Support head assembly, support axis force servo system and driving method thereof

Abstract

The present invention relates to a support head assembly, comprising a main frame, an oil tank arranged in the main frame, a controller, a pump station, a hydraulic motor, a threaded rod, a through-hole jack and a supporting device; the through-hole jack comprises a cylinder body and a piston, the center of the cylinder body is through-shaped and a through-hole is formed therein; the supporting device comprises a supporting member, a ball head support clamped at the end of the supporting member and a pressure plate connected to the supporting member through the ball head support; the hydraulic motor and the threaded rod are arranged at the rear end of the through-hole of the through-hole of the through-hole jack, the supporting device is arranged at the front end of the through-hole of the through-hole jack, the front end of the piston is abutted against the supporting member, the controller is used to control the pump station to load or unload the through-hole jack to drive the supporting device to move forward and backward, and the controller is also used to control the hydraulic motor to drive the threaded rod to move forward and backward to lock or unlock the supporting device.

Description

Technical Field

[0001] The invention relates to the field of deformation control of foundation pit retaining structures in foundation pit engineering, and in particular to a support head assembly, a support shaft force servo system and a driving method thereof for performing displacement control on the foundation pit retaining structure. Background Art

[0002] The foundation pit is a temporary structure, an underground pit that provides construction space for the foundation of a building or an underground structure. The side walls of the foundation pit need to be supported during excavation to prevent deformation of the foundation pit and damage to the underground components of the adjacent buildings. Concrete supports have been gradually replaced by steel supports due to the long construction period, difficulty in removal after the support work is completed, and waste of materials. At present, most projects only use concrete supports in the first support of the foundation pit, and steel supports are used for the rest. Generally, when using rigid supports, prestress is applied according to design requirements. However, during construction, as time goes by, the prestress applied to the steel support will decrease, sometimes a lot, even by more than 50%, and it is difficult to apply the support axial force at this time, so it causes the displacement of the foundation pit retaining structure. When the displacement is too large, it will directly affect the safety of buildings, roads, subways, etc. next to the foundation pit.

[0003] Therefore, how to design a set of foundation pit construction steel support axial force servo equipment that can effectively control the deformation of the foundation pit retaining structure and ensure the safety of the surrounding environment has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] The present invention provides a through-hole jack, a support head assembly for adjusting the supporting shaft force by using a piston and a supporting member arranged in the through-hole jack, a supporting shaft force servo system and a driving method thereof.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a support head assembly, which includes a main frame, an oil tank arranged in the main frame, a controller, a pump station, a hydraulic motor, a threaded rod, a through-hole jack and a supporting device; the through-hole jack includes a cylinder body and a piston, the center of the cylinder body is through-shaped and a through-hole is formed therein; the supporting device includes a supporting member, a ball head support clamped at the end of the supporting member and a pressure plate connected to the supporting member through the ball head support; the hydraulic motor and the threaded rod are arranged at the rear end of the through-hole of the through-hole of the through-hole jack, the supporting device is arranged at the front end of the through-hole of the through-hole jack, the front end of the piston is abutted against the supporting member, the controller is used to control the pump station to load or unload the through-hole jack to drive the supporting device to move forward and backward, and the controller is also used to control the hydraulic motor to drive the threaded rod to move forward and backward to lock or unlock the supporting device.

[0006] Optionally, an internally hollow stiffening plate is integrally provided in the main frame, and the support head assembly further includes a rotating shaft and a nut. The nut is spirally arranged on the outside of the threaded rod and clamped between the wall surface of the stiffening plate and the wall surface of the through-hole jack to fix the positions of the stiffening plate, the nut and the through-hole jack. The threaded rod is hollow inside and passes through the stiffening plate and the nut in the horizontal direction. The rotating shaft is clamped in the inner hollow area of ​​the threaded rod and is driven and connected to the hydraulic motor. The controller controls the rotation of the hydraulic motor to drive the rotating shaft to rotate and drive the threaded rod to rotate and move, and the nut locks the moved threaded rod.

[0007] Optionally, the through-hole jack is provided with a chamber for accommodating a piston, and a rodless chamber located at the rear end of the piston and a rod chamber for accommodating the piston are formed in the chamber, and the rodless chamber and the rod chamber are connected to the oil tank through a hydraulic oil circuit; the pump station includes an oil pump, a hydraulic oil circuit and a control element, and the pump station controls the hydraulic oil in the rodless chamber and the rod chamber through the hydraulic oil circuit to load or unload the through-hole jack, so that the piston in the chamber moves in the front and rear direction, thereby driving the supporting member to move in the front and rear direction.

[0008] Optionally, the support head assembly further includes a displacement sensor, and when the threaded rod locks the supporting device, the displacement sensor is used to monitor that the distance between the threaded rod and the supporting member of the supporting device is maintained between 0.5mm-1mm.

[0009] Optionally, the supporting device further includes a limiting plate, the end of the supporting member is recessed with a ball head accommodating space, the ball head support is accommodated in the ball head accommodating space and extends out of the ball head accommodating space, the limiting plate is fixed to the front wall surface of the supporting member, and the diameter surface of the ball head support in the up and down directions is flush with the vertical plane to which the supporting member and the limiting plate are fixed to limit the ball head support from detaching from the ball head accommodating space of the supporting member.

[0010] The present invention further provides a support axial force servo system, which is used for a foundation pit retaining structure. The support axial force servo system includes a support head assembly, a steel support and a local control center. The support head assembly has the above-mentioned characteristics. The support head assembly is spliced ​​with the steel support and is arranged at a designated position of the foundation pit retaining structure. The local control center is arranged around the foundation pit retaining structure and transmits signals with the support head assembly to adjust the axial force of the steel support.

[0011] Optionally, the main frame of the support head assembly is cylindrical, and the center of the main frame and the center of the steel support are located on the same axis.

[0012] The present invention further provides a driving method using the above-mentioned support axial force servo system. When the foundation pit retaining structure is displaced inside the foundation pit, the following steps are implemented: 1) Loading: applying axial force to the steel support, that is, the local control center at the foundation pit site issues a loading instruction to load the support head assembly. After the controller in the support head assembly receives the loading instruction from the local control center, it controls the operation of the pump station in the support head assembly. The pump station adjusts the hydraulic oil in the rodless cavity and the rod cavity to increase the pressure in the rodless cavity and reduce the pressure in the rod cavity, so that the piston moves forward in the cavity and pushes the support member forward. The ball head of the support head assembly is supported on the support member. The angle of the ball head of the component is automatically adjusted in the accommodating space to adjust the fit between the pressure plate and the foundation pit retaining structure, and the axial force of the steel support is transmitted to the foundation pit retaining structure to resist the displacement of the foundation pit retaining structure toward the inside of the foundation pit; 2) Mechanical positive locking: The local control center at the foundation pit site issues a mechanical positive locking command to lock the supporting component moving forward to prevent it from moving backward. After receiving the mechanical positive locking command from the local control center, the controller in the support head assembly drives the hydraulic motor, and the hydraulic motor drives the rotating shaft to rotate and drive the threaded rod to move forward. Since the nut is mechanically clamped and fixed between the stiffening plate and the through-hole jack, it fully locks the moved threaded rod.

[0013] Optionally, step 2) lags slightly behind step 1), and the support head assembly is provided with a displacement sensor to monitor the distance between the threaded rod and the supporting member in real time to ensure that in the final state, the distance between the threaded rod and the supporting member is maintained between 0.5mm-1mm; when loading is completed, the pump station stops adjusting the hydraulic oil in the rodless cavity and the rod cavity, and the supporting member is locked once by the hydraulic system and locked twice by the threaded rod; when the hydraulic locking fails, the supporting member can still be locked by the threaded rod.

[0014] Optionally, when the foundation pit retaining structure is displaced outside the foundation pit, the following steps are performed: 3) Mechanical reverse locking: The local control center at the foundation pit site issues a mechanical reverse locking command. After receiving the mechanical reverse locking command from the local control center, the controller in the support head assembly drives the hydraulic motor. The hydraulic motor drives the rotating shaft to rotate and drives the threaded rod to move backward to provide space for the support member to move backward during the subsequent unloading process; 4) Unloading: Reduce the axial force of the steel support, that is, the local control center at the foundation pit site issues an unloading command to unload the support head assembly, and the support head assembly After receiving the unloading instruction from the local control center, the controller controls the operation of the pump station in the support head assembly. The pump station adjusts the hydraulic oil in the rodless chamber and the rod chamber to reduce the pressure in the rodless chamber and increase the pressure in the rod chamber, so that the piston moves backward in the chamber and the supporting member moves backward for precise unloading. The ball head support of the support head assembly automatically adjusts the angle in the ball head accommodating space of the supporting member to adjust the fit between the pressure plate and the foundation pit retaining structure, and transmits the reduced axial force of the steel support to the foundation pit retaining structure to prevent the foundation pit retaining structure from shifting to the outside of the foundation pit.

[0015] Optionally, step 4) lags slightly behind step 3), and the support head assembly is provided with a displacement sensor that monitors the distance between the threaded rod and the supporting member in real time to ensure that in the final state, the distance between the threaded rod and the supporting member is maintained between 0.5mm-1mm; when unloading is completed, the pump station stops adjusting the hydraulic oil in the rodless cavity and the rod cavity, and the supporting member is locked once by the hydraulic system and locked twice by the threaded rod; when the hydraulic locking fails, the supporting member can still be locked by the threaded rod.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1) A supporting member is provided at the front end of the through hole of the through-hole jack in the present application. By loading or unloading the through-hole jack, the piston drives the movement of the supporting member to adjust the axial force of the steel support, and the hydraulic system for loading or unloading can lock the supporting member once.

[0018] 2) The present application has a built-in rotating shaft, a threaded rod and a nut. The hydraulic motor can drive the rotating shaft to rotate after receiving the control command of the controller, and drive the threaded rod to move in the front and rear directions to ensure that after the through-hole jack is loaded or unloaded, the threaded rod is supported at a distance of about 0.5mm-1mm from the tail end of the supporting member to prevent the supporting member from retreating to achieve secondary locking, thereby ensuring that the axial force adjustment of the steel support is effective.

[0019] 3) The double locking effect of the supporting parts in 1) and 2) above can fully ensure the stability of the axial force adjustment of the steel support.

[0020] 4) Even if the primary locking effect of the hydraulic system in 1) fails due to failure of the hydraulic power, the supporting member can be locked for the second time by the threaded rod in 2), thereby fully ensuring the stable effect of adjusting the axial force of the steel support. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the application of the supporting shaft force servo system of the present invention in field work;

[0022] Figure 2 is a three-dimensional diagram of the support head assembly of the present invention;

[0023] Figure 3 is a front view of the support head assembly of the present invention;

[0024] Figure 4 is a three-dimensional exploded view of the support head assembly of the present invention;

[0025] Figure 5 yes Figure 3 Section view from AA direction.

[0026] In the figure: 100, support head assembly; 200, steel support; 300, foundation pit retaining structure; 400, local control center; 1, main frame; 2, oil tank; 3, controller; 4, pump station; 5, hydraulic motor; 6, rotating shaft; 7, threaded rod; 8, nut; 9, through-hole jack; 91, cylinder body; 92, piston; 93, through-hole; 94, chamber; 941, rear oil port; 942, front oil port; 10, supporting member; 11, ball head support; 12, limiting plate; 13, pressure plate; 14, rear cover plate; 15, front cover plate; 101, stiffening plate; A, rodless cavity; B, rod cavity. DETAILED DESCRIPTION

[0027] In order to make the purpose and working principle of the present invention more clearly expressed, the following Figure 1 To Attachment Figure 5 The specific implementation mode of the present invention is described. Figure 5 For example, with the position of the ball head support 11 as the front end and the position of the fuel tank 2 as the rear end, a front-to-back direction and an up-and-down direction perpendicular to the front-to-back direction are formed. This direction setting is only for the convenience of describing the specific implementation method and should not have any impact on the essence of this application.

[0028] Please refer to Figure 1As shown, a support axial force servo system for a foundation pit retaining structure 300 includes a support head assembly 100, a steel support 200, and a local control center 400. The support head assembly 100 is spliced ​​with the steel support 200 and is arranged at a designated position of the foundation pit retaining structure 300. The support head assembly 100 transmits signals to the local control center 400 arranged around the foundation pit retaining structure 300 to adjust the axial force of the steel support 200.

[0029] Please refer to Figure 2 , Figure 4 and Figure 5 As shown, the support head assembly 100 of the present invention includes: a main frame 1, an oil tank 2 arranged in the main frame 1, a controller 3, a pump station 4, a hydraulic motor 5, a rotating shaft 6, a threaded rod 7, a nut 8, a through-core jack 9, a supporting device, and a rear cover plate 14 and a front cover plate 15 arranged on the front and rear sides of the main frame 1. The through-core jack 9 includes a cylinder body 91 and a piston 92, and the supporting device includes a supporting member 10, a ball head support 11, a limiting plate 12 and a pressure plate 13.

[0030] The main frame 1 and the rear cover plate 14 and the front cover plate 15 arranged on the front and rear sides of the main frame 1 together form a closed structure to prevent particles, moisture and corrosive substances from entering the support head assembly 100 and causing operating problems of the support head assembly 100. The main frame 1 is cylindrical, and a hollow stiffening plate 101 is integrally arranged therein. The oil tank 2, the controller 3, the pump station 4 and the hydraulic motor 5 are arranged on the rear side of the stiffening plate 101. The rotating shaft 6, the threaded rod 7, the nut 8, the through-hole jack 9 and the supporting member 10 are accommodated in the hollow area of ​​the stiffening plate 101 in the front and rear directions. The cylindrical main frame 1 can be selected to have the same diameter as the steel support 200, and its diameter is Φ609 or Φ800, so that the center of the main frame 1 and the center of the steel support 200 are located on the same axis.

[0031] The oil tank 2 serves as an oil storage device inside the support head assembly 100 .

[0032] The controller 3 includes a control unit, a power supply component and a data collector.

[0033] The pump station 4 is connected to the controller 3 via a cable. The pump station 4 includes an oil pump, a hydraulic oil circuit and a control element. The pump station 4 is connected to the oil tank 2 and the through-hole jack 9 via a hydraulic oil circuit.

[0034] The hydraulic motor 5 is disposed at the rear end of the stiffening plate 101 and is drivingly connected to the rotating shaft 6 , and is controlled by the controller 3 to drive the rotating shaft 6 to rotate.

[0035] The threaded rod 7 is hollow inside and passes through the hollow area of ​​the stiffening plate 101 and the nut 8 in the horizontal direction, and one end thereof extends into the through hole 93 of the through jack 9. The rotating shaft 6 is clamped in the inner hollow area of ​​the threaded rod 7 and is drivingly connected to the hydraulic motor 5.

[0036] The nut 8 is spirally arranged on the outside of the threaded rod 7 and clamped between the front wall surface of the stiffening plate 101 and the rear wall surface of the through-hole jack 9, so that the threaded rod 7 does not rotate or shift during movement in the front-back direction, that is, the positions of the stiffening plate 101, the nut 8 and the through-hole jack 9 remain fixed. The nut 8 is used to lock the threaded rod 7 after it moves.

[0037] The center of the cylinder body 91 of the through-hole jack 9 is through-shaped, and a through-hole 93 is formed therein, and the through-hole jack 9 is accommodated in the inner hollow area of ​​the stiffening plate 101. The through-hole jack 9 is provided with a chamber 94 for accommodating the piston 92, and a rodless chamber A located at the rear end of the piston 92 and a rod chamber B accommodating the piston 92 are formed in the chamber 94, the rodless chamber A is formed with a rear oil port 941 and the rod chamber B is formed with a front oil port 942, and the rear oil port 941 and the front oil port 942 are connected to the oil tank 2 through a hydraulic oil circuit.

[0038] The support member 10 is arranged at the front end of the through hole 93 of the through jack 9. A ball head accommodating space is recessed at the front end of the support member 10, and the ball head support 11 is clamped in the ball head accommodating space and extends out of the ball head accommodating space, and the pressure plate 13 is connected to the support member 10 through the ball head support 11. The limiting plate 12 is fixed to the front wall surface of the support member 10 by bolt connection, and the diameter surface of the ball head support 11 in the up-down direction is flush with the vertical plane to which the support member 10 and the limiting plate 12 are fixed to limit the ball head support 11 from being separated from the ball head accommodating space of the support member 10.

[0039] The front end of the piston 92 abuts against the front end protruding portion of the supporting member 10 to limit the displacement of the supporting member 10 and lock its position.

[0040] The controller 3 controls the pump station 4 to load or unload the through-hole jack 9 to drive the supporting device to move forward and backward and controls the rotation of the hydraulic motor 5 to drive the threaded rod 7 to move forward and backward to lock or unlock the supporting device. Specifically: the pump station 4 controls the hydraulic oil in the rodless chamber A and the rod chamber B through the hydraulic oil circuit to provide the through-hole jack 9 with the required precise hydraulic power to accurately load or unload the through-hole jack 9, so that the piston 92 in the chamber 94 moves in the front and rear direction, and drives the supporting member 10 supported by the piston 92 to move in the front and rear direction; the hydraulic motor 5 drives the rotating shaft 6 to rotate and drives the threaded rod 7 to rotate and move in the front and rear direction to unlock and make way for the movement of the supporting member 10 and finally lock the supporting member 10.

[0041] The present application sets a displacement sensor on the threaded rod 7 or the supporting member 10 to monitor the distance between the front end of the threaded rod 7 and the rear end of the supporting member 10, so that after the through-hole jack 9 is loaded or unloaded, the distance between the threaded rod 7 and the supporting member 10 is maintained between 0.5mm-1mm to lock the supporting device, so as to prevent structural mutual damage caused by the dimensional change of the threaded rod 7 or the supporting member 10 after thermal expansion and contraction. At the same time, since the threaded rod 7 is still located at the rear end of the supporting member 10, it can be prevented from excessively shifting backwards and causing servo failure. Of course, the displacement sensor in the present application can also be installed at other positions in the support head assembly 100, which can monitor the distance between the threaded rod 7 and the supporting member 10. In addition, the displacement sensor can simultaneously monitor the moving distance of the supporting member 10 in the front and rear directions.

[0042] The driving method of the support shaft force servo system of this embodiment is implemented in sequence according to the following steps:

[0043] 1) Hoisting: The rear side plate of the main frame 1 of the support head assembly 100 and the steel support 200 are connected by flanges and then hoisted to the designated position in the foundation pit and then fixed;

[0044] When the foundation pit retaining structure 300 is displaced inside the foundation pit, the following steps are performed:

[0045] 2) Loading: applying axial force to the steel support 200, that is, the local control center 400 at the foundation pit site issues a loading instruction to load the support head assembly 100. After receiving the loading instruction from the local control center 400, the controller 3 in the support head assembly 100 controls the pump station 4 in the support head assembly 100 to operate. The pump station 4 adjusts the hydraulic oil in the rodless chamber A and the rod chamber B to increase the pressure in the rodless chamber A and reduce the pressure in the rod chamber B, so that the piston 92 moves forward in the chamber 94 and pushes the support member 10 to move forward; the ball head support 11 of the support head assembly 100 automatically adjusts the angle in the ball head accommodating space of the support member 10 to adjust the fit between the pressure plate 13 and the foundation pit retaining structure 300, and transmits the axial force of the steel support 200 to the foundation pit retaining structure 300 to resist the displacement of the foundation pit retaining structure 300 toward the inside of the foundation pit;

[0046] 3) Mechanical positive locking (locking the position of the threaded rod after loading): The local control center 400 at the foundation pit site issues a mechanical positive locking command to lock the supporting member 10 moving forward to prevent it from moving backward. After receiving the mechanical positive locking command from the local control center 400, the controller 3 in the support head assembly 100 drives the hydraulic motor 5, and the hydraulic motor 5 drives the rotating shaft 6 to rotate and drive the threaded rod 7 to move forward. Since the nut 8 is mechanically clamped and fixed between the stiffening plate 101 and the through-hole jack 9, it can fully lock the threaded rod 7 after it moves;

[0047] The above step 3) lags slightly behind step 2), and the displacement sensor monitors the distance between the threaded rod 7 and the supporting member 10 in real time to ensure that the distance between the threaded rod 7 and the supporting member 10 is maintained between 0.5mm and 1mm in the final state. When loading is completed, the pump station 4 stops adjusting the hydraulic oil in the rodless chamber A and the rod chamber B, and the supporting member 10 is locked once by the hydraulic system and locked twice by the threaded rod 7; when the hydraulic locking fails (hydraulic power fails), the supporting member 10 can still be locked by the threaded rod 7.

[0048] When the foundation pit retaining structure 300 is displaced outside the foundation pit, the following steps are performed:

[0049] 4) Mechanical reverse locking (locking the position of the threaded rod during unloading): the local control center 400 at the foundation pit site issues a mechanical reverse locking command. After receiving the mechanical reverse locking command from the local control center 400, the controller 3 in the support head assembly 100 drives the hydraulic motor 5. The hydraulic motor 5 drives the rotating shaft 6 to rotate and drives the threaded rod 7 to move backward to provide clearance for the support member 10 to move backward during the subsequent unloading process.

[0050] 5) Unloading: reduce the axial force of the steel support 200, that is, the local control center 400 at the foundation pit site issues an unloading command to unload the support head assembly 100. After receiving the unloading command from the local control center 400, the controller 3 in the support head assembly 100 controls the pump station 4 in the support head assembly 100 to operate. The pump station 4 adjusts the hydraulic oil in the rodless chamber A and the rod chamber B to reduce the pressure in the rodless chamber A and increase the pressure in the rod chamber B, so that the piston 92 moves backward in the chamber 94 and the support member 10 moves backward for precise unloading. The ball head support 11 of the support head assembly 100 automatically adjusts the angle in the ball head accommodating space of the support member 10 to adjust the fit between the pressure plate 13 and the foundation pit retaining structure 300, and transmits the reduced axial force of the steel support 200 to the foundation pit retaining structure 300 to prevent the foundation pit retaining structure 300 from being displaced to the outside of the foundation pit;

[0051] The above step 5) lags slightly behind step 4), and the displacement sensor monitors the distance between the threaded rod 7 and the supporting member 10 in real time to ensure that the distance between the threaded rod 7 and the supporting member 10 is maintained between 0.5mm and 1mm in the final state. When unloading is completed, the pump station 4 stops adjusting the hydraulic oil in the rodless chamber A and the rod chamber B, and the supporting member 10 is locked once by the hydraulic system and locked twice by the threaded rod 7; when the hydraulic locking fails (hydraulic power fails), the supporting member 10 can still be locked by the follow-up mechanical lock formed by the threaded rod 7.

[0052] The present invention has the following beneficial effects:

[0053] 1) A supporting member 10 is provided at the front end of the through hole 93 of the through hole jack 9 in the present application. By loading or unloading the through hole jack 9, the piston 92 drives the movement of the supporting member 10 to adjust the axial force of the steel support 200, and the hydraulic system for loading or unloading can lock the supporting member 10 once.

[0054] 2) The present application has a built-in rotating shaft 6, a threaded rod 7 and a nut 8. The hydraulic motor 5 can drive the rotating shaft 6 to rotate after receiving the control instruction of the controller 3, and drive the threaded rod 7 to move in the front and rear directions to ensure that after the through-hole jack 9 is loaded or unloaded, the threaded rod 7 is supported at a distance of about 0.5mm-1mm from the rear end of the supporting member 10 to prevent the supporting member 10 from retreating to achieve secondary locking, thereby ensuring that the axial force adjustment of the steel support 200 is effective.

[0055] 3) The double locking effect of the supporting member 10 by the above 1) and 2) can fully ensure the stability of the axial force adjustment of the steel support 200.

[0056] 4) Even if the primary locking effect of the hydraulic system in 1) fails due to the failure of the hydraulic power, the supporting member 10 can be locked for the second time by the threaded rod 7 in 2), thereby fully ensuring the stable effect of the axial force adjustment of the steel support 200.

[0057] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A support head assembly, characterized in that: The support head assembly (100) comprises a main frame (1), an oil tank (2) arranged in the main frame (1), a controller (3), a pump station (4), a hydraulic motor (5), a threaded rod (7), a through-hole jack (9) and a supporting device, wherein a hollow stiffening plate (101) is integrally arranged in the main frame (1), and the support head assembly (100) further comprises a rotating shaft (6) and a nut (8), wherein the nut (8) is spirally arranged on the outer side of the threaded rod (7) and clamped between the wall surface of the stiffening plate (101) and the through-hole jack. (9) so that the positions of the stiffening plate (101), the nut (8) and the through-hole jack (9) are fixed; the threaded rod (7) is hollow inside and passes through the stiffening plate (101) and the nut (8) in the horizontal direction; the rotating shaft (6) is clamped in the inner hollow area of ​​the threaded rod (7) and is drivingly connected to the hydraulic motor (5); the controller (3) controls the hydraulic motor (5) to rotate to drive the rotating shaft (6) to rotate and drive the threaded rod (7) to rotate and move; the nut (8) locks the threaded rod (7) after it moves; The through-hole jack (9) comprises a cylinder (91) and a piston (92); the center of the cylinder (91) is through-hole-shaped and a through-hole (93) is formed therein; The supporting device comprises a supporting member (10), a ball head support (11) clamped at the end of the supporting member (10), and a pressure plate (13) connected to the supporting member (10) through the ball head support (11); The hydraulic motor (5) and the threaded rod (7) are arranged at the rear end of the through hole (93) of the through hole jack (9), the supporting device is arranged at the front end of the through hole (93) of the through hole jack (9), the front end of the piston (92) is abutted against the supporting member (10), the controller (3) is used to control the pump station (4) to load or unload the through hole jack (9) to drive the supporting device to move forward and backward, and the controller (3) is also used to control the hydraulic motor (5) to drive the threaded rod (7) to move forward and backward to lock or unlock the supporting device; Wherein, the support head assembly (100) further comprises a displacement sensor, and when the threaded rod (7) locks the supporting device, the displacement sensor is used to monitor the distance between the threaded rod (7) and the supporting member (10) of the supporting device to be maintained between 0.5 mm and 1 mm.

2. The support head assembly according to claim 1, characterized in that: The through-the-core jack (9) is provided with a chamber (94) for accommodating a piston (92), and a rodless chamber A located at the rear end of the piston (92) and a rod chamber B for accommodating the piston (92) are formed in the chamber (94), and the rodless chamber A and the rod chamber B are connected to the oil tank (2) via a hydraulic oil circuit; the pump station (4) includes an oil pump, a hydraulic oil circuit and a control element, and the pump station (4) controls the hydraulic oil in the rodless chamber A and the rod chamber B via the hydraulic oil circuit to load or unload the through-the-core jack (9), so that the piston (92) in the chamber (94) moves in the front-rear direction, thereby driving the supporting member (10) to move in the front-rear direction.

3. The support head assembly according to claim 1, characterized in that: The supporting device further comprises a limiting plate (12), the end of the supporting member (10) is recessed with a ball head accommodating space, the ball head support (11) is accommodated in the ball head accommodating space and extends out of the ball head accommodating space, the limiting plate (12) is fixed to the front wall surface of the supporting member (10), and the diameter surface of the ball head support (11) in the up and down directions is flush with the vertical plane to which the supporting member (10) and the limiting plate (12) are fixed so as to limit the ball head support (11) from detaching from the ball head accommodating space of the supporting member (10).

4. A support shaft force servo system, characterized in that: The support axial force servo system is used for a foundation pit retaining structure (300), and the support axial force servo system includes a support head assembly (100), a steel support (200) and a local control center (400). The support head assembly (100) is the support head assembly described in any one of claims 1 to 3. The support head assembly (100) is spliced ​​with the steel support (200) and is arranged at a designated position of the foundation pit retaining structure (300). The local control center (400) is arranged around the foundation pit retaining structure (300) and transmits signals with the support head assembly (100) to adjust the axial force of the steel support (200).

5. The support axis force servo system according to claim 4, characterized in that: The main frame (1) of the support head assembly (100) is cylindrical, and the center of the main frame (1) and the center of the steel support (200) are located on the same axis.

6. A driving method using the support shaft force servo system according to claim 4, characterized in that: When the foundation pit retaining structure (300) is displaced inside the foundation pit, the following steps are performed: 1) Loading: Applying axial force to the steel support (200), that is, the local control center (400) at the foundation pit site issues a loading command to load the support head assembly (100) After receiving the loading instruction from the local control center (400), the controller (3) in the support head assembly (100) controls the pump station (4) in the support head assembly (100) to operate, and the pump station (4) adjusts the hydraulic oil in the rodless chamber A and the rod chamber B to increase the pressure in the rodless chamber A and reduce the pressure in the rod chamber B, so that the piston (92) moves forward in the chamber (94) and pushes the support member (10) forward. The ball head support (11) of the support head assembly (100) automatically adjusts the angle in the ball head accommodating space of the support member (10) to adjust the fit between the pressure plate (13) and the foundation pit retaining structure (300), and transmits the axial force of the steel support (200) to the foundation pit retaining structure (300), thereby resisting the displacement of the foundation pit retaining structure (300) toward the inside of the foundation pit; 2) Mechanical positive locking: The local control center (400) at the foundation pit site issues a mechanical positive locking command to lock the supporting member (10) moving forward to prevent it from moving backward. After receiving the mechanical positive locking command from the local control center (400), the controller (3) in the support head assembly (100) drives the hydraulic motor (5). The hydraulic motor (5) drives the rotating shaft (6) to rotate and drives the threaded rod (7) to move forward. Since the nut (8) is mechanically clamped and fixed between the stiffening plate (101) and the through-hole jack (9), it fully locks the threaded rod (7) after it moves.

7. The driving method of the support axis force servo system according to claim 6, characterized in that: The step 2) is slightly delayed compared to the step 1), and the displacement sensor provided in the support head assembly (100) monitors the distance between the threaded rod (7) and the supporting member (10) in real time to ensure that in the final state, the distance between the threaded rod (7) and the supporting member (10) is maintained between 0.5 mm and 1 mm; When loading is completed, the pump station (4) stops adjusting the hydraulic oil in the rodless chamber A and the rod chamber B, and the support member (10) is locked once by the hydraulic system and locked twice by the threaded rod (7); When the hydraulic locking fails, the supporting member (10) can still be locked by the threaded rod (7).

8. The driving method of the support axis force servo system according to claim 6, characterized in that: When the foundation pit retaining structure (300) is displaced outside the foundation pit, the following steps are performed: 3) Mechanical reverse locking: The local control center (400) at the foundation pit site issues a mechanical reverse locking command. After receiving the mechanical reverse locking command from the local control center (400), the controller (3) in the support head assembly (100) drives the hydraulic motor (5). The hydraulic motor (5) drives the rotating shaft (6) to rotate and drives the threaded rod (7) to move backward to provide clearance for the supporting member (10) to move backward during the subsequent unloading process. 4) Unloading: reducing the axial force of the steel support (200), that is, the local control center (400) at the foundation pit site issues an unloading command to unload the support head assembly (100). After receiving the unloading command from the local control center (400), the controller (3) in the support head assembly (100) controls the operation of the pump station (4) in the support head assembly (100). The pump station (4) adjusts the hydraulic oil in the rodless chamber A and the rod chamber B to reduce the pressure in the rodless chamber A and increase the pressure in the rod chamber B, so as to The piston (92) moves backward in the chamber (94) and the supporting member (10) moves backward to perform precise unloading. The ball head support (11) of the support head assembly (100) automatically adjusts its angle in the ball head accommodating space of the supporting member (10) to adjust the fit between the pressure plate (13) and the foundation pit retaining structure (300), and transmits the reduced axial force of the steel support (200) to the foundation pit retaining structure (300), thereby preventing the foundation pit retaining structure (300) from being displaced toward the outside of the foundation pit.

9. The driving method of the support axis force servo system according to claim 8, characterized in that: The step 4) is slightly delayed compared to the step 3), and the displacement sensor provided in the support head assembly (100) monitors the distance between the threaded rod (7) and the supporting member (10) in real time to ensure that the distance between the threaded rod (7) and the supporting member (10) is maintained between 0.5 mm and 1 mm in the final state; When unloading is completed, the pump station (4) stops adjusting the hydraulic oil in the rodless chamber A and the rod chamber B, and the support member (10) is locked once by the hydraulic system and locked twice by the threaded rod (7); When the hydraulic locking fails, the supporting member (10) can still be locked by the threaded rod (7).

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