Underground limited space long-distance pipeline laying structure and construction method

Abstract

The invention provides an underground limited space long-distance pipeline laying structure and a construction method. The underground limited space long-distance pipeline laying structure comprises a first pipeline assembly and a second pipeline assembly. The first pipeline assembly comprises a sleeve, a grouting pipe set and a rail set, the sleeve is provided with an axial inner cavity, and the grouting pipe set and the rail set are arranged on the upper portion and the lower portion of the axial inner cavity respectively; the second pipeline assembly comprises a pressure pipe, a pumping pipe set and a sliding block set, the pressure pipe is coaxially arranged in the axial inner cavity, a filling gap is formed between the pressure pipe and the sleeve, and the pumping pipe set and the sliding block set are arranged on the upper portion and the lower portion of the filling gap respectively and used for being in one-to-one correspondence with the grouting pipe set and the track set respectively. Under the action of external force, the pressure pipe can move in the axial inner cavity relative to the sleeve so as to link the sliding block set to slide on the rail set. The technical problems that in the prior art, construction time is long, installation precision is low, and construction in a narrow space is not facilitated are solved.

Description

Technical Field

[0001] The invention relates to the technical field of pipe jacking construction, and in particular to a long-distance pipeline laying structure in an underground limited space and a construction method. Background Art

[0002] In the continuous evolution of urban infrastructure construction, pipe jacking construction technology has been widely promoted and used in application fields such as municipal drainage systems, power line laying and underground structure crossing due to its characteristics of not interfering with ground traffic, small footprint and environmental friendliness. However, during the process of pipe jacking, due to the need to apply a large jacking force and the friction resistance between the pipe and the surrounding soil, quality defects are prone to occur at the pipe joints, and once a problem occurs, the repair work is very difficult. Especially for pressure pipes, there are strict requirements on sealing and pressure resistance. Usually, direct jacking installation is not allowed. Instead, the outer protective casing is jacked in first, and then the internal pressure pipe is laid.

[0003] In order to ensure that the pressure pipe can effectively resist vibration during operation and reduce the impact caused by the water hammer effect, appropriate materials must be filled between the pipe and the casing. The size of the gap between the two will directly affect the selection of the filling process, the quality of the filling effect, and the amount of filling material. Given the small space between the pressure pipe and the casing, coupled with the extremely high construction precision requirements, successful cases for reference are relatively scarce. Therefore, exploring and optimizing construction parameters and developing new construction methods have become key tasks in this field. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a long-distance pipeline laying structure and construction method in an underground limited space, which solves the technical problems in the prior art of long construction time, low installation accuracy and being unfavorable for construction in a small space.

[0005] According to an embodiment of the present invention, a long-distance pipeline laying structure in an underground limited space includes:

[0006] A first pipeline assembly includes a casing, a grouting pipe group and a track group, wherein the casing has an axial inner cavity, the grouting pipe group and the track group are respectively arranged at the upper and lower parts of the axial inner cavity, and both extend along the direction of the axial inner cavity;

[0007] The second pipeline assembly includes a pressure pipe, a pumping pipe group and a slider group. The pressure pipe is coaxially arranged in the axial inner cavity and forms a filling gap with the casing. The pumping pipe group and the slider group are respectively arranged at the upper and lower parts of the filling gap, and are used to correspond to the grouting pipe group and the track group respectively. Under the action of external force, the pressure pipe can move relative to the casing in the axial inner cavity to link the slider group to slide on the track group.

[0008] Among them, a plurality of limiting I-beams are arranged at intervals along the outer peripheral surface of the pressure tube, and one end of the limiting I-beam away from the pressure tube is suspended in the filling gap and does not contact the inner wall of the casing.

[0009] Preferably, the grouting pipe group includes a plurality of grouting pipes that are independently arranged from each other, and the plurality of grouting pipes are arranged in a continuous length along the direction of the axial inner cavity.

[0010] Preferably, the pumping tube set comprises a plurality of pumping tubes independently arranged from each other, the plurality of pumping tubes are all fixed to the outer surface of the pressure tube, and have different extension lengths extending into the filling gap.

[0011] Preferably, the track assembly comprises a leveling support arranged in contact with the inner wall of the casing, and a plurality of I-beam guide rails arranged at intervals on the leveling support;

[0012] The slider group includes a plurality of sliders arranged at intervals along the outer peripheral surface of the pressure tube, and the plurality of sliders are arranged in one-to-one correspondence with the plurality of I-beam guide rails.

[0013] Preferably, the leveling support is an arc-shaped structure.

[0014] Preferably, the angle between each of the two ends of the leveling support and the line connecting the center of the sleeve is α, and α satisfies α≥90°.

[0015] Preferably, the angle between the two adjacent ends of the two sliding blocks and the line connecting the center of the pressure tube is β, and β satisfies β≤60°.

[0016] Preferably, the sliding block includes a first sliding portion and a second sliding portion which are arranged at an angle, the first sliding portion is fixed to the pressure pipe and can slide in contact with the I-beam guide rail, and the second sliding portion is located on one side of the I-beam guide rail.

[0017] Preferably, a support rod is provided in the pressure tube, and the support rod is configured as a cross-shaped structure for supporting the inner wall of the pressure tube.

[0018] On the other hand, according to an embodiment of the present invention, there is also provided a method for constructing a long-distance pipeline in an underground limited space, comprising the above-mentioned laying structure, and the construction method comprises the following steps:

[0019] Digging working wells and receiving wells;

[0020] Install jacking equipment in the working pit;

[0021] Using jacking equipment to jack the casing through the working well;

[0022] Clean the inside of the casing and check the centerline deviation of the casing;

[0023] Installing the grouting pipe group and the track group in the casing;

[0024] Hoist the pressure pipes one by one into the working well, and install the pumping pipe group, the limiting I-beam and the slider group on the outer surface of the pressure pipes;

[0025] After the slider group is in place and the center and bottom elevation of the pressure pipe are calibrated, the pressure pipe is pushed forward and sandbags are placed in the pressure pipe to increase the counterweight;

[0026] Welding two adjacent pressure pipes in the working well and pushing them into the casing through the jacking equipment;

[0027] Backfilling the filling gap by means of primary backfill grouting of a pumping pipe group and secondary backfill grouting of a grouting pipe group;

[0028] A cross-shaped support rod is constructed in the pressure tube, and the support rod is removed after the filling gap is formed.

[0029] Compared with the prior art, the present invention has the following beneficial effects: the casing and the pressure pipe are coaxially arranged, and the method of first pushing the casing and then pushing the pressure pipe into the casing can prevent the pressure pipe from directly contacting the soil and generating friction and resistance; at the same time, a filling gap can be formed between the casing and the pressure pipe for grouting backfilling, which can resist vibration and reduce the impact caused by the water hammer effect; furthermore, the cooperation of the grouting pipe group and the pumping pipe group can not only perform rapid grouting backfilling in a small space, but also adopt the method of two separate grouting to ensure the dense backfill between the casing and the pressure pipe; the cooperation of the track group and the slider group can quickly and accurately send the pressure pipe to the specified position in the casing under the action of external force, and the slider group is used to separate the pressure pipe and the casing, so that the pressure pipe is not directly connected to the track group, thereby ensuring that the corrosion protection of the outer surface of the pressure pipe is complete and reliable; in addition, the limiting I-beam is arranged at the filling gap, and one end of it is suspended, which avoids the floating of the pressure pipe during the subsequent backfilling construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a laying structure in one embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of the upper portion of the filling gap in one embodiment of the present invention;

[0032] Figure 3 is a partial cross-sectional view of an upper portion of a filling gap in one embodiment of the present invention;

[0033] Figure 4is a schematic structural diagram of the lower portion of the filling gap in one embodiment of the present invention;

[0034] Figure 5 It is a schematic structural diagram of a track group and a slider group in one embodiment of the present invention;

[0035] Figure 6 The figure is a flow chart of a construction method in one embodiment of the present invention.

[0036] In the figure:

[0037] 1. Casing; 2. Grouting pipe group; 201. Grouting pipe; 3. Track group; 301. Leveling support; 302. I-beam guide rail; 4. Pressure pipe; 5. Pumping pipe group; 501. Pumping pipe; 6. Slider; 601. First sliding part; 602. Second sliding part; 7. Filling gap; 8. Limiting I-beam; 9. Support rod. DETAILED DESCRIPTION

[0038] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", etc. 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 those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] The following will be combined with the attached Figure 1-6 , the present invention is further described.

[0040] In the embodiment of the present invention, Figure 1-Figure 5 As shown, the underground limited space long-distance pipeline laying structure includes: a first pipeline assembly and multiple second pipeline assemblies; the first pipeline assembly includes a casing 1, a grouting pipe group 2 and a track group 3, the casing 1 has an axial inner cavity, the grouting pipe group 2 and the track group 3 are respectively arranged at the upper and lower parts of the axial inner cavity, and both extend along the direction of the axial inner cavity; the second pipeline includes a pressure pipe 4, a pumping pipe group 5 and a slider group 6, the pressure pipe 4 is coaxially arranged in the axial inner cavity, and a filling gap 7 is formed between the pressure pipe 4 and the casing 1. The pumping pipe group 5 and the slider group 6 are respectively arranged at the upper and lower parts of the filling gap 7, and are used to correspond to the grouting pipe group 2 and the track group 3 respectively. Under the action of external force, the pressure pipe 4 can move in the axial inner cavity relative to the casing 1 to link the slider group 6 to slide on the track group 3; wherein, a plurality of limiting I-beams 8 are arranged at intervals along the outer peripheral surface of the pressure pipe 4, and the end of the limiting I-beam 8 facing away from the pressure pipe 4 is suspended in the filling gap 7 and has no contact with the inner wall of the casing 1.

[0041] Specifically, in an embodiment of the present invention, the casing 1 is pushed in by a pushing device, and the axial inner cavity formed inside the casing 1 can be used to install the pressure pipe 4 (the pressure pipe 4 is composed of a plurality of pipe units spliced ​​in sequence); at the same time, a filling gap 7 is constructed between the inner wall of the casing 1 and the outer wall of the pressure pipe 4, which is used to fill the corresponding material to backfill the filling gap 7, thereby ensuring the backfill density of the gap.

[0042] Specifically, the filling gap 7 is divided into an upper portion of the filling gap 7 (hereinafter referred to as the "upper portion"), and a lower portion of the filling gap 7 (hereinafter referred to as the "lower portion"). A grouting pipe group 2 and a pumping pipe group 5 are provided at the upper portion, and both pipe groups extend along the axial direction of the inner cavity. The grouting pipe group 2 is fixed to the inner wall of the casing 1, and the pumping pipe group 5 is welded to the outer wall of the pressure pipe 4 (not to be removed later). The mortar pumping backfilling is mainly performed and the cement slurry grouting is supplemented, so as to reduce cement consumption, shorten construction time, and improve economic benefits. At the same time, the pumping pipe group 5 performs one backfill grouting, and the grouting pipe group 2 performs two backfill grouting. The backfill grouting is carried out twice to improve the backfill density of the filling gap 7 in the narrow space, ensuring the construction safety and engineering quality. A matching track group 3 and a slider group 6 are arranged at the lower part. The track group 3 and the slider group 6 are respectively fixed to the inner wall of the casing 1 and the outer wall of the pressure tube 4, and the slider group 6 can slide on the track group 3 under the action of external force. On the one hand, it is convenient to push the pressure tube 4 into the corresponding position of the axial inner cavity of the casing 1, thereby improving the construction efficiency; on the other hand, the slider group 6 prevents the pressure tube 4 from contacting the track group 3, and the track can be prevented from scratching the pressure tube 4 during the movement of the pressure tube 4, thereby playing an anti-corrosion role.

[0043] In the embodiment of the present invention, in order to prevent the pressure pipe 4 from floating up and causing it to be arranged in a different axial direction from the casing 1 during the backfilling process, a plurality of limiting I-beams 8 are arranged at intervals on the outer wall of the pressure pipe 4 (such as: two limiting I-beams 8 are arranged at intervals of 3m at the top of the pressure pipe 4); one end of the limiting I-beam 8 is welded to the outer wall of the pressure pipe 4, and the other end thereof is suspended at the upper part of the filling gap 7, and does not contact the inner wall of the casing 1. On the one hand, it can avoid the friction resistance generated by the limiting I-beam 8 after contacting the casing 1, and on the other hand, it can also avoid the situation where the pressure pipe 4 floats up during the subsequent backfilling construction process. Of course, the spacing between the limiting I-beam 8 and the casing 1 can be appropriately adjusted within the allowable error range.

[0044] The present invention lays a track group 3 in the casing 1, and sets an anti-floating device (limiting I-beam 8) and an external anti-corrosion protection device (slider 6 group) on the pressure pipe 4. The pressure pipe 4 is pushed into the limited space such as the casing 1 by a hydraulic cylinder; to ensure that the backfill outside the pipeline is dense, a backfill pumping pipe group 5 and a grouting pipe group 2 are arranged above the pipeline, and the backfill is performed after the pipeline is installed. It has the following advantages: ① Reliable quality: the track group 3 is arranged in the casing 1, and the pressure pipe 4 is pushed in by the hydraulic cylinder. The pressure pipe 4 is operated on the platform in the working well, which is convenient for welding and backfilling. The pre-installed backfilling pipe (grouting pipe group 2 and pumping pipe group 5) is used to backfill the filling gap to ensure the construction quality; ② Economical and reasonable: the method of mortar pumping backfilling is mainly used and cement slurry grouting is auxiliary, which reduces cement consumption, shortens construction time and improves economic benefits; ③ Easy to operate and easy to promote: the construction process is simple, with less equipment and labor input, low labor intensity, and easy on-site operation and promotion and application; ④ Convenient construction: conventional mortar is used as the backfill material, which is more guaranteed than cement slurry in terms of strength and concrete structure integrity, has better pumping performance, and improves construction convenience.

[0045] like Figure 1 , Figure 2 As shown, in one embodiment, the grouting pipe group 2 includes a plurality of grouting pipes 201 independently arranged from each other, and the plurality of grouting pipes 201 are arranged in a full length along the direction of the axial inner cavity. Specifically, in order to improve the compactness of the filling gap 7; this embodiment defines that the grouting pipe group 2 includes a plurality of grouting pipes 201 (this embodiment takes two grouting pipes 201 as an example), and the grouting pipes 201 are independent of each other and do not affect each other. On the one hand, they can be easily installed in the casing 1, and on the other hand, grouting can be performed in different directions to shorten the construction period. In addition, the grouting pipe 201 is arranged in a full length, and the two ends extend to the two ends of the casing 1 respectively, and grouting can be performed in the working well and the receiving well, which is more convenient to operate.

[0046] like Figure 1-Figure 3 As shown, in one embodiment, the pumping pipe group 5 includes a plurality of pumping pipes 501 that are independently arranged, and the plurality of pumping pipes 501 are all fixed to the outer surface of the pressure pipe 4, and the extension lengths thereof extending into the filling gap 7 are different. Specifically, in order to pump mortar into different positions; in this embodiment, the pumping pipe group 5 is defined to include a plurality of pumping pipes 501 (four pumping pipes 501 are used as an example in this embodiment), and the pumping pipes 501 are independent of each other, so as to facilitate installation one by one; in addition, as Figure 3As shown, the lengths of the pumping pipes 501 are different, which is convenient for pumping mortar to different depths; for example: ①# pumping pipe 501 is 140m long, ②# pumping pipe 501 is 100m long, ③# pumping pipe 501 is 60m long, ④# pumping pipe 501 is 20m long, and the difference in length between two adjacent pumping pipes 501 is at least 40m. Of course, for the installation of pipelines of different sizes, the size and number of the pumping pipes 501 also need to be adjusted accordingly. At the same time, in order to further improve the construction efficiency, the pumping pipes 501 can be arranged from both ends of the pressure pipe 4 to the middle, that is: two groups of pumping pipe groups 5 are respectively set at the two ends of the pressure pipe 4, and the two groups of pumping pipes 501 are arranged in a mirror image, so as to adopt two-way backfill grouting at the working well and the receiving well.

[0047] like Figure 4 , Figure 5 As shown, in one embodiment, the track group 3 includes a leveling support 301 arranged in contact with the inner wall of the casing 1, and a plurality of I-beam guide rails 302 arranged at intervals on the leveling support 301; the slider 6 group includes a plurality of sliders 6 arranged at intervals along the outer circumferential surface of the pressure tube 4, and the plurality of sliders 6 are arranged in one-to-one correspondence with the plurality of I-beam guide rails 302. Specifically, in order to make the pressure tube 4 slide relative to the casing 1; this embodiment defines that the track group 3 includes a leveling support 301 and an I-beam guide rail 302, and the slider 6 group includes a plurality of sliders 6 arranged at intervals; in this way, the leveling support 301, on the one hand, can be fixed to the casing 1 as a support member of the I-beam guide rail 302, and on the other hand, the I-beam guide rail 302 can be leveled based on the leveling support 301, so that the I-beam guide rail 302 can be arranged equidistantly relative to the center line of the casing 1, so that the slider 6 can slide smoothly on the I-beam guide rail 302, and then not only can the pressure tube 4 be quickly put in place, but also can avoid direct contact between the pressure tube 4 and the I-beam guide rail 302, thereby ensuring the integrity of the outer wall of the pressure tube 4. Preferably, the leveling support 301 is an arc structure for better fitting inside the casing 1. Of course, the above-mentioned components built into the filling gap 7, such as: the I-beam guide rail 302, etc. can be used as a grouting reinforcement member in the filling gap 7; and a φ2000 spiral steel pipe (such as Figure 3 shown).

[0048] like Figure 4 As shown, in one embodiment, the angle between the two ends of the leveling support 301 and the line connecting the center of the casing 1 is α, and α satisfies α=90°; preferably, the angle between the two ends of the two adjacent sliders 6 and the line connecting the center of the pressure tube 4 is β, and β satisfies β=60°. This embodiment ensures the smooth sliding of the pressure tube 4 by defining the above angle to avoid "deviation".

[0049] Furthermore, if Figure 5As shown, in one embodiment, the slider 6 includes a first sliding portion 601 and a second sliding portion 602 arranged at an angle, the first sliding portion 601 is fixed to the pressure tube 4, and can slide in contact with the I-beam guide rail 302, and the second sliding portion 602 is located on one side of the I-beam guide rail 302. Specifically, in order to further prevent the inner tube from deflecting during movement; this embodiment defines that the slider 6 includes a first sliding portion 601 and a second sliding portion 602 arranged at an angle, the first sliding portion 601 is used to connect the pressure tube 4 and the I-beam guide rail 302, so that the first sliding portion 601 can slide on the I-beam guide rail 302 and link the second sliding portion 602 to slide, the second sliding portion 602 is located on one side of the I-beam guide rail 302, and can limit the pressure tube 4 from deflecting to the other side of the I-beam guide rail 302. In addition, since there are two sliders 6 in this embodiment, the two sliders 6 are mirror-imaged so that one first sliding portion 601 is close to the other first sliding portion 601. The two second sliding portions 602 are located on different sides of the I-beam guide rail 302 to limit the two directions, thereby further improving the concentricity of the casing 1 and the pressure pipe 4.

[0050] like Figure 1 As shown, in one embodiment, a support rod 9 is provided in the pressure tube 4, and the support rod 9 is configured as a cross-shaped structure, which is used to support the inner wall of the pressure tube 4. Specifically, in order to avoid deformation of the pressure tube 4 during backfilling, this embodiment installs a cross-shaped support rod 9 in the pressure tube 4 during backfilling, so that the support rod 9 can support various places of the inner wall of the pressure tube 4 to avoid deformation of the pressure tube 4; after the filling gap 7 is formed, the support rod 9 can be removed.

[0051] On the other hand, according to an embodiment of the present invention, there is also provided a method for constructing a long-distance pipeline in an underground limited space, comprising the above-mentioned laying structure, and the construction method comprises the following steps:

[0052] Digging working wells and receiving wells;

[0053] Install jacking equipment in the working pit;

[0054] Using a jacking device to jack the casing 1 through the working well;

[0055] Clean the inside of the casing 1 and check the centerline deviation of the casing 1;

[0056] Installing the grouting pipe group 2 and the track group 3 in the casing 1;

[0057] The pressure pipes 4 are hoisted one by one into the working well, and the pumping pipe group 5, the limiting I-beam 8 and the slider group 6 are installed on the outer surface thereof;

[0058] The slider group 6 is in place and the center and bottom elevation of the pressure pipe 4 are calibrated before pushing into the pressure pipe 4. Sandbags are placed in the pressure pipe 4 to increase the counterweight.

[0059] Welding two adjacent pressure pipes 4 in the working well, and pushing them into the casing 1 through the pushing equipment;

[0060] Backfill the filling gap 7 by using the pumping pipe group 5 for primary backfilling and grouting and the grouting pipe group 2 for secondary backfilling and grouting;

[0061] A cross-shaped support rod 9 is constructed in the pressure tube 4 and the support rod 9 is removed after the filling gap 7 is formed.

[0062] In the embodiment of the present invention, Figure 6 As shown, construction preparation: before laying the pressure pipe 4, clean the inside of the casing 1 to ensure that the casing 1 is clean and free of debris; review the centerline deviation of the casing 1, and only when the deviation is within the allowable range can the pressure pipe 4 be installed; if the deviation exceeds the allowable range, it is necessary to formulate treatment measures in advance and lay the track according to the established measures; the cables, lighting and ventilation equipment in the casing 1 are in place.

[0063] Installation of guide rails and operating platform: According to the pipeline measurement results, adjust and optimize the laying elevation of the I-beam guide rail 302, use the total station to lay out the laying offset of the I-beam guide rail 302, and use the level to lay out and control the laying height of the I-beam guide rail 302; drill holes at the bottom of the inner wall of the casing 1, insert expansion screws, and weld and install the leveling support 301. The leveling support 301 uses I10 I-beams, and one is set in the circumferential direction every 2m; weld and install the longitudinal I10 I-beam on the leveling support 301 as the I-beam guide rail 302. The joints of the I-beam guide rail 302 must be fully welded to ensure that the connection stiffness meets the requirements, and the welding parts are polished to ensure that the sliding surface of the I-beam guide rail 302 is flat. After the guide rails are laid, the quality of the guide rail installation is inspected on site to ensure that the track installation spacing, elevation, and flatness of the guide rail joints meet the construction requirements; during the guide rail installation welding and grinding process, a ventilator must be installed in the pipeline to ensure construction safety; the height of the operating platform is adjusted according to the guide rail elevation to ensure that the pressure pipe 4 is smoothly pushed into the casing 1.

[0064] Installation of jacking cylinder: The jacking cylinder is installed on the backrest of the original jacking working well, and the jacking direction is perpendicular to the backrest to ensure that the backrest is evenly stressed; the jacking cylinder is fixed by the jacking bracket, and the cylinder bracket is a bracket welded from square steel pipes, so that the cylinder has a reliable bracket when working. According to the jacking axis of the jacking pipe, first adjust the center line of the bracket to align with the jacking axis, and adjust the height of the bracket according to the installation height of the pressure pipe 4. After the longitudinal and elevation adjustments are made, fix the bracket firmly and hoist the cylinder onto the bracket. The positioning and installation size error of the cylinder bracket and the cylinder should be controlled within 2mm.

[0065] Lifting and welding of pressure pipes: The pressure pipe 4 is lifted to the operating platform by a car crane, and the hydraulic cylinder pushes the pressure pipe 4 to the docking working surface for pipeline welding; the materials and processes used for welding meet the relevant requirements.

[0066] Installation of anti-floating, external anti-corrosion protection device and backfill pipeline: The installation of backfill pipeline includes the installation of pumping pipe 501 and grouting pipe 201. Multiple φ125mm seamless steel pipes are arranged on the top of the pressure pipe 4 as pumping pipe 501. The length and number of pumping pipe 501 are determined according to the length of the section. Two full-length φ42mm grouting pipes 201 are arranged on the top of the casing 1 to ensure the secondary backfill is dense. The pumping pipe 501 is connected by welding and fixed on the top of the pressure pipe 4. It is installed and welded synchronously with the pressure pipe 4 in the working well. The pumping pipe 501 is arranged from both ends of the pressure pipe 4 to the middle. A single long The length is determined by the total length of the pressure pipe 4. The longest pumping pipe 501 is L / 2-40m (L is the total length of the pressure pipe 4). The lengths of the remaining pumping pipes 501 decrease by 40m. The pipelines are arranged according to the plan during installation; two I16 I-beams are set at intervals of 3m on the top of the pressure pipe 4 as limit I-beams 8 to prevent the pressure pipe 4 from floating up during the subsequent backfill construction process; after the pressure pipe 4 is welded, unequal angle steels are welded and installed at the junction of its bottom and the guide rail as sliders 6 to ensure that the pressure pipe 4 does not directly contact the I-beam guide rail 302 when walking in the casing 1, thereby ensuring that the external corrosion protection of the pressure pipe 4 is complete and reliable.

[0067] Pipeline jacking: Before the pressure pipe 4 is jacked in, the inside of the casing 1 is cleaned and the cables, lighting and ventilation equipment and facilities in the casing 1 are removed. The jacking of the pressure pipe 4 must be carried out at a uniform and stable speed to avoid stress concentration in the pipeline due to too fast jacking, which may cause the pipeline to bounce or derail. In order to avoid large bounces or derailments of the guide rails, 1 ton sandbags are placed in the pressure pipe 4 every 50m to increase the counterweight.

[0068] Jacking construction process: first lower the pressure pipe 4 to the operating platform of the working well, install the jacking iron after it is in place, and check whether the center of the pipe and the elevation of the bottom of the pipe meet the design requirements. After passing the test, jacking can be carried out; install the jacking iron and squeeze it firmly. After the front end of the pipe moves a certain length, start the oil pump, let the jack fill with oil, and the piston extends a working stroke to push the pipeline to a certain distance; stop the oil pump, open the control valve, return the oil to the jack, and retract the piston; add the jacking iron, and repeat the above operations until the next section of the pressure pipe 4 needs to be installed; remove the jacking iron, install and weld the lower pipe; reinstall the jacking iron and repeat the above operations.

[0069] Backfill and grouting behind the pipeline: After the pressure pipe 4 is installed, the gap between the pressure pipe 4 and the casing 1 is backfilled, and the delivery pump uses a high-pressure long-distance delivery pump; in order to avoid deformation of the pipeline during the backfill pouring process, a "M"-shaped support rod 9 is set every 3m in the pipeline, and the support rod 9 is made of 15×15cm square wood; before the construction of the pipeline support rod 9, cables, lighting, and ventilation equipment are installed in the steel pipe to ensure construction safety; commercial self-leveling mortar is used for backfill pouring, and the mortar is transported by concrete tankers. A high-pressure long-distance delivery ground pump is set at the bottom of the well. The mortar is pumped into the ground pump hopper through the sky pump, and the ground pump is connected to the pre-buried pumping pipe 501. Pumping is carried out one by one from the longest to the shortest length of the pumping pipe 501. The pumping backfill process During the process, a special person is arranged to check the deformation of the pipeline in the pipeline to avoid deformation of the pipeline caused by mortar backfill squeezing the pipeline; the total amount of mortar backfill is determined by the gap between the pressure pipe 4 and the casing 1, and the amount of mortar pumped by a single pipe is not less than the gap of the 440m length of the pressure pipe. At the same time, a rubber hammer is used to knock on the pipeline during the backfill process to determine whether the backfill is full. The backfill mortar amount and rubber hammer knocking can ensure that the backfill is dense; before pumping backfill, the two ends are sealed and reinforced with bricks, and an observation port is reserved on the top; after the mortar backfill is completed, the pre-buried φ42 grouting pipe 201 is used for secondary backfill grouting. The grouting uses pure cement slurry with a water-cement ratio of 1:1 and a grouting pressure of 1.2~1.5MPa to ensure that the backfill between the casing 1 and the pressure pipe 4 is dense.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A long-distance pipeline laying structure in an underground limited space, characterized in that: include: A first pipeline assembly includes a casing, a grouting pipe group and a track group, wherein the casing has an axial inner cavity, the grouting pipe group and the track group are respectively arranged at the upper and lower parts of the axial inner cavity, and both extend along the direction of the axial inner cavity; The second pipeline assembly includes a pressure pipe, a pumping pipe group and a slider group. The pressure pipe is coaxially arranged in the axial inner cavity and forms a filling gap with the casing. The pumping pipe group and the slider group are respectively arranged at the upper and lower parts of the filling gap, and are used to correspond to the grouting pipe group and the track group respectively. Under the action of external force, the pressure pipe can move relative to the casing in the axial inner cavity to link the slider group to slide on the track group. Among them, a plurality of limiting I-beams are arranged at intervals along the outer peripheral surface of the pressure tube, and one end of the limiting I-beam away from the pressure tube is suspended in the filling gap and does not contact the inner wall of the casing.

2. The underground limited space long distance pipeline laying structure according to claim 1 is characterized in that: The grouting pipe group comprises a plurality of grouting pipes which are independently arranged from each other, and the plurality of grouting pipes are arranged in a continuous length along the direction of the axial inner cavity.

3. The underground limited space long distance pipeline laying structure according to claim 1 is characterized in that: The pumping pipe group includes a plurality of pumping pipes that are independently arranged. The plurality of pumping pipes are all fixed to the outer surface of the pressure pipe, and have different extension lengths extending into the filling gap.

4. The underground limited space long distance pipeline laying structure according to claim 1 is characterized in that: The track assembly includes a leveling support arranged in contact with the inner wall of the casing, and a plurality of I-beam guide rails arranged at intervals on the leveling support; The slider group includes a plurality of sliders arranged at intervals along the outer peripheral surface of the pressure tube, and the plurality of sliders are arranged in one-to-one correspondence with the plurality of I-beam guide rails.

5. The underground limited space long distance pipeline laying structure according to claim 4 is characterized in that: The leveling support is an arc-shaped structure.

6. The underground limited space long distance pipeline laying structure according to claim 4 is characterized in that: The angle between the lines connecting the two ends of the leveling support and the center of the sleeve is α, and α satisfies α≥90°.

7. The underground limited space long distance pipeline laying structure according to claim 4 is characterized in that: The angle between the two adjacent ends of the two sliding blocks and the line connecting the center of the pressure tube is β, and β satisfies β≤60°.

8. The underground limited space long distance pipeline laying structure according to any one of claims 4 to 7, characterized in that: The sliding block includes a first sliding portion and a second sliding portion which are arranged at an angle, wherein the first sliding portion is fixed to the pressure pipe and can slide in contact with the I-beam guide rail, and the second sliding portion is located at one side of the I-beam guide rail.

9. The underground limited space long distance pipeline laying structure according to claim 1, characterized in that: A support rod is arranged inside the pressure tube, and the support rod is configured as a cross-shaped structure for supporting the inner wall of the pressure tube.

10. A method for constructing long-distance pipelines in underground limited spaces, characterized in that: Comprising the laying structure according to any one of claims 1 to 9, the construction method comprises the following steps: Digging working wells and receiving wells; Install jacking equipment in the working pit; Using jacking equipment to jack the casing through the working well; Clean the inside of the casing and check the centerline deviation of the casing; Installing the grouting pipe group and the track group in the casing; Hoist the pressure pipes one by one into the working well, and install the pumping pipe group, the limiting I-beam and the slider group on the outer surface of the pressure pipes; After the slider group is in place and the center and bottom elevation of the pressure pipe are calibrated, the pressure pipe is pushed forward and sandbags are placed in the pressure pipe to increase the counterweight; Welding two adjacent pressure pipes in the working well and pushing them into the casing through the jacking equipment; Backfilling the filling gap by means of primary backfill grouting of a pumping pipe group and secondary backfill grouting of a grouting pipe group; A cross-shaped support rod is constructed in the pressure tube, and the support rod is removed after the filling gap is formed.

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