Method for forming anti-sliding vibro-replacement stone pile under ultra-deep overburden layer of ultra-strong earthquake belt

Abstract

The application discloses a method for forming anti-sliding vibro-replacement gravel pile under super-deep overburden layer in super-strong earthquake zone, which comprises the following steps: forming a gravel pile hole; filling the gravel pile hole with filling material and performing vibro-replacement construction to form a vibro-replacement gravel pile with effective pile diameter, wherein the vibro-replacement gravel pile comprises the following steps: performing vibro-replacement on the gravel filling material put into the gravel pile hole below the sliding layer by a vibrator; performing vibro-replacement on the filling material put into the gravel pile hole corresponding to the sliding layer by the vibrator, so that the filling material is vibrated into the sliding layer around the gravel pile hole; then, performing vibro-replacement on the gravel filling material put into the gravel pile hole by the vibrator to form a sliding layer gravel pile section; and continuously performing vibro-replacement on the gravel filling material put into the gravel pile hole by the vibrator. The method can ensure that the super-deep vibro-replacement gravel pile formed in the super-strong earthquake zone has good water permeability and will not be broken under strong earthquakes, thereby ensuring the safety of the vibro-replacement gravel pile under strong earthquakes.

Description

Technical Field

[0001] This invention relates to the field of pile driver construction technology, and in particular to a method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones. Background Technology

[0002] Vibro-compaction is a method of foundation treatment that uses horizontal vibration of a vibro-compactor and the combined action of high-pressure water or high-pressure air to compact loose foundation soil layers; or, after drilling holes in the foundation soil layers, backfilling with stable, hard, coarse-grained materials, and then forming a reinforced structure (vibro-compacted pile) through vibration compaction, which together with the surrounding foundation soil forms a composite foundation.

[0003] During the vibro-compaction process, different construction methods are used for strata with different geological conditions. If a special stratum with a complex structure is encountered, and the construction effect cannot be guaranteed even with the combined action of horizontal vibration of the vibro-compaction device and high-pressure water, high-pressure air can be used as an auxiliary. The stratum is pre-damaged by the combined action of high-pressure water and high-pressure air, which helps to improve the penetration and hole-making capabilities of the vibro-compaction device.

[0004] However, the provisions on water supply pressure and water supply volume in the "Technical Specification for Vibro-Compaction Foundation Treatment of Hydropower and Water Conservancy Projects" (DL / T524-2016) are only a general summary based on engineering practice (the current construction level of vibro-compaction stone piles in China is within 35m, and all are shallow hole vibro-compaction with relatively simple strata). It only gives a general range of water pump supply pressure and water supply volume, without specifying the water pressure to be adopted for different strata, and without specifying the gas supply.

[0005] Furthermore, conventional methods for constructing vibro-compacted stone piles are unsuitable for strata with thick overburden, frequent strong earthquakes, and especially those prone to major earthquakes, because vibro-compacting stone pile construction is extremely difficult under such geological conditions.

[0006] 1. The overburden is thick. Some strata contain weak interlayers (such as lacustrine or marine silty clay layers) between two relatively dense hard layers (such as sand layers or sand layers with gravel). This makes the problems encountered in drilling completely different for these two types of strata. Especially when such strata are in conditions of frequent strong earthquakes, especially when they are prone to mega-earthquakes, the above regulations are completely inapplicable.

[0007] 2. Because the hard layer contains weak interlayers, if conventional vibro-compaction methods are used to form crushed stone piles, the portion of the crushed stone pile located in the weak interlayer will undergo significant horizontal displacement under extremely strong earthquakes. This will cause the crushed stone piles to break, affecting the stability and safety of the composite foundation. Summary of the Invention

[0008] The purpose of this invention is to solve the above-mentioned problems and provide a method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones. This method ensures that the ultra-deep vibratory compaction stone piles formed under ultra-deep overburden in ultra-strong earthquake zones have good permeability and can not break under strong earthquake conditions. It can also vertically transmit the deep ultra-static pore water pressure to the stone cushion layer, ensuring the safety of the vibratory compaction stone piles under strong earthquakes.

[0009] To achieve the above-mentioned objectives of this invention, this invention provides a method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones, comprising:

[0010] Drilling is carried out in strata containing slip layers with high viscosity to form gravel pile holes;

[0011] The process involves filling the formed crushed stone pile hole with filler and then vibrating and compacting the filler using a vibratory compactor to form a vibratory crushed stone pile with an effective pile diameter, including:

[0012] The vibratory compactor compacts and densifies the crushed stone filling material placed into the crushed stone pile hole located below the slip layer, forming the lower crushed stone pile section;

[0013] The vibratory compactor vibrates the filling material placed into the gravel pile hole corresponding to the slip layer, and vibrates the filling material into the slip layer around the gravel pile hole in order to enhance the stability of the slip layer;

[0014] After the filler is vibrated into the slip layer around the gravel pile hole, the vibratory compactor vibrates and compacts the gravel filler material placed into the gravel pile hole to form a slip layer gravel pile segment.

[0015] The slip layer crushed stone pile section is formed, and the vibratory compactor continues to compact and densify the crushed stone filling material that has been placed into the crushed stone pile hole to form the upper crushed stone pile section.

[0016] The filling material placed into the gravel pile hole corresponding to the slip layer is the excavated material dug above and / or below the slip layer during the drilling construction.

[0017] Preferably, the vibratory compaction of the fill material using a vibratory compactor to form vibratory compacted stone piles with an effective pile diameter includes:

[0018] During the compaction of the packing material by the vibratory compactor, a flow rate sensor installed inside the vibratory compactor generates a real-time electrical signal corresponding to the amplitude of the vibratory compactor.

[0019] The vibration compaction of the vibratory compactor is controlled based on the real-time electrical signal generated by the flow velocity sensor installed inside the vibratory compactor, so that the filler material filled into the crushed stone pile hole forms a crushed stone pile with a pile diameter equal to the effective pile diameter.

[0020] Preferably, the flow rate sensor disposed within the vibratory shock absorber includes:

[0021] One end of it is mounted on the support rod on the motor housing of the vibratory impactor;

[0022] A cylinder containing liquid is installed at the other end of the support rod;

[0023] A piston, including a piston rod and a piston head, is installed inside the housing of the vibratory impactor and extends into the cylinder body. The piston head divides the inner cavity of the cylinder body into a first cavity and a second cavity.

[0024] Piping connecting the first cavity and the second cavity;

[0025] A flow rate detector installed on the pipeline;

[0026] During the movement of the piston within the cylinder as the vibrating shock housing vibrates, the liquid within the cylinder flows through the flow rate detector via the pipeline, causing the flow rate detector to generate an electrical signal corresponding to the vibration amplitude of the vibrating shock housing.

[0027] Preferably, the flow rate sensor disposed within the vibratory shock absorber includes:

[0028] A cylinder containing liquid is installed inside the housing of the vibratory impactor;

[0029] One end of it is mounted on the support rod of the vibratory impactor motor housing;

[0030] A piston, including a piston rod and a piston head, is installed at the other end of the support rod. The piston head extends into the cylinder body, dividing the inner cavity of the cylinder body into a first cavity and a second cavity.

[0031] Piping connecting the first cavity and the second cavity;

[0032] A flow rate detector installed on the pipeline;

[0033] During the movement of the cylinder relative to the piston as the vibrator housing vibrates, the liquid inside the cylinder flows through the pipeline to the flow rate detector, causing the flow rate detector to generate an electrical signal corresponding to the vibration amplitude of the vibrator housing.

[0034] Preferably, controlling the vibration intensity of the vibratory compactor based on the real-time electrical signal generated by the flow velocity sensor installed inside the vibratory compactor includes:

[0035] The amplitude of the real-time electrical signal is compared with the preset amplitude;

[0036] When the amplitude of the real-time electrical signal is less than or equal to the preset amplitude, it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter, and the vibratory compactor is lifted upward to vibrate the crushed stone in the middle part of the crushed stone pile to be formed, thereby finally forming a crushed stone pile with a pile diameter equal to the effective pile diameter.

[0037] When the amplitude of the real-time electrical signal is greater than the preset amplitude, the vibratory compactor is controlled to continue vibrating the gravel embedded in the soil layer around the gravel pile hole.

[0038] Preferably, the preset amplitude is the value obtained beforehand when the vibrator amplitude is reduced to its minimum.

[0039] Preferably, controlling the vibration intensity of the vibratory compactor based on the real-time electrical signal generated by the flow velocity sensor installed inside the vibratory compactor includes:

[0040] The amplitudes of the electrical signals obtained by the flow velocity sensor before and after the vibration period are analyzed.

[0041] When the amplitude of the subsequent electrical signal is less than that of the preceding electrical signal and remains so for a period of time, it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter. The vibratory compactor is then raised to vibrate the crushed stone in the middle part of the crushed stone pile to be formed, thus ultimately forming a crushed stone pile with a pile diameter equal to the effective pile diameter.

[0042] Preferably, drilling for gravel pile holes in strata containing a high-viscosity slip layer includes:

[0043] The pipe used to supply sewage passes through the telescopic guide rod and the vibratory flusher and extends from the bottom of the vibratory flusher so that the sewage is sprayed out from the bottom of the vibratory flusher to pre-damage the formation with water.

[0044] Obtain the current formation density during vibro-compaction construction;

[0045] Obtain the instantaneous drainage pressure of the supplied water and determine the obtained instantaneous drainage pressure as the current drainage pressure;

[0046] Based on the preset correspondence between groundwater pressure and formation density, find the target groundwater pressure corresponding to the current formation density;

[0047] Control the flow rate of the supplied water to bring the current water pressure to the target water pressure, so as to complete the vibratory compaction of the crushed stone pile hole by using the vibratory compactor and the target water pressure.

[0048] The step of obtaining the current formation density includes: obtaining the current vibration current of the vibratory compactor; finding the formation density corresponding to the current vibration current according to a preset correspondence between vibration current and formation density; and determining the found formation density as the current formation density.

[0049] Preferably, obtaining the current pulse current of the oscillator includes: obtaining the instantaneous value of the pulse current of the oscillator; and determining the obtained instantaneous value of the pulse current as the current pulse current.

[0050] Alternatively, obtaining the current pulse current of the oscillator may include: obtaining multiple instantaneous values ​​of the pulse current of the oscillator; averaging the multiple instantaneous values ​​of the pulse current to obtain an average pulse current; and determining the average pulse current as the current pulse current.

[0051] Preferably, the time interval between obtaining two adjacent instantaneous values ​​of the oscillation current is equal.

[0052] Preferably, averaging the multiple instantaneous values ​​of the oscillating current includes: arranging the n (n≥2) consecutively acquired instantaneous values ​​of the oscillating current into a queue, and adding the n instantaneous values ​​of the oscillating current in the queue and taking the average value.

[0053] Preferably, each newly acquired instantaneous value of oscillating current is added to the tail of the queue, while the instantaneous value of oscillating current at the head of the queue is removed to form a new queue. The n instantaneous values ​​of oscillating current in the new queue are then added together and the average value is taken.

[0054] Preferably, controlling the flow rate of the supplied sewage to make the current sewage pressure reach the target sewage pressure includes: comparing the current sewage pressure and the target sewage pressure to obtain the difference between the current sewage pressure and the target sewage pressure; and controlling the flow rate of the water pump to supply sewage based on the difference between the current sewage pressure and the target sewage pressure to make the current sewage pressure reach the target sewage pressure.

[0055] Preferably, controlling the flow rate of the water pump supplying the sewage based on the difference between the current sewage pressure and the target sewage pressure includes: controlling the water pump to reduce the sewage flow rate when the current sewage pressure is greater than the upper limit of the target sewage pressure; controlling the water pump to increase the sewage flow rate when the current sewage pressure is less than the lower limit of the target sewage pressure; and controlling the water pump to maintain the sewage flow rate when the current sewage pressure is within the range of the target sewage pressure.

[0056] Preferably, during the vibratory compaction of the filler, the method further includes: using a mud pump to detect the mud density of the mud above the surface of the crushed stone filler in the pile hole, so that the mud density in the pile hole meets the requirements.

[0057] Compared with existing technologies, the method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones has the following advantages:

[0058] 1. The present invention provides a method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones. This method ensures that the formed ultra-deep vibratory compaction stone piles do not break under strong earthquake conditions. It can vertically transmit the deep ultra-static pore water pressure to the stone cushion layer, ensuring the safety of the vibratory compaction stone piles under strong earthquake conditions.

[0059] 2. The method of the present invention, for complex strata with deep overburden, precisely controls the supply of water pressure according to the different densities of the strata, so that the vibratory compactor and the appropriate water pressure work together to successfully complete the deep hole vibratory compaction construction in complex strata, thereby solving the problem of vibratory compaction construction in strata with deep overburden of more than 50m.

[0060] 3. The method of the present invention averages the instantaneous values ​​of the vibratory current obtained from strata with uneven local distribution, avoiding frequent adjustments to the water supply pressure due to frequent changes in the vibratory current, ensuring stable water supply from the pump and extending the service life of the pump.

[0061] 4. The method of the present invention enables the crushed stone pile to be tightly bonded to the surrounding soil layer, so that the pile diameter of the crushed stone pile truly meets the design requirements.

[0062] 5. The method of the present invention performs real-time detection of mud density during the process of vibro-compaction to form crushed stone piles, ensuring that the permeability of the crushed stone piles meets the preset requirements, and ensuring that the crushed stone piles can still vertically transmit the excess pore water pressure from deep strata along the crushed stone piles under conditions of major earthquakes (such as earthquakes of magnitude 8.5-9).

[0063] The present invention will now be described in detail with reference to the accompanying drawings. Attached Figure Description

[0064] Figure 1 This is a schematic diagram of the method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones according to the present invention;

[0065] Figure 2 This is a schematic diagram of the vibratory stone crushing pile machine used in this invention;

[0066] Figure 3 This is a schematic block diagram of the drainage control system of the vibratory stone crushing pile machine of the present invention;

[0067] Figure 4 This is a flowchart of a method for obtaining the current formation density according to an embodiment of the present invention;

[0068] Figure 5 This is a flowchart of the drainage control method according to an embodiment of the present invention;

[0069] Figure 6This is a schematic diagram of the flow rate sensor installed inside the vibratory impactor according to the present invention;

[0070] Figure 7a yes Figure 6 Enlarged schematic diagram of the first instance in Part A;

[0071] Figure 7b yes Figure 6 Enlarged schematic diagram of the second example in Part A;

[0072] Figure 8 This is a schematic diagram of the encryption control part of the present invention, which is used to control the vibratory compactor to encrypt the crushed stone filler.

[0073] Figure 9 yes Figure 8 A flowchart of the first embodiment of the encryption control section in the system performing vibration encryption control;

[0074] Figure 10 yes Figure 8 A flowchart of the second embodiment of vibration encryption control in the encryption control section;

[0075] Figure 11 This is a flowchart of the mud density control process of the present invention. Detailed Implementation

[0076] like Figure 1 The diagram shown is a flowchart of the method for controlling the permeability of vibratory compaction stone piles according to the present invention. Figure 1 It can be seen that the method of the present invention includes:

[0077] Drilling is carried out in strata containing slip layers with high viscosity to form gravel pile holes;

[0078] The process involves filling the formed crushed stone pile hole with filler and then vibrating and compacting the filler using a vibratory compactor to form a vibratory crushed stone pile with an effective pile diameter, including:

[0079] The vibratory compactor compacts and densifies the crushed stone filling material placed into the crushed stone pile hole located below the slip layer, forming the lower crushed stone pile section;

[0080] The vibratory compactor vibrates the filling material placed into the gravel pile hole corresponding to the slip layer, and vibrates the filling material into the slip layer around the gravel pile hole in order to enhance the stability of the slip layer;

[0081] After the filler is vibrated into the slip layer around the gravel pile hole, the vibratory compactor vibrates and compacts the gravel filler material placed into the gravel pile hole to form a slip layer gravel pile segment.

[0082] The slip layer crushed stone pile section is formed, and the vibratory compactor continues to compact and densify the crushed stone filling material that has been placed into the crushed stone pile hole to form the upper crushed stone pile section.

[0083] The filling material placed into the gravel pile hole corresponding to the slip layer in this invention is the excavated material dug above and / or below the slip layer during the drilling construction. The gravel pile hole corresponding to the slip layer refers to the portion of the gravel pile hole between approximately 2 meters below the slip layer and approximately 2 meters above the slip layer.

[0084] The invention controls the permeability of vibratory crushed stone piles during the construction process of the vibratory crushing stone pile machine. Figure 2 The diagram shows the structure of the vibratory compaction stone pile driver 1000 used in the construction process of this invention. Figure 2 As shown, the vibratory compaction stone pile machine 1000 includes a hoisting device, a guide rod 10, a vibratory compactor 13, and an automatic feeding device.

[0085] Specifically, the hoisting device includes the main unit of the vibratory stone crushing pile machine, the mast 11 connected to the main unit, and the main winch device installed at the rear of the main unit. The guide rod 10 is hoisted by the wire rope of the main winch device and the mast 11 so that the guide rod is vertically positioned under its own weight.

[0086] In addition, an automatic feeding device is installed on the main unit, which is located at the rear of the hoisting device and can be used as a counterweight for the main unit. The automatic feeding device includes a pneumatic winch, a cable winch, and a water pipe winch, and these three devices are configured to feed synchronously with the main winch.

[0087] The guide rod 10 has an upper connecting section for connecting to the wire rope of the main winch, a middle support section, and a lower working section for connecting to the vibratory compactor 13. The guide rod 10 is telescopic, allowing its axial length to be adjusted to change the lowering or raising position of the vibratory compactor system relative to the ground. Specifically, the guide rod 10 has multiple layers of sleeves sequentially connected from the inside out, with the connecting section being the top layer sleeve, the working section the bottom layer sleeve, and the support section including one or more intermediate sleeves. Adjacent layers of sleeves can be connected together using existing connection structures, ensuring smooth axial sliding between adjacent layers while preventing mutual torsion. During operation, the number and length of the multiple layers of sleeves in the guide rod can be determined according to usage requirements; for example, more than four layers of sleeves can be used, with each layer being 18-25 meters long (the top layer sleeve can be even longer). When in use, the length of the multi-layer sleeve of the guide rod can be extended or shortened. When all the multi-layer sleeves of the telescopic guide rod are extended, the total length of the telescopic guide rod can reach 100 meters or even longer. Therefore, the vibratory crushing stone pile machine of the present invention can be used to vibrate and crush holes in strata with a depth greater than 50 meters.

[0088] Water is sprayed from the bottom of the vibratory compactor to pre-damage the strata. The vibratory compactor and the water work together to complete the vibratory compaction construction. Vibratory compaction construction typically includes: 1) vibratory compaction to form gravel pile holes, and 2) the vibratory compactor vibrating the gravel filled into the gravel pile holes to form gravel piles.

[0089] This invention forms stone pile holes by controlling the water flow of a vibratory stone crushing pile machine, including: obtaining the current ground compaction during vibratory compaction; and controlling the water flow rate supplied by the water pump in real time according to the current ground compaction, so that the vibratory compactor and the water flow work together to quickly construct the stone pile holes.

[0090] This invention automatically controls the water supply based on the current formation density, making it suitable for both shallow-hole vibratory compaction in relatively simple formations and deep-hole vibratory compaction in complex formations, ensuring the smooth progress of shallow or deep-hole vibratory compaction operations.

[0091] like Figure 5 As shown, this embodiment provides a method for controlling the drainage of a vibratory compaction stone pile driver, including:

[0092] S100, the pipe for supplying sewage passes through the telescopic guide rod and the vibratory flusher and extends from the bottom of the vibratory flusher so that the sewage is sprayed out from the bottom of the vibratory flusher to pre-damage the formation with water.

[0093] S101, obtain the current formation density during vibro-compaction construction;

[0094] S102, obtain the instantaneous drainage pressure of the supplied drainage, and determine the obtained instantaneous drainage pressure as the current drainage pressure;

[0095] S103, based on the preset correspondence between groundwater pressure and formation density, find the target groundwater pressure corresponding to the current formation density;

[0096] S104, control the flow rate of the supplied water to make the current water pressure reach the target water pressure, so as to complete the vibratory flushing construction by using the vibratory flusher and the target water pressure.

[0097] like Figure 4 As shown, the current formation density obtained during the vibro-compaction process by S101 includes:

[0098] S201, obtain the current oscillation current of the oscillator;

[0099] S202, based on the preset relationship between vibratory current and formation density, find the formation density corresponding to the current vibratory current;

[0100] S203, the found formation density is determined as the current formation density.

[0101] like Figure 2As shown, the vibrator 3 is connected to the controller 1 through the vibrator frequency converter cabinet 2. The vibrator frequency converter cabinet 2 and the controller 1 are connected wirelessly or wiredly.

[0102] In one embodiment of this example, when encountering a locally uniformly distributed stratum, the instantaneous value of the obtained oscillating current is stable. S201 obtains the current oscillating current of the oscillator in the following way: obtains the instantaneous value of the oscillating current of the oscillator; and determines the obtained instantaneous value of the oscillating current as the current oscillating current.

[0103] In this implementation, controller 1 obtains the vibration current signal of vibrator 3 from vibrator inverter cabinet 2 and determines the obtained vibration current as the current vibration current. Alternatively, a current detection sensor (not shown in the figure) is installed on the vibration output line of vibrator 3 connected to vibrator inverter cabinet 2; when vibrator 3 is started, the current detection sensor generates a vibration current signal, which is transmitted to controller 1 in real time via wired or wireless means. Controller 1 determines the vibration current transmitted from the current detection sensor in real time as the current vibration current. The current detection sensor can be any sensor capable of detecting current in the prior art, such as a current transformer.

[0104] In another embodiment of this example, when encountering locally unevenly distributed strata, the instantaneous values ​​of the acquired vibratory current jump significantly. S201 acquires the current vibratory current of the vibrator in the following way: acquire multiple instantaneous values ​​of the vibratory current; average the acquired multiple instantaneous values ​​of the vibratory current to obtain the average vibratory current; and determine the average vibratory current as the current vibratory current. The time interval between acquiring two adjacent instantaneous values ​​of the vibratory current is equal. The method for averaging the acquired multiple instantaneous values ​​of the vibratory current is as follows: n (n≥2) consecutively acquired instantaneous values ​​of the vibratory current are grouped into a queue, and the n instantaneous values ​​in the queue are summed and averaged; each newly acquired instantaneous value of the vibratory current is added to the tail of the queue, while the first instantaneous value of the vibratory current is removed, forming a new queue, and the n instantaneous values ​​in the new queue are summed and averaged.

[0105] In specific implementation, the method for obtaining the instantaneous value of the oscillation current is the same as that described in the previous implementation. Specifically, a current averaging module can be set up inside the controller. The controller obtains the instantaneous value of the oscillation current from the oscillator inverter cabinet 2 or the current detection sensor. The current averaging module averages the n (n≥2) instantaneous values ​​of the oscillation current in the queue to obtain the average oscillation current. The controller determines the average oscillation current as the current oscillation current.

[0106] Specifically, S202 searches for the formation density corresponding to the current vibratory current based on a preset correspondence between vibratory current and formation density; and S203 determines the found formation density as the current formation density. The specific implementation method is as follows:

[0107] The controller has a pre-set relationship between vibratory current and soil density. This relationship is obtained through testing; that is, before formal construction, test piles are built on site, and the controller analyzes the large amount of data obtained from the test piles to determine the relationship between vibratory current and soil density.

[0108] In one embodiment of this study, the relationship between vibratory current and formation density is shown in Table 1. Formation density is divided into three levels: soft, medium, and hard. The relationship between different levels of formation density and vibratory current is obtained through field test data.

[0109] Table 1. Correspondence between vibratory current and formation density

[0110] I<0.3Ie soft 0.3Ie <I<0.8Ie middle I>0.8Ie hard

[0111] In Table 1, Ie represents the rated current of the vibrator.

[0112] After obtaining the current vibration current, the controller determines the current formation density by looking up Table 1. For example, when the controller 1 obtains the current vibration current I = 0.3Ie, it determines the current formation density as medium by looking up Table 1.

[0113] It should be noted that Table 1 only shows one correspondence between the vibration current and the formation density. For more complex formations, the controller can obtain other more complex correspondences based on field test data.

[0114] Specifically, S102 acquires the instantaneous sewage pressure of the supplied sewage and determines the acquired instantaneous sewage pressure as the current sewage pressure. The specific implementation method is as follows:

[0115] like Figure 3 As shown, a water supply pressure detection sensor 41 is installed on the outlet pipe of the water pump 4 to obtain the instantaneous water pressure supplied by the water pump 4 and transmit it to the controller 1. The controller 1 determines the instantaneous water pressure transmitted from the water supply pressure detection sensor 41 as the current water pressure.

[0116] Because screw pumps have the characteristics of pulsation-free water supply pressure and stable instantaneous flow rate, this embodiment uses a screw pump to supply sewage. However, other pumps with pulsation-free water supply pressure and stable instantaneous flow rate can also be used, as long as the supplied sewage pressure and flow rate meet the requirements. A water supply pressure detection sensor 41 is installed on the outlet pipe of the screw pump to obtain the instantaneous sewage pressure supplied by the screw pump. The water supply pressure detection sensor 41 can be any sensor capable of detecting water pressure available in the prior art. For example, a pressure transmitter can be used.

[0117] In addition, such as Figure 3 As shown, a water supply flow detection sensor 42 is also installed on the outlet pipe of water pump 4 to detect the instantaneous flow rate of water supplied by water pump 4 in real time. The water supply flow detection sensor 42 can be any sensor capable of detecting water flow rate in the prior art. For example, an electromagnetic flow meter can be used. The water supply flow detection sensor 42 transmits the detected instantaneous flow rate of water supplied by water pump 4 to controller 1, and the controller determines the instantaneous flow rate as the current flow rate.

[0118] like Figure 3 As shown, the water supply pressure detection sensor 41 and the water supply flow detection sensor 42 transmit the real-time detected instantaneous water pressure signal and instantaneous water flow signal to the remote terminal unit (RTU), and the RTU transmits the signal to the controller 1 wirelessly.

[0119] Specifically, S103, based on the preset correspondence between groundwater pressure and formation density, finds the target groundwater pressure corresponding to the current formation density. The specific implementation method is as follows:

[0120] The controller has a pre-set relationship between water pressure and soil density. This relationship is obtained through testing; that is, test piles are built on-site before formal construction, and the controller analyzes the large amount of data obtained from the test piles to determine the relationship between water pressure and soil density.

[0121] In one embodiment of this example, the relationship between groundwater pressure and formation density is shown in Table 2. Formation density is divided into three levels: soft, medium, and hard. The relationship between different levels of formation density and groundwater pressure is obtained through field test data.

[0122] Table 2. Correspondence between groundwater pressure and formation density

[0123] 0.3～0.5 soft 0.5～0.7 middle 0.7～0.8 hard

[0124] Controller 1 uses lookup table 2 to find the target groundwater pressure corresponding to the current formation density. As shown in Table 2, upper and lower limits are set for the groundwater pressure corresponding to each level of formation density. For example, when controller 1 determines the current formation density to be medium using lookup table 1, it uses lookup table 2 to find the target groundwater pressure corresponding to the medium-level current formation density, which is 0.5–0.7 MPa.

[0125] It should be noted that Table 2 only shows one relationship between groundwater pressure and formation density. For more complex formations, the controller can obtain other more complex relationships based on field test data.

[0126] S104 controls the flow rate of the supplied sewage to make the current sewage pressure reach the target sewage pressure. The specific implementation method is as follows: compare the current sewage pressure and the target sewage pressure to obtain the difference between the current sewage pressure and the target sewage pressure; the controller controls the flow rate of the pump to supply sewage based on the difference between the current sewage pressure and the target sewage pressure to make the current sewage pressure reach the target sewage pressure.

[0127] Specifically, the controller controls the flow rate of water supplied by pump 4 based on the difference between the current drainage pressure and the target drainage pressure, including: when the current drainage pressure is greater than the upper limit of the target drainage pressure, controlling pump 4 to reduce the drainage flow rate; when the current drainage pressure is less than the lower limit of the target drainage pressure, controlling pump 4 to increase the drainage flow rate; and when the current drainage pressure is within the range of the target drainage pressure, controlling pump 4 to maintain the drainage flow rate.

[0128] like Figure 3 As shown, in this embodiment, the water pump 4 is connected to the controller 1 via the water pump frequency converter cabinet 5. The water pump frequency converter cabinet 5 and the controller 1 are connected wirelessly, but a wired connection can also be used. The controller 1 controls the speed of the water pump 4 by changing the output frequency of the water pump frequency converter cabinet 5, thereby changing the flow rate of the water supplied by the water pump 4. When the flow rate of the water discharged from the water pump outlet pipe increases, the water pressure also increases; when the flow rate of the water discharged from the water pump outlet pipe decreases, the water pressure also decreases.

[0129] This embodiment uses an SV-70 vibratory compactor for stone crushing piles. The telescopic guide rod connects to the vibratory compactor. The water control process is as follows:

[0130] 1. After the vibratory flusher 3 is started, the water supply pressure detection sensor 41 detects the instantaneous water pressure in real time, and the water supply flow detection sensor 42 detects the instantaneous water flow in real time.

[0131] 2. Controller 1 acquires the current vibration current, current drainage pressure, and current drainage flow rate;

[0132] 3. Controller 1 determines the current formation density corresponding to the current vibration current by looking up table 1; and determines the target groundwater pressure corresponding to the current formation density by looking up table 2.

[0133] 4. The controller 1 compares the current drainage pressure with the target drainage pressure, converts the difference signal into a control signal to control the output frequency of the water pump frequency converter cabinet 5, and changes the drainage flow rate of the water pump 4 by controlling the speed of the water pump 4, thereby changing the drainage pressure so that the current drainage pressure is within the target drainage pressure range.

[0134] After forming the crushed stone pile hole using the above method, filler is added into the formed crushed stone pile hole, that is, crushed stone filler is put into the crushed stone pile hole, and then the crushed stone filler is vibrated and compacted using a vibratory compactor to form a vibratory crushed stone pile with an effective pile diameter.

[0135] It should be noted that when the strata are located in areas prone to strong earthquakes and have extremely deep overburden, there will be slip layers with high viscosity interspersed within the strata. These slip layers (or slip zones) are typically located below 50m above the ground, are mainly composed of cohesive soil, have very low permeability (permeability coefficient mostly below 10⁻⁵ cm / s), and low bearing capacity. The upper and lower layers of the slip layer are layers of sand and gravel, with better density and higher bearing capacity.

[0136] The inventors discovered that since the slip layer is mainly composed of cohesive soil, if traditional artificial sand and gravel are used for vibratory compaction, the pile body at the corresponding slip layer location will have less fine particles filling during the formation process, resulting in a decrease in pile density and affecting its anti-slip ability. When a super earthquake occurs, the strata above the slip layer will slide relative to the strata below the slip layer under the action of seismic shear waves, causing the pile body to break, which will pose a significant threat to the overall safety of the project.

[0137] Therefore, the inventors believe that the pile segments of vibratory crushed stone piles corresponding to the slip layer should have both high permeability and high density: high permeability, so that water in the overburden layer and bedrock below the slip layer can be transmitted from bottom to top along the pile body of the vibratory crushed stone pile, dissipating the overall pore water pressure; and high density, so that the bearing capacity of the composite foundation can be improved, and it plays a role in resisting slip to a certain extent.

[0138] To achieve both of the above objectives simultaneously, the inventors propose that, during the borehole drilling process, the excavated material located above and / or below the slip layer during the pilot hole excavation is simply screened and used as filler material. This filler material is then backfilled into the corresponding slip layer area, and a vibratory compactor is used to compact the filler material (to enhance the compaction intensity), ensuring that the area around the pile diameter in the corresponding slip layer area is filled with filler material, thereby improving the overall load-bearing capacity of the project. Furthermore, this approach offers two additional advantages: firstly, the backfilling cost of the excavated material from the pilot hole excavation is lower; and secondly, it is environmentally friendly, reducing the pressure on waste disposal.

[0139] Specifically, during the drilling process, the borehole is drilled to the bottom, and the well-graded stones from the excavation are briefly screened and piled up nearby to serve as filler material for the corresponding part of the slip layer around the pile hole. Then, chemical mud is applied to the bottom of the pile hole to protect the hole wall and prevent collapse. Next, the pile hole is cleaned. Finally, the pile hole is filled with filler material so that the filler material can be vibrated and compacted by a vibratory compactor to form a crushed stone pile.

[0140] As can be seen, the present invention provides two types of fillers for use in the holes of crushed stone piles. One type is obtained by excavating the original strata during the hole-making process, which is called filler material. The other type is filler material that meets the requirements in advance according to the strata requirements, which is called crushed stone filler.

[0141] The process of the vibratory compactor of the present invention for compacting and densifying the packing is as follows:

[0142] The crushed stone filler is filled into the crushed stone pile hole below the corresponding slip layer formed during the hole drilling construction (the corresponding slip layer refers to the position located about 2m below the lower edge of the slip layer as measured in advance). The crushed stone filler is then vibrated and compacted using a vibratory compactor to form the lower crushed stone pile section.

[0143] Then, the filling material obtained from the excavation during the drilling construction is backfilled into the gravel pile hole corresponding to the slip layer. The vibratory compactor vibrates the filling material placed into the gravel pile hole corresponding to the slip layer, so that the filling material is vibrated into the slip layer around the gravel pile hole, so as to enhance the stability of the slip layer around the gravel pile hole.

[0144] After the filler is vibrated into the slip layer around the gravel pile hole, the gravel filler is put into the gravel pile hole of the corresponding slip layer. The gravel filler put into the corresponding gravel pile hole is vibrated and compacted by a vibratory compactor to form a gravel pile segment of slip layer.

[0145] After the slip layer crushed stone pile segment is formed, crushed stone filler is put into the crushed stone pile hole above the slip layer. The crushed stone filler put into the crushed stone pile hole is further vibrated and compacted by a vibratory compactor to form the upper crushed stone pile segment. Thus, through the lower crushed stone pile segment, the slip layer crushed stone pile segment, and the upper crushed stone pile segment from bottom to top, a continuous, uniform, and slip-resistant vibratory crushed stone pile with an effective pile diameter is formed.

[0146] Among them, the crushed stone piles with effective pile diameter formed during vibro-compaction compaction include:

[0147] During the process of the vibratory compactor compacting the packing around it, a flow rate sensor located inside the vibratory compactor generates a real-time electrical signal corresponding to the amplitude of the vibratory compactor.

[0148] The vibration compaction of the vibratory compactor is controlled based on the real-time electrical signal generated by the flow velocity sensor installed in the vibratory compactor, so that the diameter of the crushed stone pile formed by the crushed stone filling the crushed stone pile hole is equal to the effective pile diameter.

[0149] In this invention, the effective pile diameter of the crushed stone pile refers to the pile diameter in which the crushed stone pile formed in the crushed stone pile hole is tightly bonded to the surrounding soil layer. The effective pile diameter of the crushed stone pile of this invention has the following meanings:

[0150] First, the crushed stone pile formed in the crushed stone pile hole is tightly bonded to the soil layer around the hole;

[0151] Secondly, the effective pile diameter of the crushed stone pile is the pile diameter that meets the requirements of vibro-compaction densification. Therefore, it is not required to calculate the actual pile diameter during vibro-compaction construction, which speeds up the vibro-compaction construction process.

[0152] The present invention controls the vibration encryption of the vibratory compactor based on the real-time electrical signal generated by the flow velocity sensor installed inside the vibratory compactor, including:

[0153] The amplitude of the real-time electrical signal is compared with the preset amplitude;

[0154] When the amplitude of the electrical signal is less than or equal to the preset amplitude, it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter, and the vibratory compactor is lifted upward to vibrate the crushed stone in the middle part of the crushed stone pile to be formed, thereby finally forming a crushed stone pile with a pile diameter equal to the effective pile diameter.

[0155] When the amplitude of the electrical signal is greater than the preset amplitude, the vibratory compactor is controlled to continue vibrating the gravel embedded in the soil layer around the gravel pile hole.

[0156] The preset amplitude of the present invention is the amplitude at which the pre-obtained vibrator amplitude is reduced to its minimum.

[0157] The present invention controls the vibration encryption of the vibratory compactor based on the real-time electrical signal generated by the flow velocity sensor installed inside the vibratory compactor, including:

[0158] The amplitudes of the electrical signals obtained by the flow velocity sensor before and after the vibration period are analyzed.

[0159] When the amplitude of the subsequent electrical signal is less than that of the preceding electrical signal and remains so for a period of time, it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter. The vibratory compactor is then raised to vibrate the crushed stone in the middle part of the crushed stone pile to be formed, thus ultimately forming a crushed stone pile with a pile diameter equal to the effective pile diameter.

[0160] Figure 6The structure of the vibratory impactor of the present invention is shown. The difference between the vibratory impactor of the present invention and the existing vibratory impactor is that a flow rate sensor 1311 and a support rod 1312 for fixing the flow rate sensor are installed inside the vibratory impactor. The support rod 1312 passes through the through hole of the bearing seat for supporting the shaft 1306 and is fixed to the motor housing 1304. Figure 6 The vibratory impactor 13 shown also includes a hanger 1301, a water pipe 1302, a cable 1303, a motor 1304, a coupling 1305, a shaft 1306, an eccentric block 1307, a housing 1308, fins 1309, a drain pipe 1310, and a flow rate sensor 1311.

[0161] Vibratory compactor 13, by energizing motor 1304, begins to densify the packing material. Under the excitation force of the vibratory compactor, the packing material in the densification section is forced horizontally into the original formation, while the upper packing material falls into the mud under its own weight. The packing height can be measured in real time. As the densification process proceeds, the following phenomena occur:

[0162] First, the encryption current gradually increases;

[0163] Second, the excitation force at the vibratory impactor housing increases;

[0164] Third, the amplitude of the vibratory beater decreases accordingly;

[0165] Fourth, with the vibratory compactor as the center, the surrounding fill material gradually becomes denser, gradually forming a roughly circular vibratory crushed stone pile body with the highest density in the vibratory compactor's vibratory range, and the lateral pressure that can be provided by the original stratum when it reaches the periphery of the pile hole is basically equivalent to that provided by the original stratum.

[0166] Existing technology mainly controls the packing density based on the density of the 1304 motor, but it has the following four problems:

[0167] First, the physical and engineering significance is unclear, and there is no direct relationship between it and the density. The magnitude of the densification current needs to be determined experimentally, and the density data of the pile body can only be roughly obtained after the experiment. However, when the depth of the vibratory compaction stone pile is as high as 70m or even reaches the level of 100m, the density data of the pile body cannot be obtained through traditional experiments at this depth, and therefore the densification current cannot be determined experimentally.

[0168] Second, different models and power oscillators have different currents in different strata;

[0169] Third, from an engineering practice perspective, even vibratory beaters from the same manufacturer and of the same model can have significantly different no-load currents.

[0170] Fourth, in colder regions, the no-load current of the vibratory compactor is relatively large when it is first used; however, as the project progresses, the temperature of the vibratory compactor itself increases, and the no-load current decreases accordingly.

[0171] Therefore, using the densification current as a measure of compactness cannot characterize the compactness of piles under ultra-deep overburden conditions.

[0172] To address the aforementioned problems in the prior art, this invention proposes a technique for controlling the vibratory compactor to perform vibratory compaction (i.e., vibratory compaction of the packing) based on the vibration signal frequency of the vibratory compactor during packing compaction. The core technology of this vibratory compaction technique is:

[0173] During the process of the vibratory compactor compacting the surrounding packing, a flow velocity sensor located inside the vibratory compactor generates a real-time electrical signal corresponding to the amplitude of the vibratory compactor.

[0174] The vibration compaction of the vibratory compactor is controlled based on the real-time electrical signal generated by the flow velocity sensor installed inside the vibratory compactor, so that the diameter of the crushed stone pile formed by the crushed stone filling the crushed stone pile hole is equal to the effective pile diameter.

[0175] Figure 7a An example of the flow rate sensor 1311 of the present invention disposed within the vibratory shock absorber is shown, such as Figure 7a As shown, the flow sensor 1311 includes: a support rod 1312 with one end mounted on the housing of the vibratory motor 1304; a cylinder 1313 containing liquid mounted on the other end of the support rod 1312; and a piston 1314, including a piston rod 13141 and a piston head 13142, mounted inside the vibratory motor housing 1308 and extending into the cylinder 1313, the piston head 13142 dividing the inner cavity of the cylinder into a first cavity. Figure 7a The cavity on the left) and the second cavity ( Figure 7a The cavity on the right side); a pipe 1315 connecting the first cavity and the second cavity; a flow rate detector 1316 installed on the pipe; during the movement of the piston within the cylinder as the vibrating impactor housing vibrates, the liquid within the cylinder flows through the pipe to the flow rate detector, causing the flow rate detector to generate an electrical signal corresponding to the vibration amplitude of the vibrating impactor housing.

[0176] Figure 7b Another example of the flow rate sensor 1311 of the present invention, disposed within the vibratory shock absorber, is shown, such as Figure 7bAs shown, the flow rate sensor 1311 includes: a cylinder 1313 containing liquid, installed inside the vibratory impactor housing 1308; a support rod 1312, one end of which is mounted on the vibratory impactor motor 1304 housing; and a piston 1314, including a piston rod 13141 and a piston head 13142, installed at the other end of the support rod 1312, the piston head 13142 extending into the cylinder 1313 and dividing the inner cavity of the cylinder into a first cavity. Figure 7b The cavity on the left) and the second cavity ( Figure 7b The cavity on the right side; a pipe connecting the first cavity and the second cavity; a flow rate detector installed on the pipe; during the movement of the cylinder relative to the piston as the vibrator housing vibrates, the liquid in the cylinder flows through the pipe to the flow rate detector, causing the flow rate detector to generate an electrical signal corresponding to the vibration amplitude of the vibrator housing.

[0177] This invention can use any existing sensor that converts flow rate into an electrical signal.

[0178] Figure 8 The control unit shown is used to control the vibratory compactor to vibrate and densify the packing, including a flow rate sensor 1311 for generating an electrical signal corresponding to the amplitude of the vibratory compactor, an amplifier for amplifying the electrical signal output by the flow rate sensor 1311, an analog-to-digital converter for converting the electrical signal output by the amplifier, a processor for processing the output of the analog-to-digital converter, a memory for storing the data output by the processor, and a display for displaying the data output by the processor.

[0179] In addition, the processor is connected to the main winch so that when it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter, the vibratory compactor 13 is lifted upward.

[0180] The amplifier, analog-to-digital converter, processor, memory, and display of the present invention can be installed on the ground, and the amplifier can be connected to the flow sensor 1311 via a cable.

[0181] It should be noted that when the processor of the present invention processes the amplitude of the electrical signal, it first processes the "amplitude of the electrical signal" into the "absolute value of the amplitude of the electrical signal" and then performs other processing.

[0182] Compared to another patent application filed by the inventors for a pressure sensor mounted on the housing of a vibratory compactor, this invention can significantly extend the service life of the flow rate sensor. In other words, because the flow rate sensor 1311 is mounted inside the vibratory compactor housing, it is not subject to the pressure of the packing and vibrator as is the case with a pressure sensor mounted on the housing, and is therefore less prone to damage.

[0183] Figure 9The control flow of a first embodiment of controlling a vibratory oscillator for vibration encryption control is shown. This flow is mainly implemented by a processor and specifically includes:

[0184] Step S301: During the vibratory compaction of the packing material by the vibratory compactor, a flow rate sensor installed inside the vibratory compactor generates a real-time electrical signal corresponding to the amplitude of the vibratory compactor housing.

[0185] Step S302: Obtain the absolute value of the amplitude of the real-time electrical signal by performing analog-to-digital conversion on the real-time electrical signal;

[0186] Step S303: Determine whether the absolute value of the real-time electrical signal amplitude is less than or equal to the preset amplitude value;

[0187] Step S304: If the judgment result of step S302 is yes, determine that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter.

[0188] Step S305: Raise the vibratory compactor upwards to vibrate and compact the crushed stone in the middle part of the vibratory crushed stone pile to form a crushed stone pile with a pile diameter equal to the effective pile diameter.

[0189] Step S306: If the judgment result of step S302 is negative, control the vibratory compactor to continue vibrating the crushed stone embedded in the soil layer around the crushed stone pile hole.

[0190] Figure 10 The control flow of a second embodiment for controlling the vibratory oscillator to perform vibration encryption control is shown, including:

[0191] Step S401: During the vibratory compaction of the packing material by the vibratory compactor, a flow rate sensor installed inside the vibratory compactor generates a real-time electrical signal corresponding to the amplitude of the vibratory compactor housing.

[0192] Step S402: By performing analog-to-digital conversion on the real-time electrical signal, the absolute values ​​of the amplitudes of the preceding and following electrical signals are obtained.

[0193] Step S403: Determine whether the absolute value of the amplitude of the subsequent electrical signal is less than or equal to the absolute value of the amplitude of the preceding electrical signal.

[0194] Step S404: If the judgment result of step S403 is yes, then further determine whether the absolute value of the amplitude of the subsequent electrical signal remains unchanged for a period of time.

[0195] Step S405: If the judgment result of step S404 is yes, then it is determined that the diameter of the crushed stone pile to be formed is greater than or equal to the effective pile diameter.

[0196] Step S405: Raise the vibratory compactor upwards to vibrate and compact the crushed stone in the middle part of the vibratory crushed stone pile to be formed, thereby finally forming a crushed stone pile with a pile diameter greater than or equal to the effective pile diameter.

[0197] Step S406: If the judgment result of step S403 or step S404 is negative, then control the vibratory compactor to continue vibrating the crushed stone embedded in the soil layer around the crushed stone pile hole.

[0198] It should be noted that one of the features of this invention is the introduction of the concept of effective pile diameter, which is the pile diameter of the crushed stone pile formed in the crushed stone pile hole that is tightly bonded to the soil layer around the hole and meets the requirements of vibratory compaction.

[0199] The effective pile diameter of the crushed stone pile of the present invention solves the technical problem that the crushed stone pile may not be able to bond tightly with the soil layer in the prior art.

[0200] In addition, during the vibratory compaction of the filler using a vibratory compactor, the density of the mud slurry above the surface of the crushed stone filler in the pile hole needs to be tested by a mud pump to ensure that the mud slurry density in the pile hole meets the requirements, thereby ensuring that the permeability of the formed crushed stone pile meets the requirements.

[0201] The determination of the mud density above the surface of the crushed stone fill material in the crushed stone pile hole includes:

[0202] The mud pump is used to pump the mud above the surface of the crushed stone filling material in the crushed stone pile hole upward to the mud density meter.

[0203] The density of the pumped mud is measured using a mud density meter to obtain the current mud density value above the surface of the crushed stone filling material in the crushed stone pile hole.

[0204] In application, the mud density meter can be installed on the ground, such as on the outermost upper part of a telescopic guide rod, on a mast, or on the pile frame of a vibratory stone crushing machine. The mud pump can be lowered into the stone pile hole via a winch, positioned 10-50cm above the top of the stone filler material. The mud pumped from above the stone filler material surface is then delivered to the mud density meter on the ground via a pipeline. Alternatively, the mud pump and mud density meter can be integrated and placed on the ground, such as on the outermost upper part of a telescopic guide rod, on a mast, or on the pile frame of a vibratory stone crushing machine. Then, the pipeline is lowered into the stone pile hole via a winch, ensuring the lower end of the pipeline reaches the top of the stone filler material surface. The mud pumped from above the stone filler material surface is then delivered to the mud density meter on the ground via the pipeline.

[0205] When installing mud density meters and mud pumps, they can be connected to other components in a detachable manner so that they can be removed when mud density testing is not required.

[0206] The control of the flow rate of the supplied sewage and the flow rate of the pressurized air based on the obtained mud density includes:

[0207] After obtaining the current mud density value above the surface of the crushed stone filling material in the crushed stone pile hole, compare the current mud density value with the preset mud density threshold.

[0208] Based on the comparison between the current mud density value and the preset mud density threshold, the flow rate of the supplied water and the flow rate of the supplied pressurized air are controlled.

[0209] Specifically, such as Figure 11 As shown, based on the comparison between the current mud density value and the preset mud density threshold, the control of the sewage flow rate and the pressurized air flow rate includes:

[0210] The comparison result shows that when the current mud density value is within the preset first threshold of mud density, the vibratory compactor is controlled to work together under the current water flow rate and the current air flow rate to complete the vibratory compaction construction.

[0211] When the comparison result shows that the current mud density value exceeds the preset first threshold, the flow rate of the supplied water and the flow rate of the supplied pressurized air are controlled to keep the mud density value within the preset first threshold, including:

[0212] If the current mud density value is greater than the upper limit of the preset first threshold of mud density but within the preset second threshold of mud density, control the flow rate to increase to 75-80% of the rated maximum flow rate, and control the air pressure to remain unchanged until the mud density value is within the preset first threshold of mud density.

[0213] If the current mud density value is greater than the upper limit of the second preset mud density threshold and within the third preset mud density threshold, control the flow rate of the sewage to increase to 85-90% of the rated maximum sewage flow rate, and control the flow rate of the air to increase to 85-90% of the rated maximum air flow rate, until the mud density value is within the first preset mud density threshold.

[0214] If the current mud density value is greater than the upper limit of the preset third threshold of mud density, the flow rate of the sewage is increased to the rated maximum flow rate, and the flow rate of the air is increased to the rated maximum flow rate, until the mud density value is within the preset first threshold of mud density.

[0215] The controller is pre-programmed with the correlation between the mud density inside the crushed stone pile hole and different permeability crushed stone piles. This correlation is obtained through testing; that is, test piles are constructed on-site before formal construction, and the controller analyzes the extensive data obtained from these test piles to determine the correlation between mud density and different permeability crushed stone piles. The preset mud density threshold is the mud density value corresponding to crushed stone piles that meet the preset permeability requirements.

[0216] In application, the preset mud density threshold is determined according to the actual construction conditions. For example, in this invention, the first preset mud density threshold is [1.03-1.10 g / cm³]. 3 The preset second threshold for mud density is (1.10-1.12 g / cm³). 3 The preset third threshold for mud density is (1.12-1.15 g / cm³). 3 ].

[0217] The rated maximum water flow rate and rated maximum air flow rate are determined based on the vibratory compactor and the water and air pumps used in the vibratory compaction of stone pile construction. The current water flow rate and current air flow rate are typically 40-60% of the rated maximum water flow rate and 50% of the rated maximum air flow rate, respectively.

[0218] This invention detects the mud density above the fill material surface in the crushed stone pile hole during the vibratory compaction process of crushed stone filler, and controls the flow rate of the supplied water and air based on the detection results. This allows the vibrator to perform vibratory compaction of the crushed stone filler under the synergistic effect of the adjusted water and air, thereby ensuring that the permeability of the crushed stone pile formed by vibratory compaction meets the preset requirements. It also ensures that the crushed stone pile can vertically transmit the excess pore water pressure from deep within the stratum to the crushed stone cushion layer under strong earthquake conditions, preventing the vibratory compaction of the crushed stone pile from breaking under strong earthquakes, thus improving stability and safety.

[0219] In summary, the method of this invention allows for the construction of gravel pile holes based on geological conditions, and enables the monitoring and control of the process of vibro-compaction to form gravel piles, ensuring pile quality. This method changes the existing concept of inspecting and repairing piles after completion. It solves the problems of poor continuity of gravel piles formed by existing technologies and easy breakage under strong earthquakes. It also solves the problems of difficulty in achieving ideal results after vibro-compaction gravel pile construction in strata with ultra-deep overburden in ultra-strong earthquake zones, and the inability to repair piles after discovering quality defects.

[0220] Although the present invention has been described in detail above, the present invention is not limited thereto. Those skilled in the art can make modifications based on the principles of the present invention. Therefore, all modifications made in accordance with the principles of the present invention should be understood as falling within the protection scope of the present invention.

Claims

1. A method for forming anti-sliding vibratory compaction stone piles under ultra-deep overburden in ultra-strong earthquake zones, comprising: Drilling is carried out on strata consisting of an upper layer of sand and gravel, a lower layer of sand and gravel, and a slip layer with high viscosity in between the upper and lower sand and gravel layers to form crushed stone pile holes. In the event of a super earthquake, the sand and gravel layer above the slip layer can slip relative to the sand and gravel layer below it. The process involves filling the formed gravel pile hole containing the slip layer with filler material and then vibrating and compacting the filler material using a vibratory compactor to form a continuous, uniform, and slip-resistant vibratory-compacted gravel pile with an effective pile diameter, including: The vibratory compactor compacts and densifies the crushed stone filling material placed into the crushed stone pile hole located below the slip layer, forming the lower crushed stone pile section; The vibratory compactor vibrates the fill material obtained during the drilling process by excavating above and / or below the slip layer and placing it into the gravel pile hole corresponding to the slip layer. The fill material is excavated material located above and / or below the slip layer during the drilling process. After the excavated material is vibrated and compacted into the slip layer around the gravel pile hole, gravel filler is put into the gravel pile hole of the corresponding slip layer. The vibratory compactor compacts and densifies the gravel filler to form a gravel pile segment in the slip layer. After the slip layer crushed stone pile section is formed, the vibratory compactor continues to compact and densify the crushed stone filling material in the crushed stone pile hole above the slip layer to form the upper crushed stone pile section. During the process of vibratory compaction of the packing, a flow velocity sensor located between the inner side of the vibratory compactor housing and the vibratory compactor motor housing generates a real-time electrical signal corresponding to the vibration amplitude of the vibratory compactor housing. Based on the real-time electrical signal corresponding to the vibration amplitude of the vibratory compactor housing, the vibratory compaction of the vibratory compactor is controlled by comparing the amplitude of the real-time electrical signal of the vibratory compactor with a preset amplitude, so that the filler material filled into the crushed stone pile hole forms a crushed stone pile with a pile diameter equal to the effective pile diameter, that is, the crushed stone pile is tightly bonded to the soil layer around the hole.

2. The method according to claim 1, wherein the flow rate sensor disposed within the vibratory shock absorber comprises: One end of it is mounted on the support rod on the motor housing of the vibratory impactor; A cylinder containing liquid is installed at the other end of the support rod; A piston, including a piston rod and a piston head, is installed inside the housing of the vibratory impactor and extends into the cylinder body. The piston head divides the inner cavity of the cylinder body into a first cavity and a second cavity. Piping connecting the first cavity and the second cavity; A flow rate detector installed on the pipeline; During the movement of the piston within the cylinder as the vibrating impactor housing vibrates, the liquid within the cylinder flows through the pipeline to the flow rate detector, causing the flow rate detector to generate an electrical signal corresponding to the vibration amplitude of the vibrating impactor housing.

3. The method according to claim 1, wherein the flow rate sensor disposed within the vibratory shock absorber comprises: A cylinder containing liquid is installed inside the housing of the vibratory impactor; One end of it is mounted on the support rod on the motor housing of the vibratory impactor; A piston, including a piston rod and a piston head, is installed at the other end of the support rod. The piston head extends into the cylinder body, dividing the inner cavity of the cylinder body into a first cavity and a second cavity. Piping connecting the first cavity and the second cavity; A flow rate detector installed on the pipeline; During the movement of the cylinder relative to the piston as the vibrator housing vibrates, the liquid inside the cylinder flows through the pipeline to the flow rate detector, causing the flow rate detector to generate an electrical signal corresponding to the vibration amplitude of the vibrator housing.

4. The method according to claim 2 or 3, wherein controlling the vibration intensity of the vibratory compactor based on the real-time electrical signal generated by the flow velocity sensor disposed within the vibratory compactor comprises: The amplitude of the real-time electrical signal is compared with the preset amplitude; When the amplitude of the real-time electrical signal is less than or equal to the preset amplitude, it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter, and the vibratory compactor is lifted upward to vibrate the crushed stone in the middle part of the crushed stone pile to be formed, thereby finally forming a crushed stone pile with a pile diameter equal to the effective pile diameter. When the amplitude of the real-time electrical signal is greater than the preset amplitude, the vibratory compactor is controlled to continue vibrating the gravel embedded in the soil layer around the gravel pile hole.

5. The method according to claim 4, wherein the preset amplitude is a value obtained in advance when the vibrator amplitude is reduced to its minimum.

6. The method according to claim 2 or 3, wherein controlling the vibration encryption of the vibratory compactor based on the real-time electrical signal generated by the flow velocity sensor disposed within the vibratory compactor comprises: The amplitudes of the electrical signals obtained by the flow velocity sensor before and after the vibration period are analyzed. When the amplitude of the subsequent electrical signal is less than that of the preceding electrical signal and remains so for a period of time, it is determined that the diameter of the crushed stone pile to be formed is equal to the effective pile diameter. The vibratory compactor is then raised to vibrate the crushed stone in the middle part of the crushed stone pile to be formed, thus ultimately forming a crushed stone pile with a pile diameter equal to the effective pile diameter.

7. The method according to claim 1, wherein drilling is performed on strata containing a slip layer with high viscosity to form a gravel pile hole includes: The pipe used to supply sewage passes through the telescopic guide rod and the vibratory flusher and extends from the bottom of the vibratory flusher so that the sewage is sprayed out from the bottom of the vibratory flusher to pre-damage the formation with water. Obtain the current formation density during vibro-compaction; Obtain the instantaneous drainage pressure of the supplied drainage and determine the obtained instantaneous drainage pressure as the current drainage pressure; Based on the preset correspondence between groundwater pressure and formation density, find the target groundwater pressure corresponding to the current formation density; Control the flow rate of the supplied water to bring the current water pressure to the target water pressure, so as to complete the vibratory compaction of the crushed stone pile hole by using the vibratory compactor and the target water pressure.

8. The method according to claim 1, further comprising, during the vibratory compaction of the packing using a vibratory compactor: The density of the mud above the surface of the crushed stone fill material in the pile hole is tested by using a mud pump to ensure that the mud density in the pile hole meets the requirements.

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