Grouting reinforcement device and method for loose soil layer behind shield segment wall

Abstract

The application discloses a kind of grouting reinforcement device and method for loose soil layer behind shield segment wall, belong to shield construction technical field, it includes grouting drill rod, grouting drill rod propulsion mechanism and the embedded conduit being arranged in shield segment, the grouting drill rod propulsion mechanism is used to insert grouting drill rod into loose soil layer behind shield segment wall, and make grouting drill rod and embedded conduit connect.In the application, embedded conduit is positioned and buried when shield segment is produced, and shield segment does not need to be damaged secondly.Grouting drill rod propulsion mechanism is fixed to shield segment through embedded conduit, and it is not necessary to drill and fix on shield segment, so as to simplify operation process.Spiral drill rod can increase its side frictional resistance with loose soil layer, so as to reduce the reverse force generated by grouting pressure on shield segment.

Description

Technical Field

[0001] This invention relates to a grouting reinforcement device and method for locally loose soil layers behind the tunnel lining segments, belonging to the field of tunnel boring machine (TBM) construction technology. Background Technology

[0002] Shield tunneling is the most commonly used construction technology in urban subway construction. During shield tunneling, the tunnel boring machine (TBM) excavates and removes muck while simultaneously assembling reinforced concrete segments to form the tunnel lining. During tunneling, the TBM inevitably encounters loose soil layers with poor stability and impermeability. While immediately stopping tunneling and reinforcing the loose soil with grouting can achieve good reinforcement, the presence of the TBM increases the difficulty of grouting in the loose soil layers ahead and delays construction progress. Therefore, to ensure safe and efficient tunneling, construction workers typically employ a series of measures, including earth pressure balance control, muck improvement, TBM attitude adjustment, and surface settlement monitoring, to accelerate construction and reduce costs. However, these methods only reinforce the loose soil layers in the shallow area surrounding the tunnel segments. The loose soil layers in deeper areas are still subject to the loads of the operating subway, leading to uneven settlement of the tunnel segments and increasing safety risks during subway operation. Therefore, grouting reinforcement is necessary for the loose soil within a certain depth range around shield tunnel segments located in loose soil layers to improve the stability of the shield tunnel segment structure. However, the grouting holes currently reserved on the shield tunnel segments are often used for secondary supplementary grouting when synchronous grouting fails to meet design requirements, and cannot be used for grouting reinforcement of the loose soil within a certain depth range around the shield tunnel segments. If holes are drilled in the shield tunnel segments for grouting, it would require damaging the internal steel reinforcement, which not only increases the difficulty of drilling but also seriously affects the stability of the segment structure. Furthermore, a device to resist the reaction force generated during pressure grouting needs to be considered, making the process complex and difficult to operate. Therefore, how to economically, quickly, and effectively improve the structural stability of shield tunnel segments located in loose soil layers is a practical engineering problem that urgently needs to be solved. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a grouting reinforcement device and method for local loose soil layers behind the shield tunnel segment wall, which is convenient for construction and has a good reinforcement effect.

[0004] The present invention achieves the above objectives by adopting the following technical solutions:

[0005] On one hand, the present invention provides a grouting reinforcement device for a local loose soil layer behind the shield tunnel segment wall, including a grouting drill rod, a grouting drill rod propulsion mechanism, and a pre-embedded conduit installed in the shield tunnel segment. The grouting drill rod propulsion mechanism is used to insert the grouting drill rod into the loose soil layer behind the shield tunnel segment wall and connect the grouting drill rod to the pre-embedded conduit. The surface of the grouting drill rod is provided with helical blades.

[0006] The pre-embedded conduit includes a pipe body and a pipe head coaxially connected to the rear end of the pipe body. The inner diameter of the pipe head is larger than the inner diameter of the pipe body. The front end of the pipe body is a tapered hole with a narrow opening. The inner wall of the pipe head and the wall of the tapered hole with a narrow opening are both provided with internal threads.

[0007] The grouting drill rod propulsion mechanism includes a frame and a spiral thrust rod;

[0008] The frame includes a front mounting plate and a rear mounting plate spaced apart. The front mounting plate and the rear mounting plate are connected by several connecting rods. The front mounting plate and the rear mounting plate are respectively coaxially provided with a front mounting hole and a rear mounting hole. The wall of the rear mounting hole is provided with internal threads. A front connecting pipe is provided on the side of the front mounting plate away from the rear mounting plate. The front connecting pipe is connected to the front mounting hole with the same diameter. The inner diameter of the front connecting pipe is not greater than the inner diameter of the pipe head. The outer wall of the front connecting pipe is provided with external threads.

[0009] The spiral thrust rod is provided with an external thread that mates with the rear mounting hole. The rear end of the spiral thrust rod is provided with a rotating handle. The front end of the spiral thrust rod is provided with an external thread that mates with the grouting drill rod. The rotating handle is used to increase the adjustable length of the torque.

[0010] The inner wall of the rear end of the grouting drill rod is provided with an internal thread that mates with the front end of the spiral thrust rod. A conical boss is coaxially provided on the outer side of the rear end of the grouting drill rod. An external thread is provided on the conical boss that mates with the conical hole at the end of the pre-embedded conduit. The outer diameter of the conical boss is smaller than the diameter of the front mounting hole and larger than the outer diameter of the spiral blade.

[0011] In a preferred embodiment, the grouting reinforcement device for locally loose soil layers behind the shield tunnel segment wall provided by the present invention further includes a drill rod anti-retrograde mechanism, wherein the drill rod anti-retrograde mechanism includes:

[0012] The buckle body has a snap-fit ​​interface on its end face, which can snap into a spiral blade. The buckle body has an elongated hole in its middle, through which the buckle body is slidably fitted onto one of the connecting rods.

[0013] A clamping bolt is located near the snap-fit ​​body and is parallel to the axis of the connecting rod. The clamping bolt is threaded onto the front mounting plate, and the snap-fit ​​body can be clamped between the nut of the clamping bolt and the front mounting plate.

[0014] Optionally, a spring pin is provided at the rear end of the grouting drill rod, and the spring pin is capable of telescoping relative to the grouting drill rod;

[0015] The distance between the end of the spring pin and the central axis of the grouting drill rod is L, the inner diameter of the front mounting hole is R1, and the outer diameter of the pipe body is R2.

[0016] When the spring pin retracts, L < R1; when the spring pin extends, L > R2.

[0017] Optionally, the outer wall of the pre-embedded conduit is provided with positioning claws, which are used to connect with the steel cage of the tunnel segment.

[0018] Optionally, the rear mounting plate is provided with a rear connecting pipe on the side away from the front mounting plate, and the inner wall of the rear connecting pipe is provided with internal threads and is connected to the rear mounting hole with the same diameter.

[0019] On the other hand, the present invention also provides a grouting reinforcement method for locally loose soil layers behind the shield tunnel segment wall, which uses the aforementioned grouting reinforcement device and includes the following steps:

[0020] S1: Obtain the shield tunnel segment with pre-embedded conduit, so that the front end and rear end of the pre-embedded conduit are exposed from the outer and inner ring surfaces of the shield tunnel segment, respectively.

[0021] S2: Install the shield tunnel segments obtained in step S1 into the tunnel, and install the grouting drill rod propulsion mechanism on the pre-embedded guide pipe that needs grouting.

[0022] S3: Use the grouting drill rod propulsion mechanism to insert the grouting drill rod into the loose soil layer behind the shield tunnel segment wall, and connect the end of the grouting drill rod to the pre-embedded conduit.

[0023] S4: Connect the grouting pipe to the pre-embedded conduit. The grout is introduced into the grouting drill rod through the grouting pipe and then injected into the loose soil layer through the grouting hole on the grouting drill rod.

[0024] S5: After grouting is completed and the grout reaches its final setting time, the grouting drill rod propulsion mechanism is removed, and stainless steel bolts are screwed into the pre-embedded guide pipe to complete the grouting reinforcement of the local loose soil layer behind the shield tunnel segment wall.

[0025] Further, the operation method of step S3 is as follows: rotate the spiral thrust rod in the forward direction so that its front end passes through the rear mounting hole on the rear mounting plate, connect the grouting drill rod to the front end of the spiral thrust rod, continue to rotate the spiral thrust rod in the forward direction so that the front end of the grouting drill rod passes through the pre-embedded guide pipe in the front mounting plate and the shield segment in sequence, and is inserted into the loose soil layer behind the shield segment wall.

[0026] Furthermore, in step S5, before dismantling the grouting drill rod propulsion mechanism, it is necessary to separate the helical thrust rod from the grouting drill rod. The separation method is as follows:

[0027] The spring pin at the rear end of the grouting drill rod enters the loose soil layer behind the shield tunnel segment wall along with the grouting drill rod. The spring pin extends and blocks the front end of the pipe body. When the helical thrust rod is rotated in the opposite direction, the grouting drill rod is blocked by the spring pin and cannot retract into the pre-embedded guide pipe. Thus, the helical thrust rod can be rotated in the opposite direction alone until it separates from the grouting drill rod.

[0028] In a preferred embodiment, the grouting drill rod adopts a multi-segment assembly structure. The operation method of step S3 is as follows: after inserting the previous grouting drill rod into the loose soil layer behind the shield tunnel segment using a spiral thrust rod, the spiral blade at the rear end of the previous grouting drill rod is locked by the drill rod anti-retraction mechanism. Then, the spiral thrust rod is rotated in the reverse direction to retract it. During the retraction process, the spiral thrust rod separates from the previous grouting drill rod. Subsequently, the drill rod anti-retraction mechanism is returned to its original position, the spiral thrust rod is rotated in the reverse direction to retract it to a suitable position, and the next grouting drill rod is installed at its front end. Then, the spiral thrust rod is rotated in the forward direction to drive the next grouting drill rod forward. During the forward movement of the next grouting drill rod, it connects with the previous grouting drill rod and is inserted into the loose soil layer behind the shield tunnel segment.

[0029] Furthermore, in step S1, the method for obtaining the shield tunnel segment with pre-embedded guide pipes includes the following steps:

[0030] S110: Pre-embedded conduits are fixed in the steel cage of the tunnel segment. Each pre-embedded conduit is filled with a sealing plug. The sealing plug is made of polystyrene foam, natural rubber or butyl rubber.

[0031] S120: Place the segment reinforcement cage obtained in step S110 into the casting mold, pour concrete into the casting mold, remove the casting mold after the concrete is formed, and cure it to produce shield tunnel segments.

[0032] S130: Remove the sealing plug from the pre-embedded conduit and install stainless steel bolts in the pre-embedded conduit that does not require grouting.

[0033] The beneficial effects of this application include, but are not limited to:

[0034] The grouting reinforcement device and method for loose soil layers behind shield tunnel segments provided by this invention includes a pre-embedded guide pipe inside the shield tunnel segment, and a grouting drill rod advancing mechanism connected to the rear end of the pre-embedded guide pipe. The grouting drill rod advancing mechanism allows the grouting drill rod to be inserted into the loose soil layer behind the shield tunnel segment and connected to the front end of the pre-embedded guide pipe. Subsequently, removing the grouting drill rod advancing mechanism allows grout to be injected into the grouting drill rod from the pre-embedded guide pipe. The grout is injected into the loose soil layer through the grouting holes on the grouting drill rod. After hardening, a grouting solidified body is formed within the loose soil layer, completing the reinforcement of the loose soil layer.

[0035] In this invention, the pre-embedded guide pipe is positioned and installed during the production of the tunnel lining segments, eliminating the need for secondary damage to the segments. The grouting drill rod propulsion mechanism is fixed to the tunnel lining segments via the pre-embedded guide pipe, eliminating the need for drilling and fixing operations on the segments, thus simplifying the operation process. The auger drill rod can increase its lateral friction resistance with the loose soil layer, thereby reducing the reverse force generated by the grouting pressure on the tunnel lining segments. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0037] Figure 1 A schematic diagram of the grouting drill rod propulsion mechanism and the grouting drill rod;

[0038] Figure 2 A 3D view of the pre-embedded conduit;

[0039] Figure 3 This is a cross-sectional view of the pre-embedded conduit;

[0040] Figure 4 A schematic diagram of the positioning claws on the pre-embedded conduit;

[0041] Figure 5 This is a schematic diagram of the steel reinforcement cage and embedded guide pipes inside the tunnel segment of a shield tunnel.

[0042] Figure 6 This is a cross-sectional view of the front mounting plate;

[0043] Figure 7 This is a sectional view of the rear mounting plate;

[0044] Figure 8 A cross-sectional view of the assembly state of the grouting drill rod propulsion mechanism, the grouting drill rod, and the pre-embedded guide pipes inside the shield tunnel segments;

[0045] Figure 9 for Figure 8 Enlarged view of section A;

[0046] Figure 10 This is a schematic diagram showing the assembly state of the grouting drill rod propulsion mechanism, the grouting drill rod, and the tunnel lining segments.

[0047] Figure 11 for Figure 10 Enlarged view of section B;

[0048] Figure 12 This is a schematic diagram of a stainless steel bolt;

[0049] Figure 13 A schematic diagram of a multi-segment assembly structure for grouting drill rods;

[0050] Figure 14 for Figure 11 Enlarged view of section C;

[0051] Figure 15 This is a schematic diagram of the buckle body;

[0052] Figure 16 A schematic diagram of the loose soil layer behind the shield tunnel segment wall within the longitudinal section of the tunnel;

[0053] Figure 17 This is a schematic diagram showing the distribution of grouting pipes within the loose soil layer in the longitudinal section of the tunnel.

[0054] Figure 18 This is a schematic diagram showing the distribution of grouting pipes within the loose soil layer in the tunnel cross-section.

[0055] Figure 19 This is a schematic diagram of the grouting consolidation body formed within the loose soil layer after grouting.

[0056] In the picture:

[0057] 1. Shield tunnel segments; 2. Segment reinforcement cage; 3. Tunnel; 4. Loose soil layer; 5. Grouting consolidation body;

[0058] 100. Grouting drill rod; 101. Spiral blade; 102. Conical boss; 103. Grouting channel; 104. Grouting hole; 105. Spring pin; 110. First section of drill rod; 120. Middle section of drill rod; 130. Tail section of drill rod;

[0059] 200. Grouting drill rod propulsion mechanism; 210. Frame; 211. Front mounting plate; 2111. Front mounting hole; 2112. Front connecting pipe; 212. Rear mounting plate; 2121. Rear mounting hole; 2122. Rear connecting pipe; 213. Connecting rod; 220. Helical thrust rod; 221. Rotating handle;

[0060] 300. Embedded conduit; 310. Pipe body; 311. Tapered end hole; 320. Pipe head; 330. Positioning claw;

[0061] 400. Drill pipe anti-reverse mechanism; 410. Buckle body; 411. Buckle interface; 412. Long hole; 420. Clamping bolt;

[0062] 500 stainless steel bolts. Detailed Implementation

[0063] To clearly illustrate the technical features of this solution, the invention will be described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0064] It should be noted that many specific details are set forth in the following description to provide a thorough understanding of the invention; however, the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0065] Example 1:

[0066] like Figure 1 , Figure 2 , Figure 5 and Figure 10 As shown, the grouting reinforcement device for the loose soil layer behind the shield tunnel segment wall provided by the present invention includes a grouting drill rod 100, a grouting drill rod propulsion mechanism 200, and a pre-embedded conduit 300 disposed in the shield tunnel segment 1. The grouting drill rod propulsion mechanism 200 is used to insert the grouting drill rod 100 into the loose soil layer behind the shield tunnel segment wall and connect the grouting drill rod 100 with the pre-embedded conduit 300.

[0067] like Figures 2-4 As shown, the pre-embedded conduit 300 includes a pipe body 310 and a pipe head 320 coaxially connected to the rear end of the pipe body 310. The inner diameter of the pipe head 320 is larger than the inner diameter of the pipe body 310. The front end of the pipe body 310 is a tapered hole 311. The inner wall of the pipe head 320 and the hole wall of the tapered hole 311 are both provided with internal threads.

[0068] The grouting drill rod propulsion mechanism 200 includes a frame 210 and a helical thrust rod 220, which is connected to the frame 210 by a threaded connection.

[0069] Specifically, the frame 210 includes a front mounting plate 211 and a rear mounting plate 212 spaced apart, and the front mounting plate 211 and the rear mounting plate 212 are connected by several connecting rods 213. For example... Figure 6 and Figure 7 As shown, the front mounting plate 211 and the rear mounting plate 212 are respectively coaxially provided with a front mounting hole 2111 and a rear mounting hole 2121.

[0070] A front connecting pipe 2112 is provided on the side of the front mounting plate 211 away from the rear mounting plate 212. The front connecting pipe 2112 is connected to the front mounting hole 2111 with the same diameter. The outer wall of the front connecting pipe 2112 is provided with external threads, and the front connecting pipe 2112 is connected to the pipe head 320 of the pre-embedded conduit 300 through threaded engagement. Thus, as Figure 8 and Figure 9 As shown, the frame 210 is connected and installed onto the pre-embedded conduit 300.

[0071] After the front connecting pipe 2112 is connected to the pipe head 320 of the pre-embedded conduit 300 by thread, the end of the front connecting pipe 2112 should contact and connect with the pipe head 320 of the pre-embedded conduit 300.

[0072] The rear mounting hole 2121 has an internal thread on its wall and the helical thrust rod 220 has an external thread. The helical thrust rod 220 is connected to the rear mounting hole 2121 by a threaded connection.

[0073] The front end of the spiral thrust rod 220 is provided with an external thread that mates with the grouting drill rod 100, and the inner wall of the rear end of the grouting drill rod 100 is provided with an internal thread. The grouting drill rod 100 is threadedly connected to the front end of the spiral thrust rod 220.

[0074] like Figure 10 and Figure 11 As shown, when the helical thrust rod 220 is rotated, it spirals forward relative to the frame 210, thereby driving the grouting drill rod 100 to spiral forward as well. During this spiral advance, the grouting drill rod 100 first passes through the front mounting hole 2111 on the front mounting plate 211, and then enters the soil layer behind the shield tunnel segment wall. The surface of the grouting drill rod 100 is equipped with helical blades 101, which improves its tunneling efficiency within the soil layer.

[0075] The rear end of the helical thrust rod 220 is equipped with a rotating handle 221 for easy gripping and rotation, and the adjustable length can increase torque.

[0076] like Figure 1 As shown, a tapered boss 102 is coaxially provided on the outer rear end of the grouting drill rod 100. The tapered boss 102 is provided with an external thread that mates with the tapered hole 311 of the pre-embedded conduit 300. The rest of the structure of the grouting drill rod 100 adopts conventional settings. For example, the front end of the grouting drill rod 100 is a closed cone, the interior of the grouting drill rod 100 is provided with a grouting channel 103, and grouting holes 104 communicating with the grouting channel 103 are distributed on the grouting drill rod 100.

[0077] The outer diameter of the conical boss 102 on the grouting drill rod 100 is smaller than the diameter of the front mounting hole 2111 but larger than the outer diameter of the helical blade 101. This design ensures that the grouting drill rod 100 can smoothly pass through the front mounting hole 2111 and the front connecting pipe 2112, while also allowing the main body of the grouting drill rod 100 with the helical blade 101 to pass through the pre-embedded guide pipe 300 into the soil layer behind the shield tunnel segment wall. Furthermore, as... Figure 9 As shown, when the main body of the grouting drill rod 100 with the helical blades 101 is completely pushed into the soil layer behind the shield tunnel segment wall by the helical thrust rod 220, the conical boss 102 on the grouting drill rod 100 and the tapered hole 311 of the pre-embedded guide pipe 300 are connected by a threaded fit. Furthermore, constrained by the conical shapes of both, the helical thrust rod 220 cannot continue to rotate forward at this point, indicating that the grouting drill rod 100 has been installed in place. The next step is to separate the helical thrust rod 220 from the grouting drill rod 100 to complete the installation of the grouting drill rod.

[0078] When separating the helical thrust rod 220, it is necessary to rotate the helical thrust rod 220 in the opposite direction to disengage its threaded connection with the grouting drill rod 100. To prevent the grouting drill rod 100 from rotating in the opposite direction along with the helical thrust rod 220, in a preferred embodiment, a spring pin 105 is provided at the rear end of the grouting drill rod 100 near the conical boss. The spring pin 105 is retractable relative to the grouting drill rod 100. The distance between the end of the spring pin 105 and the central axis of the grouting drill rod 100 is L, the inner diameter of the front mounting hole 2111 is R1, and the outer diameter of the tube body 310 is R2. When the spring pin 105 retracts, L < R1; when the spring pin 105 extends, L > R2. Moreover, the inner diameter r1 of the front connecting pipe 2112 is not greater than the inner diameter r2 of the pipe head 320, so that after the front connecting pipe 2112 is connected to the pipe head 320, the spring pin 105 can pass smoothly through the connection point between the two.

[0079] During the installation phase of the grouting drill rod 100, when the grouting drill rod 100 moves to the opening of the front mounting hole 2111 of the front mounting plate 211, the spring pin 105 is pressed to retract it, allowing the grouting drill rod 100 to pass smoothly through the front mounting hole 2111. The spring pin 105 remains retracted as the grouting drill rod 100 passes through the front mounting hole 2111 and the pre-embedded guide pipe 300. After the spring pin 105 has passed through the pre-embedded guide pipe 300 with the grouting drill rod 100, the spring pin 105 extends. At this time, the helical thrust rod 220 is rotated in the opposite direction to retract it. Because the spring pin 105 on the grouting drill rod 100 is blocked by the pre-embedded guide pipe 300, the grouting drill rod 100 cannot retract with the helical thrust rod 220. Thus, the helical thrust rod 220 is smoothly separated from the grouting drill rod 100, while the grouting drill rod 100 maintains its connection with the pre-embedded guide pipe 300.

[0080] Specifically, the spring pin 105 can adopt the following structure: The spring pin 105 includes a pin rod, an insertion hole is opened on the grouting drill rod 100 near the conical boss 102, the head end of the pin rod is set as an arc surface, the tail end of the pin rod is inserted into the grouting channel 103 through the insertion hole, an annular boss is set in the middle of the pin rod, and a spring is sleeved on the pin rod between the annular boss and the grouting drill rod 100. With this configuration, when the head end of the pin rod is pressed, the pin rod will retract into the grouting channel 103, and the spring will be compressed accordingly; when the pressing force is removed, the spring extends, causing the pin rod to extend.

[0081] To prevent the pin from completely detaching from the insertion hole, protrusions can be provided on both sides of the pin's tail end, and grooves that mate with the protrusions can be provided on both sides of the insertion hole. During pin installation, the protrusions can pass through the grooves, and then steel wire is welded into the grooves to seal them, thus preventing the pin from detaching from the insertion hole. It should be noted that the structure of the spring pin is not limited to this; other conventional structures from existing technology can also be used.

[0082] In one embodiment, the outer wall of the pre-embedded conduit 300 is provided with positioning claws 330, which are used to connect with the segment reinforcement cage 2. During operation, the pre-embedded conduit 300 is first clamped and fixed to the segment reinforcement cage using the positioning claws 330, and then the positioning claws 330 are welded and fixed to the segment reinforcement cage using carbon dioxide gas shielded welding. Typically, two positioning claws 330 can be provided on the pre-embedded conduit 300.

[0083] In another embodiment, the rear mounting plate 212 is provided with a rear connecting pipe 2122 on the side away from the front mounting plate 211. The inner wall of the rear connecting pipe 2122 is provided with internal threads and is connected to the rear mounting hole 2121 with the same diameter. A stable threaded connection relationship is formed between the rear mounting hole 2121, the rear connecting pipe 2122 and the helical thrust rod 220.

[0084] Example 2:

[0085] This embodiment provides a grouting reinforcement method for locally loose soil layers behind the tunnel lining segment wall. Based on the grouting reinforcement device of Embodiment 1, it further includes the following steps:

[0086] S1: As Figure 10 As shown, a shield tunnel segment 1 with a pre-embedded conduit 300 is obtained, with the front end and rear end of the pre-embedded conduit 300 protruding from the outer and inner ring surfaces of the shield tunnel segment 1, respectively.

[0087] S2: As Figure 16 As shown in the figure, the shield tunnel segment 1 obtained in step S1 is installed in the loose soil layer 4 of the tunnel 3, and each shield tunnel segment 1 is assembled to form a ring lining. The grouting drill rod propulsion mechanism 200 is installed on the pre-embedded conduit 300 that needs grouting.

[0088] S3: As Figure 17 and Figure 18 As shown, the grouting drill rod 100 is inserted into the loose soil layer behind the shield tunnel segment wall using the grouting drill rod propulsion mechanism 200, and the end of the grouting drill rod 100 is connected to the pre-embedded conduit 300.

[0089] S4: Connect the grouting pipe to the pre-embedded conduit 300, such as Figure 19 As shown, the grout is introduced into the grouting drill rod 100 through the grouting pipe, and then injected into the loose soil layer through the grouting hole 104 on the grouting drill rod 100, finally forming the grouting solidified body 5;

[0090] S5: When the grouting pressure reaches the design grouting pressure, stop grouting. After the grout reaches the final setting time, remove the grouting drill rod propulsion mechanism 200 and screw stainless steel bolts 500 into the pre-embedded guide pipe 300. This completes the grouting reinforcement of the local loose soil layer behind the shield tunnel segment 1 wall.

[0091] In this embodiment, the grouting drill rod 100 adopts an integral structure. The specific operation method of step S3 is as follows: rotate the spiral thrust rod 220 in the forward direction so that its front end passes through the rear mounting hole 2121 on the rear mounting plate 212, connect the grouting drill rod 100 to the front end of the spiral thrust rod 220, continue to rotate the spiral thrust rod 220 in the forward direction so that the front end of the grouting drill rod 100 passes through the front mounting plate 211 and the pre-embedded guide pipe 300 in the shield segment in sequence, and is inserted into the loose soil layer behind the shield segment wall.

[0092] In step S5, before dismantling the grouting drill rod propulsion mechanism 200, it is necessary to separate the helical thrust rod 220 from the grouting drill rod 100. The separation method is as follows:

[0093] The spring pin 105 at the rear end of the grouting drill rod 100 enters the loose soil layer behind the shield tunnel segment wall along with the grouting drill rod 100. The spring pin 105 extends and blocks the front end of the pipe body 310. When the helical thrust rod 220 is rotated in the reverse direction, the grouting drill rod 100 is blocked by the spring pin 105 and cannot retract into the pre-embedded guide pipe 300, thus allowing the helical thrust rod 220 to be rotated in the reverse direction independently until it separates from the grouting drill rod 100. When the helical thrust rod 220 is rotated in the reverse direction, the frame body 210 can be held by hand or with the assistance of other tools.

[0094] In step S1, the method for obtaining the shield tunnel segment 1 with the pre-embedded conduit 300 includes the following steps:

[0095] S110: The pre-embedded guide pipes 300 are fixed in the steel cage of the tunnel segment. Each pre-embedded guide pipe 300 is filled with a sealing plug. The sealing plug is made of polystyrene foam, natural rubber, butyl rubber and other materials. In actual operation, the size of the pre-embedded guide pipes 300 should be determined according to the overall size of the shield tunnel segment 1, the spacing of the steel bars in the shield tunnel segment 1 and the stability requirements of the grouting drill rod propulsion mechanism 200 and the grouting drill rod 100. The pre-embedded positions of the pre-embedded guide pipes 300 should be arranged according to the position that is favorable to improving the bearing capacity of the loose soil foundation.

[0096] S120: Place the steel cage for the tunnel segment obtained in step S110 into the casting mold, pour concrete into the casting mold, remove the casting mold after the concrete is formed, and cure it to produce the shield tunnel segment 1.

[0097] S130: Remove the sealing plug from the pre-embedded conduit 300 and install stainless steel bolts inside the pre-embedded conduit 300 that does not require grouting. For example... Figure 12 As shown, the stainless steel bolts can be made of hexagonal socket head cap screws with external threads, so that the hexagonal socket head cap screws can be threadedly connected to the pipe head 320 of the pre-embedded conduit 300.

[0098] It should be noted that the helical direction of the internal and external threads on the helical blade 101 and its various structures must be consistent.

[0099] Example 3:

[0100] Typically, the length of the helical thrust rod 220 and the frame 210 are limited, while the thickness of the soil layer requiring grouting behind the shield tunnel segment wall may be relatively large. Therefore, the required length of the grouting drill rod 100 will be greater than the length of the helical thrust rod 220. To ensure that the required length of the grouting drill rod 100 can be pushed into the soil layer by the helical thrust rod 220, based on Example 1, in the grouting reinforcement device for the locally loose soil layer behind the shield tunnel segment 1 provided in this embodiment, the grouting drill rod 100 adopts a multi-segment assembly structure. For example, as... Figure 13 As shown, the grouting drill rod 100 is assembled from three sections: the first section 110, the middle section 120, and the last section 130. A tapered boss 102 and a spring pin 105 are mounted on the last section 130. Adjacent drill rod sections are connected by threads; the connection method can employ conventional techniques. It is understood that the distance between the front mounting plate 211 and the rear mounting plate 212 in the frame 210 should be greater than the length of the single-section grouting drill rod 100 to ensure smooth installation of the single-section grouting drill rod 100 at the front end of the helical thrust rod 220.

[0101] Specifically, during operation, the first section of drill rod 110 is first connected to the front end of the auger thrust rod 220, and the first section of drill rod 110 is pushed into the soil by rotating the auger thrust rod 220 in the forward direction; then, the auger thrust rod 220 is rotated in the reverse direction to separate it from the first section of drill rod 110 and retract it to the rear mounting plate 212. Next, the above actions are repeated to install the middle section of drill rod 120 and the tail section of drill rod 130.

[0102] In the process of separating the helical thrust rod 220 from the first section of drill rod 110 or the middle section of drill rod 120, in order to prevent the first section of drill rod 110 or the middle section of drill rod 120 from retracting along with the helical thrust rod 220, the grouting reinforcement device provided in this embodiment also includes a drill rod anti-retraction mechanism 400.

[0103] Specifically, such as Figure 11 , Figure 14 and Figure 15As shown, the drill pipe anti-retraction mechanism 400 includes a snap-fit ​​body 410 and a clamping bolt 420. The snap-fit ​​body 410 has a snap-fit ​​interface 411 on its end face, which can snap into the spiral blade 101. The clamping bolt 420 is located near the snap-fit ​​body 410, parallel to the axial direction of the connecting rod, and threaded onto the front mounting plate 211. The snap-fit ​​body 410 can be clamped between the nut of the clamping bolt 420 and the front mounting plate 211. Furthermore, the snap-fit ​​body 410 has an elongated hole 412 in its middle, through which it slides onto one of the connecting rods, preventing it from falling off. The elongated hole facilitates the movement of the snap-fit ​​body 410 towards or away from the spiral blade 101.

[0104] During operation, before reversing the spiral thrust rod 220, the moving locking body 410 engages with the spiral blade 101 of the first drill rod 110 or the intermediate drill rod 120 via the locking interface 411. Then, the clamping bolt 420 is tightened to prevent the locking body 410 from separating from the spiral blade 101. Subsequently, reversing the spiral thrust rod 220 prevents the first drill rod 110 or the intermediate drill rod 120 from retracting.

[0105] Example 4:

[0106] The grouting reinforcement method for loose soil layers behind the shield tunnel segment wall provided in this embodiment is applicable to cases where the grouting drill rod 100 adopts a multi-segment assembly structure. Based on embodiments 2 and 3, the specific operation method of step S3 is as follows: After inserting the first section drill rod 110 into the loose soil layer behind the shield tunnel segment wall using the helical thrust rod 220, the helical blade 101 at the rear end of the first section drill rod 110 is locked through the locking interface 411 on the drill rod anti-retraction mechanism. Then, the helical thrust rod 220 is rotated in the reverse direction to retract it. During the retraction process, the helical thrust rod 220 separates from the first section drill rod 110. Subsequently, the drill rod anti-retraction mechanism is returned to its position, the helical thrust rod 220 is rotated in the reverse direction to retract it to a suitable position, and the middle section drill rod 120 is installed at its front end. Then, the helical thrust rod 220 is rotated in the forward direction to drive the middle section drill rod 120 forward. During the forward movement of the middle section drill rod 120, it connects with the first section drill rod 110 and is inserted into the loose soil layer behind the shield tunnel segment wall.

[0107] After the intermediate drill pipe 120 is installed, the tail drill pipe 130 can be installed using the method described above. The method for separating the tail drill pipe 130 from the auger thrust rod 220 is described in step S5 of Example 2.

[0108] It should be noted that the accompanying drawings of this invention are schematic diagrams of grouting drill rod propulsion mechanism 200 installed on pre-embedded guide pipes inside the bottom shield tunnel segments for grouting. In actual operation, the grouting drill rod propulsion mechanism 200 can be installed on the required pre-embedded guide pipes as needed.

[0109] In this invention, the pre-embedded guide pipe is positioned and installed during the production of the tunnel lining segments, eliminating the need for secondary damage to the segments. The grouting drill rod propulsion mechanism is fixed to the tunnel lining segments via the pre-embedded guide pipe, eliminating the need for drilling and fixing operations on the segments, thus simplifying the operation process. The auger drill rod can increase its lateral friction resistance with the loose soil layer, thereby reducing the reverse force generated by the grouting pressure on the tunnel lining segments.

[0110] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0111] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0112] Any aspects of this invention not described in detail are well-known to those skilled in the art.

Claims

1. A grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls, characterized in that, The system includes a grouting drill rod, a grouting drill rod propulsion mechanism, and a pre-embedded conduit installed inside the shield tunnel segment. The grouting drill rod propulsion mechanism is used to insert the grouting drill rod into the loose soil layer behind the shield tunnel segment wall and connect the grouting drill rod to the pre-embedded conduit. The surface of the grouting drill rod is provided with helical blades. The pre-embedded conduit includes a pipe body and a pipe head coaxially connected to the rear end of the pipe body. The inner diameter of the pipe head is larger than the inner diameter of the pipe body. The front end of the pipe body is a tapered hole with a narrow opening. The inner wall of the pipe head and the wall of the tapered hole with a narrow opening are both provided with internal threads. The grouting drill rod propulsion mechanism includes a frame and a spiral thrust rod; The frame includes a front mounting plate and a rear mounting plate spaced apart. The front mounting plate and the rear mounting plate are connected by several connecting rods. The front mounting plate and the rear mounting plate are respectively coaxially provided with a front mounting hole and a rear mounting hole. The wall of the rear mounting hole is provided with internal threads. A front connecting pipe is provided on the side of the front mounting plate away from the rear mounting plate. The front connecting pipe is connected to the front mounting hole with the same diameter. The inner diameter of the front connecting pipe is not greater than the inner diameter of the pipe head. The outer wall of the front connecting pipe is provided with external threads. The spiral thrust rod is provided with an external thread that mates with the rear mounting hole, the rear end of the spiral thrust rod is provided with a rotating handle, and the front end of the spiral thrust rod is provided with an external thread that mates with the grouting drill rod. The inner wall of the rear end of the grouting drill rod is provided with an internal thread that mates with the front end of the spiral thrust rod. A conical boss is coaxially provided on the outer side of the rear end of the grouting drill rod. An external thread is provided on the conical boss that mates with the conical hole at the end of the pre-embedded conduit. The outer diameter of the conical boss is smaller than the diameter of the front mounting hole and larger than the outer diameter of the spiral blade. The rear end of the grouting drill rod is provided with a spring pin, which can extend and retract relative to the grouting drill rod; the distance between the end of the spring pin and the central axis of the grouting drill rod is L, the inner diameter of the front mounting hole is R1, and the outer diameter of the pipe body is R2; when the spring pin retracts, L < R1; when the spring pin extends, L > R2. The method of using the grouting reinforcement device includes the following steps: S1: Obtain the shield tunnel segment with pre-embedded conduit, so that the front end and rear end of the pre-embedded conduit are exposed from the outer and inner ring surfaces of the shield tunnel segment, respectively. S2: Install the shield tunnel segments obtained in step S1 into the tunnel, and install the grouting drill rod propulsion mechanism on the pre-embedded guide pipe that needs grouting. S3: Use the grouting drill rod propulsion mechanism to insert the grouting drill rod into the loose soil layer behind the shield tunnel segment wall, and connect the end of the grouting drill rod to the pre-embedded conduit. S4: Connect the grouting pipe to the pre-embedded conduit. The grout is introduced into the grouting drill rod through the grouting pipe and then injected into the loose soil layer through the grouting hole on the grouting drill rod. S5: After grouting is completed and the grout has reached its final setting time, the grouting drill rod propulsion mechanism is removed, and stainless steel bolts are screwed into the pre-embedded guide pipe to complete the grouting reinforcement of the local loose soil layer behind the shield tunnel segment wall. The operation method of step S3 is as follows: rotate the spiral thrust rod in the forward direction so that its front end passes through the rear mounting hole on the rear mounting plate, connect the grouting drill rod to the front end of the spiral thrust rod, continue to rotate the spiral thrust rod in the forward direction so that the front end of the grouting drill rod passes through the pre-embedded guide pipe in the front mounting plate and the shield segment in sequence, and is inserted into the loose soil layer behind the shield segment wall.

2. The grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls according to claim 1, characterized in that, It also includes a drill pipe anti-retraction mechanism, which comprises: The buckle body has a snap-fit ​​interface on its end face, which can snap into a spiral blade. The buckle body has an elongated hole in its middle, through which the buckle body is slidably fitted onto one of the connecting rods. A clamping bolt is located near the snap-fit ​​body and is parallel to the axis of the connecting rod. The clamping bolt is threaded onto the front mounting plate, and the snap-fit ​​body can be clamped between the nut of the clamping bolt and the front mounting plate.

3. The grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls according to claim 1, characterized in that, The outer wall of the pre-embedded conduit is provided with positioning claws, which are used to connect with the steel cage of the pipe segment.

4. The grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls according to claim 1, characterized in that, The rear mounting plate has a rear connecting pipe on the side away from the front mounting plate. The inner wall of the rear connecting pipe has internal threads and is connected to the rear mounting hole with the same diameter.

5. The grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls according to claim 1, characterized in that, In step S5, before dismantling the grouting drill rod propulsion mechanism, it is necessary to separate the helical thrust rod from the grouting drill rod. The separation method is as follows: The spring pin at the rear end of the grouting drill rod enters the loose soil layer behind the shield tunnel segment wall along with the grouting drill rod. The spring pin extends and blocks the front end of the pipe body. When the helical thrust rod is rotated in the opposite direction, the grouting drill rod is blocked by the spring pin and cannot retract into the pre-embedded guide pipe. Thus, the helical thrust rod can be rotated in the opposite direction alone until it separates from the grouting drill rod.

6. The grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls according to claim 1, characterized in that, When the grouting drill rod adopts a multi-segment assembly structure, the operation method of step S3 is as follows: After inserting the previous grouting drill rod into the loose soil layer behind the shield tunnel segment wall using the helical thrust rod, the helical blade at the rear end of the previous grouting drill rod is locked by the drill rod anti-retraction mechanism. Then, the helical thrust rod is rotated in the reverse direction to retract it. During the retraction process, the helical thrust rod separates from the previous grouting drill rod. Subsequently, the drill rod anti-retraction mechanism is returned to its position, the helical thrust rod is rotated in the reverse direction to retract it to a suitable position, and the next grouting drill rod is installed at its front end. Then, the helical thrust rod is rotated in the forward direction to drive the next grouting drill rod forward. During the forward movement of the next grouting drill rod, it connects with the previous grouting drill rod and is inserted into the loose soil layer behind the shield tunnel segment wall.

7. The grouting reinforcement device for locally loose soil layers behind shield tunnel segment walls according to claim 1, characterized in that, In step S1, the method for obtaining shield tunnel segments with pre-embedded guide pipes includes the following steps: S110: Pre-embedded conduits are fixed in the steel cage of the tunnel segment. Each pre-embedded conduit is filled with a sealing plug. The sealing plug is made of polystyrene foam, natural rubber or butyl rubber. S120: Place the segment reinforcement cage obtained in step S110 into the casting mold, pour concrete into the casting mold, remove the casting mold after the concrete is formed, and cure it to produce shield tunnel segments. S130: Remove the sealing plug from the pre-embedded conduit and install stainless steel bolts in the pre-embedded conduit that does not require grouting.

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