Single-double liquid switching grouting system for large longitudinal slope water-rich sand mudstone interbed shield tunnel

Abstract

The single-double fluid switching grouting system for the large longitudinal slope water-rich sand mudstone interbed shield tunnel is simple in structure and convenient to install, the grouting system and a sand improvement system are fused, and construction processes such as muck improvement, advanced grouting, shield tail synchronous grouting and segment grouting can be carried out in the excavation process of the shield tunnel. The designed grouting pipe and the mixer can achieve the effect of switching between single and double liquid grouting pipelines, the effects of advanced grouting for improving a soil body and shield tail synchronous grouting for rapidly fixing a pipe piece can be achieved, the pneumatic injection mode and the extrusion injection mode can be switched, and the purpose of fully supplementing grout is achieved. According to the system, the grouting system can be switched in real time according to the stratum adaptability, the engineering problems that under the large longitudinal slope water-rich sand shale interbed working condition, the soil body settlement amount is large, and water leakage is likely to happen can be solved, and the obvious effect on fixed duct piece floating resistance is achieved.

Description

Technical Field

[0001] This utility model relates to the field of tunnel and underground space engineering, and in particular to a grouting system used for excavation of shield tunnels in water-rich sandy mudstone interbedded strata on a steep longitudinal slope. Specifically, it relates to a single-to-double liquid switching grouting system for shield tunnels in water-rich sandy mudstone interbedded strata on a steep longitudinal slope. Background Technology

[0002] With the increasing number of tunnel projects in my country, people's demands for the user experience of tunnels are also increasing, and the geological conditions they face are becoming more complex. Interbedded layers of water-rich sandstone and mudstone on long longitudinal slopes present typical engineering challenges, including surrounding rock pressure, uneven settlement, susceptibility to erosion by flowing water during simultaneous grouting, easy dispersion, and inadequate filling.

[0003] The main purposes of synchronous grouting in shield tunnels are: (1) to fill gaps as early as possible to prevent ground deformation; (2) to fix the position of the tunnel lining segments; (3) to ensure the compactness of the gaps at the shield tail so that the segments are subjected to uniform stress; (4) to serve as the first line of defense for waterproofing the lining, providing long-term, stable and effective waterproofing; and (5) to serve as a reinforcing layer for the tunnel segment structure, providing a certain load-bearing capacity. Therefore, how to improve the grouting system and grouting device has become a necessary solution.

[0004] In the construction of shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes, one section of the stratum is often water-rich while another is non-water-rich. Generally, single-liquid grouting is used for the non-water-rich layer, while double-liquid grouting is used for the water-rich layer. However, using single-liquid grouting in the water-rich layer can easily lead to ground subsidence, segregation of the grout layer, and susceptibility to groundwater influence. Conversely, directly using double-liquid grouting increases costs when entering the non-water-rich layer. Therefore, we propose a single-to-double-liquid switching grouting system for shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes, aiming to address the shortcomings of existing technologies. Utility Model Content

[0005] To address the shortcomings of existing technologies, the purpose of this utility model is to provide a single-to-double liquid grouting system for shield tunnels with interbedded water-rich sandstone and mudstone on steep longitudinal slopes. In order to effectively cope with the problems of surrounding rock pressure and uneven settlement under steep longitudinal slope excavation conditions, the designed grouting switch device can achieve the effect of switching between single and double liquid grouts. This allows the single liquid grout to penetrate into the stratum in advance, and the double liquid grout to fill the shield tail gap as the main component, thereby reducing the amount of stratum settlement and reducing groundwater infiltration.

[0006] In order to achieve the above objectives, the technical solution of this utility model is as follows:

[0007] A single-to-double liquid switching grouting system for a shield tunnel with alternating layers of water-rich sandstone and mudstone on a large longitudinal slope includes: a shield tail grouting device, a segment grouting device, and a spoil improvement system.

[0008] The shield tail grouting device includes an A-liquid grout storage tank, a B-liquid grout storage tank, a second grouting pipe switching device, and grouting pipelines;

[0009] The segment grouting device includes an A-liquid storage tank, a B-liquid storage tank, a first grouting pipe switch device, a jacking rod, a grouting piston, a grouting pipe, a cleaning pipe, and a grouting perforated pipe;

[0010] The slag improvement system includes a bentonite slurry storage tank, a T-junction, and a mixer;

[0011] The A liquid storage tank and the B liquid storage tank are respectively connected to the two inlet ends of the first grouting pipe switch device through the A liquid delivery pipe and the B liquid delivery pipe, and the outlet end of the first grouting pipe switch device is connected to the side wall of the grouting pipe.

[0012] The grouting piston is installed inside one end of the grouting pipe. The grouting piston can move in the grouting pipe by piston-like extrusion through the extension and retraction of the jacking rod. The cleaning pipe is connected to the side wall of the grouting pipe. The other end of the grouting pipe is connected to the grouting perforated pipe.

[0013] The A-liquid storage tank and the B-liquid storage tank are respectively connected to the two inlet ends of the second grouting pipe switch device via grout pipes, and the outlet end of the second grouting pipe switch device is connected to a delivery pipe.

[0014] The bentonite slurry storage tank is connected to one port of the tee, and the other two ports of the tee are connected to the mixer and the A liquid storage tank respectively through bentonite slurry pipes.

[0015] Furthermore, the size of the grouting pipe of the segment grouting device matches the reserved hole of the segment, and the grouting pipe is equipped with a grouting plug and a grouting recorder.

[0016] Furthermore, the second grouting pipe switching device includes a housing and an outer valve core. The housing is provided with two inlet ends and a delivery pipe. The outer valve core has a spherical outer contour and is assembled inside the housing. The outer valve core is provided with a grouting channel inside.

[0017] Rotating the outer valve core allows both inlet ends of the outer casing to be connected to the delivery pipe together, or one inlet end to be connected to the delivery pipe individually.

[0018] Furthermore, the grouting channel of the outer valve core has a circular cross-section, and an inner valve core is assembled inside the grouting channel of the outer valve core. The inner valve core is annular, and a small flow hole is opened on the side wall of the inner valve core.

[0019] Furthermore, a rotating shaft is fixed to the top of the outer side of the outer valve core, and the upper end of the rotating shaft extends through the side wall of the housing to the outside and is connected to a rotating wheel;

[0020] A rotating rod is fixed to the bottom outer side of the inner valve core. The lower end of the rotating rod passes through the side wall of the outer valve core and the outer shell, extends to the outside, and is connected to a rotating handle.

[0021] Furthermore, the cross-sectional area of ​​the grouting channel of the outer valve core is smaller than the sum of the cross-sectional areas of the two inlet ends of the outer shell.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. This utility model features simple operation and low material cost. It allows for rapid switching between single- and double-liquid grouting systems based on geological conditions, effectively solving engineering challenges such as large soil settlement and easy water leakage in water-rich sandstone-mudstone interbedded conditions on steep longitudinal slopes. It also has a significant effect on fixing tunnel segments and preventing uplift. By using this grouting system, safe and efficient excavation of tunnel boring machines under water-rich sandstone-mudstone interbedded conditions on steep longitudinal slopes can be achieved. Furthermore, the production method is simple, has a high fault tolerance rate, and offers higher production efficiency and lower cost compared to existing technologies.

[0024] 2. By combining two simultaneous grouting methods, tail grouting and segment grouting, the optimized grouting device has both pneumatic and extrusion grouting power supply methods, which can effectively improve grouting filling efficiency and grout density, reduce filling voids, and stabilize segment position.

[0025] 3. To effectively address the challenges of simultaneous grouting with two liquids in water-rich sandstone-mudstone interbedded conditions, such as susceptibility to erosion by flowing water, easy dispersion, and insufficient filling, this system comprehensively addresses these issues. It optimizes the grouting pipeline design and device, integrating both tail grouting and segment grouting methods. The optimized device features both pneumatic and extrusion-based grouting power supply, effectively improving grouting efficiency and density, reducing voids, and stabilizing segment positions. By using this grouting system, safe and efficient excavation of the tunnel boring machine (TBM) in water-rich sandstone-mudstone interbedded conditions on steep longitudinal slopes can be achieved. Attached Figure Description

[0026] Figure 1 A schematic diagram of the shield tunneling grouting system provided by this utility model;

[0027] Figure 2 A structural diagram of a grouting pipe capable of single- to dual-liquid switching provided by this utility model (grouting process).

[0028] Figure 3 A structural diagram of a grouting pipe capable of single- to dual-liquid switching provided by this utility model (cleaning process);

[0029] Figure 4 This is a schematic diagram of the internal structure of the second grouting pipe switching device provided by this utility model;

[0030] Figure 5This is a schematic diagram of the appearance of the second grouting pipe switching device provided by this utility model;

[0031] Figure 6 This is a schematic diagram of the single-liquid state of the second grouting pipe switching device provided by this utility model;

[0032] Figure 7 This is a schematic diagram of the dual-liquid state of the second grouting pipe switching device provided by this utility model;

[0033] In the diagram: 1. Segment grouting device; 2. Second grouting pipe switch device; 3. T-junction; 4. Mixer; 5. Cutterhead; 6. A-liquid storage tank; 7. B-liquid storage tank; 8. Bentonite slurry storage tank; 9. Segment; 10. Shield tail gap; 101. A-liquid storage tank; 102. A-liquid delivery pipe; 103. B-liquid storage tank; 104. B-liquid delivery pipe; 105. First grouting pipe switch device; 10 6. Push rod; 107. Grouting piston; 108. Grouting pipe; 109. Cleaning pipe; 1010. Grouting plug; 1011. Grouting perforated pipe; 1012. Grouting recorder; 201. Rotary wheel; 202. Rotary shaft; 203. Conveying pipe; 204. Inner valve core; 205. Outer valve core; 206. Small flow hole; 207. Rotating rod; 208. Rotating handle; 209. Second conveying pipe. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0035] like Figure 1-7 As shown, the single-to-dual liquid switching grouting system for the shield tunnel with interbedded water-rich sandstone and mudstone on a large longitudinal slope includes a tail grouting device, a segment grouting device 1, and a spoil improvement system. The tail grouting device includes an A-liquid storage tank 6, a B-liquid storage tank 7, a second grouting pipe switch device 2, and grouting pipelines. The segment grouting device includes an A-liquid storage tank 101, an A-liquid delivery pipe 102, a B-liquid storage tank 103, a B-liquid delivery pipe 104, a first grouting pipe switch device 105, a jacking rod 106, a grouting piston 107, a grouting pipe 108, a cleaning pipe 109, a grouting plug 1010, a grouting perforated pipe 1011, and a grouting recorder 1012. The spoil improvement system includes a bentonite slurry storage tank 8, a tee 3, and a mixer 4.

[0036] In the segment grouting device, the upper parts of liquid A storage tank 101 and liquid B storage tank 103 are respectively connected to the two inlet ends of the first grouting pipe switch device 105 through liquid A delivery pipe 102 and liquid B delivery pipe 104. The outlet end of the first grouting pipe switch device 105 is connected to the side wall of the grouting pipe 108. Pressure pumps are installed on liquid A delivery pipe 102 and liquid B delivery pipe 104 respectively, which can pump liquid A and liquid B to the first grouting pipe switch device 105 respectively. The pumping pressure of liquid B is greater than that of liquid A, which can mix the two in the first grouting pipe switch device 105. A grouting piston 107 is installed inside one end of the grouting pipe 108. The jacking rod 106 is located outside the grouting pipe 108. The grouting piston 107 can move in a piston-like squeezing motion in the grouting pipe 108 by extending and retracting the jacking rod 106. The cleaning pipe 109 is connected to the side wall of the grouting pipe 108; the other end of the grouting pipe 108 is connected to the grouting perforated pipe 1011, and a grouting plug 1010 and a grouting recorder 1012 are installed on the grouting perforated pipe 1011. The grouting pipe 108 can collect grout from the A liquid delivery pipe 102 and the B liquid delivery pipe 104, and finally squeeze the grout towards the grouting perforated pipe 1011.

[0037] The grouting pipe 1011 of the segment grouting device is sized to match the pre-drilled holes in the segments. During operation, the grouting pipe needs to be inserted into the pre-drilled holes. The segment grouting device offers two injection modes: pneumatic and extrusion pumping. In the pneumatic mode, the grouting power is provided by a pneumatic pump, resulting in a high flow rate. During operation, the jacking rod 106 extends to its maximum distance, the central channel is closed, and the grout is injected into the segment gaps after being mixed in the A-liquid delivery pipe 102 and B-liquid delivery pipe 104 via the first grouting pipe switching device 105. The extrusion pumping mode is used when the initial grouting is completed and voids exist in the grout layer; in this case, pneumatic grouting is ineffective. In the extrusion pumping mode, the jacking rod 106 drives the grouting piston 107 to reciprocate and extrude the mixed grout, causing it to enter the segment gaps and complete the filling.

[0038] When the segment grouting device finishes its work and enters the cleaning stage, the grouting plug is closed, clean water is flushed in through the cleaning pipe 109, and mainly flows out in reverse from the A liquid delivery pipe 102 and the B liquid delivery pipe 104 to complete the cleaning.

[0039] In the tail grouting device, liquid A storage tank 6 and liquid B storage tank 7 are respectively transported through grout pipelines.

[0040] The pump is connected to the two inlet ends of the second grouting pipe switch device 2, and the outlet of the second grouting pipe switch device 2 is...

[0041] The inlet is connected to a delivery pipe 203, which extends to the shield tail gap. The bentonite slurry storage tank 8 is connected...

[0042] One port of T-junction 3 is connected to the mixer via bentonite slurry pipes.

[0043] 4 and A-liquid storage tank 6. In the single-to-double liquid switching grouting system of the shield tunnel with water-rich sandstone and mudstone interlayers on the longitudinal slope, the bentonite slurry required to prepare A-liquid is provided by bentonite slurry storage tank 8; the remaining bentonite slurry is transported to the slag improvement system to improve the slag and reduce the pressure on the cutterhead.

[0044] During the shield tail grouting process, when encountering water-rich areas, dual-liquid grouting is required; when encountering non-water-rich areas, single-liquid grouting is sufficient. To achieve rapid switching between single and dual-liquid grouting, the second grouting pipe switching device 2 mainly includes a shell, a rotating wheel 201, a rotating shaft 202, a conveying pipe 203, an inner valve core 204, an outer valve core 205, a small flow hole 206, a rotating rod 207, and a rotating handle 208.

[0045] The outer casing has two inlet ends and a delivery pipe 203. The outer valve core 205 has a spherical outer contour and is assembled inside the outer casing. A rotating shaft 202 is fixed to the top outer side of the outer valve core 205. The upper end of the rotating shaft 202 extends through the side wall of the outer casing to the outside and connects to the rotating wheel 201. A grouting channel with a circular cross-section is machined inside the outer valve core 205. The cross-sectional area of ​​the grouting channel of the outer valve core 205 is larger than the cross-sectional area of ​​the inlet end, smaller than the sum of the cross-sectional areas of the two inlet ends of the outer casing, and smaller than the cross-sectional area of ​​the delivery pipe 203. The delivery pipe 203 is on the same axis as one of the inlet ends, and the other inlet end is at an angle of less than 45° to the axis of the first inlet end. Rotating the outer valve core 205 by the rotating wheel 201 allows the two inlet ends of the outer casing to be connected to the delivery pipe 203 through the grouting channel, or allows one inlet end to be connected to the delivery pipe 203 through the grouting channel alone.

[0046] To control the grout flow rate within the grouting channel, an inner valve core 204 is installed within the grouting channel of the outer valve core 205. The inner valve core 204 is circular in shape, and a small flow hole 206 is formed on its side wall. A rotating rod 207 is fixed to the bottom outer side of the inner valve core 204. The lower end of the rotating rod 207 passes through the side wall of the outer valve core 205 and the outer shell, extending to the outside and connecting to a rotating handle 208. When the axis of the inner valve core 204 coincides with the axis of the grouting channel, the flow area of ​​the grouting channel is at its maximum. When the inner valve core 204 is rotated 90°, the axis of the small flow hole 206 coincides with the axis of the grouting channel, and the flow area of ​​the grouting channel is at its minimum. This allows the grout flow rate to be controlled to a certain extent by the inner valve core 204. The outer valve core 205 and the inner valve core 204 can rotate independently, thereby controlling the opening and closing of the grouting delivery pipe and achieving single-to-dual liquid switching.

[0047] The specific working process of the single-to-dual-liquid switching grouting system for shield tunnels with interbedded water-rich sandstone and mudstone on steep longitudinal slopes described in this embodiment is as follows:

[0048] The tail grouting device grouts the gap at the tail of the shield, while the segment grouting device replenishes the grout in the segments. When the tunnel boring machine (TBM) excavates into non-water-rich strata, the tail grouting device only needs to operate in single-liquid grouting mode. Figure 6 As shown, by rotating the outer valve core, only the inlet end of the A-liquid grout storage tank 6 is allowed to be connected to the delivery pipe 203 through the grouting channel, thus using a single-liquid grouting mode; when the tunnel boring machine excavates into a water-rich stratum, a dual-liquid grouting mode is required, such as... Figure 7 As shown, by rotating the outer valve core, the inlet end of the A liquid storage tank 6 and the inlet end of the B liquid storage tank 7 are connected to the delivery pipe 203 through the grouting channel, thereby grouting in a dual-liquid mode.

[0049] Although specific embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A single-to-double-liquid switching grouting system for a shield tunnel with alternating layers of water-rich sandstone and mudstone on a steep longitudinal slope, characterized in that, include: Shield tail grouting device, segment grouting device (1) and slag improvement system; The shield tail grouting device includes an A-liquid grout storage tank (6), a B-liquid grout storage tank (7), a second grouting pipe switch device (2), and grouting pipelines; The segment grouting device includes an A liquid storage tank (101), a B liquid storage tank (103), a first grouting pipe switch device (105), a jacking rod (106), a grouting piston (107), a grouting pipe (108), a cleaning pipe (109), and a grouting perforated pipe (1011). The slag improvement system includes a bentonite slurry storage tank (8), a tee (3), and a mixer (4). The A liquid storage tank (101) and the B liquid storage tank (103) are respectively connected to the two inlet ends of the first grouting pipe switch device (105) through the A liquid delivery pipe (102) and the B liquid delivery pipe (104), and the outlet end of the first grouting pipe switch device (105) is connected to the side wall of the grouting pipe (108). The grouting pipe (108) is fitted with the grouting piston (107) at one end. The grouting piston (107) can be moved in the grouting pipe (108) by piston-like extrusion through the extension and retraction of the jacking rod (106). The cleaning pipe (109) is connected to the side wall of the grouting pipe (108). The other end of the grouting pipe (108) is connected to the grouting flower pipe (1011). The A liquid storage tank (6) and the B liquid storage tank (7) are respectively connected to the two inlet ends of the second grouting pipe switch device (2) through grout pipes, and the outlet end of the second grouting pipe switch device (2) is connected to a delivery pipe (203). The bentonite slurry storage tank (8) is connected to one interface of the tee (3), and the other two interfaces of the tee (3) are connected to the mixer (4) and the A liquid storage tank (6) respectively through the bentonite slurry pipeline.

2. The single-to-double liquid switching grouting system for shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes as described in claim 1, is characterized in that, The grouting pipe (1011) of the segment grouting device (1) is sized to match the reserved hole of the segment, and the grouting pipe (1011) is provided with a grouting plug (1010) and a grouting recorder (1012).

3. The single-to-double-liquid switching grouting system for shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes as described in claim 1, is characterized in that... The second grouting pipe switching device (2) includes a housing and an outer valve core (205). The housing is provided with two inlet ends and a delivery pipe (203). The outer valve core (205) has a spherical outer contour. The outer valve core (205) is assembled inside the housing. The outer valve core (205) is provided with a grouting channel. By rotating the outer valve core (205), the two inlet ends of the outer casing can be connected to the delivery pipe (203) together, or one inlet end can be connected to the delivery pipe (203) alone.

4. The single-to-double liquid switching grouting system for shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes as described in claim 3, is characterized in that... The grouting channel of the outer valve core (205) has a circular cross-section. An inner valve core (204) is installed inside the grouting channel of the outer valve core (205). The inner valve core (204) is annular. A small flow hole (206) is opened on the side wall of the inner valve core (204).

5. The single-to-double liquid switching grouting system for shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes according to claim 4, characterized in that, A rotating shaft (202) is fixed to the top of the outer side of the outer valve core (205). The upper end of the rotating shaft (202) extends through the side wall of the housing to the outside and is connected to a rotating wheel (201). A rotating rod (207) is fixed to the bottom outer side of the inner valve core (204). The lower end of the rotating rod (207) passes through the outer valve core (205) and the side wall of the outer shell, extends to the outside, and is connected to a rotating handle.

6. The single-to-double liquid switching grouting system for shield tunnels with alternating layers of water-rich sandstone and mudstone on steep longitudinal slopes according to any one of claims 3-5, characterized in that, The cross-sectional area of ​​the grouting channel of the outer valve core (205) is smaller than the sum of the cross-sectional areas of the two inlet ends of the outer shell.

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