	Soft and soft
0.3Ie<I<0.8Ie	In (a)
		I>0.8Ie	Hard

Here, ie shown in table 1 is the rated current of the vibrator.

After the controller obtains the current vibroflotation current, the formation compactness corresponding to the current vibroflotation current is determined as the current formation compactness through the lookup table 1. For example, when the controller 1 obtains the current vibroflotation current i=0.3 Ie, the current formation compaction is determined as a middle level by looking up table 1.

It should be noted that table 1 only shows one correspondence between vibroflotation current and formation compactness, and for more complex formations, the controller may also obtain other more complex correspondences according to field test data.

Wherein, S102 obtains the instantaneous launching pressure of the supply launching, and determines the obtained instantaneous launching pressure as the current launching pressure, and the specific embodiments are as follows:

as shown in fig. 3, a water supply pressure detection sensor 41 is installed on the water outlet pipe of the water pump 4, for acquiring the instantaneous water supply pressure of the water pump 4 for supplying the water to the controller 1, and the controller 1 determines the instantaneous water supply pressure transmitted from the water supply pressure detection sensor 41 as the current water supply pressure.

Because the screw pump has the characteristics of no pulsation of water supply pressure and stable instantaneous flow, the embodiment adopts the screw pump to supply the sewage, and can also adopt other water pumps with no pulsation of water supply pressure and stable instantaneous flow to supply the sewage, so long as the supplied sewage pressure and the supplied sewage flow meet the requirements. The water supply pressure detection sensor 41 is installed on the water outlet line of the screw pump, and acquires the instantaneous sewage pressure of the supply sewage of the screw pump. The water supply pressure detection sensor 41 may be any sensor capable of detecting water pressure in the related art. For example, a pressure transmitter may be employed.

In addition, as shown in fig. 3, a water supply flow rate detection sensor 42 is further installed on the water outlet pipe of the water pump 4 for detecting the instantaneous discharge flow rate of the water supplied from the water pump 4 in real time. The water supply flow rate detection sensor 42 may be any sensor capable of detecting water flow rate in the prior art. For example, an electromagnetic flowmeter may be employed. The water supply flow rate detection sensor 42 transmits the instantaneous discharge flow rate of the water supplied from the water pump 4 detected in real time to the controller 1, which determines the instantaneous discharge flow rate as the current discharge flow rate.

As shown in fig. 3, the water supply pressure detection sensor 41 and the water supply flow rate detection sensor 42 transmit the instantaneous water supply pressure signal and the instantaneous water supply flow rate signal detected in real time to the remote terminal unit RTU, which transmits the signals to the controller 1 by wireless.

And S103, searching a target launching pressure corresponding to the current formation compactness according to a preset corresponding relation between the launching pressure and the formation compactness, wherein the specific implementation mode is as follows:

the corresponding relation between the sewage pressure and the formation compactness is preset in the controller. The corresponding relation between the drainage pressure and the formation compactness is obtained through a test, namely, before the formal construction, a test pile is firstly made on site, and the controller analyzes and determines the corresponding relation between the drainage pressure and the formation compactness through a large amount of data obtained by the test pile.

In one implementation of this example, the correlation of the drainage pressure to formation compaction is shown in table 2. The formation compactness is divided into three grades of soft, medium and hard, and the corresponding relation between the formation compactness of different grades and the sewage pressure is obtained through field test data.

TABLE 2 correspondence between the downforce pressure and formation compaction

Downdraft pressure P (MPa)	Formation solidity Dr
		0.3～0.5	Soft and soft
0.5～0.7	In (a)
		0.7～0.8	Hard

The controller 1 finds a target sewage pressure corresponding to the current formation compactness by looking up the table 2. As shown in table 2, the lower and upper limits are set for the lower water pressure for each level of formation compaction. For example, when the controller 1 determines the current formation compactness as a middle level through the lookup table 1, the target sewage pressure corresponding to the middle level current formation compactness is found to be 0.5 to 0.7MPa through the lookup table 2.

It should be noted that table 2 only shows one correspondence between the pressure of the sewage and the formation compactness, and for more complex formations, the controller may also obtain other more complex correspondences according to the field test data.

Wherein, S104 controls the flow rate of the sewage supplied to the sewage, so that the current sewage pressure reaches the target sewage pressure, and the specific implementation modes are as follows: comparing the current sewage pressure with the target sewage pressure to obtain a difference value between the current sewage pressure and the target sewage pressure; the controller controls the water pump to supply the water outlet flow according to the difference value of the current water outlet pressure and the target water outlet pressure, so that the current water outlet pressure reaches the target water outlet pressure.

Specifically, the controller controls the discharge flow rate of the water supplied by the water pump 4 according to the difference between the current discharge pressure and the target discharge pressure, and includes: when the current sewage pressure is greater than the upper limit of the target sewage pressure, controlling the water pump 4 to reduce the sewage flow; when the current sewage pressure is smaller than the lower limit of the target sewage pressure, controlling the water pump 4 to increase the sewage flow; when the current sewage pressure is within the target sewage pressure range, the water pump 4 is controlled to maintain the sewage flow rate.

As shown in fig. 3, the water pump 4 of this embodiment is connected to the controller 1 through the water pump variable frequency cabinet 5, and the water pump variable frequency cabinet 5 and the controller 1 are connected wirelessly, or may be connected by a wire. The controller 1 controls the rotation speed of the water pump 4 by controlling the water pump variable frequency cabinet 5 to change the output frequency, so that the discharge flow of the water supplied by the water pump 4 is changed, and when the discharge flow of the water discharged by the water pump outlet pipeline is increased, the discharge pressure is also increased; when the discharge flow rate of the water discharged from the water outlet pipeline of the water pump is reduced, the pressure of the water is also reduced.

The embodiment adopts an SV-70 type vibroflotation gravel pile machine, a telescopic guide rod is connected with the vibroflotation device, and the control process of the drainage is as follows:

1. after the vibroflotation device 3 is started, the water supply pressure detection sensor 41 detects the instantaneous water discharge pressure in real time, and the water supply flow detection sensor 42 detects the instantaneous water discharge flow in real time;

2. the controller 1 obtains the current vibroflotation current, the current sewer pressure and the current sewer flow;

3. the controller 1 determines the current formation compactness corresponding to the current vibroflotation current according to the obtained current vibroflotation current lookup table 1; determining a target sewage pressure corresponding to the current formation compactness through a lookup table 2;

4. the controller 1 compares the obtained current sewage pressure with the target sewage pressure which is determined by searching, converts the difference signal into a control signal to control the output frequency of the water pump variable-frequency cabinet 5, changes the sewage flow of the water pump 4 by controlling the rotating speed of the water pump 4, and further changes the sewage pressure to enable the current sewage pressure to be positioned in the target sewage pressure range.

Fig. 6 shows a structure of the vibrator of the present invention, and the vibrator 1000 of the present invention is different from the conventional vibrator in that a flow rate sensor 1311 and a support rod 1312 for fixing the flow rate sensor are installed in the vibrator, and the support rod 1312 is fixed to a housing of the motor 1304 through a through hole for supporting a bearing housing of the shaft 1306. The vibroflotation device 13 shown in fig. 6 further comprises a hanger 1301, a water pipe 1302, a cable 1303, a motor 1304, a coupling 1305, a shaft 1306, an eccentric weight 1307, a housing 1308, fins 1309, a water down pipe 1310, and a flow rate sensor 1311.

The vibroflotation device 13 begins to encrypt the crushed stone filler by powering up the motor 1304. The filler in the encrypted section is extruded into the original stratum along the horizontal direction under the action of the exciting force of the vibroflotation device, the filler at the upper part falls down in slurry under the action of dead weight, and the height of the filler can be measured in real time. As the encryption process proceeds, several phenomena occur:

first, the encryption current gradually increases;

secondly, the exciting force at the shell of the vibroflotation device is increased;

thirdly, the amplitude of the vibroflotation device is reduced;

fourthly, the packing around the vibroflotation device is gradually compacted, and the vibroflotation gravel pile body which is approximately circumference-shaped and has the highest compactness in the vibration receiving range around the vibroflotation device and basically equivalent to the lateral pressure provided by the original stratum when reaching the periphery of the pile hole is gradually formed.

The prior art mainly controls the encryption of the crushed stone filler according to the encryption current of the motor 1304, but has the following four problems:

first, there is no direct relationship between physical and engineering implications and compactness. The encryption current is required to be determined through a test, and the compactness data of the pile body can be obtained approximately after the test. However, when the depth of the vibroflotation gravel pile reaches more than 70m and even reaches the level of hundred meters, the compactness data of the pile body cannot be obtained through a traditional test under the depth, so that the encryption current cannot be determined through experiments;

secondly, different types of vibroflotation devices with different powers have different currents in different stratum;

thirdly, from engineering practice, even though the vibroflotation devices are of the same manufacturer and model, the idle current of the vibroflotation devices is greatly different;

fourth, in colder areas, the idle current is larger when the vibroflotation device is used initially; and as the engineering expands, the temperature of the vibroflotation device per se increases, and the no-load current decreases.

Therefore, the pile compactness under the ultra-deep overburden condition cannot be represented by taking the encryption current as the compactness.

In order to solve the above problems in the prior art, the present invention proposes a technique for controlling the vibroflotation encryption (i.e., vibroflotation of the crushed stone filler) of the vibroflotation device according to the frequency of the vibration signal of the vibroflotation device when the vibroflotation device vibroflotates the crushed stone filler. The core technology of the vibroflotation encryption technology is as follows:

during the vibration-impact encryption of the surrounding crushed stone filler by the vibration-impact device, a flow velocity sensor arranged in the vibration-impact device generates a real-time electric signal corresponding to the vibration amplitude of the vibration-impact device;

controlling vibration and impact encryption of the vibration and impact device according to the real-time electric signals generated by the flow velocity sensor arranged in the vibration and impact device, so that the pile diameter of the crushed stone filled in the crushed stone pile hole to form a crushed stone pile is equal to the effective pile diameter

Fig. 7a shows an example of a flow rate sensor 1311 provided in a vibroflot according to the present invention, as shown in fig. 7a, the flow rate sensor 1311 includes: a support bar 1312 having one end mounted to the housing of the vibroflotation motor 1304; a cylinder 1313 containing a liquid mounted to the other end of the support rod 1312; a piston 1314 including a piston rod 13141 and a piston head 13142 mounted inside the vibroflotation housing 1308 and extending into the cylinder 1313, the piston head 13142 dividing the cylinder interior into a first cavity (cavity on the left side of fig. 7 a) and a second cavity (cavity on the right side of fig. 7 a); a conduit 1315 connecting the first cavity and the second cavity; a flow rate detector 1316 mounted on the pipe; during movement of the piston within the cylinder as the vibroflotator housing vibrates, liquid within the cylinder flows through the flow rate detector via the conduit, causing the flow rate detector to generate an electrical signal corresponding to the amplitude of vibration of the vibroflotator housing.

Fig. 7b shows another example of a flow rate sensor 1311 provided in a vibroflot according to the present invention, as shown in fig. 7b, the flow rate sensor 1311 includes: a cylinder 1313 mounted inside the vibrator housing 1308 and containing a liquid therein; a support bar 1312 having one end mounted to the housing of the vibroflotation motor 1304; a piston 1314 including a piston rod 13141 and a piston head 13142 mounted to the other end of the support rod 1312, the piston head 13141 extending into the cylinder 1313 dividing the cylinder interior into a first cavity (the cavity on the left side of fig. 7 b) and a second cavity (the cavity on the right side of fig. 7 b); a conduit connecting the first cavity and the second cavity; a flow rate detector mounted on the pipe; during movement of the cylinder body relative to the piston as the vibroflotator housing vibrates, liquid within the cylinder body flows through the flow rate detector via the conduit, causing the flow rate detector to generate an electrical signal corresponding to the amplitude of vibration of the vibroflotator housing.

Any of the existing sensors that convert flow rate into an electrical signal may be used with the present invention.

Fig. 8 shows a control section for controlling vibroflotation of a vibroflotation filler to carry out vibroflotation encryption control, comprising a flow rate sensor 1311 for generating an electric signal corresponding to the amplitude of the vibroflotation filler, an amplifier for amplifying the electric signal output from the flow rate sensor 1311, an analog-to-digital converter for analog-to-digital converting the electric signal output from the amplifier, a processor for processing the output of the analog-to-digital converter, a memory for storing data output from the processor, and a display for displaying the data output from the processor.

The processor is further connected to a main hoisting device to lift the vibroflotation device 13 upwards when it is determined that the diameter of the gravel pile to be formed is equal to the effective pile diameter.

The amplifier, analog to digital converter, processor, memory and display of the present invention may be located on the surface and the amplifier may be connected to the flow sensor 1311 by a cable.

It should be noted that when the processor processes the amplitude of the electrical signal, the processor processes the "amplitude of the electrical signal" into the "absolute value of the amplitude of the electrical signal" and then performs other processes.

The present invention can greatly extend the service life of the flow rate sensor relative to the inventor's other patent application for a pressure sensor mounted on the housing of the vibroflotation device. That is, since the flow rate sensor 1311 is installed in the vibrator housing, it is not pressed by the crushed stone packing and the vibrator like the pressure sensor installed on the vibrator housing, and thus is not easily damaged.

Fig. 9 shows a control flow of the first embodiment of controlling the vibroflotation device to perform vibration encryption control, which is mainly implemented by a processor, and specifically includes:

step S301, during the vibration-impact encryption of the broken stone filler by the vibration-impact device, a flow velocity sensor arranged in the vibration-impact device generates a real-time electric signal corresponding to the vibration amplitude of the vibration-impact device shell;

step S302, obtaining the amplitude absolute value of the real-time electric signal by carrying out analog-digital conversion on the real-time electric signal;

step S303, judging whether the absolute value of the amplitude of the real-time electric signal is smaller than or equal to a preset amplitude value;

step S304, when the judgment result of the step S302 is yes, judging that the pile diameter of the gravel pile to be formed is equal to the effective pile diameter;

step S305, lifting the vibroflotator upwards, and vibroflotating broken stone in the middle part of the vibroflotation broken stone pile to be formed, so that the broken stone pile with the pile diameter equal to the effective pile diameter is finally formed;

and step S306, when the judgment result of the step S302 is negative, controlling the vibroflotator to continuously vibroflotate the gravels embedded in the soil layer around the gravel pile hole.

Fig. 10 shows a control flow of a second embodiment of controlling a vibroflotation device to perform vibration encryption control, including:

step S401, during the vibration impact encryption of the broken stone filler by the vibration impact device, a flow velocity sensor arranged in the vibration impact device generates a real-time electric signal corresponding to the vibration amplitude of the vibration impact device shell;

step S402, obtaining the absolute value of the amplitude of the previous electric signal and the absolute value of the amplitude of the subsequent electric signal by carrying out analog-digital conversion on the real-time electric signal;

step S403, judging whether the absolute value of the amplitude of the subsequent electric signal is smaller than or equal to the absolute value of the amplitude of the previous electric signal;

step S404, if the judgment result of step S403 is yes, further judging whether the absolute value of the amplitude of the subsequent electric signal is kept unchanged in a period of time;

step S405, if the judgment result of the step S404 is yes, judging that the pile diameter of the gravel pile to be formed is larger than or equal to the effective pile diameter;

step S405, lifting the vibroflotator upwards, and vibroflotating broken stone in the middle part of the vibroflotation broken stone pile to be formed, so as to finally form the broken stone pile with the pile diameter being greater than or equal to the effective pile diameter;

step S406, if the judgment result of step S403 or step S404 is no, controlling the vibroflotation device to continuously vibroflotate the gravels embedded in the soil layer around the gravel pile hole.

It should be pointed out that one of the characteristics of the invention is to provide a concept of effective pile diameter, namely the pile diameter of the gravel pile which is formed in the gravel pile hole, is tightly combined with soil layers around the hole and meets the vibroflotation encryption requirement.

The effective pile diameter of the gravel pile solves the technical problem that the gravel pile possibly existing in the prior art cannot be tightly combined with a soil layer.

Although the present invention has been described in detail, the present invention is not limited thereto, and those skilled in the art can make modifications according to the principles of the present invention, and thus, all modifications made according to the principles of the present invention should be construed as falling within the scope of the present invention.

Claims

1. The utility model provides a can realize rubble stake effective stake footpath vibroflotation which characterized in that includes:

2. The vibroflotation method of claim 1 wherein the flow rate sensor disposed within the vibroflotation device comprises:

a support bar with one end mounted to the housing of the vibroflotation motor;

a conduit connecting the first cavity and the second cavity;

a flow rate detector mounted on the pipe;

3. The vibroflotation method of claim 1 wherein the flow rate sensor disposed within the vibroflotation device comprises:

a support bar with one end mounted to the housing of the vibroflotation motor;

a conduit connecting the first cavity and the second cavity;

a flow rate detector mounted on the pipe;

4. A vibroflotation method according to claim 2 or 3, characterized in that controlling the vibroflotation encryption of the vibroflotation device according to the real-time electrical signal generated by a flow rate sensor arranged in the vibroflotation device comprises:

when the amplitude of the real-time electric signal is smaller than or equal to the preset amplitude, judging that the pile diameter of the crushed stone pile to be formed is equal to the effective pile diameter, and lifting the vibroflotation device upwards to vibroflotate crushed stone in the middle part of the crushed stone pile to be formed, so that the crushed stone pile with the pile diameter equal to the effective pile diameter is finally formed;

when the amplitude of the real-time electric signal is larger than the preset amplitude, controlling the vibroflotation device to continuously vibroflotate the gravels embedded in the soil layer around the gravel pile hole.

5. The vibroflotation method of claim 4 wherein the predetermined amplitude is a value obtained in advance when the amplitude of the vibrator is reduced to a minimum.

6. A vibroflotation method according to claim 2 or 3, characterized in that controlling the vibroflotation encryption of the vibroflotation device according to the real-time electrical signal generated by a flow rate sensor arranged in the vibroflotation device comprises:

7. The vibroflotation method of claim 1, wherein the rapid completion of vibroflotation construction of the gravel pile hole by controlling the sewage of the vibroflotation gravel pile machine including the telescopic guide rod and the vibroflotation device comprises:

and controlling the flow of the sewer to enable the current sewer pressure to reach the target sewer pressure so as to finish the vibroflotation construction of the gravel pile hole by using the vibroflotation of the vibroflotation device and the target sewer pressure.

8. The vibroflotation method of claim 7, wherein the obtaining the current formation compaction comprises:

acquiring the current vibroflotation current of a vibroflotation device;

searching the formation compactness corresponding to the current vibroflotation current according to the preset corresponding relation between the vibroflotation current and the formation compactness;

and determining the found formation compactness as the current formation compactness.

9. The vibroflotation method of claim 8, wherein the obtaining the present vibroflotation current of the vibroflotation device comprises:

acquiring an instantaneous value of the vibroflotation current of the vibroflotation device;

and determining the obtained instantaneous value of the vibroflotation current as the current vibroflotation current.

10. The vibroflotation method of claim 7, wherein said obtaining a present vibroflotation current of the vibroflotation device comprises:

acquiring a plurality of instantaneous values of vibroflotation current of a vibroflotation device;

carrying out average treatment on the obtained instantaneous values of the plurality of vibroflotation currents to obtain average vibroflotation currents;

the average vibroflotation current is determined as the present vibroflotation current.