Pre-punching air knife device

Abstract

The utility model relates to the technical field of pre-punching air knife devices, and discloses a pre-punching air knife device which can be matched with a pile driver to punch downwards, and an annular soft channel, namely an annular pre-punched hole, is pre-formed in the position where a steel pipe pile is formally driven; in the punching process, ultrahigh-pressure compressed air is sprayed out from the air nozzle along the air channel of the air conveying pipe fitting to cut the soil body and hard objects such as block stones and gravels in the soil body which hinder descending of the steel pipe pile, and the steel pipe pile is pulled out until the steel pipe pile is driven to the designed specified elevation. The problems that vibration is too large due to hard objects, and the pipe is clamped by block stones are solved, and the penetration degree can also be increased. During construction, the pre-punching air knife device is used for forming the annular pre-punching hole with the vertical depth, due to the fact that the annular pre-punching hole is not affected by hard objects, when a pile driver is used for driving the steel pipe pile subsequently, the perpendicularity deviation can be guaranteed to be within the design range, the qualified rate of the driving quality of the steel pipe pile is increased, and the project progress is accelerated.

Description

Technical Field

[0001] The utility model relates to the technical field of steel pipe pile construction, in particular to a pre-punching air knife device. Background Art

[0002] At present, in the construction of such urban deep foundation pit projects, the pile-anchor composite support technology has become a more effective way to solve this series of problems. Steel pipe piles are often the most commonly used in the pile-anchor composite support system, because steel pipe piles can give full play to their advantages of high rigidity, fast construction, low cost and recyclability in the entire support system, and have obvious comprehensive advantages in deformation and stability of the foundation pit.

[0003] In the process of driving steel pipe piles, a pile driver is generally used to carry the steel pipe piles into the stratum to a certain depth by vibration or hammering. For example, a vibration and hammering integrated pile driver and a vibration hammer shown in Chinese patent CN 201817813 U are used to drive steel pipe piles. However, there are the following problems:

[0004] During the process of steel pipe pile driving, when encountering hard soil layers or soil layers containing gravel and boulders, problems such as excessive vibration and boulders blocking the pipes will occur. In severe cases, gravel will deviate from the pipes, resulting in low penetration of the steel pipe piles and large vertical deviations, ultimately causing the erected steel pipe piles to fail to meet the design requirements. Utility Model Content

[0005] The purpose of the utility model is to provide a pre-punching air knife device, which solves the problems of pipe sticking, small penetration and large verticality deviation of the pile driver in the background technology when encountering a hard soil layer or a soil layer containing gravel or blocks of stone, and has the function of preventing pipe sticking, improving the qualified rate of steel pipe pile driving, and speeding up the progress of the project and saving investment to a certain extent.

[0006] In order to solve the above technical problems, the utility model provides the following technical solutions:

[0007] A pre-punching air knife device is provided, comprising:

[0008] The installation substrate comprises a steel pipe pile and a gas delivery pipe connected to the outer surface of the steel pipe pile; one end of the gas delivery pipe has a connection port and the other end is closed; the gas delivery pipe is arranged along the length direction of the steel pipe pile, and the closed end is annularly surrounding the outer side of the bottom end of the steel pipe pile; the gas delivery pipe is provided with a plurality of cutting air nozzles connected to the internal airway; the cutting air nozzles are arranged at the annular position of the closed end and are distributed along the annular interval;

[0009] The gas supply assembly is connected to the connecting port of the gas delivery pipe to provide high-pressure compressed gas.

[0010] The pre-punching air knife device can cooperate with the pile driver to punch holes downwards, and pre-form a circular soft channel at the location where the steel pipe pile is officially driven, that is, a circular pre-punching hole; during the punching process, ultra-high pressure compressed air is ejected from the air nozzle along the airway of the gas transmission pipe fittings to cut the soil and hard objects such as boulders and gravels in the soil that hinder the downward movement of the steel pipe pile, until it is driven to the specified elevation and then pulled out. In this process, the gas ejected from the cutting air nozzle can be used to cut the soil and hard objects such as boulders and gravels in the soil that hinder the downward movement of the steel pipe pile, avoiding the problem of excessive vibration caused by hard objects and boulders blocking the pipe, and the penetration rate can also be increased, reducing the discomfort of driving, and it will not be affected by the hard soil layer or gravel and boulders soil layer, and its verticality will be guaranteed.

[0011] Preferably, the gas delivery pipe is made of seamless steel pipe and welded to the outer surface of the mounting substrate; the cutting air nozzle is made of tungsten steel.

[0012] Preferably, the air supply assembly comprises an air compressor unit and a high-pressure anti-expansion connecting hose, and the high-pressure anti-expansion connecting hose is connected to the connecting port of the air delivery pipe through a connecting joint.

[0013] Preferably, the outer surface of the installation substrate is connected with an anti-knot ring; the high-pressure anti-expansion connecting hose is connected to the gas transmission pipe through the anti-knot ring. This prevents the high-pressure anti-expansion connecting hose from directly contacting the installation substrate, reduces friction, and limits the movement trajectory of the high-pressure anti-expansion connecting hose to reduce kinking.

[0014] Preferably, the surface of one side of the gas delivery pipe that contacts the installation substrate is welded to the installation substrate along the trajectory direction of the gas delivery pipe; and / or,

[0015] The gas delivery pipe is provided with a plurality of fixed welding pieces, both ends of which are welded to the installation base material, and a compression space for compressing the gas delivery pipe is formed in the middle.

[0016] Preferably, the installation substrate further comprises a plurality of thickened sheets, which are circumferentially distributed on the outside of the top of the steel pipe pile and are fitted and connected to the outer surface of the steel pipe pile.

[0017] Compared with the prior art, the beneficial effects achieved by the utility model are:

[0018] 1. Using steel pipe piles as the base material, setting gas pipe fittings on the outside, and combining the pre-punching air knife device formed by the gas supply assembly, the production cost is low, and it can be reused on steel pipe piles of the same specification. And the formed annular pre-punching hole matches the steel pipe pile to be driven.

[0019] 2. The pre-punching air knife device can cooperate with the pile driver to punch downwards, forming a circular soft channel in advance at the location where the steel pipe pile is officially driven, i.e., a circular pre-punching hole; during the punching process, ultra-high pressure compressed air is ejected from the air nozzle along the air passage of the gas transmission pipe fittings, cutting the soil and hard objects such as rocks and gravels in the soil that hinder the downward movement of the steel pipe pile until it is driven to the designated elevation and then pulled out. This process avoids the problem of excessive vibration caused by hard objects and the problem of rocks blocking the pipe, and the penetration rate can also be increased.

[0020] 3. During construction, the utility model first uses a pre-punching air knife device to form a circular pre-punching hole with a vertical depth. Since it will not be affected by a hard soil layer or a soil layer containing gravel or blocks of stone, its verticality can be guaranteed. When a pile driver is used to drive steel pipe piles later, the verticality deviation can be guaranteed to be within the design range, thereby improving the quality pass rate of steel pipe pile driving and accelerating the progress of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A state diagram of the guide purlin provided in the embodiment of the present application during construction;

[0022] Figure 2 A front view of a pre-punching air knife device provided in an embodiment of the present application;

[0023] Figure 3 for Figure 2 A partially enlarged schematic diagram of the upper part of the pre-punching air knife device;

[0024] Figure 4 for Figure 2 A partial enlarged schematic diagram of the lower part of the pre-punching air knife device;

[0025] Figure 5 A side view of a pre-punching air knife device provided in an embodiment of the present application;

[0026] Figure 6 for Figure 5 A partially enlarged schematic diagram of the upper part of the pre-punching air knife device;

[0027] Figure 7 for Figure 5 A partial enlarged schematic diagram of the lower part of the pre-punching air knife device;

[0028] Figure 8 Schematic diagram of the top of the substrate installed with the pre-punching air knife device.

[0029] Fig. 9 Schematic diagram of the connection between the bottom end of the installation substrate of the pre-punching air knife device and the air delivery pipe.

[0030] Among them: 1. Installation base material; 2. Gas transmission pipe fittings; 3. Cutting air nozzle; 4. Anti-knot ring; 5. High-pressure anti-expansion connecting hose; 6. Fixed welding piece; 7. Thickening piece; 8. Guide purlin; 9. Annular pre-punching hole. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] The following understanding should be given to this utility model:

[0033] With the acceleration of urbanization in my country, the comprehensive transformation of urban pumps and gates has led to the emergence of more and more deep foundation pit projects under complex environmental conditions. The environment around the deep foundation pit is complex, with existing buildings, as well as municipal infrastructure such as electricity, gas, communications, municipal rainwater, and sewage pipe networks. During the construction process, the foundation pit support not only needs to ensure a safe construction space when the underground structure of the building is constructed, but also needs to ensure that the impact on the surrounding environment is minimal and cannot affect the normal use of various facilities. Under complex environmental conditions, higher technical requirements are also put forward for the support construction of deep foundation pits. At present, in the construction of such urban deep foundation pit projects, the pile-anchor composite support technology has become a more effective way to solve this series of problems. Steel pipe piles are often the most commonly used in pile-anchor composite support systems, because steel pipe piles can give full play to their advantages of high rigidity, fast construction, low cost, and recyclability in the entire support system, and have obvious comprehensive advantages in deformation and stability of the foundation pit.

[0034] At present, the construction situations that this utility model copes with are:

[0035] The geological conditions of the project site are complex. The rock and soil of the shallow foundation of 25m can be divided into 7 large layers and 8 sub-layers. The north side of the foundation pit of the sluice pump section, the inlet and outlet pool section, and the north and south sides of the foundation pit of the inner river diversion channel section are adjacent to old industrial plants. There are old sewage pipes on the north slope. The south side is close to the Dongshaoxi Bridge, and there is a natural gas pipeline buried under the bridge, which meets the characteristics of deep foundation pit engineering under complex environmental conditions. During the construction, 133 Φ920mm×16mm steel pipe piles were designed on the slope on the south side of the foundation pit, and 12 Φ920mm×16mm steel pipe piles were designed on the downstream of the north slope near the factory building, totaling 145 piles, each 18m long. Conventional steel pipe piles are driven without the aid of external force devices and are only suitable for homogeneous soft foundations. However, for the complex geological conditions of this project, our project started on January 11, 2023, and it took 2 days to drive only 5 test piles. The maximum penetration of the 5 test piles was 93%. In addition, there were large vertical deviations and stuck pipes, which resulted in the 5 steel pipe piles not meeting the design quality requirements. In addition, based on the construction progress of 5 steel pipe piles / 2 days, it will take 58 days to drive 145 steel pipe piles, which will seriously delay the construction progress and fail to meet the entire project schedule requirements.

[0036] Considering the above two practical difficulties of project quality and progress, it is urgent to develop an air knife device that can pre-punch holes when driving steel pipe piles to solve the quality problems of steel pipe pile construction and the impact on the project schedule.

[0037] The reason for the above is that when a vibrating reciprocating pile driver encounters a hard soil layer or a soil layer containing gravel or boulders during the driving of steel pipe piles, it will affect the driving effect, which is manifested in excessive vibration, boulders blocking the pipe, gravel deviation, small penetration rate, large verticality deviation, etc., which ultimately leads to the steel pipe piles not meeting the design requirements and requiring rework.

[0038] Therefore, see Figure 2-Figure 9 , a pre-punching air knife device is proposed, which comprises:

[0039] The installation substrate 1 comprises a steel pipe pile and a gas delivery pipe 2 connected to the outer surface of the steel pipe pile; one end of the gas delivery pipe 2 has a connection port and the other end is closed; the gas delivery pipe 2 is arranged along the length direction of the steel pipe pile, and the gas sealing end is annularly surrounding the outer side of the bottom end of the steel pipe pile; the gas delivery pipe 2 is provided with a plurality of cutting air nozzles 3 connected to the internal airway; the cutting air nozzles 3 are arranged at an annular position and are distributed along the annular interval;

[0040] The gas supply assembly is connected to the connection port of the gas delivery pipe 2 to provide high-pressure compressed gas.

[0041] In the above, the installation substrate 1 is replaced according to the specifications and sizes of the steel pipe piles to be driven, so that an annular soft channel is pre-formed at the position where the steel pipe piles are officially driven, so that the steel pipe piles to be driven later can be adapted. The gas supply component provides ultra-high pressure compressed gas.

[0042] The present device can be used with a pile driver to punch holes downwards, and a circular soft channel, i.e., a circular pre-punched hole 9, is pre-formed at the location where the steel pipe pile is formally driven. During the punching process, ultra-high pressure compressed air is ejected from the air nozzle along the air passage of the gas transmission pipe 2 to cut the soil and the hard objects such as boulders and gravels in the soil that hinder the downward movement of the steel pipe pile, until the pile is driven to the designated elevation and then pulled out. In this process, the gas ejected from the cutting air nozzle 3 can be used to cut the soil and the hard objects such as boulders and gravels in the soil that hinder the downward movement of the steel pipe pile, thereby avoiding the problem of excessive vibration and boulders stuck in the pipe caused by hard objects, and the penetration rate can also be increased, reducing the discomfort of driving, and the pile will not be affected by the hard soil layer or the gravel and boulders soil layer, and its verticality will be guaranteed.

[0043] Of course, the pre-punching air knife device can be used not only in this environment, such as some hole-opening operations, etc. The pile driver that can be matched can be a vibrating reciprocating pile driver, or includes but is not limited to the pile driver mentioned in the background technology.

[0044] Further, the above device structure is described in detail:

[0045] The gas transmission pipe 2 is made of seamless steel pipe and welded to the outer surface of the installation base material 1; the cutting air nozzle 3 is made of tungsten steel; the seamless steel pipe is a thick-walled seamless carbon steel pipe; this structure has the function of ensuring stable transmission of the airway, and can withstand high pressure without being changed by external forces. It is also wear-resistant.

[0046] Correspondingly, the air supply assembly includes an air compressor unit and a high-pressure anti-expansion connecting hose 5, and the high-pressure anti-expansion connecting hose 5 is connected to the connecting port of the air supply pipe 2 through a connecting joint. The high-pressure anti-expansion connecting hose is an existing pipe material and will not be introduced in detail here. For example, a pneumatic brake hose with pressure-resistant and explosion-proof functions mentioned in CN 211901902 U belongs to the technical field of automotive accessories. It includes a hose body, and the hose body is provided with an inner rubber layer for conveying a medium, a reinforcement layer for pressure resistance, and an outer rubber layer for protecting the inside of the hose body from damage from the inside to the outside. The hose body is also provided with an inner pressure-resistant component and an outer pressure-resistant component, and the inner pressure-resistant component is arranged on the inner rubber layer. The reinforcement layer can enhance the pressure resistance and explosion-proof capability of the hose body itself. Together with the internal pressure-resistant component and several external reinforcement rings in the external pressure-resistant component, the pressure resistance of the hose body in the radial direction and the explosion-proof capability of the hose body under high pressure can be enhanced. It can also reduce the expansion of the hose body under high pressure, thereby enhancing the braking force of the vehicle brake shoe or brake caliper. The uniformly spaced outer reinforcement rings along the axial direction can make the pressure resistance of the hose body more balanced.

[0047] The air compressor unit is a machine that compresses air and stores it in an air tank. It consists of the following components: Compressor: The compressor is the core component of the air compressor and is responsible for compressing the air. Common compressors include screw compressors, piston compressors, etc. Drive device: The drive device provides power to the compressor, which can be an electric motor, a diesel engine, etc. Cooling system: During the compression process, the air temperature will rise and needs to be cooled by the cooling system. The cooling system generally includes fans, radiators, etc. Oil system: The oil system is mainly responsible for protecting and lubricating various components of the compressor, such as compressor bearings, cylinders, etc. The oil system generally includes oil pumps, oil tanks, etc. Control system: The control system is used to monitor and adjust the state of the air compressor, such as the pressure, temperature, running time and other parameters of the compressor. Common control systems include PLC control systems, electronic control systems, etc. Air tank: The air tank is a device for storing compressed air in the air compressor. The air tank can reduce the number of times the compressor is switched on and off and stabilize the output air pressure. The above are the main components of the air compressor, and different types of air compressors may differ in composition. When using an air compressor, you need to choose the appropriate model and configuration according to actual needs to ensure the normal operation and efficient work of the equipment.

[0048] In the process of cooperating with the pile driver, the high-pressure anti-expansion connecting hose 5 has the problem of wear and knotting, so the following settings are made:

[0049] The outer surface of the mounting substrate 1 is connected with an anti-knot ring 4; the high-pressure anti-expansion connecting hose 5 passes through the anti-knot ring 4 and is connected to the gas transmission pipe 2. The anti-knot ring 4 is made of soft material and has a smooth surface. It prevents the high-pressure anti-expansion connecting hose 5 from directly contacting the mounting substrate 1, reducing friction. It also limits the movement trajectory of the high-pressure anti-expansion connecting hose 5 to reduce kinking.

[0050] Furthermore, in order to realize the connection between the gas delivery pipe 2 and the installation substrate 1, the following configuration is provided:

[0051] The first type is that the surface of the gas delivery pipe 2 is in contact with the mounting substrate 1 and is welded to the mounting substrate 1 along the trajectory direction of the gas delivery pipe 2;

[0052] Second, the gas delivery pipe 2 is provided with a plurality of fixed welding pieces 6, the two ends of the fixed welding pieces 6 are welded to the mounting substrate 1, and the middle part forms a compression space for compressing the gas delivery pipe 2. The use of the fixed welding pieces 6 facilitates positioning and fixing in the early stage, and facilitates subsequent operations.

[0053] The third type is that the surface of one side of the gas pipe fitting 2 is in contact with the installation substrate 1, and is welded to the installation substrate 1 along the trajectory direction of the gas pipe fitting 2; a plurality of fixed welding plates 6 are provided on the gas pipe fitting 2, and both ends of the fixed welding plates 6 are welded to the installation substrate 1, and a compression space for compressing the gas pipe fitting 2 is formed in the middle.

[0054] The above three solutions are sufficient to be adopted. During welding, the gas transmission pipe 2 is fully welded on both sides along the outer wall of the pipe body, and is laid in a circular manner with a smooth curve transition to full welding on both sides at the bottom of the steel pipe pile.

[0055] Furthermore, in actual use, the hydraulic clamps of the pile driver will cause deformation or damage to the steel pipe piles, so the following design is required:

[0056] The installation substrate 1 also includes a plurality of thickening sheets 7, which are circumferentially distributed on the outside of the top of the steel pipe pile and are fitted and connected to the outer surface of the steel pipe pile. The thickening sheet 7 is fully welded to the steel pipe pile body on one side. The top edge of the steel pipe pile used is thickened by 50cm thickening sheet 7 to prevent deformation during the hydraulic clamping and lifting of the pile driver. The top of the steel pipe pile is extended by 1m to leave space for the pile driver clamp to operate.

[0057] Through the above description, the beneficial effects achieved by the utility model are:

[0058] 1. Using steel pipe piles as the base material, setting the gas pipe 2 on the outside thereof, and combining the pre-punching air knife device formed by the gas supply component, the manufacturing cost is low, and it can be reused on steel pipe piles of the same specification. And the formed annular pre-punching hole 9 matches the steel pipe pile to be driven.

[0059] 2. The pre-punching air knife device can cooperate with the pile driver to punch downwards, and pre-form an annular soft channel, i.e., an annular pre-punching hole 9, at the location where the steel pipe pile is officially driven; during the punching process, ultra-high pressure compressed air is ejected from the air nozzle along the air passage of the gas transmission pipe 2, cutting the soil and hard objects such as rocks and gravels in the soil that hinder the downward movement of the steel pipe pile, until it is pulled out after being driven to the designated elevation. This process avoids the problem of excessive vibration caused by hard objects and the problem of rocks blocking the pipe, and the penetration rate can also be increased.

[0060] 3. The utility model first uses a pre-punching air knife device to form a circular pre-punched hole 9 with a vertical depth during construction. Since it will not be affected by the hard soil layer or the gravel or blocky soil layer, its verticality can be guaranteed. When the pile driver is used to drive the steel pipe piles later, the verticality deviation can be guaranteed to be within the design range, thereby improving the quality pass rate of the steel pipe pile driving and accelerating the progress of the project.

[0061] 4. This set of equipment uses local materials and is processed on site. It is simple to make and has low cost. It not only speeds up the construction progress, but also can be reused on steel pipe piles of the same specifications, and ensures the quality pass rate of steel pipe pile driving.

[0062] After the device was actually used in this project, the following statistical data was obtained: it took 3 days to make and repair the device, and 17 days to drive 145 steel pipe piles. Among them, 8 piles were located close to the bedrock of the mountain, with a penetration rate between 94% and 100%, and the rest were all 100%, and the verticality was all controlled below 1%. All data in various items met the expectations of the project team and construction requirements.

[0063] Here is a practical application case to illustrate the construction steps:

[0064] The south side of the Xinminqiao sluice station foundation pit adopts the support method of vertical support of steel pipe piles + slope excavation. The steel pipe piles are Φ920*16 and made of Q355B. According to the actual situation on site, 700-type hydraulic hammers are used for driving. The closest distance between the west building and the steel pipe piles is about 25 meters. When driving the steel pipe piles in this section, the guide holes are firstly made, and then the hydraulic hammer is used for static pressure pressing. The monitoring is strengthened during the construction.

[0065] Construction process:

[0066] Clear the debris → lay out and position → make guide purlins → drive guide piles → drive steel pipe piles → shift guide purlins and repeat.

[0067] 1. Preparation

[0068] 1.1. Clean the soil and dig out concrete blocks, gravel, etc. that may affect the construction.

[0069] 1.2. Check the steel pipe piles one by one and do not use steel pipe piles with unqualified materials, serious structural deformation, or serious damage to the pile structure.

[0070] 1.3. Hydraulic hammer inspection: Hydraulic hammer is the key equipment for driving and pulling steel sheet piles. Before driving and pulling, special inspection must be carried out to ensure that the line is unobstructed and the function is normal.

[0071] 2. Measurement and staking out - staking out and positioning

[0072] 2.1. According to the measurement control point data provided by the owner, use GPS in conjunction with the total station to determine the location and range of the steel pipe piles on site, measure and lay out the starting point, turning point, end point and other characteristic points of the steel pipe piles, mark them with colored flags and fix them.

[0073] 2.2. Production of guide purlin 8

[0074] The guide purlins are made of 12-meter blocks using No. 32 channel steel with a width of 1.10m and a length of 12 meters.

[0075] 3. Driving of guide piles and steel pipe piles

[0076] Install and fix the guide purlin 8 at the staked pile position, that is, drive a guide pile at both ends to fix the guide purlin 8, and use a pile driver and a pre-punching air knife device to drive down into the soil in the guide purlin 8 until it reaches the specified elevation; then pull out the pre-punching air knife device to form the annular pre-punching hole 9; then use a pile driver to drive steel pipe piles in the annular pre-punching hole 9. After a block of 12 meters is driven, move to the next position for driving. You can refer to Figure 1 As shown, the function of the guide purlin 8 is explained. Figure 1 The mark a shown is a steel pipe pile.

[0077] Overall construction sequence:

[0078] According to the on-site inspection, the length of the steel pipe pile section on the south side is about 130m, so it was decided to adopt the construction method of driving from the inner river side (outer river side). On the leveled 3.70m platform, a 700-type crawler hydraulic pile driver was used to drive the pile, with 12m as a construction section, and after driving, it was moved to the next section for construction.

[0079] The deviation standards for steel pipe pile driving are shown in the following table.

[0080] project Tolerance Horizontal deviation of pile top ±15cm Pile top elevation +10cm, -0cm Pile verticality 1.0% (vertical to the longitudinal axis)

[0081] Steel pipe pile acceptance

[0082] After the steel pipe piles are completed, the construction unit, supervision unit and construction unit will jointly conduct a special acceptance inspection on the steel pipe piles. Only after they pass the inspection can other construction work in the foundation pit be carried out.

[0083] Steel pipe pile removal

[0084] After the pump station and adjacent parts reached an elevation of 3.0m, the removal of the steel pipe piles began.

[0085] A vibratory hammer is used for pulling out piles: the forced vibration generated by the vibratory hammer is used to disturb the soil, destroy the cohesion of the soil around the steel pipe pile to overcome the resistance to pile pulling, and the pile is pulled out by relying on the additional lifting force.

[0086] Before pulling out the piles, communicate with surrounding residents and relevant units, listen to opinions from all parties, carry out monitoring simultaneously during the removal, observe the settlement and displacement of the foundation pit and surrounding buildings, organize and compare data in a timely manner, and stop construction immediately if it is found that the warning value is exceeded.

[0087] Before removing the steel pipe piles, install auxiliary steel cables on the piles before proceeding with the operation.

[0088] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit thereof, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A pre-punching air knife device, characterized in that , which includes: The installation substrate (1) comprises a steel pipe pile and a gas delivery pipe (2) connected to the outer surface of the steel pipe pile; one end of the gas delivery pipe (2) has a connection port and the other end is closed; the gas delivery pipe (2) is arranged along the length direction of the steel pipe pile, and the closed end is annularly surrounding the outer side of the bottom end of the steel pipe pile; the gas delivery pipe (2) is provided with a plurality of cutting air nozzles (3) connected to the internal air passage; the cutting air nozzles (3) are arranged at an annular position of the closed end and are distributed at intervals along the annular direction; A gas supply assembly is connected to the connection port of the gas delivery pipe (2) to provide high-pressure compressed gas.

2. A pre-punching air knife device according to claim 1, characterized in that: The gas delivery pipe (2) is made of a seamless steel pipe and is welded to the outer surface of the mounting base material (1); the cutting air nozzle (3) is made of tungsten steel.

3. A pre-punching air knife device according to claim 1, characterized in that: The air supply assembly comprises an air compressor unit and a high-pressure anti-expansion connecting hose (5), and the high-pressure anti-expansion connecting hose (5) is connected to the connecting port of the air delivery pipe (2) via a connecting joint.

4. A pre-punching air knife device according to claim 3, characterized in that: The outer surface of the installation base material (1) is connected to an anti-knot ring (4); the high-pressure anti-expansion connecting hose (5) is passed through the anti-knot ring (4) and connected to the gas transmission pipe (2).

5. The pre-punching air knife device according to claim 2, characterized in that: The surface of the gas delivery pipe (2) on one side in contact with the installation substrate (1) is welded to the installation substrate (1) along the trajectory direction of the gas delivery pipe (2); and / or, The gas delivery pipe (2) is provided with a plurality of fixed welding plates (6), both ends of the fixed welding plates (6) are welded to the mounting base material (1), and a compression space for compressing the gas delivery pipe (2) is formed in the middle.

6. The pre-punching air knife device according to claim 1, characterized in that: The installation base material (1) further comprises a plurality of thickened sheets (7), the plurality of thickened sheets (7) being distributed circumferentially on the outside of the top of the steel pipe pile and being fitted and connected to the outer surface of the steel pipe pile.

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