Rotating spray lifting structure and construction method

Abstract

The present invention discloses a rotary spraying lifting structure and a construction method, wherein the rotary spraying lifting structure comprises MJS construction piles (51) located on both sides of the tunnel axis, the MJS construction piles (51) comprise a semicircular spraying section (511) and a full-circular spraying section (512), the full-circular spraying section (512) is located at the lower part of the semicircular spraying section (511), and the end of the full-circular spraying section (512) extends horizontally to the bottom of the tunnel. The rotary spraying lifting structure disclosed by the present invention has a simple, ingenious and reasonable structure, plays a good role in promoting the stability of the subway tunnel, and is convenient for subsequent tunnel construction, and the construction method of the rotary spraying lifting structure has strong operability and great application and promotion prospects.

Description

Technical Field

[0001] The invention relates to a tunnel anti-settlement structure, in particular to a rotary spraying lifting structure and a construction method. Background Art

[0002] The settlement of the subway itself and the settlement or uplift of the tunnel caused by the construction of the adjacent site affect the safe operation of the subway. Reinforcement measures must be taken to reduce the impact of foundation pit excavation on the existing tunnel. At present, some subway construction units have proposed some methods to control the deformation of existing shield tunnels, such as soil grouting reinforcement method. However, this reinforcement method has a wide construction scope, is difficult to implement, and the reinforcement effect is difficult to guarantee. In addition, the impact on the adjacent tunnels during construction is difficult to control. Summary of the invention

[0003] The invention relates to a rotary spray lifting structure and a construction method, wherein the rotary spray lifting structure is simple and ingenious in design, has a firm lifting, is easy to construct and has strong operability, and can effectively solve the problems in the background technology.

[0004] The present invention is achieved through the following technical solutions:

[0005] The rotary spraying support structure includes MJS construction piles located on both sides of the tunnel axis. The MJS construction piles include a semicircular spraying section and a full-circular spraying section. The full-circular spraying section is located at the lower part of the semicircular spraying section, and the end of the full-circular spraying section extends horizontally to the bottom of the tunnel.

[0006] The MJS construction piles are located on both sides of the subway tunnel. The full-circle spray section (circular cross section) is located at the bottom of the semi-circular spray section (semi-circular cross section). The upper surface of the full-circle spray section is below the lower surface of the subway tunnel. The height of the semi-circular spray section is greater than or equal to the diameter of the tunnel. The upper section of the rotary spray lifting structure is the semi-circular spray section, and the lower section is the full-circular spray section. The rotary spray lifting structure is reasonably designed to save raw materials, and the upper surface of the full-circle spray section is below the lower surface of the subway tunnel, which can more effectively support the tunnel above. The height of the semi-circular spray section is preferably the height of the subway tunnel, which can effectively reduce tunnel displacement, improve tunnel safety and extend the service life of the project.

[0007] As a further improvement of the present invention, the tunnel includes an upper tunnel and a lower tunnel arranged up and down, the MJS method piles are located above the lower tunnel, the MJS method piles are arranged on both sides of the upper tunnel, and the ends of the full-circle spraying section extend horizontally to the bottom of the upper tunnel. The upper tunnel is wrapped and supported by the MJS method piles, which, on the one hand, reinforces the upper tunnel, and on the other hand, can effectively reduce the influence of the upper tunnel settlement or floating caused by the excavation of the foundation pit or the construction of the lower tunnel below.

[0008] As a further improvement of the present invention, the tunnel includes an upper tunnel and a lower tunnel arranged up and down, the upper tunnel and the lower tunnel are tunnels intersecting in different planes, the MJS construction method piles are arranged on both sides of the upper tunnel in the intersection area, and the end of the full-circle spraying section extends horizontally to the bottom of the upper tunnel. The rotary spraying lifting structure is mainly used in the staggered or different-plane intersection of the two tunnels, which can effectively improve the structural strength below the upper tunnel, ensure the safety of the construction of the lower tunnel, and reduce the settlement of the upper tunnel.

[0009] As a further improvement of the present invention, the longitudinal section of the MJS construction pile is L-shaped or inverted T-shaped, the semicircular spray section is vertically arranged, and the full-circular spray section is horizontally arranged. By adopting the above technical solution, the horizontal extension part of the full-circular spray section can support and reinforce the bottom of the tunnel, and the vertically arranged semicircular spray section is conducive to the drilling of the hole and occupies a small space.

[0010] As a further improvement of the present invention, an extension section is provided on the semicircular spray section. By providing the extension section, the contact area between the MJS method pile and the ground is increased, the anti-sinking property of the MJS method pile is greatly improved, and at the same time, the tunnel provided in the method pile can be better protected and reinforced, effectively reducing the settlement or floating of the tunnel caused by its own settlement and the construction of the adjacent site.

[0011] The extension section is arranged along the outer surface of the semicircular spray section. There are multiple extension sections, and the extension section is a columnar section. The extension section is a columnar section, similar to fish scales, which penetrates deep into the soil outside the semicircular spray section. The contact area is large, which effectively improves the anti-sinking property of the MJS method pile, thereby providing better protection and support for the tunnel inside the MJS method pile. The plane where the columnar section of the extension section is located is at an arbitrary angle to the axial center axis of the semicircular spray section. The extension section is sprayed by a jet drilling rig, and its direction is irregular, which is more conducive to improving the anti-sinking property of the MJS method pile.

[0012] The extension section is a hole sprayed out by a jet drill. Grouting is performed in the hole. The center axis of the hole forms an arbitrary angle with the axial center axis of the semicircular spray section. By jet drilling in the semicircular spray section, the contact area between the semicircular spray section and the soil is increased. During external construction, the construction pile can absorb external stress better and more gently, thereby improving the structural strength and anti-sinking property of the entire construction pile and the protection effect on the internal tunnel. The angle between the center axis of the hole and the axial center axis of the semicircular spray section toward the center of the earth is an acute angle. When the hole is set obliquely, especially when the above-mentioned angle is an acute angle, the hole after grouting forms a cylinder. If it encounters large rocks and other objects in the soil, it can bond with them, increasing the resistance of the construction pile when it sinks, making the construction pile more resistant to sinking.

[0013] The radius of the semicircular spray section is 1.2m-1.8m, and the diameter of the full-circular spray section is 2.4m-3.6m. By adopting the above technical solution, the semicircular spray section and the full-circular spray section of this size, combined with the size of the guide hole, can also achieve stable lifting.

[0014] As a further improvement of the present invention, the upper tunnel includes an upper tunnel and an upper second tunnel, the lower tunnel includes a lower tunnel and a lower second tunnel, MJS method long piles are set on both sides of the upper tunnel between the lower tunnel and the lower second tunnel, and MJS method long piles are set on both sides of the upper second tunnel between the lower tunnel and the lower second tunnel, and the bottom of the MJS method long piles extends to be flush with the bottom of the lower tunnel. When multiple tunnels intersect, by setting up MJS method long piles, each tunnel can be isolated to a certain extent, reducing the stress impact between the tunnels.

[0015] The construction method of the rotary spray lifting structure is applied to the rotary spray lifting structure described in any of the above schemes, comprising the following steps:

[0016] S1, drilling a pilot hole on one side of the tunnel;

[0017] S2, MJS jet drill rig is in place, drilling along the pilot borehole, when the MJS jet drill nozzle is located under the tunnel, full circle mode is adopted to form a full circle spray section;

[0018] S3 and MJS jet drilling rigs spray from bottom to top. After the full-circle spraying section is completed, a semi-circular swing spraying mode is adopted to form a semi-circular spraying section.

[0019] S4, MJS jet drilling rig exits.

[0020] Before step S1, that is, before the step of adjusting the drilling rig in place, a trenching step is also included: trenches are dug 0.5 m on both sides of the center of the method pile, and the trench excavation depth is 3 m to ensure that the underground pipelines are not damaged.

[0021] Before the trench excavation step, the pile position layout step is also included; before construction, precise layout is carried out on site according to the drawings. After the re-test line is qualified, the pile position is arranged on site with a steel ruler and a measuring line, and marked to ensure that the displacement deviation of the pile hole center is less than 50mm.

[0022] When drilling the pilot hole in step S1: after the pilot drill is tested and runs normally, start pilot hole drilling and bury casing in the empty drilling section; after the pilot drill is in place, level and center the pile driver, adjust the verticality of the pile driver, ensure that the drill rod is consistent with the pile position, the deviation should be within 10mm, and the verticality error of the drill hole is less than 0.5%; before drilling, the mud pump should be debugged to make the equipment run normally; check the drill rod length to ensure that the bottom elevation of the hole meets the designed depth; when the pile driver is in place, adjust the position and verticality of the pile driver to ensure that the drilling position is the set position and the drill is vertical.

[0023] In step S2: the MJS jet drill is in place and the drill rod is lowered; the pilot hole drill is removed, the MJS jet drill is in place, centered and leveled, the number of sections of the drill rod to be lowered is calculated according to the designed hole depth, the drill rod is lowered section by section so that the nozzle position is at the designed elevation, the number of sections of the drill rod to be lowered is recorded during the lowering process, and the seals of the drill rod need to be checked to see if they are intact, and the worn seals need to be replaced in time;

[0024] In step S2: MJS jet drill jetting: after the drill rod is lowered to the designed elevation, grouting begins. A high-pressure pump and high-pressure air are used for spraying. To ensure the quality of the bottom of the pile, when the nozzle sinks to the designed depth, it rotates at the original position for more than 60 seconds. After the ground pressure reaches the designed value, water backflow is started and the jetting step is increased.

[0025] By adopting the above technical solution, in step S1, when drilling the guide hole, after the pile foundation position and verticality are fixed, the hole is drilled downward. This step is because the MJS jet drilling rig has weak downward drilling ability. The drilling rig is first used to clear underground obstacles to ensure that the shotcrete pipe can reach the predetermined shotcrete position. After the guide hole drilling rig completes the hole drilling, the guide hole drilling rig withdraws, the MJS jet drilling rig is moved to the hole position, and the shotcrete pipe is lowered along the hole guided by the guide hole drilling rig.

[0026] As a further improvement of the present invention, in step S3, when the MJS jet drilling rig rises, an extension section is first formed, and then a semicircular spray section is formed.

[0027] As a further improvement of the present invention, in step S2: the MJS jet drilling rig sprays, and after the drill rod is lowered to the designed elevation, grouting begins. A high-pressure pump and high-pressure air are used for spraying. When the nozzle sinks to the designed depth, it rotates at the original position for more than 60 seconds. After the ground pressure reaches the designed value, water is sucked back and the step-by-step lifting of the rotary spraying is started. When the nozzle sinks to the designed depth, it rotates at the original position for more than 60 seconds to ensure that the bottom slurry is fully mixed and the quality of the bottom end of the pile is improved. In the above steps, after the ground pressure reaches the designed value, rotary spraying begins from bottom to top, and the mud is sucked back and discharged at the same time. The rotary spraying pipe can be prevented from being twisted off to ensure safe operation.

[0028] As a further improvement of the present invention, in step S2, after the ground pressure reaches the design value, the jetting starts from the bottom to the top, and the mud is sucked back and discharged at the same time. When the slurry nozzle is lifted to 100mm above the designed pile top elevation, the jetting stops, the drill rod is lifted and the hole opening is removed section by section, the drill rod, grouting pump and delivery pipeline are cleaned, and then the MJS jet drilling rig is moved to the next hole. The pile top elevation and quality can be ensured.

[0029] During construction, the pilot drill drills one hole, and the MJS jet drill sprays one hole. Adjacent holes are not constructed continuously, and skipping is required. This can prevent the holes from being connected during spraying.

[0030] According to the rotary spray lifting structure of the present invention, at least the following beneficial effects are achieved: the upper section of the rotary spray lifting structure is a semicircular spray section, and the lower section is a full-circular spray section. The rotary spray lifting structure is reasonably designed to save raw materials, and the full-circular spray section extends to the bottom of the tunnel, which can effectively support the tunnel. The construction method of the rotary spray lifting structure is simple and easy to operate, occupies a small space, and has strong applicability.

[0031] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below with reference to the accompanying drawings for detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a cross-sectional schematic diagram of the rotary spray lifting structure of the present invention;

[0033] Figure 2 for Figure 1 Top view;

[0034] Figure 3 This is a structural schematic diagram of a rotary spray lifting structure embodiment 2;

[0035] Figure 4 for Figure 3 Top view;

[0036] Figure 5 for Figure 4 Top view;

[0037] Figure 6 This is a schematic diagram of a rotary spray lifting structure embodiment 3;

[0038] Figure 7 It is a schematic diagram of a rotary spray lifting structure embodiment 4;

[0039] Figure 8 for Figure 7 Top view;

[0040] Fig. 9 This is a schematic diagram of a rotary spray lifting structure embodiment 5;

[0041] Fig.10 for Fig. 9 Top view;

[0042] Fig.11 This is a schematic diagram of a rotary spray lifting structure embodiment 6;

[0043] Fig.12 for Fig.11 Top view.

[0044] A cross-sectional schematic diagram of a structural rotating spray lifting structure provided in another embodiment of the present invention.

[0045] In the figure: 1-upper tunnel; 2-lower tunnel; 51-MJS method pile; 52-MJS method long pile; 100-lower tunnel; 101-lower second tunnel; 102-upper tunnel; 103-upper second tunnel; 511-semicircular spraying section; 512-full-circular spraying section; 513-occlusal section; 514-extension section. DETAILED DESCRIPTION

[0046] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below with reference to the accompanying drawings and preferred embodiments.

[0047] In the description of the present application, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0049] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0050] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0051] It should be noted that MJS is the abbreviation of Metro Jet System, and its Chinese translation is all-round high-pressure jet.

[0052] Example 1

[0053] Rotating spray lifting structure, such as Figure 1 , 2 As shown, it includes MJS construction piles 51 located on both sides of the tunnel axis. The MJS construction piles 51 include a semicircular spraying section 511 and a full-circular spraying section 512. The full-circular spraying section 512 is located at the lower part of the semicircular spraying section 511, and the end of the full-circular spraying section 512 extends horizontally to the bottom of the tunnel.

[0054] The MJS construction method pile 51 is located on both sides of the subway tunnel, the full circle spraying section is located at the bottom of the semicircular spraying section, the upper surface of the full circle spraying section 512 is below the lower surface of the subway tunnel, and the height of the semicircular spraying section 511 is greater than or equal to the diameter of the tunnel. The diameter of the full circle spraying section 512 is preferably 2.4m-3.6m. When the diameter of the full circle spraying section 512 is 2.4m, a cylindrical pile with a diameter of 2.4m is formed, and the semicircular spraying section is a semi-cylindrical pile with a semicircular cross section.

[0055] The tunnel includes an upper tunnel 1 and a lower tunnel 2 arranged in a vertical manner, and the MJS method piles 51 are located above the lower tunnel 2. The MJS method piles 51 are arranged on both sides of the upper tunnel 1, and the ends of the full-circle spraying sections 512 extend horizontally to the bottom of the upper tunnel 1. The upper tunnel 1 is wrapped and supported by the method piles 51, which, on the one hand, reinforces the upper tunnel, and on the other hand, can effectively reduce the influence of the upper tunnel settlement or floating caused by the excavation of the foundation pit or the construction of the lower tunnel 2 below.

[0056] The diameter of the full-circle spray section 512 is preferably 2.4m-3.6m. When the diameter of the full-circle spray section 512 is 3m, a cylindrical pile with a diameter of 3m is formed. By adopting the above technical solution, the semicircle spray section and the full-circle spray section of this size, combined with the size of the lead hole, can also achieve stable lifting.

[0057] The upper section of the rotary spraying lifting structure is a semicircular spraying section 511, and the lower section is a full-circular spraying section 512. The rotary spraying lifting structure is rationally designed to save raw materials, and the upper surface of the full-circular spraying section 521 is below the lower surface of the subway tunnel, which can provide more effective support for the tunnel above.

[0058] The height of the semicircular spraying section is preferably the height of the subway tunnel, which can effectively reduce tunnel displacement, improve tunnel safety and extend the service life of the project.

[0059] The longitudinal section of the construction pile 51 is L-shaped, the semicircular spray section 511 is vertically arranged, and the full-circular spray section 512 is horizontally arranged. By adopting the above technical solution, the horizontal extension of the full-circular spray section can support and reinforce the bottom of the tunnel, and the vertically arranged semicircular spray section is conducive to the drilling of the hole and occupies a small space.

[0060] The construction method of the rotary spray lifting structure is applied to the rotary spray lifting structure described in any of the above schemes, comprising the following steps:

[0061] S1, drilling a pilot hole on one side of the tunnel;

[0062] S2, the MJS jet drill is in place and drills down along the pilot borehole. When the MJS jet drill nozzle is located below the tunnel, a full circle mode is adopted to form a full circle spray section (512);

[0063] S3, MJS jet drilling rigs spray from bottom to top, and after the full circle spray section (512) is completed, a semi-circular swing spray mode is adopted to form a semi-circular spray section (511);

[0064] S4, MJS jet drilling rig exits.

[0065] Before step S1, that is, before the step of adjusting the drilling rig in place, a trenching step is also included: trenches are dug 0.5 m on both sides of the center of the method pile, and the trench excavation depth is 3 m to ensure that the underground pipelines are not damaged.

[0066] Before the trench excavation step, the pile position layout step is also included; before construction, precise layout is carried out on site according to the drawings. After the re-test line is qualified, the pile position is arranged on site with a steel ruler and a measuring line, and marked to ensure that the displacement deviation of the pile hole center is less than 50mm.

[0067] When drilling the pilot hole in step S1: after the pilot drill is tested and runs normally, start pilot hole drilling and bury casing in the empty drilling section; after the pilot drill is in place, level and center the pile driver, adjust the verticality of the pile driver, ensure that the drill rod is consistent with the pile position, the deviation should be within 10mm, and the verticality error of the drill hole is less than 0.5%; before drilling, the mud pump should be debugged to make the equipment run normally; check the drill rod length to ensure that the bottom elevation of the hole meets the designed depth; when the pile driver is in place, adjust the position and verticality of the pile driver to ensure that the drilling position is the set position and the drill is vertical.

[0068] In step S2: the MJS jet drill is in place and the drill rod is lowered; the pilot hole drill is removed, the MJS jet drill is in place, centered and leveled, the number of sections of the drill rod to be lowered is calculated according to the designed hole depth, the drill rod is lowered section by section so that the nozzle position is at the designed elevation, the number of sections of the drill rod to be lowered is recorded during the lowering process, and the seals of the drill rod need to be checked to see if they are intact, and the worn seals need to be replaced in time;

[0069] In step S2: MJS jet drill jetting: after the drill rod is lowered to the designed elevation, grouting begins. A high-pressure pump and high-pressure air are used for spraying. To ensure the quality of the bottom of the pile, when the nozzle sinks to the designed depth, it rotates at the original position for more than 60 seconds. After the ground pressure reaches the designed value, water backflow is started and the jetting step is increased.

[0070] By adopting the above technical solution, in step S1, when drilling the guide hole, after the pile foundation position and verticality are fixed, the hole is drilled downward. This step is because the MJS jet drilling rig has weak downward drilling ability. The drilling rig is first used to clear underground obstacles to ensure that the shotcrete pipe can reach the predetermined shotcrete position. After the guide hole drilling rig completes the hole drilling, the guide hole drilling rig withdraws, the MJS jet drilling rig is moved to the hole position, and the shotcrete pipe is lowered along the hole guided by the guide hole drilling rig.

[0071] In step S3, when the MJS jet drill rises, it first jet drills the outer wall of the semicircular spray section 511 to form the extension section 514, and then forms the semicircular spray section 511.

[0072] In step S2: the MJS jet drilling rig sprays, and after the drill rod is lowered to the design elevation, the grouting begins. The grouting is sprayed with a high-pressure pump and high-pressure air. When the nozzle sinks to the design depth, it rotates in the original position for more than 60 seconds. After the ground pressure reaches the design value, it starts to suck back water and start the rotary spraying step-up. When the nozzle sinks to the design depth, it rotates in the original position for more than 60 seconds to ensure that the bottom slurry is fully mixed and improve the quality of the bottom end of the pile. In the above steps, when the ground pressure reaches the design value, the rotary spraying begins from bottom to top, and the mud is sucked back and discharged at the same time. It can prevent the rotary spraying pipe from being twisted off to ensure safe operation.

[0073] In step S2, after the ground pressure reaches the design value, the grouting starts from the bottom to the top, and the mud is sucked out at the same time. When the slurry nozzle is raised to 100mm above the designed pile top elevation, the grouting stops, the drill rod is lifted and the hole outlet is removed section by section, the drill rod, grouting pump and delivery pipeline are cleaned, and then the MJS jet drilling rig is moved to the next hole. The pile top elevation and quality can be ensured.

[0074] During construction, the pilot drill drills one hole, and the MJS jet drill sprays one hole. Adjacent holes are not constructed continuously, and skipping is required. This can prevent the holes from being connected during spraying.

[0075] Example 2

[0076] like Figures 3 to 5 As shown, the tunnel of this embodiment includes an upper tunnel 1 and a lower tunnel 2 arranged up and down, the upper tunnel 1 and the lower tunnel 2 are tunnels intersecting in different planes, and the MJS construction method piles 51 are arranged on both sides of the upper tunnel 1 in the intersection area. The rotary spraying lifting structure is mainly used in the staggered or different plane intersection of two tunnels, which can effectively improve the structural strength under the upper tunnel, ensure the safety of the construction of the lower tunnel, and reduce the settlement of the upper tunnel.

[0077] The upper tunnel 1 includes an upper tunnel 102 and an upper second tunnel 103, and the lower tunnel 2 includes a lower tunnel 100 and a lower second tunnel 101. MJS long piles 52 are set on both sides of the upper tunnel 102 between the lower tunnel 100 and the lower second tunnel 101; MJS long piles 52 are set on both sides of the upper second tunnel 103 between the lower tunnel 100 and the lower second tunnel 101, and the bottom of the MJS long piles 52 extends to be flush with the bottom of the lower tunnel. When multiple tunnels intersect, by setting up MJS long piles 52, the tunnels can be isolated to a certain extent, reducing the stress impact between the tunnels.

[0078] like Figure 5 There are four rows of MJS piles 51, which are arranged on both sides of the upper tunnel 102 and the upper second tunnel 103. The pile positions can be adjusted according to the excavation of underground pipelines during construction. MJS piles support the bottom of the tunnel and control the settlement of the tunnel. The height range of the subway tunnel is reinforced by semicircular 180-degree swing spraying. The MJS long piles 52 between the shields of the lower tunnel 100 and the lower second tunnel 101 are all sprayed in a full circle, which is used to isolate the two tunnels of the expressway to prevent the shield construction from affecting the other tunnel.

[0079] like Figure 5 As shown, the center distance between two adjacent interlocking MJS construction piles 51 is 2m-2.9m, preferably 2.4m, and the interlocking distance of the interlocking section 513 is 0.4m-0.7m, preferably 0.6m, which can be adjusted according to the actual situation of the on-site pipeline.

[0080] In this embodiment, the longitudinal section of the MJS method pile 51 is L-shaped, the semicircular spray section 511 is vertically arranged, and the full-circular spray section 512 is horizontally arranged.

[0081] The radius A of the semicircular spray section 511 is 1.2m-1.8m, preferably 1.5m, the height C of the semicircular spray section is 5.8m-6.4m, preferably 6.2m, the diameter B of the full-circular spray section 512 is 2.4m-3.6m, preferably 3m, and the height D of the full-circular spray section is 2.8m-3.6m, preferably 3m. The distance F between the center of the MJS method pile and the outer edge of the previous tunnel 102 is 0.8m-1.2m, preferably controlled at 1m. The distance G between the upper edge of the side of the full-circular spray section and the outer edge of the subway tunnel is 0.8m-1.2m, preferably 1m. The distance E between the lower surface of the full-circular spray section and the upper surface of the expressway tunnel is 0.4m-0.7m, preferably 0.5m. The size, position distance, and layout of the MJS construction piles on both sides of the upper second tunnel 103 can be consistent with the shape, size, position distance, and layout of the MJS construction piles on both sides of the upper tunnel 102. Of course, in other embodiments, they can be different or only the shape and size of the MJS can be the same.

[0082] Example 3

[0083] like Figures 3 to 6 As shown, in this embodiment, the rotary spray lifting structure is as follows Figure 6 , which is different from Example 2, in this embodiment, above the lower second tunnel, the first MJS construction pile on the left section of the tunnel side does not interlock with the adjacent MJS construction pile. The radius A of the semicircular spray section 511 is 1.2m-1.8m, preferably 1.5m, the height C of the semicircular spray section is 5.8m-6.4m, preferably 6.2m, the diameter B of the full-circle spray section 512 is 2.4m-3.6m, preferably 3m, and the height D of the full-circle spray section is 2.4m-2.7m, preferably 2.6m. The distance F between the center of the MJS construction pile and the outer edge of the upper tunnel 102 is 0.8m-1.2m, preferably controlled at 1m. The distance G between the upper edge of the side of the full-circle spray section and the outer edge of the subway tunnel is 0.8m-1.2m, preferably 1m. The distance E between the lower surface of the full-circle spray section and the upper surface of the expressway tunnel is 0.4m-0.7m, preferably 0.5m.

[0084] The construction method of the rotary spray lifting structure includes the following steps: the first step: stakeout; before construction, accurate stakeout is carried out on site according to the completion drawings of Metro Line 2. After the retest line is qualified, the pile position is arranged on site with a steel ruler and a measuring line, and marked to ensure that the displacement deviation of the pile hole center is less than 50mm.

[0085] Step 2: Dig trenches. Before entering the construction site, dig trenches about 0.5m on both sides of the center of the jet grouting pile. The trench excavation depth is 3m to ensure that the underground pipelines are not damaged. According to the center of the pile position, bury a steel pipe with a diameter of 219mm to 500mm below the bottom of the pipeline, and backfill around the steel pipe to 1m below the ground.

[0086] Step 3: Put the drilling rig in place; after the drilling rig is in place, level and center the pile driver, adjust the verticality of the pile driver, ensure that the drill rod is consistent with the pile position, the deviation should be within 10mm, and the verticality error of the drill hole is less than 0.5%; before drilling, the mud pump should be debugged to make the equipment operate normally; check the length of the drill rod to ensure that the bottom elevation of the hole meets the designed depth.

[0087] Step 4: Drilling the pilot hole; before the drilling rig is constructed, start drilling the pilot hole after the drilling machine is tested and running normally. During the drilling process, the number of drill rod sections should be recorded in detail to ensure the accuracy of the drilling depth. During the pilot hole process, the mud wall protection should be strengthened, and an appropriate amount of bentonite should be added to the mud to ensure that there is no sediment in the hole after the pilot hole is completed; in order to prevent the MJS rotary spraying process from collapsing and locking the drill rod in the soil layer with poor geology, causing difficulty in pulling out the pipe, the casing should be buried in the empty drilling section (for particularly poor soil formations, it needs to be buried 2-3m above the pile bottom). Considering that the diameter of the rotary spraying drill rod is 142mm, the inner diameter of the buried outer casing should not be less than 219mm, and the pilot hole diameter should not be less than 220mm.

[0088] To prevent perforation during rotary grouting construction, there should be a certain distance between the guide holes and the rotary grouting, and construction should be carried out at intervals of 3 holes or after the temporary piles have reached 36 hours (depending on the requirements of the construction site).

[0089] Step 5: Put the MJS jet drill in place and lower the drill pipe. After the hole is drilled to the designed depth and the casing is buried, remove the guide drill, put the MJS all-round ultra-high pressure rotary jet drill (MJS jet drill) in place, center it and adjust the level. Calculate the number of drill pipe sections to be lowered according to the designed hole depth, lower the drill pipe section by section so that the nozzle position is at the designed elevation. During the lowering process, keep a record of the number of drill pipe sections lowered, and check whether the seals of the drill pipe are intact. If the seals are worn, replace them in time.

[0090] Step 6: MJS injection; after the drill rod reaches the designed elevation (nozzle position), start spraying. Use a high-pressure pump and high-pressure air to spray. To ensure the quality of the bottom of the pile, when the nozzle sinks to the designed depth, rotate at the original position for more than 60 seconds. After the ground pressure reaches the designed value, start back suction and start rotary spraying step increase.

[0091] Step 7: MJS rotary jet lifting; after turning on the high-pressure jet pump and high-pressure air, the jet is jetted from bottom to top, and the mud is sucked out at the same time. During jetting, the jetting pipe should be gradually lifted after reaching the predetermined jetting pressure to prevent the jetting pipe from being twisted off. The rotation and lifting of the drill rod should be continuous and not interrupted. If the drilling rig fails, the lifting and rotation of the drill rod should be stopped to prevent the pile from breaking, and the fault should be repaired and eliminated immediately. In order to improve the quality of the bottom end of the pile, the jetting time of the drill rod should be appropriately increased within 1.0m of the bottom of the pile. During the jet lifting process, the jet parameters can be adjusted according to different soil layers.

[0092] Step 8: Shift the drilling rig; To ensure the pile top elevation and quality, stop the rotary spraying when the slurry nozzle is raised to 100mm above the designed pile top elevation, lift the drill rod and remove the hole outlet section by section, clean the drill rod, grouting pump and delivery pipeline, and then move the drilling rig to the next hole.

[0093] Example 4

[0094] like Figure 7 , 8 As shown, the longitudinal section of the construction pile 51 in this embodiment is L-shaped, and an extension section 514 is provided on the semicircular spray section 511. By providing the extension section 514, the contact area between the construction pile 51 and the ground is increased, and the anti-sinking property of the construction pile 51 is greatly improved. At the same time, the tunnel set in the construction pile 41 can be better protected and reinforced, and the settlement or floating caused by the tunnel's own settlement and the construction of the adjacent site can be effectively reduced.

[0095] The extension section 514 is arranged along the outer surface of the semicircular spray section 511. There are multiple extension sections 514, and the extension section 514 is a columnar cut. The extension section 514 is a columnar cut, similar to fish scales, which penetrates deep into the soil outside the semicircular spray section 511 and has a large contact area, which effectively improves the anti-sinking property of the construction method pile 41, thereby also providing better protection and support for the tunnel inside the construction method pile 41. The plane where the columnar cut of the extension section 514 is located forms an arbitrary angle with the axial center axis of the semicircular spray section 511. The extension section 514 is sprayed by a jet drilling rig, and its direction is irregular, which is more conducive to improving the anti-sinking property of the construction method pile 41.

[0096] Example 5

[0097] like Fig. 9 , 10 As shown, the difference between this embodiment and embodiment 4 is that the extension section 514 is a borehole sprayed by a jet drill, grouting is performed in the borehole, and the center axis of the borehole forms an arbitrary angle with the axial center axis of the semicircular spray section 511. By jetting the borehole in the semicircular spray section 511, the contact area between the semicircular spray section 511 and the soil is increased. During external construction, the construction pile can absorb external stress better and more gently, thereby improving the structural strength and anti-sinking property of the entire construction pile, and the protection effect on the internal tunnel. The angle between the center axis of the borehole and the axial center axis of the semicircular spray section 511 in the direction of the center of the earth is an acute angle. When the borehole is arranged obliquely, especially when the above-mentioned angle is an acute angle, the borehole after grouting forms a cylinder. If it encounters large rocks and other objects in the soil, it can be bonded to them, increasing the resistance of the construction pile when it sinks, making the construction pile more resistant to sinking.

[0098] Example 6

[0099] like Fig.11 , 12As shown, the difference between this embodiment and embodiment 1 is that the longitudinal section of the construction pile 51 is inverted T-shaped, which increases the contact area between the construction pile and the soil, and significantly improves the anti-sinking property of the construction pile compared with the T-shaped structure.

[0100] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. Rotating spray lifting structure, characterized in that: The invention comprises an MJS construction pile (51) located on both sides of the tunnel axis, wherein the MJS construction pile (51) comprises a semicircular spraying section (511) and a full-circular spraying section (512), wherein the full-circular spraying section (512) is located at the lower part of the semicircular spraying section (511), and the end of the full-circular spraying section (512) extends horizontally to the lower part of the tunnel, and the upper surface of the full-circular spraying section (512) is located below the lower surface of the subway tunnel, and the height of the semicircular spraying section (511) is greater than or equal to the diameter of the tunnel.

2. The rotary spray lifting structure according to claim 1 is characterized in that: The tunnel comprises an upper tunnel (1) and a lower tunnel (2) arranged vertically, the MJS construction piles (51) are located above the lower tunnel (2), the MJS construction piles (51) are arranged on both sides of the upper tunnel (1), and the ends of the full-circle spraying sections (512) extend horizontally to the bottom of the upper tunnel (1).

3. The rotary spray lifting structure according to claim 1 is characterized in that: The tunnel comprises an upper tunnel (1) and a lower tunnel (2) arranged in a vertical direction, the upper tunnel (1) and the lower tunnel (2) being tunnels intersecting in different planes, the MJS construction method piles (51) being arranged on both sides of the upper tunnel (1) in the intersection area, and the end of the full-circle spraying section (512) extending horizontally to the bottom of the upper tunnel (1).

4. The rotary spray lifting structure according to claim 2 or 3, characterized in that: The longitudinal section of the MJS construction method pile (51) is L-shaped or inverted T-shaped, the semicircular spray section (511) is arranged vertically, and the full-circular spray section (512) is arranged horizontally.

5. The rotary spray lifting structure according to claim 1, 2 or 3, characterized in that: An extension section (514) is arranged on the semicircular spray section (511).

6. The rotary spray lifting structure according to claim 3, characterized in that: The upper tunnel (1) comprises an upper tunnel (102) and an upper second tunnel (103), and the lower tunnel (2) comprises a lower tunnel (100) and a lower second tunnel (101), MJS method long piles (52) are arranged on both sides of the upper tunnel (102) between the lower tunnel (100) and the lower second tunnel (101), and MJS method long piles (52) are arranged on both sides of the upper second tunnel (103) between the lower tunnel (100) and the lower second tunnel (101), and the bottom of the MJS method long piles (52) extends to be flush with the bottom of the lower tunnel.

7. The construction method of the rotary spray lifting structure is characterized in that: The rotary spray lifting structure according to any one of claims 1 to 6 comprises the following steps: S1, drilling a pilot hole on one side of the tunnel; S2, the MJS jet drill is in place and drills down along the pilot borehole. When the MJS jet drill nozzle is located below the tunnel, a full circle mode is adopted to form a full circle spray section (512); S3, MJS jet drilling rigs spray from bottom to top, and after the full circle spray section (512) is completed, a semi-circular swing spray mode is adopted to form a semi-circular spray section (511); S4, MJS jet drilling rig exits.

8. The construction method of the rotary spray lifting structure according to claim 7, characterized in that: In step S3, when the MJS jet drilling machine rises, it first drills to form an extension section (514) and then forms a semicircular jet section (511).

9. The construction method of the rotary spray lifting structure according to claim 7, characterized in that: In step S2: the MJS jet drilling rig jets, and after the drill rod is lowered to the designed elevation, grouting begins. A high-pressure pump and high-pressure air are used for spraying. When the nozzle sinks to the designed depth, it rotates at the original position for more than 60 seconds. After the ground pressure reaches the designed value, water backflow is started and the jetting step is increased.

10. The construction method of the rotary spray lifting structure according to claim 7, characterized in that: In step S2, after the ground pressure reaches the design value, rotary jetting starts from bottom to top, and the mud is sucked out at the same time. When the slurry nozzle is lifted to 100 mm above the designed pile top elevation, the rotary jetting is stopped, the drill rod is lifted and the hole outlet is removed section by section, the drill rod, grouting pump and delivery pipeline are cleaned, and then the MJS jet drilling rig is moved to the next hole.

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