Supporting device for deformation treatment of elliptical change shield tunnel and construction method of supporting device

Abstract

The invention provides a supporting device for elliptic change shield tunnel deformation treatment. The supporting device comprises a sliding guide rail base, a supporting frame, a jacking assembly, an arc-shaped cushion block and a mechanical locking device. The sliding guide rail base is fixed to the bottom of the inner wall of the tunnel segment. The supporting frame is movably installed on the sliding guide rail base. The jacking assembly comprises a servo actuator and is used for applying controllable jacking force; the arc-shaped cushion block is connected with the jacking assembly through a self-adaptive connecting mechanism and used for being attached to the inner wall of a tunnel segment; the mechanical locking device is arranged on the jacking and supporting assembly and used for locking the jacking and supporting assembly to maintain the static load after the target displacement is reached. According to the method, the hydraulic servo actuator realizes two-way precise control of the jacking force; jacking force and displacement are adjusted in real time through a servo valve group and a displacement load sensor, and local unbalance loading is avoided; the tunnel ellipticity is directly corrected, the repairing precision and the structural safety are improved, and the bottleneck of a traditional passive deviation correcting technology is broken through.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tunnel disease treatment, and particularly relates to a supporting device for deformation treatment of an elliptical deformation shield tunnel and a construction method thereof. BACKGROUND

[0002] With the rapid development of urban rail transit, shield tunneling has been widely used in complex strata and high groundwater environments as the main construction method of subway engineering. During the long-term operation of shield tunnels, influenced by external disturbances such as adjacent foundation pit excavation, sudden surface load, and groundwater level fluctuation, tunnel structures often appear problems such as convergence deformation, horizontal deviation, uneven settlement or uplift. Among them, transverse elliptical deformation is the most typical, which is manifested as convergence of the top and bottom of the tunnel and expansion of the two sides, making the lining ring force uneven and the waterproof layer damaged or even cracked and leaked. If such deformation exists for a long time, it will lead to diseases such as redistribution of lining structure stress, ring joint dislocation, and joint opening, seriously affecting the structural safety and durability of the tunnel.

[0003] In view of the above problems, the current treatment method mainly adopts ring grouting or internal lining reinforcement measures, but there are still the following main problems in actual engineering:

[0004] 1. The ring grouting reinforcement method relies on the penetration and diffusion of grout in the stratum. Especially in water-rich fine sand strata, due to the strong connectivity of the pore, high permeability coefficient, and large underground water pressure, the grout is easy to escape along the permeation channel, the grouting range is difficult to control, the interface bonding force between the grouting body and the segment is weak, and it lacks active repair effect on the geometric deformation that has occurred.

[0005] 2. The internal lining mechanical jacking deviation correction method can directly apply a counterforce to the segment to repair the elliptical deformation, but the counterforce is concentrated and the influence range is limited, and it cannot form a synergistic effect with stratum reinforcement. If the stratum behind the wall is still loose after jacking, the segment is easy to appear secondary rebound and deformation, affecting the long-term stability.

[0006] 3. The internal space of the shield tunnel is narrow, and the ventilation pipeline, pedestrian passage and pipeline layout occupy a large cross-sectional space. The conventional steel arch has a large volume and is complex to install, lacks mobility, and is difficult to flexibly arrange in the limited space, causing large operation interference and low arrangement efficiency. The existing rigid steel support relies on manual jacks or screw jacking to load, and the loading force is difficult to accurately control, the jacking force is unevenly distributed, and local stress concentration of the segment is easy to occur, leading to secondary damage or crack propagation. Moreover, the traditional steel support device is a fixed structure, which needs to be disassembled and reassembled after completing the treatment of each section, resulting in long construction period, low repeated positioning accuracy, reduced repair efficiency, and increased risk of interference with normal operation of the tunnel.

[0007] Therefore, existing technologies generally suffer from a disconnect between passive correction and active reinforcement: grouting methods cannot control deformation recovery, while top-support methods neglect long-term formation stability. Especially in high-risk water-rich sand layers, a single technology cannot simultaneously meet the three core requirements of geometric repair accuracy, formation reinforcement sustainability, and construction efficiency. Summary of the Invention

[0008] The purpose of this invention is to provide a support device and its construction method for deformation control of elliptical shield tunnels, which have the effects of accurately repairing deformation, continuously reinforcing the strata, and achieving efficient construction.

[0009] The present invention provides a support device for managing deformation of elliptic shield tunnels, comprising a sliding guide rail, a support frame, a top support assembly, an arc-shaped pad, and a mechanical locking device. The sliding guide rail is fixed to the bottom of the inner wall of the tunnel segment. The support frame is movably mounted on the sliding guide rail. The top support assembly includes a servo actuator for applying a controllable jacking force. The arc-shaped pad is connected to the top support assembly via an adaptive connection mechanism to conform to the inner wall of the tunnel segment. The mechanical locking device is disposed on the top support assembly and is used to lock the top support assembly to maintain static load after the target displacement is reached.

[0010] In one embodiment of the above-mentioned device, the sliding guide rail includes a pulley and a limiting block; the pulley is disposed in the rolling channel of the sliding guide rail to achieve low-resistance movement; the limiting block is disposed at both ends of the pulley to limit the movement range of the pulley.

[0011] In one embodiment of the above device, the servo actuator includes a hydraulic cylinder, a piston rod, a servo valve assembly, and a displacement load sensor; the hydraulic cylinder drives the piston rod to extend and retract via hydraulic oil; the servo valve assembly controls the flow rate and direction of the hydraulic oil; and the displacement load sensor monitors the piston rod stroke and output reaction force in real time.

[0012] In one embodiment of the above-mentioned device, the arc-shaped pad includes a force-transmitting layer and a buffer layer; the inner side of the force-transmitting layer is connected to the adaptive connection mechanism for transmitting the jacking force; the buffer layer is disposed on the outer side of the force-transmitting layer for conforming to the inner wall of the tunnel segment and absorbing impact.

[0013] In one embodiment of the above-mentioned device, the adaptive connection mechanism is a ball joint, which enables the top support assembly to automatically adjust its tilt angle according to the curvature of the tunnel cross section, thereby avoiding eccentric loading.

[0014] In one embodiment of the above-mentioned device, the mechanical locking device is a wedge-shaped buckle, which is installed at the lower end of the piston rod of the servo actuator and is used to pop out and achieve self-locking after the target displacement.

[0015] In one embodiment of the above-mentioned device, a grouting bag is also included. The grouting bag is made of highly permeable non-woven geotextile and is disposed on the outer wall of the tunnel segment for connection to the grouting system through grouting holes.

[0016] A construction method for treating deformation of elliptic shield tunnels using the above-mentioned device, comprising the following specific steps:

[0017] S1. After determining the location of the elliptical deformation of the shield tunnel cross section, the construction area is first cleaned and measured. The deformation curve data of the inner wall of the tunnel segment is obtained using a laser profiler and a three-dimensional scanning system. The top deformation concentration area, the support layout baseline, and the maximum deformation are marked. Based on the deformation characteristics, the support spacing, the stroke range of the servo actuator, and the top support force threshold are determined.

[0018] S2. Fix the sliding guide rail seat to the bottom of the inner wall of the tunnel segment, so that the axis of the guide rail is parallel to the center line of the tunnel. After installation, check the smoothness of sliding and parallelism to ensure the positioning accuracy of the support.

[0019] S3. Move the support frame along the sliding guide to the target deformation section;

[0020] S4. Start the servo actuator and push the arc-shaped pad to fit the inner wall of the tube segment through the adaptive connection mechanism to apply a controllable jacking force to correct the deformation;

[0021] S5. Inject grout into the grouting bags on the outer wall of the tunnel segments, and control the grouting rate and pressure to achieve periodic pulsating grouting and form a dynamic grouting effect; the dynamic grouting is carried out in coordination with the inner jacking process;

[0022] S6. When the servo actuator reaches the target displacement, the mechanical locking device is activated; the hydraulic system is depressurized appropriately, and the mechanical locking device bears the static load to maintain a constant correction force;

[0023] S7. Monitor displacement and pressure changes, and after confirming that the tunnel cross-section has returned to the design roundness range, release the lock and retrieve the device.

[0024] In step S4, starting the servo actuator involves adjusting the flow and direction of the hydraulic oil in real time through the servo valve group and displacement load sensor to achieve bidirectional control of the thrust and displacement.

[0025] In step S5, the periodic pulsating grouting includes adjusting the grouting rate to generate alternating flow of grout, which promotes the backfill liquid to penetrate into the formation behind the wall and form a dense solidified body; at the same time, the residual filter cake in the bag forms a continuous back pressure on the segment after water hardening.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. The combination structure of hydraulic servo actuator and ball joint-arc pad enables bidirectional precise control and adaptive fitting of the jacking force; this structure adjusts the jacking force and displacement in real time through servo valve group and displacement load sensor to avoid local eccentric loading; the rubber buffer layer of ball joint and arc pad automatically adapts to the irregular surface of the tunnel segment, evenly distributes stress, and prevents damage to the tunnel segment; it directly corrects the ellipticity of the tunnel, improves the repair accuracy and structural safety, and breaks through the bottleneck of traditional passive correction technology;

[0028] 2. The movable sliding guide rail system and mechanical locking device enable rapid positioning and reuse of the support device; the sliding guide rail seat achieves low-resistance movement and precise positioning through pulleys and limit blocks, and the support frame can quickly slide along the tunnel to the defect section; the wedge-shaped buckle self-locks after the target displacement to maintain static load, without the need for continuous power supply; it greatly shortens the construction cycle, reduces disassembly and reassembly time, reduces interference with tunnel operation, and is suitable for efficient repetitive operations in narrow spaces;

[0029] 3. By setting grouting holes and geotextile bags on both sides of the shield tunnel outer wall, and while the inner hydraulic servo support is supported, the grouting rate and frequency are controlled to achieve periodic pulsation and permeation diffusion of the grout inside the bag, forming a dynamic grouting effect; the backfill liquid permeates through the bag to the water-rich fine sand layer behind the wall, causing the soil particles to re-compact and form a highly dense grout body; the filter cake remaining in the bag, after dehydration and hardening, forms a continuous back pressure on the segment, which works together with the inner servo support force to construct a comprehensive reinforcement system of internal and external bidirectional compression repair, thereby significantly improving the structural recovery capacity of deformed segments and the stratum stability effect. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of one embodiment of the present invention.

[0031] Figure 2 for Figure 1 A frontal view of the structure.

[0032] Figure 3 for Figure 1 A schematic diagram of the structure of a single-sided sliding guide rail.

[0033] Figure 4 for Figure 1 A schematic diagram of the structure of a servo actuator.

[0034] Figure 5 for Figure 1 A schematic diagram of the structure of the wedge-shaped buckle and the piston rod ball joint. Detailed Implementation

[0035] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are only a part of the embodiments, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 and Figure 2 As shown, the support device for deformation control of elliptical shield tunnels disclosed in this embodiment includes a sliding guide rail seat 1, a support frame 2, a top support assembly 3, an arc-shaped pad 4, a wedge-shaped buckle 5, a servo actuator 6, and a grouting bag 19.

[0037] The sliding guide rail 1 is fixed to the bottom of the inner wall of the tunnel segment, serving as a base for movement. The support frame 2 is installed above the sliding guide rail 1 to support the upper structure. The top support assembly 3 is vertically mounted on the upper end of the steel support frame 2, with its bottom hinged to the support frame and its upper end connected to the arc-shaped pad 4 via a ball joint 9. The arc-shaped pad 4 is located above the top support assembly 3, with its outer arc surface conforming to the inner wall of the tunnel segment. The wedge-shaped buckle 5 is arranged at the lower end of the piston rod 10 of the servo actuator 6 for mechanical self-locking. The servo actuator 6 is integrated into the top support assembly 3 and is driven by a hydraulic system. The device moves via the sliding guide rail 1 and applies a controllable jacking force via the top support assembly 3.

[0038] like Figure 3 As shown, the sliding guide rail base 1 is arranged circumferentially along the bottom of the tunnel and is made of high-strength channel steel. A rolling channel is provided on its upper surface, and reinforcing ribs are provided on both sides to improve rigidity and bending resistance. The sliding guide rail base 1 is fixed to the base on the tunnel floor or the lower part of the segment ring by expansion bolts or welded base plates to ensure guiding accuracy and stability.

[0039] Multiple pulleys 16 are installed in the inner channel of the sliding guide rail 1 and connected to the sliding seat, allowing the sliding seat to move smoothly along the guide rail. Limiting blocks 17 are arranged at both ends of the pulleys 16 to limit the range of movement of the pulleys. The blocks are fixed to the ends of the guide rail with bolts. After the support device is in place, the blocks lock the pulleys to ensure that the overall support system remains stable during the loading stage.

[0040] The support frame 2 is mounted above the sliding guide rail 1 and is slidably connected to the guide rail via the sliding base. It is used to support the servo actuator 6 and its upper structure.

[0041] The lower end of the support frame 2 is fixed to the sliding seat, and the upper end is hinged to the top support assembly 3, forming a movable support unit that can be adjusted towards the tunnel. The entire frame is welded from high-strength steel to bear all the reaction forces during the loading process, ensuring overall stability. The support frame 2 slides on the guide rail with low resistance through the sliding seat, allowing the device to be flexibly positioned to the target defect section.

[0042] like Figure 4 As shown, the top support assembly 3 includes a servo actuator 6 and a piston rod 10. The servo actuator is vertically arranged on the upper end of the support frame 2, and its cylinder body 15 is fixedly connected to the support frame through a hinged lug at the bottom. The piston rod 10 extends along the axial direction of the servo actuator, and its front end is connected to the steel plate force transmission layer 8 of the arc-shaped pad block 4 through a ball joint 9 to transmit axial thrust.

[0043] The servo actuator 6 has an internal hydraulic cylinder 15 that drives the piston rod 10 to extend and retract via high-pressure oil. A servo valve assembly 12 is fixed to the oil circuit board on the side of the cylinder, directly controlling the flow and direction of the high-pressure oil. A displacement load sensor 14 is located at the connection between the servo valve assembly 12 and the actuator, monitoring the piston rod stroke and output reaction force in real time. An accumulator 11 is installed on the side of the actuator and connected to the cylinder 15 via a high-pressure oil pipe 13, used to store hydraulic energy and absorb pressure fluctuations. The oil pipe 13 uses a quick-connect coupling design for easy installation and disassembly, and is protected by an explosion-proof sleeve. Under the control of the hydraulic system, the servo actuator outputs an adjustable thrust, achieving bidirectional control of thrust and displacement.

[0044] like Figure 5 As shown, the arc-shaped pad 4 is located above the servo actuator 6 and is composed of a high-strength steel plate force transmission layer 8 and a rubber buffer layer 7. The inner side of the steel plate force transmission layer 8 is connected to the piston rod 10 through a ball joint 9 to uniformly transmit the jacking force. The rubber buffer layer 7 is located on the outer side of the steel plate force transmission layer 8 and is in close contact with the inner wall of the tunnel segment to absorb transient impacts during the jacking process, homogenize contact stress, and avoid stress concentration in the tunnel segment caused by point contact. The curvature of the arc-shaped pad 4 matches the inner wall of the tunnel segment to ensure adaptive fit and uniform force distribution.

[0045] The ball joint 9 is arranged between the end of the piston rod 10 and the steel plate force transmission layer 8, so that the piston rod can automatically adjust the tilt angle according to the curvature of the tunnel section during loading, avoiding the generation of eccentric load and shear stress, and ensuring that the jacking direction is always perpendicular to the inner surface of the segment, thereby improving the stress stability and force transmission efficiency.

[0046] The wedge-shaped latch 5, acting as a mechanical locking device, is installed at the lower end of the piston rod 10 of the servo actuator 6. The wedge-shaped latch automatically pops out after the hydraulic system reaches the target support displacement, locking itself against the lower flange and bearing static load to prevent system pressure loss and retraction. After locking, the hydraulic system can be depressurized, maintaining a constant correction force.

[0047] The overall component functions to address the elliptic deformation of the shield tunnel through hydraulic servo jacking. The principle behind this is that the hydraulic servo actuator 6 applies a controllable jacking force, which is evenly transmitted to the inner wall of the tunnel segments via the arc-shaped pad 4, directly correcting the ellipticity of the tunnel cross-section, restoring the tunnel's roundness, and enhancing ground stability. The sliding guide rail 1 and the support frame 2 enable the movable deployment and repeated positioning of the device, improving construction efficiency.

[0048] When this support device is used, it can be used in conjunction with the outer grouting bags 19 for synergistic treatment. The outer grouting bags are installed on the outer walls of the left and right sides of the tunnel segments and are sealed to the external grouting system through grouting holes. The grouting bags are made of highly permeable non-woven geotextile, and grout is introduced into them, forming a filter layer during the grouting process. The grout permeates and diffuses through the bags to the strata behind the wall, improving the density and impermeability of the strata.

[0049] During the loading process, the grouting rate and pressure changes of the grouting holes on both sides of the tunnel segment are controlled by the grouting bag 19, causing the grout to form a periodic, alternating pulsating flow inside the bag, thus generating a dynamic grouting effect during grout injection and infiltration. This pulsating grouting can, on the one hand, promote the re-densification of the contact interface between the lining and the grout body behind the wall, eliminating local voids and micro-cracks; on the other hand, under saturated sand or silty soil conditions, especially in water-rich fine sand strata, the pulsating pressure will cause a brief rearrangement and loosening of soil particles, significantly improving the permeability and diffusion range of the grout. Through this dynamic grouting process, the grout can fully fill the voids behind the tunnel segment and form a dense solidified body, thereby effectively enhancing the waterproofness and overall stability of the strata behind the wall while restoring the tunnel's roundness.

[0050] After the filter cake remaining in the bag hardens, it applies continuous counter pressure to the tunnel segments, which, together with the inner top support force, forms a bidirectional compression repair system, thereby restoring the tunnel's roundness and enhancing the stability of the strata.

[0051] A method for construction using this support device, comprising the following specific steps:

[0052] 1. After determining the location of the elliptical deformation of the shield tunnel cross section, the construction area is first cleaned and measured. The deformation curve data of the inner wall of the tunnel segment is obtained using a laser profiler and a three-dimensional scanning system. The top deformation concentration area, the support layout baseline, and the maximum deformation are marked. Based on the deformation characteristics, the support spacing, the stroke range of the servo actuator, and the top support force threshold are determined to provide parameter basis for subsequent installation.

[0053] 2. Install sliding guide rails along both sides of the tunnel floor. The guide rails are fixed to the segment base using high-strength anchor bolts or welding to ensure that the guide rail axis is parallel to the tunnel centerline. Then, assemble the sliding seat assembly on the guide rail and achieve rolling displacement through pulleys. Set limit blocks at both ends of the guide rail to control the movement range of the support device and prevent sliding beyond the limit. After the guide rail is installed, check the smoothness and parallelism of sliding to ensure the positioning accuracy of the support.

[0054] 3. The support frame and servo actuator system are hoisted into the tunnel ring as a whole and slid to the predetermined position; the servo actuator 6 is vertically arranged on the guide rail sliding seat, and its upper piston rod 10 is connected to the arc-shaped pad 4 through the ball joint 9. The rubber buffer layer 7 on the upper part of the arc-shaped pad faces the inner wall of the tunnel segment, and the steel plate force transmission layer 8 faces inward to ensure that the force is evenly transmitted during the jacking process and has a certain flexible buffering capacity; the two sets of actuators are symmetrically arranged in the tunnel section, and the positions are located on both sides of the center of the deformation zone.

[0055] 4. Start the hydraulic servo control system. High-pressure oil is transmitted to the servo actuator 6 through the high-pressure oil pipe 13. The servo valve group 12 automatically adjusts the pressure and flow rate according to the feedback data of the displacement load sensor 14 to achieve precise displacement control of the piston rod 10. As the piston rod slowly extends, the arc-shaped pad 4 contacts the inner wall of the tube segment and applies a supporting force to gradually correct the deformation. The rubber buffer layer 7 provides buffer support during the supporting process to prevent local stress concentration. The steel plate layer 8 evenly distributes the actuator thrust to the tube segment structure.

[0056] 5. Grout is injected into the bags 19 on the outer walls of the left and right sides of the tunnel segments through the grouting pipeline; the grouting rate is adjusted according to the permeability characteristics of the stratum, so that the grout in the bags produces a periodic alternating pulsating flow, thereby forming a dynamic grouting effect; the grout seeps out of the bags, and the filter residue in the bags forms a filter cake that solidifies rapidly. During the grouting process, the bags expand rapidly and generate a lateral pushing force on the tunnel segments, achieving a synchronous correction and repair effect; the dynamic grouting and the inner jacking process are carried out in tandem, which can effectively enhance the density and support capacity of the stratum behind the tunnel segments, and improve the overall effect of tunnel roundness repair and waterproof reinforcement.

[0057] 6. When the servo actuator reaches the designed top support displacement, the mechanical locking device is automatically activated, and the limit wedge 5 pops out of the locking groove and abuts against the flange to achieve self-locking of the piston rod; at this time, the hydraulic system can be depressurized appropriately, and the mechanical locking can bear the static load to maintain a constant correction force and prevent the support from shrinking due to system pressure loss.

[0058] 7. After the support is stabilized, the pressure and displacement changes of each servo actuator are continuously monitored by sensor 14 to ensure that the tunnel cross section is restored to the design roundness range.

[0059] 8. Once the alignment meets the design standards, release the mechanical locking device, slowly depressurize to allow the piston rod to retract, and the arc-shaped pad to gradually disengage from the tube segment. Then, release the guide rail end stop and retract the sliding base along the guide rail to a safe area.

[0060] 9. If repeated construction is required in adjacent rings, the steel support frame can be moved along the guide rail to the next treatment ring segment, and the above process can be repeated to achieve continuous segment repair. After all elliptic sections are repaired, the sliding guide rail and limiting device are removed, the steel support body and hydraulic system components are recovered, the guide rail fixing holes are sealed with cement mortar, and the integrity of the tunnel interior surface and protective layer is restored.

[0061] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A support device for treatment of elliptical deformation of a shield tunnel, characterized by: The application relates to a tunnel segment support device, which comprises a sliding guide rail base, a support frame, a top support assembly, an arc-shaped cushion block and a mechanical locking device. The sliding guide rail base is fixed to the inner wall bottom of a tunnel segment; the support frame is movably installed on the sliding guide rail base; the top support assembly comprises a servo actuator for applying controllable jacking force; the arc-shaped cushion block is connected with the top support assembly through an adaptive connecting mechanism and is used for adhering to the inner wall of the tunnel segment; and the mechanical locking device is arranged on the top support assembly and is used for locking the top support assembly to maintain static load after reaching the target displacement.

2. The support device for the treatment of the deformation of the elliptical shield tunnel according to claim 1, characterized in that: The sliding guide rail base comprises a pulley and a limiting block; the pulley is arranged in a rolling channel of the sliding guide rail base and realizes low-resistance movement; and the limiting block is arranged at both ends of the pulley and limits the movement range of the pulley.

3. The support device for the treatment of the deformation of the elliptical shield tunnel according to claim 1, characterized in that: The servo actuator comprises a hydraulic cylinder, a piston rod, a servo valve group and a displacement load sensor; the hydraulic cylinder drives the piston rod to extend and retract through hydraulic oil; the servo valve group is used for controlling the flow and direction of the hydraulic oil; and the displacement load sensor is used for monitoring the piston rod stroke and output reaction force in real time.

4. The support device for the treatment of elliptical deformation of a shield tunnel according to claim 1, characterized in that: The arc-shaped cushion block comprises a force transmission layer and a buffer layer; the inner side of the force transmission layer is connected with the adaptive connecting mechanism and is used for transmitting jacking force; and the buffer layer is arranged on the outer side of the force transmission layer and is used for adhering to the inner wall of the tunnel segment and absorbing impact.

5. The support device for the treatment of elliptical deformation of a shield tunnel according to claim 1, characterized in that: The adaptive connecting mechanism is a spherical hinge, so that the top support assembly can automatically adjust the inclination angle according to the curvature of the tunnel section, thereby avoiding partial load.

6. The support device for the treatment of elliptical deformation of a shield tunnel according to claim 1, characterized in that: The mechanical locking device is a wedge-shaped buckle and is installed at the lower end of the piston rod of the servo actuator and is used for being popped out and achieving self-locking after the target displacement.

7. The support device for the treatment of elliptical deformation of a shield tunnel according to claim 1, characterized in that: The application further comprises a grouting bag, which is made of high-permeability non-woven geotextile, is arranged on the outer wall of the tunnel segment and is used for being connected with a grouting system through a grouting hole.

8. A construction method for treating the deformation of an elliptical tunnel using the support device according to any one of claims 1 to 7, characterized by, The specific steps are as follows: S1. After the deformed position of the elliptical section of the shield tunnel is determined, the construction area is cleaned and measured, the deformed curve data of the inner wall of the segment are obtained by using a laser section instrument and a three-dimensional scanning system, the top deformation concentration area, the support arrangement reference line and the maximum deformation are calibrated, the support spacing, the stroke range of the servo actuator and the top support force threshold are determined according to the deformation characteristics; S2. The sliding guide rail base is fixed to the inner wall bottom of the tunnel segment, the guide rail axis is parallel to the tunnel center line, the sliding smoothness and parallelism are detected after installation is completed, and the support alignment accuracy is ensured; S3. The support frame is moved to the target deformed section along the sliding guide rail base; S4. The servo actuator is started, the arc-shaped cushion block is pushed to adhere to the inner wall of the segment through the adaptive connecting mechanism, controllable jacking force is applied to correct the deformation; S5. Grout is injected into the grouting bag on the outer wall of the tunnel segment, the grouting rate and pressure are controlled to realize periodic pulsating grouting, and the dynamic grouting effect is formed; the dynamic grouting and the inner side top support process are cooperated; S6. When the servo actuator reaches the target displacement, the mechanical locking device is started; the hydraulic system is moderately depressurized, the static load is borne by the mechanical locking device, and the correction force is kept constant; S7. The displacement and pressure changes are monitored, and after the tunnel section is restored to the design roundness range, the locking is released and the device is recovered.

9. The construction method of claim 8, wherein: In step S4, the servo actuator is started, including adjusting the flow and direction of hydraulic oil in real time through the servo valve group and displacement load sensor to realize bidirectional control of the jacking force and displacement.

10. The construction method of claim 8, wherein: In step S5, the periodic pulsating grouting includes adjusting the grouting rate to produce alternating flow of the slurry, which promotes the penetration of the filter liquid to the wall back formation and forms a dense reinforced body; at the same time, the residual filter cake in the capsule bag forms a sustained counter pressure on the segment after being hardened by water.

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