A built-in steel pipe positioning device for tunnel advanced horizontal jet grouting piles

Abstract

The present invention belongs to the technical field of tunnel reinforcement safety steel pipe positioning, and discloses a built-in steel pipe positioning device for tunnel advanced horizontal rotary jet piles to solve the positional offset problem of steel pipe construction in the prior art. The steel pipe positioning device includes a plurality of front support rods arranged at intervals in the small section of the steel pipe tip cone and a plurality of rear support rods arranged at intervals in the large section of the steel pipe tip cone, a support body is hinged between the front support rod and the rear support rod, one end of the rear support rod away from the support body is hinged to the side wall of the steel pipe tip cone, and one end of the front support rod away from the support body is provided with an elastic movable snap ring, and the elastic movable snap ring is provided with a tension mechanism that can be used for the elastic movable snap ring to be clamped in the groove of the large section of the steel pipe tip cone. The present invention positions and constrains the position of the steel pipe through the "umbrella beam" telescopic structure, thereby achieving the purpose of precise construction and improving the strength of the pile body. In addition, the device can be centrally manufactured by a factory, and the new steel pipe positioning fixing head is simple to weld and install on site, with low cost and high efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel reinforcement steel pipe positioning, and in particular to a tunnel advanced horizontal jet grouting pile built-in steel pipe positioning device. Background Art

[0002] In recent years, during the construction of highway tunnels, some sections pass through loose sandstone, sandy structure, thick layered structure, weak mud cementation (contact cementation), poor diagenesis, easy to soften and disintegrate when exposed to water, and natural compressive strength of 1.33~4.13MPa, which is extremely soft rock. When the tunnel passes through this stratum, with the excavation of the tunnel, the surrounding rock is in an air-free state, which changes the stress conditions. The original rock stress releases and the excavation disturbs the surrounding rock, resulting in fast stress release, large initial deformation rate and deformation, resulting in almost no self-stabilizing ability of the surrounding rock. It is very easy to have a vault collapse and landslide at the moment of tunnel excavation, and the amount of landslide is large, which has caused great difficulties for construction.

[0003] In order to establish a closed tunnel working environment, peripheral reinforcement or full-section reinforcement can be used as needed. For the tunnel section passing through the sand layer, full-section pre-reinforcement is required. Horizontal jet grouting piles are set within the reinforcement range. The length is generally 15m, the pile diameter is 600mm, the pile spacing is 400mm, the design external insertion angle is 3~5%, and the overlap length of each cycle is not less than 2m. The 120° horizontal jet grouting piles in the arch are inserted with Φ89 seamless steel pipes for pre-reinforcement. The circumferential spacing of the Φ89 steel pipes is consistent with the spacing of the horizontal jet grouting piles, and the length is 15m. Therefore, the adjacent jet grouting piles are bitten by 10cm, forming a closed shell outside the tunnel excavation range to prevent sand leakage.

[0004] Combined with the construction technology of horizontal jet grouting piles, horizontal holes are drilled using horizontal drilling, but it is difficult to drill holes in loose sandstone layers. The pile body formed by single-tube or double-tube grouting has low tensile and bending strength, and steel pipes need to be inserted into the pile body for strength enhancement. However, the steel pipe moves downward under the action of weight, so that it is not in the center of the pile body, and the strength enhancement effect of the pile body cannot be exerted. The existing technology cannot solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of position deviation in the construction process of steel pipes in the prior art, and to provide a built-in steel pipe positioning device for tunnel advanced horizontal jet grouting piles that can fully exert the reinforcement effect of horizontal jet grouting piles and ensure that the steel pipe is located at the center of the pile body.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A tunnel advanced horizontal rotary jet grouting pile built-in steel pipe positioning device, comprising a plurality of front support rods arranged at intervals in a small section of a steel pipe tip cone portion and a plurality of rear support rods arranged at intervals in a large section of a steel pipe tip cone portion, a support body is hinged between the front support rods and the rear support rods, one end of the rear support rod away from the support body is hinged to the side wall of the steel pipe tip cone portion, an elastic movable clamp is provided at one end of the front support rod away from the support body, and a tension mechanism is provided on the elastic movable clamp to enable the elastic movable clamp to be clamped in a groove in the large section of the steel pipe tip cone portion.

[0008] Furthermore, the pulling mechanism comprises a pulling rod, one end of which passes through the steel pipe, and the other end of which is connected to an umbrella bundle, which is connected to an elastic movable clamping ring.

[0009] Furthermore, a plurality of gaps for passing the parachute bundle are arranged at intervals on the tip cone portion of the steel tube.

[0010] Furthermore, the elastic movable clamp includes a plurality of control tubes connected into a ring shape by hard springs, each control tube is fixed to the end of the front support rod, and the control tube is connected to the umbrella bundle.

[0011] Furthermore, the support body includes a support plate hinged to each group of front support rods and rear support rods, a sleeve is fixed to the bottom of each support plate, and soft springs are inserted between the sleeves for connection.

[0012] Furthermore, hinges are fixed on both sides of the bottom of each support plate, one end of one hinge is fixed to the front support rod, and one end of the other hinge is fixed to the rear support rod.

[0013] Furthermore, a hinge is fixed to one end of the rear support rod away from the support body, and one end of the hinge is fixed to the side wall of the pointed cone portion of the steel pipe.

[0014] Furthermore, a fixing ring is fixed on each control tube, and the fixing ring is connected to the parachute bundle.

[0015] Furthermore, the parachute bundle is connected to the pull rod via a connecting ring.

[0016] Furthermore, the gap is 2mm-3mm, the arc length of each control tube is 2~3cm, and the diameter is 1cm; the width of the fixing ring is smaller than the diameter of the control tube.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The present invention provides an elastic movable clamp and a front support rod and a rear support rod. The elastic movable clamp can be moved toward the large section of the steel pipe tip cone through a tension mechanism and clamped in the groove of the large section of the steel pipe tip cone. At the same time, the front support rod and the rear support rod are contracted to position the steel pipe. The present invention can ensure that the steel pipe is located at the center of the pile body and can give full play to the reinforcement effect of the horizontal jet grouting pile. It can effectively control the construction accuracy and ensure the purpose of advanced closed support of the tunnel.

[0019] The present invention uses the "umbrella bundle" telescopic structure to position and constrain the steel pipe position of the horizontal jet grouting pile, thereby achieving the purpose of precise construction and improving the strength of the pile body. In addition, the device can be centrally manufactured by the factory, and the new steel pipe positioning fixing head is easy to weld and install on site, with low cost and high efficiency. The device is simple, light in weight, and convenient to construct. It can become a part of the standardized construction of tunnels, and can also be used in other fields to achieve the purpose of steel pipe positioning.

[0020] The invention provides a plurality of long grooves at intervals on the pointed cone portion of the steel tube, wherein the width of the long grooves is 2-3 mm, and can provide a movable space for the parachute bundle.

[0021] The invention utilizes a hard spring to connect the control tube into a ring shape, which can ensure that the elastic movable clamping ring is in an open state when in a working state. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the general assembly structure of the present invention.

[0023] Figure 2 It is a schematic diagram of the manufacturing process of the pointed cone portion of the steel pipe of the present invention.

[0024] Figure 3 It is a schematic diagram of the static state of the elastic movable clamp ring of the present invention.

[0025] Figure 4 It is a schematic diagram of the working state of the elastic movable clamp ring of the present invention.

[0026] Figure 5 It is a schematic diagram of the static state of the support body of the present invention.

[0027] Figure 6 It is a schematic diagram of the working state of the support body of the present invention.

[0028] Figure 7 It is a schematic diagram of the working state structure of the present invention.

[0029] Figure 8 For the present invention Figure 1 and Figure 7 Schematic diagram of the static state at point C in the middle.

[0030] Fig. 9 For the present invention Figure 1 and Figure 7 Schematic diagram of the working status at point C in the middle.

[0031] Fig.10 It is a schematic diagram of the steel pipe groove of the present invention.

[0032] Fig.11 It is a schematic diagram of the connection ring of the present invention.

[0033] The meanings of the accompanying numbers are as follows: 1. steel tube tip cone; 2. front support rod; 3. rear support rod; 4. umbrella bundle; 5. control tube; 6. hard spring; 7. sleeve; 8. fixing ring; 9. hinge; 10. support plate; 11. soft spring; 12. pull rod; 13. connecting ring; 14. groove; A. steel tube; B. elastic movable clamp; D. support body. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0035] like Figure 1-11 As shown, a tunnel advanced horizontal rotary jet pile built-in steel pipe positioning device includes multiple front support rods 2 arranged at intervals in a small section of a steel pipe cone 1 and multiple rear support rods 3 arranged at intervals in a large section of a steel pipe cone 1, a support body D is arranged between the front support rods 2 and the rear support rods, and the support body D includes a support plate 10, hinges 9 are welded on both sides of the bottom of each support plate 10, one end of a hinge 9 is welded to the front support rod 2, and one end of another hinge 9 is welded to the rear support rod 3, and a sleeve 7 is welded at the bottom of each support plate 10, and soft springs 11 are inserted between the sleeves 7 for connection, and the two ends of the soft spring 11 are connected by hooks. The number of top plates 10 is the same as the number of front and rear support rods.

[0036] A hinge 9 is welded to one end of the rear support rod 3 away from the support body D, and one end of the hinge 9 is welded to the side wall of the steel pipe tapered portion 1 .

[0037] An elastic movable clasp B is provided at one end of the front support rod 2 away from the support body D. The elastic movable clasp B includes a plurality of control tubes 5 connected into a ring shape by hard springs 6. The two ends of the hard springs 6 are connected by hooks, and the tube mouths need to be rounded to facilitate the expansion and contraction of the hard springs 6. The arc length of each control tube 5 is 2 to 3 cm, and the diameter of each control tube 5 is about 1 cm. The control tube 5 is tightly attached to the tube wall of the steel pipe tip cone 1. Each control tube 5 is welded to the end of the front support rod 2. A fixing ring 8 is fixed on each control tube 5. The width of the fixing ring 8 is about 8 mm, which should not be larger than the diameter of the control tube 5. The fixing ring 8 is tied and connected with the umbrella bundle 4. The steel pipe tip cone 1 is provided with a plurality of gaps for passing the umbrella bundle 4 (such as Figure 1-2 , a section of the steel pipe is processed into a pointed cone head by cutting, and a 2-3mm gap is left between each serrated steel sheet to increase the activity space for the umbrella bundle 4). The umbrella bundle 4 is connected to the pull rod 12 through the connecting ring 13. One end of the pull rod 12 passes through the steel pipe A. The pull rod 12 can be made of Φ6 steel bars.

[0038] When the support body D is manufactured, the two hinges 9 are first welded to the bottom surface of the top plate 10, and then the sleeve 7 is welded to the middle of the bottom surface of the assembled top plate 10. Then, the sleeve 7 is connected with the soft spring 11 and sleeved on the Φ89 / 108 steel pipe (the round end of the steel pipe cone 1), so that the two ends of the soft spring 11 can be hooked and connected.

[0039] Further connection is made at C, where one end of multiple hinges 9 is welded to the side wall of the steel pipe cone portion 1 in sequence, and then one end of the rear support rod 3 is welded to the other end of the hinge 9, and then the other end of the rear support rod 3 is welded to the hinge 9 at the support body D.

[0040] In addition, in order to facilitate the steel pipe positioning device to maintain a supporting state, a groove 14 of a certain depth is provided on the pipe wall of the steel pipe pointed cone portion 1, and the diameter of the groove 14 is slightly larger than the diameter of the control pipe 5. At this point, the built-in steel pipe positioning device of the tunnel advanced horizontal jet grouting pile is assembled.

[0041] Here’s how it works:

[0042] The installed positioning device is transported to the tunnel working face by a transport vehicle. After the pile grouting is completed, the built-in steel pipe with the positioning device is slowly inserted into the pile body. In order to prevent the top plate 10 from "sinking" into the loose sandstone on the pile side when the support body D is in the working state, the positioning device can be packaged and tied with high-strength bags such as nylon, so that the force-bearing area of ​​the top plate 10 of the support body is increased, and mud is prevented from entering the pointed cone head to affect the extension and retraction of the positioning device.

[0043] When the steel pipe penetrates into the specified depth of the pile body, the pull rod 12 is slowly pulled out from the mouth of the steel pipe by using a tensioner while shaking the steel pipe, so that the movable body B is stuck in the groove 14 on the wall of the steel pipe cone 1. Finally, the proximal end of the steel pipe (the overlap with the steel arch frame) is fixed at the center of the pile body by using a triangular support element. Therefore, the construction of a single horizontal jet grouting pile is completed, and the construction sequence of other piles is consistent with the above process.

Claims

1. A tunnel advanced horizontal jet grouting pile built-in steel pipe positioning device, characterized by: The invention comprises a plurality of front support rods (2) arranged at intervals in a small section of a steel pipe pointed cone portion (1) and a plurality of rear support rods (3) arranged at intervals in a large section of the steel pipe pointed cone portion (1), a support body (D) being hingedly connected between the front support rods (2) and the rear support rods, an end of the rear support rod (3) away from the support body (D) being hingedly connected to a side wall of the steel pipe pointed cone portion (1), an end of the front support rod (2) away from the support body (D) being provided with an elastic movable clamping ring (B), and a tension mechanism being provided on the elastic movable clamping ring (B) for clamping the elastic movable clamping ring (B) in a groove (14) in the large section of the steel pipe pointed cone portion (1).

2. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 1 is characterized by: The pulling mechanism comprises a pulling rod (12), one end of the pulling rod (12) passes through the steel pipe (A), the other end of the pulling rod (12) is connected to an umbrella bundle (4), and the umbrella bundle (4) is connected to an elastic movable clamp (B).

3. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 2 is characterized by: A plurality of gaps for passing the parachute bundle (4) are provided at intervals on the steel tube cone portion (1).

4. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 3 is characterized by: The elastic movable clamp (B) comprises a plurality of control tubes (5) connected into a ring shape by hard springs (6), each control tube (5) is fixed to the end of a corresponding front support rod (2), and the control tube (5) is connected to the umbrella bundle (4).

5. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 4 is characterized by: The support body (D) comprises a support plate (10) hinged to each group of front support rods (2) and rear support rods (3), a sleeve (7) being fixed to the bottom of each support plate (10), and soft springs (11) are provided between the sleeves (7) for connection.

6. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 5 is characterized by: Hinges (9) are fixed to both sides of the bottom of each support plate (10), one end of one hinge (9) is fixed to the front support rod (2), and one end of the other hinge (9) is fixed to the rear support rod (3).

7. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 1 is characterized by: A hinge (9) is fixed to one end of the rear support rod (3) away from the support body (D), and one end of the hinge (9) is fixed to the side wall of the steel pipe tapered portion (1).

8. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 4 is characterized by: A fixing ring (8) is fixed on each of the control tubes (5), and the fixing ring (8) is connected to the umbrella bundle (4).

9. The built-in steel pipe positioning device for advanced horizontal jet grouting piles in a tunnel according to claim 8 is characterized by: The umbrella bundle (4) is connected to the pull rod (12) via a connecting ring (13).

Images