Excavation disturbance deviation prevention device and method for deep silt soil prefabricated pipe pile

Abstract

The invention discloses an excavation disturbance deviation prevention device and method for a deep silt soil prefabricated pipe pile. The device comprises a clamping mechanism, an adjusting mechanism and a connecting mechanism. The clamping mechanism comprises a sleeve, a clamping plate and a clamping wheel, wherein the prefabricated pipe pile is sleeved with the sleeve, the clamping plate is arranged in the sleeve, the clamping wheel is arranged on the sleeve, and the clamping wheel is driven by a driving motor so that the clamping plate can clamp the prefabricated pipe pile. The adjusting mechanism comprises an adjusting plate rotationally connected to the top of the sleeve and a telescopic rod arranged at the front end of the adjusting plate. The connecting mechanism comprises connectors arranged at the output ends of the telescopic rods, connecting rods arranged between the connectors on the two adjacent prefabricated pipe piles and fixing sleeves arranged at the two ends of the connecting rods and used for fixing the connectors. The top of each prefabricated pipe pile is sleeved with one clamping mechanism, the clamping mechanisms are clamped and fixed to the prefabricated pipe piles, and the multiple clamping mechanisms are connected into a whole through the adjusting mechanisms and the connecting mechanisms, so that the multiple prefabricated pipe piles are combined to form the overall rigidity.

Description

Technical Field

[0001] The present invention belongs to the technical field of pipe pile construction, and more specifically, relates to a device and method for preventing deviation of prefabricated pipe piles in thick silt soil during excavation disturbance. Background Art

[0002] Prefabricated pipe piles are industrially produced, with high pile strength, reliable quality, strong single pile bearing capacity, high degree of mechanization and fast construction speed. They are widely used in industrial and civil construction engineering foundations and have broad development prospects. However, due to the soil squeezing effect during the sinking of prefabricated pipe piles, it is easy to cause the soil around the piles to bulge and displace, endangering the safety of adjacent piles and adjacent underground buildings, structures, deep foundations, surrounding municipal roads and pipelines. In addition, when excavating pile groups in deep silt areas, the plasticity of silt soil, the height difference of foundation pits and mechanical vibrations can easily cause large displacement or bending damage of the pipe piles. The effect is particularly obvious in coastal mudflats and deep silt soil.

[0003] The Chinese patent with the publication number CN118422729A discloses an anti-deflection device and a method for using a prefabricated pipe pile in a soft soil area, which includes a steel sleeve, a steel section and a bolt assembly. The steel sleeve is sleeved on the concrete pipe pile, and a bolt A is pre-welded on the upper part of the steel sleeve. A perforated steel gasket is sleeved on the bolt A, and a steel pressing sheet is pressed on the perforated steel gasket. The perforated steel gasket and the steel pressing sheet are used to connect and fix the steel sleeve and the steel section. When in use, the steel sleeves of the two piles are first rotated to a certain angle according to the positional relationship of the adjacent piles, the top steel section is fixed, and then the steel sleeves of the two piles are respectively fixed to the pile body with pre-buried bolts. It can effectively prevent the pile body from being deformed and damaged due to uneven soil pressure, which affects the safety and progress of the project. In addition, the steel section of the present invention is not welded, and the steel section can be removed by removing the bolts. The subsequent removal is convenient and quick. The perforated steel gasket, the steel pressing sheet and the bolt assembly can be reused to reduce costs.

[0004] However, the Chinese patent with publication number CN118422729A requires a large number of manual operations during construction, resulting in slow construction speed and waste of manpower and material resources. Therefore, a device and method for preventing displacement of prefabricated pipe piles in deep silt soil during excavation is needed to automatically control the large displacement or bending damage of the pipe pile body during pile excavation in deep silt areas. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a device and method for preventing the displacement of prefabricated pipe piles in deep silt soil during excavation disturbance. By connecting multiple prefabricated pipe piles into a whole to form an overall rigidity, the prefabricated pipe piles are prevented from generating abnormal conditions including displacement, tilt and broken piles, thereby saving the time wasted by deliberately slowing down the construction speed to avoid abnormal conditions during operation, thereby speeding up the construction speed and improving the operation efficiency. The frequency of monitoring abnormal conditions during operation is reduced, the construction steps are simplified, and the safety hazard of falling and injuring people at the core hole of the pipe pile is solved.

[0006] To achieve the above objectives, according to a first aspect of an embodiment of the present invention, there is provided an excavation disturbance anti-deflection device for prefabricated pipe piles in thick silt soil, comprising: a clamping mechanism, an adjusting mechanism and a connecting mechanism;

[0007] The clamping mechanism comprises a sleeve sleeved on the prefabricated pipe pile, a clamping plate arranged in the sleeve, and a clamping wheel arranged on the sleeve, wherein the clamping wheel is driven by a driving motor so that the clamping plate clamps the prefabricated pipe pile;

[0008] The adjustment mechanism includes an adjustment plate rotatably connected to the top of the sleeve and a telescopic rod arranged at the front end of the adjustment plate;

[0009] The connecting mechanism includes a connecting head provided at the output end of the telescopic rod, a connecting rod provided between the connecting heads on two adjacent prefabricated pipe piles, and a fixing sleeve provided at both ends of the connecting rod for fixing the connecting head and the connecting head;

[0010] The clamping mechanism is sleeved on the top of each prefabricated pipe pile and is clamped and fixed on the prefabricated pipe pile. The multiple clamping mechanisms are connected together through the adjustment mechanism and the connection mechanism to combine the multiple prefabricated pipe piles.

[0011] Furthermore, the sleeve is a cylindrical structure with an opening at the bottom, and an end cap is provided at the top, and the end cap contacts the top of the prefabricated pipe pile so that the sleeve is hung on the prefabricated pipe pile;

[0012] The inner diameter of the sleeve is larger than the diameter of the prefabricated pipe pile, that is, a cavity is left between the inner wall of the sleeve and the pipe wall of the prefabricated pipe pile, and the clamping plate is arranged in the cavity;

[0013] The clamping plates are a plurality of arc-shaped plates, which are equidistantly and concentrically arranged along the inner wall of the sleeve.

[0014] Furthermore, the sleeve wall is provided with clamping holes of the same number as the arc-shaped plates at equal intervals, the clamping holes penetrate the inside and outside of the sleeve, and the clamping wheel is arranged in the clamping holes;

[0015] The front end of the clamping wheel is a gear, and the rear end is fixed with a rotating rod, the rotating rod is connected to the clamping hole through a bearing, and the rear end of the rotating rod extends inwardly to be provided with a threaded hole, and a screw is provided in the threaded hole, and the rear end of the screw is fixedly connected to the clamping plate.

[0016] Furthermore, guide holes are provided on both sides of the clamping hole on the sleeve, and guide pins sliding therein are provided in the guide holes, and the rear ends of the guide pins are fixed on the arc plate.

[0017] Furthermore, a transmission gear is provided on the outer cylindrical surface of the sleeve;

[0018] The transmission gear is a ring gear, which is rotatably connected to the sleeve and meshes with the gear at the front end of each clamping wheel;

[0019] A motor frame is also provided on the outer cylindrical surface of the sleeve, a driving motor is fixed on the motor frame, a driving gear is provided at the output end of the driving motor, and the driving gear is meshed with the transmission gear.

[0020] Furthermore, by rotating the driving gear, the transmission gear transmits power to the clamping wheel, driving the clamping wheel to rotate, so that the screw in the clamping wheel rotates to push the clamping plate, so that it clamps the prefabricated pipe pile, thereby achieving fixation between the clamping mechanism and the prefabricated pipe pile.

[0021] Furthermore, a circular protrusion is provided at the top of the sleeve as a mounting platform;

[0022] The rear end of the adjustment plate is a circular ring structure, which is sleeved on the mounting platform and rotates with the mounting platform as an axis, and a square rod extends from the front end;

[0023] The rear end of the telescopic rod is fixed on the square rod of the adjusting plate.

[0024] Furthermore, the rear end of the connector is fixed to the output end of the telescopic rod, and two connecting seats are provided on both sides of the front end thereof, and the head of the connecting seat is arc-shaped and has a connecting hole;

[0025] The connecting rod is arranged between the connecting heads on two adjacent prefabricated pipe piles, and the two ends of the connecting rod are rotatably connected to the connecting seat by connecting pins respectively.

[0026] Furthermore, threads are provided at both ends of the connecting rod, and a fixing sleeve is sleeved on the threads. The fixing sleeve is rotated to be pressed against the connecting head to achieve fixation between the connecting rod and the connecting head.

[0027] According to a second aspect of an embodiment of the present invention, a method for preventing displacement of prefabricated pipe piles in thick silt soil during excavation disturbance is provided, which specifically includes the following steps:

[0028] S100, by driving the motor to rotate, the transmission gear and the clamping wheel cooperate to push the clamping plate to move toward the prefabricated pipe pile, thereby achieving joint fixation of multiple prefabricated pipe piles;

[0029] S200, using the connection mechanism to adjust the relative positions of the prefabricated pipe piles and then locking them through the fixing sleeve to ensure the stability of the connection between the prefabricated pipe piles;

[0030] S300, a stress meter is installed on the telescopic rod to monitor the stress changes caused by soil disturbance between the prefabricated pipe piles in real time, and the displacement or damage of the pipe piles caused by excessive stress can be discovered and prevented in time through the monitoring data;

[0031] S400. According to the monitoring data fed back by the stress meter, the connection status between the prefabricated pipe piles is adjusted in time to adapt to the soil pressure changes that may occur during the excavation process to ensure construction safety.

[0032] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0033] 1. The excavation disturbance anti-displacement device for prefabricated pipe piles in deep silt soil of the present invention connects multiple prefabricated pipe piles into a whole to form an overall rigidity, thereby preventing the prefabricated pipe from generating abnormal conditions including displacement, tilting and broken piles, saving the time wasted by deliberately slowing down the construction speed to avoid abnormal conditions during operation, thereby speeding up the construction speed, improving the operation efficiency, reducing the frequency of monitoring abnormal conditions during operation, simplifying the construction steps, and solving the potential safety hazard of falling and injuring people at the core hole of the pipe pile.

[0034] 2. The present invention provides an anti-displacement device for excavation disturbance of prefabricated pipe piles in deep silt soil. A stress gauge is provided on the telescopic rod to monitor the stress between two adjacent prefabricated pipe piles to avoid excessive stress caused by displacement of the pipe piles, resulting in overall displacement and pile body damage, so as to ensure the overall rigidity of multiple prefabricated pipe piles. At the same time, the lateral pressure of the prefabricated pipe piles during foundation pit excavation is monitored to prevent accidents.

[0035] 3. The present invention is a device for preventing deviation of prefabricated pipe piles caused by excavation disturbance in thick silt soil. The upper part of the sleeve adopts a rotatable tightening mechanism with adjustable angle, which solves the problem of fixing pipe piles at different angles and distances, and connects multiple adjacent pipe piles as a whole, thereby increasing the rigidity of the pipe piles and greatly reducing the influence of excavation disturbance on the pipe piles in a large area of ​​thick silt soil.

[0036] 4. The excavation disturbance anti-deviation device for prefabricated pipe piles in thick silt soil of the present invention is provided with a driving device to drive the gear bolts to move the steel plate to clamp the pipe piles, which reduces the construction difficulty of the equipment, simplifies the process, and improves the production efficiency.

[0037] 5. The excavation disturbance anti-deviation device for prefabricated pipe piles in deep silt soil of the present invention is provided with connecting parts to connect adjacent pipe piles, and an adjustable tensioning force is applied by a liquid level pull rod, thereby improving the overall rigidity. By using standard connecting parts, the applicability of the equipment is increased, the cost of different construction environments is reduced, and the economic benefits are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the structural connection of a device for preventing the excavation disturbance of a prefabricated pipe pile in thick silt soil according to an embodiment of the present invention;

[0039] Figure 2 This is a schematic diagram of the structure of a clamping mechanism of an excavation disturbance anti-deviation device for prefabricated pipe piles in thick silt soil according to an embodiment of the present invention;

[0040] Figure 3 It is an exploded schematic diagram of the clamping mechanism structure of an excavation disturbance anti-deviation device for prefabricated pipe piles in thick silt soil according to an embodiment of the present invention;

[0041] Figure 4 A bottom view of the clamping mechanism structure of an excavation disturbance anti-deviation device for prefabricated pipe piles in thick silt soil according to an embodiment of the present invention;

[0042] Figure 5 It is a schematic diagram of the structure of an adjustment mechanism of an excavation disturbance anti-deviation device for prefabricated pipe piles in thick silt soil according to an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the structure of a connection mechanism of an excavation disturbance anti-deviation device for prefabricated pipe piles in thick silt soil according to an embodiment of the present invention;

[0044] Figure 7 The present invention is a flowchart of a method for preventing displacement of prefabricated pipe piles in thick silt soil during excavation disturbance according to an embodiment of the present invention.

[0045] In all the drawings, the same figure marks represent the same technical features, specifically: 1-clamping mechanism, 11-sleeve, 12-clamping plate, 13-guide pin, 14-clamping wheel, 15-drive motor, 16-drive gear, 17-transmission gear, 2-adjusting mechanism, 21-adjusting plate, 22-telescopic rod, 3-connecting mechanism, 31-connecting head, 32-connecting rod, 33-fixing sleeve. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] Example 1

[0048] like Figure 1 As shown, an embodiment of the present invention provides an anti-deflection device for excavation disturbance of prefabricated pipe piles in deep silt soil, comprising a clamping mechanism 1 arranged at the top of the prefabricated pipe pile, an adjusting mechanism 2 arranged at the top of the clamping mechanism 1, and a connecting mechanism 3 arranged between adjacent adjusting mechanisms 2. The clamping mechanism 1 is sleeved on the top of each prefabricated pipe pile, clamped and fixed on the prefabricated pipe pile, and multiple clamping mechanisms 1 are connected together through the adjusting mechanism 2 and the connecting mechanism 3, so that multiple prefabricated pipe piles are combined, and the overall rigidity is formed by connecting multiple prefabricated pipe piles into a whole, so as to prevent the prefabricated pipe pile from generating abnormal conditions including deviation, tilt and broken piles, saving the time wasted by deliberately slowing down the construction speed to avoid abnormal conditions during operation, thereby speeding up the construction speed, improving the operation efficiency, reducing the monitoring frequency of abnormal conditions during operation, simplifying the construction steps, and solving the safety hazard of falling and injuring people at the core hole of the pipe pile.

[0049] like Figure 2-4 As shown, the clamping mechanism 1 includes a sleeve 11, a clamping plate 12, a guide pin 13, a clamping wheel 14, a driving motor 15, a driving gear 16 and a transmission gear 17. The sleeve 11 is a cylindrical structure with an opening at the bottom end and an end cover at the top end. The end cover contacts the top of the prefabricated pipe pile so that the sleeve 11 is hung on the prefabricated pipe pile. The inner diameter of the sleeve 11 is larger than the diameter of the prefabricated pipe pile, that is, a cavity is left between the inner wall of the sleeve 11 and the pipe wall of the prefabricated pipe pile, and a clamping plate 12 is provided in the cavity. The clamping plate 12 is a plurality of arc-shaped plates, which are equidistantly and concentrically arranged along the inner wall of the sleeve 11. The sleeve 11 has the same number of clamping holes as the arc-shaped plates, which run through the inside and outside of the sleeve 11. A clamping wheel 14 is provided in the clamping hole of the sleeve 11. The front end of the clamping wheel 14 is a gear, and a rotating rod is fixed to the rear end. The rotating rod is connected to the clamping hole through a bearing, and a threaded hole is extended inward from the rear end of the rotating rod. A screw is provided in the threaded hole, and the rear end of the screw is fixedly connected to the clamping plate 12. Guide holes are also provided on both sides of the clamping hole of the sleeve 11. A guide pin 13 is provided in the guide hole to slide therein, and the rear end of the guide pin 13 is fixed to the arc plate.

[0050] A transmission gear 17 is provided on the outer cylindrical surface of the sleeve 11. The transmission gear 17 is a ring gear, which is rotatably connected to the sleeve 11 and meshes with the gear at the front end of each clamping wheel 14. A motor frame is also provided on the outer cylindrical surface of the sleeve 11. A driving motor 15 is fixed on the motor frame. A driving gear 16 is provided at the output end of the driving motor 15. The driving gear 16 meshes with the transmission gear 17. The driving gear 16 rotates, so that the transmission gear 17 transmits power to the clamping wheel 14, driving the clamping wheel 14 to rotate, so that the screw in the clamping wheel 14 rotates to push the clamping plate 12, so that it holds the prefabricated pipe pile tightly, so as to achieve the fixation between the clamping mechanism 1 and the prefabricated pipe pile.

[0051] Preferably, when the driving motor 15 drives the driving gear 16 to rotate, all the clamping wheels 14 are driven to rotate through the transmission gear 17. Under the guidance of the guide pin 13, the clamping plate 12 is pushed to move toward the prefabricated pipe pile until it clamps the prefabricated pipe pile.

[0052] like Figure 5 As shown, the top of the sleeve 11 is also provided with a circular protrusion as a mounting platform, and the adjustment mechanism 2 is arranged on the mounting platform, including an adjustment plate 21 and a telescopic rod 22. The rear end of the adjustment plate 21 is a circular ring structure, which is sleeved on the mounting platform and rotates with the mounting platform as an axis. A square rod extends from the front end of the adjustment plate 21, and the rear end of the telescopic rod 22 is fixed on the square rod of the adjustment plate 21.

[0053] like Figure 6 As shown, the connection mechanism 3 includes a connector 31, a connecting rod 32 and a fixing sleeve 33. The rear end of the connector 31 is fixed to the output end of the telescopic rod 22, and two connecting seats are provided on both sides of the front end. The head of the connecting seat is arc-shaped and has a connecting hole. The connecting rod 32 is provided between the connectors 31 on two adjacent prefabricated pipe piles, and the two ends of the connecting rod 32 are respectively rotatably connected to the connecting seats by connecting pins. The two ends of the connecting rod 32 are also provided with threads, and a fixing sleeve 33 is sleeved on the threads. By rotating the fixing sleeve 33, it is pressed against the connector 31 to achieve fixation between the connecting rod 32 and the connector 31, so that the prefabricated pipe piles connected together are firmly connected and do not rotate.

[0054] Preferably, the adjusting plate 21 is rotated so that the connecting mechanism 3 on the adjacent prefabricated pipe piles has a rough connection angle, the distance between the connecting heads 31 is adjusted by the telescopic rod 22 according to the distance between the adjacent prefabricated pipe piles, and then the connecting rod 32 is rotated on the connecting head 31 to fine-tune its connection angle, and finally the fixing sleeve 33 is rotated to fix it between two adjacent prefabricated pipe piles, so that multiple prefabricated pipe piles are connected and fixed together.

[0055] The telescopic rod 22 is provided with a stress gauge for monitoring the stress between two adjacent prefabricated pipe piles to avoid excessive stress caused by displacement of the pipe piles, resulting in overall displacement and pile body damage, so as to ensure the overall rigidity of the multiple prefabricated pipe piles and monitor the lateral pressure of the prefabricated pipe piles during foundation pit excavation to prevent accidents.

[0056] Example 2

[0057] like Figure 7 As shown, an embodiment of the present invention provides a method for preventing displacement of prefabricated pipe piles in thick silt soil during excavation disturbance, which specifically includes the following steps:

[0058] S100, by driving the motor 15 to rotate, the transmission gear 17 and the clamping wheel 14 cooperate to push the clamping plate 12 to move toward the prefabricated pipe pile, thereby achieving joint fixation of multiple prefabricated pipe piles;

[0059] S200, using the connection mechanism 3 to adjust the relative position between the prefabricated pipe piles and then locking them through the fixing sleeve 33 to ensure the stability of the connection between the prefabricated pipe piles;

[0060] S300, a stress meter is arranged on the telescopic rod 22 to monitor in real time the stress change between the prefabricated pipe piles caused by soil disturbance, and the displacement or damage of the pipe piles caused by excessive stress is timely discovered and prevented through the monitoring data;

[0061] S400. According to the monitoring data fed back by the stress meter, the connection status between the prefabricated pipe piles is adjusted in time to adapt to the soil pressure changes that may occur during the excavation process to ensure construction safety.

[0062] In step S100, the clamping force of the clamping mechanism 1 needs to be controlled, and the clamping force is:

[0063] F c =∫ A μ i (P s , ρ i )·dA·R i (A);

[0064] Among them, F c is the clamping force applied by the clamping mechanism to the precast pipe pile.

[0065] μ i is the friction coefficient,

[0066] P s is the soil pressure,

[0067] ρ i is the soil density,

[0068] A is the contact area,

[0069] R i (A) is the roughness function.

[0070] The roughness function R i (A) Specifically:

[0071] R i (A)=R 0i +R 1i sin(ω i x i +φ i );

[0072] Among them, R 0i is the average roughness of the prefabricated pipe pile surface, indicating the basic roughness of the prefabricated pipe pile surface.

[0073] R 1i is the fluctuation amplitude of the surface roughness of the prefabricated pipe pile, indicating the fluctuation size of the roughness.

[0074] ω i is the wave number of the surface roughness fluctuation of the prefabricated pipe pile, which indicates the number of periodic changes of the surface roughness of the prefabricated pipe pile within a unit length.

[0075] φ i is the phase angle of the fluctuation of the surface roughness of the prefabricated pipe pile, indicating the starting position of the periodicity of the surface roughness of the prefabricated pipe pile within a unit length.

[0076] x i is the coordinate position along the surface of the precast pipe pile.

[0077] In step S200, it is also necessary to measure the tension T on the connecting rod 32 in the connecting mechanism 3. i , specifically:

[0078]

[0079] Among them, K i (T i ) is the temperature-dependent elastic modulus of the connecting rod,

[0080] ΔL i is the length change of the connecting rod,

[0081] T 0i is the initial temperature,

[0082] g i (T i ) is the effect of temperature on the tension of the connecting rod.

[0083] The temperature-dependent elastic modulus K of the connecting rod i (T i )for:

[0084] K i (T i )=K 0i +K 1i ·(T i -T 0i );

[0085] Among them, K 0i is the elastic modulus at the reference temperature,

[0086] K 1i is the temperature coefficient,

[0087] T i is the current temperature,

[0088] T 0i is the reference temperature.

[0089] In step S200, the overall stiffness of the prefabricated pipe piles after connection is completed needs to be measured, specifically:

[0090] k t =∫ V (k pi +k ci )ρ i (v)dv;

[0091] Among them, k t The overall stiffness of the prefabricated pile after the connection is completed.

[0092] k pi is the stiffness of a single prefabricated pipe pile,

[0093] k ci is the additional stiffness of the connecting rod,

[0094] ρ i (v) is the density function of precast piles,

[0095] V is the volume of prefabricated pipe piles,

[0096] dv is the volume element of the precast pipe pile.

[0097] The effect of temperature on the tension of the connecting rod g i (T i )for:

[0098] In step S300, the data detected by real-time monitoring of stress changes between prefabricated pipe piles due to soil disturbance is expressed using a partial differential equation, specifically:

[0099]

[0100] in, is the Laplace operator,

[0101] σ i is the stress field, expressed in (x i ,y i , z i ) position,

[0102] x i ,y i , z i is the three-dimensional coordinate of the prefabricated pipe pile,

[0103] f i (σ i , x i ,y i , z i ) is a nonlinear term used to describe the relationship between stress and position.

[0104] The nonlinear term f i (σ i , x i ,y i , z i ) Specifically,

[0105]

[0106] Among them, f0 is a constant term, which represents the background value when there is no stress, that is, a fixed stress field value.

[0107] a i is the linear coefficient, and its value is related to the stress field σ i Proportional,

[0108] b i is the nonlinear coefficient, and its value is related to the stress field σ i Inversely proportional,

[0109] c i For x i The pressure gradient coefficient in the direction is related to the stress field σ i In x i The direction is proportional to the square of the rate of change,

[0110] d i for y i The pressure gradient coefficient in the direction is related to the stress field σ i In y i The direction is proportional to the square of the rate of change,

[0111] e i For z i The pressure gradient coefficient in the direction is related to the stress field σ i In z iThe direction is proportional to the square of the rate of change,

[0112] σ i is the stress field, expressed in (x i ,y i , z i ) is the stress value at the position.

[0113] Among them, a i σ i Describes the linear relationship between stress and position; Describes the nonlinear relationship between stress and position; Describes the stress in x The square of the gradient in the i, yi, and zi directions reflects the influence of the rate of change of the stress field in different directions on the total stress.

[0114] In step S400, according to the monitoring data fed back by the stress gauge, if it is determined that the stress on one of the prefabricated pipe piles exceeds its bearing capacity, it is necessary to redistribute the stress by adjusting the connection state between the prefabricated pipe piles to ensure the stability of the prefabricated pipe piles. The objective function of stress redistribution is:

[0115]

[0116] in, is the minimum objective function,

[0117] ∈ i (u i )dv is the energy functional,

[0118] σ i (u i ) is the stress tensor,

[0119] ∈ i (u i ) is the strain tensor,

[0120] st is the constraint condition,

[0121] u i =0 means the displacement on the boundary is 0,

[0122] represents a boundary with zero boundary conditions,

[0123] Indicates at the border Upward displacement u i is 0.

[0124] Stress redistribution ensures that when prefabricated pipe piles are subjected to external disturbances, they can disperse stress by adjusting the connection state between the prefabricated pipe piles to prevent the prefabricated pipe piles from being damaged due to excessive local stress. Through numerical simulation or finite element analysis, the displacement field that minimizes stress energy can be found, thereby achieving a reasonable distribution of stress between prefabricated pipe piles and improving the structural stability after the prefabricated pipe piles are connected into a whole.

[0125] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil, characterized in that: include: A clamping mechanism (1), an adjusting mechanism (2) and a connecting mechanism (3); The clamping mechanism (1) comprises a sleeve (11) sleeved on the prefabricated pipe pile, a clamping plate (12) arranged in the sleeve (11), and a clamping wheel (14) arranged on the sleeve (11); the clamping wheel (14) is driven by a driving motor (15) so that the clamping plate (12) clamps the prefabricated pipe pile; The adjusting mechanism (2) comprises an adjusting plate (21) rotatably connected to the top of the sleeve (11) and a telescopic rod (22) arranged at the front end of the adjusting plate (21); The connecting mechanism (3) comprises a connecting head (31) provided at the output end of the telescopic rod (22), a connecting rod (32) provided between the connecting heads (31) on two adjacent prefabricated pipe piles, and a fixing sleeve (33) provided at both ends of the connecting rod (32) for fixing the connecting head (31) and the connecting head (31); The clamping mechanism (1) is sleeved on the top of each prefabricated pipe pile and is clamped and fixed on the prefabricated pipe pile. A plurality of clamping mechanisms (1) are connected together through an adjustment mechanism (2) and a connection mechanism (3) to combine the plurality of prefabricated pipe piles.

2. The device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to claim 1 is characterized in that: The sleeve (11) is a cylindrical structure with an open bottom end and an end cover at the top end, and the end cover contacts the top of the prefabricated pipe pile so that the sleeve (11) is hung on the prefabricated pipe pile; The inner diameter of the sleeve (11) is greater than the diameter of the prefabricated pipe pile, that is, a cavity is left between the inner wall of the sleeve (11) and the pipe wall of the prefabricated pipe pile, and the clamping plate (12) is arranged in the cavity; The clamping plates (12) are a plurality of arc-shaped plates, which are arranged equidistantly and concentrically along the inner wall of the sleeve (11).

3. The device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to claim 2 is characterized in that: The sleeve (11) has a wall with equidistant clamping holes, the number of which is the same as that of the arc-shaped plates. The clamping holes penetrate the inside and outside of the sleeve (11), and the clamping wheel (14) is arranged in the clamping holes. The front end of the clamping wheel (14) is a gear, and the rear end is fixed with a rotating rod, the rotating rod is connected to the clamping hole via a bearing, and the rear end of the rotating rod extends inwardly to be provided with a threaded hole, in which a screw is provided, and the rear end of the screw is fixedly connected to the clamping plate (12).

4. The device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to claim 3 is characterized in that: Guide holes are also provided on both sides of the clamping hole on the sleeve (11), and guide pins (13) are provided in the guide holes for sliding therein, and the rear end of the guide pins (13) is fixed to the arc plate.

5. The device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to claim 4 is characterized in that: A transmission gear (17) is provided on the outer cylindrical surface of the sleeve (11); The transmission gear (17) is a ring gear, which is rotatably connected to the sleeve (11) and meshes with the gear at the front end of each clamping wheel (14); A motor frame is also provided on the outer cylindrical surface of the sleeve (11), a driving motor (15) is fixed on the motor frame, a driving gear (16) is provided at the output end of the driving motor (15), and the driving gear (16) is meshed with a transmission gear (17).

6. The device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to claim 5 is characterized in that: The driving gear (16) rotates, causing the transmission gear (17) to transmit power to the clamping wheel (14), driving the clamping wheel (14) to rotate, thereby causing the screw in the clamping wheel (14) to rotate and push the clamping plate (12), causing it to clamp the prefabricated pipe pile, thereby achieving fixation between the clamping mechanism (1) and the prefabricated pipe pile.

7. A device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to any one of claims 1 to 6, characterized in that: The top end of the sleeve (11) is also provided with a circular protrusion as a mounting platform; The rear end of the adjustment plate (21) is a circular ring structure, which is sleeved on the mounting platform and rotates with the mounting platform as an axis, and a square rod extends from the front end; The rear end of the telescopic rod (22) is fixed on the square rod of the adjustment plate (21).

8. A device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to any one of claims 1 to 6, characterized in that: The rear end of the connector (31) is fixed to the output end of the telescopic rod (22), and two connector seats are provided on both sides of the front end. The head of the connector seat is arc-shaped and has a connecting hole. The connecting rod (32) is arranged between the connecting heads (31) on two adjacent prefabricated pipe piles, and both ends of the connecting rod (32) are rotatably connected to the connecting seat by connecting pins.

9. The device for preventing displacement caused by excavation disturbance of prefabricated pipe piles in thick silt soil according to claim 8, characterized in that: Both ends of the connecting rod (32) are also provided with threads, and a fixing sleeve (33) is sleeved on the threads. The fixing sleeve (33) is rotated to press the fixing sleeve against the connecting head (31) so as to achieve fixation between the connecting rod (32) and the connecting head (31).

10. A method for preventing the displacement of prefabricated pipe piles in thick silt soil during excavation disturbance, which is implemented by using a device for preventing the displacement of prefabricated pipe piles in thick silt soil during excavation disturbance as claimed in any one of claims 1 to 9, characterized in that: The specific steps include: S100, by driving the motor (15) to rotate, the transmission gear (17) and the clamping wheel (14) are used to push the clamping plate (12) toward the prefabricated pipe pile, thereby achieving joint fixation of a plurality of prefabricated pipe piles; S200, using the connection mechanism (3) to adjust the relative positions between the prefabricated pipe piles and then locking them with the fixing sleeve (33) to ensure the stability of the connection between the prefabricated pipe piles; S300, a stress meter is arranged on the telescopic rod (22) to monitor in real time the stress change between the prefabricated pipe piles caused by soil disturbance, and the displacement or damage of the pipe piles caused by excessive stress is timely discovered and prevented through the monitoring data; S400. According to the monitoring data fed back by the stress meter, the connection status between the prefabricated pipe piles is adjusted in time to adapt to the soil pressure changes that may occur during the excavation process to ensure construction safety.

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