Long-distance pipe jacking construction technology

Abstract

The invention discloses a long-distance pipe jacking construction process. The long-distance pipe jacking construction process comprises the following steps that S1, a working well / receiving well is constructed; s2, soft soil reinforcement; s3, pipe jacking back wall and guide rail construction; s4, a pipe jacking machine and auxiliary equipment are installed; s5, pipe jacking construction is conducted; s6, installing and constructing the intermediate jacking station; s7, measuring and correcting; s8, slurry replacement; s9, performing a hydrostatic test; wherein the top pipe is divided into a steel pipe top pipe and a cast iron pipe top pipe, the steel pipe top pipe adopts a D2200 steel pipe, and the cast iron pipe top pipe adopts a D2200 cast iron pipe; the steel pipe jacking pipe is provided with a D2800 steel pipe inner sleeve; according to the long-distance pipe jacking construction technology, construction of the large-diameter ultra-long jacking pipe is achieved, the automation degree is high, and the long-distance pipe jacking construction technology has the advantages of being small in construction occupied area, low in construction noise, high in obstacle crossing capacity, free of influence on existing facilities, high in construction speed, high in construction quality and high in safety.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a long-distance pipe jacking construction process and its accessory structure. Background Art

[0002] For the construction section of the raw water pipeline with a long length, because the pipeline needs to pass through farmland, villages, roads, and some of the pipelines are buried deep underground, some pipelines are constructed by jacking. Especially for the construction of jacking pipes of different materials in complex sections, the technicians in this field are in urgent need of developing a long-distance jacking construction process and its auxiliary structure. Summary of the invention

[0003] The purpose of the present invention is to provide a long-distance jacking pipe construction process, which realizes the construction of large-diameter and ultra-long jacking pipes, has a high degree of automation, and has the advantages of small construction footprint, low construction noise, strong obstacle crossing ability, no impact on existing facilities, fast construction speed, high construction quality and high safety.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The long-distance pipe jacking construction process of the present invention is suitable for the construction of large-diameter and long-distance pipe jacking, and the construction process comprises the following steps:

[0006] S1. Construction of working well / receiving well;

[0007] S2, soft soil reinforcement;

[0008] S3, construction of the back wall and guide rails of the jacking pipe;

[0009] S4. Installation of pipe jacking machine and auxiliary equipment;

[0010] S5, pipe jacking construction;

[0011] S6. Installation and construction of relay room;

[0012] S7, measurement and correction;

[0013] S8, mud replacement;

[0014] S9, water pressure test;

[0015] The jacking pipe is divided into steel pipe jacking pipe and cast iron pipe jacking pipe. The steel pipe jacking pipe adopts D2200 steel pipe, and the cast iron pipe jacking pipe adopts D2200 cast iron pipe.

[0016] The steel pipe jacking pipe is equipped with a D2800 steel pipe inner sleeve;

[0017] The maximum one-time jacking length of D2200 steel pipe is 300m;

[0018] The longest one-time jacking length of D2800 steel pipe is 137m;

[0019] The maximum one-time jacking length of D2200 cast iron pipe is 605m;

[0020] The steel pipes are fixed by welding, and the cast iron pipes are connected by socket-type connection.

[0021] Furthermore, in step S1, the working well is a circular well made of reinforced concrete, and the working well is made of 60 cm thick C30 concrete, and the diameter of the working well is 11 m-14 m;

[0022] The receiving well is a circular well made of reinforced concrete, and the receiving well uses 60cm thick C30 concrete. The diameter of the receiving well is 8m-11m.

[0023] Furthermore, in step S2, the soft stratum section needs to be pre-grouted and reinforced before the pipe jacking construction;

[0024] The grouting range is within 1.5m around the pipe wall, and a crawler-type shallow hole drill is used to drill holes and insert grouting pipes for grouting.

[0025] Furthermore, in step S3, after the working pit is excavated to the designed elevation, it is leveled in time and the bottom plate concrete is poured, and then the back wall of the top pipe is constructed;

[0026] The rear wall is made of C30 reinforced concrete, and the surface of the rear wall is straight and perpendicular to the axis of the pipeline's forward direction.

[0027] Furthermore, a downhole guide rail is arranged in the working well / receiving well to support the jacking pipe;

[0028] The underground guide rail comprises:

[0029] A plurality of cross beams located at the bottom and arranged at intervals, wherein the cross beams are made of 200mm*200mm steel plates, and the spacing between adjacent cross beams is 1000mm; and

[0030] An I-beam guide rail is welded and fixed to the upper part of the plurality of cross beams, wherein the I-beam guide rail adopts I20a I-beam, and a reinforcing rib is welded and fixed between the outer side surface of the I-beam guide rail and the cross beam;

[0031] Pre-embedded steel bars are welded and fixed on both sides of the crossbeam near both ends, and the diameter of the pre-embedded steel bars is 28 mm. The lower part of the pre-embedded steel bars is embedded underground, and the length of the exposed part of the pre-embedded steel bars is 20 cm.

[0032] Furthermore, a shim is provided between the back wall and the pipe jacking machine, the shim is 20 mm thick, the size of the shim is 4000 mm*4000 mm, and the gap between the shim and the back wall is filled with cement mortar;

[0033] A 500mm*500mm*30mm steel plate is arranged between the hydraulic cylinder of the pipe jacking machine and the washer.

[0034] Furthermore, a relay room is provided when the jacking length of the pipe exceeds 100m;

[0035] The number of relay rooms is one relay room per 100m;

[0036] 20 hydraulic jacks with a jacking force of 20t are arranged in the relay room, and the outer diameter of the relay room is consistent with that of the jacking pipe.

[0037] Furthermore, the measurement in step S7 is mainly carried out in two ways, namely:

[0038] Measurement method 1: A laser target is installed at the center of the pipe jacking machine as a measurement target. The operator observes the situation inside the machine through the display on the console outside the machine and makes corrections based on the position of the laser point.

[0039] Measurement method 2: Set an inclinometer on the head of the pipe jacking machine and perform correction according to the value displayed by the inclinometer on the background operating system.

[0040] Furthermore, in step S8, firstly, the openings at both ends of the pipeline between the working well and the receiving well of the designated top pipe section are fully sealed with MU10 cement mortar bricks, and then cement slurry is injected between the pipeline and the outer soil through the grouting holes reserved in the pipeline to replace the mud, so as to reinforce the soil outside the pipe body;

[0041] The grouting pressure of cement slurry is controlled at 0.3MPa-0.4MPa.

[0042] Furthermore, in step S9, after the mud replacement is completed, a water pressure test is required before the working well is closed;

[0043] Before the water pressure test, seal both ends of the pipe, open a small opening at one end and fill it with water and install a pressure device;

[0044] First, conduct a preliminary test, slowly raise the water pressure in the pipeline to the test pressure and maintain the pressure for 30 minutes. If the pressure drops during this period, water can be injected to replenish the pressure, but it must not be higher than the test pressure;

[0045] Check whether there is any leakage or damage at the pipe joints and fittings; if there is any leakage or damage, stop the pressure test immediately, find out the cause and take corresponding measures before retesting the pressure;

[0046] After completion, water injection and pressure replenishment should be stopped and stabilized for 30 minutes; when the pressure drop does not exceed 70% of the test pressure after 30 minutes, the pre-test is completed; otherwise, water injection and pressure replenishment should be restarted and stabilized for 30 minutes before observation, until the pressure drop does not exceed 70% of the test pressure after 30 minutes;

[0047] After the preliminary test is passed, the main test is carried out. Stop water injection and pressure replenishment and stabilize for 15 minutes. When the pressure drop does not exceed 0.03MPa after 15 minutes, reduce the test pressure to the working pressure and maintain constant pressure for 30 minutes. Perform an appearance inspection. If there is no water leakage, the water pressure test is qualified.

[0048] In the above technical solution, the present invention provides a long-distance pipe jacking construction process, which has the following beneficial effects:

[0049] The long-distance jacking pipe construction process of the present invention realizes the construction of large-diameter and ultra-long jacking pipes, has a high degree of automation, and has the advantages of small construction footprint, low construction noise, strong obstacle-crossing ability, no impact on existing facilities, fast construction speed, high construction quality and high safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. It is obvious that the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0051] Figure 1 A top view of a pipe jacking guide rail in a long-distance pipe jacking construction process disclosed in an embodiment of the present invention;

[0052] Figure 2 It is a side view of a pipe jacking guide rail in a long-distance pipe jacking construction process disclosed in an embodiment of the present invention;

[0053] Figure 3 The present invention is a diagram of the coordination structure of the back wall and the pipe jacking machine in the long-distance pipe jacking construction process disclosed in an embodiment of the present invention.

[0054] Description of reference numerals:

[0055] 10. Pipe jacking;

[0056] 101. crossbeam; 102. I-beam guide rail; 103. embedded steel bars; 104. reinforcing ribs;

[0057] 2. Back wall;

[0058] 201. Washer iron; 202. Steel plate; 203. Cement mortar. DETAILED DESCRIPTION

[0059] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0060] See also Figures 1 to 3 As shown;

[0061] The long-distance pipe jacking construction process of this embodiment is suitable for the construction of a large-diameter and long-distance pipe jacking 10. The construction process includes the following steps:

[0062] S1. Construction of working well / receiving well;

[0063] S2, soft soil reinforcement;

[0064] S3, construction of back wall 2 and guide rails behind top pipe 10;

[0065] S4. Installation of pipe jacking machine and auxiliary equipment;

[0066] S5, jacking construction of pipe 10;

[0067] S6. Installation and construction of relay room;

[0068] S7, measurement and correction;

[0069] S8, mud replacement;

[0070] S9, water pressure test;

[0071] Among them, the jacking pipe 10 is divided into a steel pipe jacking pipe and a cast iron pipe jacking pipe, the steel pipe jacking pipe adopts a D2200 steel pipe, and the cast iron pipe jacking pipe adopts a D2200 cast iron pipe;

[0072] The steel pipe jacking is equipped with a D2800 steel pipe inner sleeve;

[0073] The maximum one-time jacking length of D2200 steel pipe is 300m;

[0074] The longest one-time jacking length of D2800 steel pipe is 137m;

[0075] The maximum one-time jacking length of D2200 cast iron pipe is 605m;

[0076] Steel pipes are fixed by welding, and cast iron pipes are connected by socket connection.

[0077] Preferably, in step S1 of this embodiment, the working well is a circular well made of reinforced concrete, and the working well is made of 60 cm thick C30 concrete, and the diameter of the working well is 11 m-14 m;

[0078] The receiving well is a circular well made of reinforced concrete, and the receiving well uses 60cm thick C30 concrete. The diameter of the receiving well is 8m-11m.

[0079] In order to prevent surface water from flowing into the working well and eroding the well bottom foundation and the soil around the walls, the retaining wall of the working well is 50cm above the ground and ground drainage is well done.

[0080] Preferably, in step S2 of this embodiment, the soft stratum section needs to be pre-grouted and reinforced before the jacking construction of the jacking pipe 10;

[0081] The grouting range is within 1.5m around the pipe wall, and a crawler-type shallow hole drill is used to drill holes and insert grouting pipes for grouting.

[0082] Specific grouting requirements are:

[0083] (1) Grouting treatment is currently being considered for the pipe jacking section. The final solution will be determined based on the actual treatment effect after the field test section is completed.

[0084] (2) Grouting should be carried out before the jacking work 10 is carried out. A grouting test should be carried out before grouting, and the grouting parameters should be adjusted according to the test results.

[0085] (3) The grouting material used is ordinary cement single-liquid slurry with a ratio of W:C=1:1, which can be adjusted on site according to actual geological conditions.

[0086] (4) Ordinary Portland cement with a grade not less than 425 should be used for grouting.

[0087] (5) Grouting adopts high-pressure grouting method with a grouting pressure of 0.2-0.5 MPa. The grouting sequence is generally from bottom to top, from outside to inside, and finally to the middle.

[0088] (6) The hole spacing should be arranged in a plum blossom shape of 1mx1m. The grouting influence radius is 0.6~0.7m, and grouting should be done in alternate holes.

[0089] (7) The depth error of the grouting hole is within 200 mm and the verticality deviation is less than 1%.

[0090] (8) If necessary, a coagulant can be added during the grouting process to prevent the grouting range from exceeding the required range.

[0091] (9) There are 5 grouting holes per linear meter, and the amount of cement slurry is calculated based on the actual amount of work incurred.

[0092] (10) The general grouting range of the top pipe 10 is 1.5m at the top and 1m at the left and right. If rock strata are encountered within 1m of the bottom, reinforcement can be carried out to the rock surface.

[0093] (11) The length of the grouting flower tube should be determined according to the grouting range requirements.

[0094] Preferably, in step S3 of this embodiment, after the working pit is excavated to the designed elevation, it is leveled in time and the bottom plate concrete is poured, and then the back wall 2 of the top pipe 10 is constructed;

[0095] The back wall 2 is made of C30 reinforced concrete. The surface of the back wall 2 is straight and perpendicular to the axis of the pipeline's forward direction to avoid eccentric pressure during the pipeline jacking process, resulting in jacking force loss and quality and safety accidents.

[0096] Secondly, a downhole guide rail is arranged in the working well / receiving well to support the jacking pipe 10;

[0097] The underground guide rail of this embodiment includes:

[0098] A plurality of cross beams 101 are located at the bottom and arranged at intervals, the cross beams 101 are made of 200mm*200mm steel plates, and the spacing between adjacent cross beams 101 is 1000mm; and

[0099] An I-beam guide rail 102 is welded and fixed to the upper part of the plurality of cross beams 101. The I-beam guide rail 102 is made of I20a I-beam, and a reinforcing rib 104 is welded and fixed between the outer side surface of the I-beam guide rail 102 and the cross beam 101;

[0100] Embedded steel bars 103 are welded and fixed on both sides of the cross beam 101 near both ends, and the diameter of the embedded steel bars 103 is 28 mm. The lower part of the embedded steel bars 103 is embedded underground, and the length of the exposed part of the embedded steel bars 103 is 20 cm.

[0101] In this embodiment, when pouring concrete for the bottom plate, two φ28 steel bars 103 are pre-buried at both ends of each cross beam 101 and exposed 20 cm. The pre-buried steel bars 103 are firmly welded to the cross beam 101 to ensure that there is no displacement, deformation or settlement due to collision when the pipeline is pushed in and hoisted into place.

[0102] Preferably, a shim 201 is provided between the back wall 2 and the pipe jacking machine in this embodiment, the shim 201 has a thickness of 20 mm, a size of 4000 mm*4000 mm, and a gap between the shim 201 and the back wall 2 is filled with cement mortar 203;

[0103] A 500mm*500mm*30mm steel plate 202 is arranged between the hydraulic cylinder of the pipe jacking machine and the washer 201 .

[0104] In step S4, the auxiliary equipment of the pipe jacking machine mainly includes: ① combined jack frame; ② main top jack; ③ oil pump station and pipe valve; ④ shim 201; ⑤ laser theodolite, etc. Among them, the shim 201 is 20mm thick, providing a vertical force surface for the reaction force of the jacking pipe 10 to ensure that the back concrete is evenly stressed. A 30mm thick steel plate of 500×500mm is welded on the force surface of each jack as shown in the figure below. After the rear shim 201 is installed correctly, fill and pour cement mortar 203 between the rear shim 201 and the back wall 2 of the working pit to ensure that the two are fully close.

[0105] After the pipe jacking machine is installed and debugged, the pipeline jacking construction can be carried out. The first section of the pipeline is hoisted onto the guide rail by the truck crane and firmly connected to the pipe jacking machine. Then the pipe jacking machine is started to push forward. A small part of the mud generated during the process is used to lubricate the outer side of the pipe wall to reduce the friction between the pipe and the surrounding soil layer, and the rest is discharged to the mud pool outside the working well and transported out.

[0106] After the first section of the pipeline is pushed into the soil layer, the hydraulic jack is retracted and the second section of the pipeline can be installed, and then the pipeline is pushed in again, and the construction of subsequent pipelines is continued in this cycle. For cast iron pipes, the pipes are connected by sockets, and for steel pipes, they are welded and tested. Construction can only continue after the test is qualified.

[0107] Preferably, a relay room is provided when the jacking length of the jacking pipe 10 in this embodiment exceeds 100m;

[0108] The number of relay rooms is one for every 100m;

[0109] Twenty hydraulic jacks with a jacking force of 20t are arranged in the relay room, and the outer diameter of the relay room is consistent with that of the jacking pipe 10.

[0110] The pipe for pipe jacking 10 construction is relatively long, and the jacking force of the hydraulic jack in the working well is limited, which cannot meet the requirements of the relatively long pipe jacking construction, so additional relay rooms are required. According to the calculation, the number of additional relay rooms required for each section of pipe jacking is as follows:

[0111] Table 1 Number of relay rooms

[0112]

[0113] During the process of pipe jacking, first start the jack in the relay room to push the pipe in front of it forward, then start the jack at the back to continue pushing the pipe forward, and so on, gradually advancing the construction.

[0114] Preferably, the measurement in step S7 of this embodiment mainly adopts two methods, namely:

[0115] Measurement method 1: A laser target is installed at the center of the pipe jacking machine as a measurement target. The operator observes the situation inside the machine through the display on the console outside the machine and makes corrections based on the position of the laser point.

[0116] Measurement method 2: Set an inclinometer on the head of the pipe jacking machine and perform correction according to the value displayed by the inclinometer on the background operating system.

[0117] This embodiment uses the above two measurement methods to turn complex measurements into simple and intuitive operations. When correcting the deviation, the deviation can be corrected by adjusting the deflection angle of the pipe jacking machine head through the operating system.

[0118] Preferably, in step S8 of this embodiment, firstly, the openings at both ends of the pipeline between the working well and the receiving well of the designated jacking section are fully sealed with MU10 cement mortar bricks, and then cement slurry is injected between the pipeline and the outer soil through the grouting holes reserved in the pipeline to replace the mud, so as to reinforce the soil outside the pipe body;

[0119] The grouting pressure of cement slurry is controlled at 0.3MPa-0.4MPa.

[0120] It should be noted that grouting should be carried out from low to high in sequence, and no jumping is allowed. The grouting pressure should be controlled at 0.3-0.4MPa, and the grouting holes should be sealed in time after the grouting is completed.

[0121] Preferably, in step S9 of this embodiment, after the mud replacement is completed, a water pressure test is required before the working well is closed;

[0122] Before the water pressure test, seal both ends of the pipe, open a small opening at one end and fill it with water and install a pressure device;

[0123] First, conduct a preliminary test, slowly raise the water pressure in the pipeline to the test pressure and maintain the pressure for 30 minutes. If the pressure drops during this period, water can be injected to replenish the pressure, but it must not be higher than the test pressure;

[0124] Check whether there is any leakage or damage at the pipe joints and fittings; if there is any leakage or damage, stop the pressure test immediately, find out the cause and take corresponding measures before retesting the pressure;

[0125] After completion, water injection and pressure replenishment should be stopped and stabilized for 30 minutes; when the pressure drop does not exceed 70% of the test pressure after 30 minutes, the pre-test is completed; otherwise, water injection and pressure replenishment should be restarted and stabilized for 30 minutes before observation, until the pressure drop does not exceed 70% of the test pressure after 30 minutes;

[0126] After the preliminary test is passed, the main test is carried out. Stop water injection and pressure replenishment and stabilize for 15 minutes. When the pressure drop does not exceed 0.03MPa after 15 minutes, reduce the test pressure to the working pressure and maintain constant pressure for 30 minutes. Perform an appearance inspection. If there is no water leakage, the water pressure test is qualified.

[0127] Based on the technical research of the large-diameter and ultra-long jacking pipe construction process of this embodiment of the above construction process, the matters needing attention are summarized as follows:

[0128] (1) Before pipe jacking construction is carried out, the geological conditions of the construction area must be investigated and analyzed in detail in combination with the geological survey report. If soft foundations are encountered, they must be treated in advance, and the conditions of underground pipelines and structures must be identified to avoid affecting the construction.

[0129] (2) Select areas with good geological conditions and high soil bearing capacity as the locations of working wells and receiving wells, and avoid setting them up in areas with soft soil layers or high groundwater levels, which will affect the construction progress of working wells and receiving wells and create greater construction safety hazards.

[0130] (3) During the pipeline jacking construction process, it is necessary to continuously monitor the jacking direction and head offset of the pipeline. If the offset exceeds the warning value, timely measures should be taken to adjust it.

[0131] (4) During the construction of pipe jacking 10, there must be unified command by a dedicated person, full coordination and cooperation, and it is strictly forbidden for operators to operate blindly.

[0132] (5) For long-distance jacking, a diesel generator should be equipped as a temporary emergency power source to ensure the normal operation of power generation and distribution equipment.

[0133] In the above technical solution, the present invention provides a long-distance pipe jacking construction process, which has the following beneficial effects:

[0134] The long-distance jacking pipe construction process of the present invention realizes the construction of large-diameter and ultra-long jacking pipes, has a high degree of automation, and has the advantages of small construction footprint, low construction noise, strong obstacle-crossing ability, no impact on existing facilities, fast construction speed, high construction quality and high safety.

[0135] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. Long distance pipe jacking construction process, characterized in that: The construction process is suitable for the construction of a large-diameter and long-distance jacking pipe (10), and the construction process comprises the following steps: S1. Construction of working well / receiving well; S2, soft soil reinforcement; S3, construction of the back wall (2) and guide rails of the top pipe (10); S4. Installation of pipe jacking machine and auxiliary equipment; S5, jacking construction of pipe jacking (10); S6. Installation and construction of relay room; S7, measurement and correction; S8, mud replacement; S9, water pressure test; Wherein, the jacking pipe (10) is divided into a steel pipe jacking pipe and a cast iron pipe jacking pipe, the steel pipe jacking pipe adopts a D2200 steel pipe, and the cast iron pipe jacking pipe adopts a D2200 cast iron pipe; The steel pipe jacking pipe is equipped with a D2800 steel pipe inner sleeve; The maximum one-time jacking length of D2200 steel pipe is 300m; The longest one-time jacking length of D2800 steel pipe is 137m; The maximum one-time jacking length of D2200 cast iron pipe is 605m; The steel pipes are fixed by welding, and the cast iron pipes are connected by socket-type connection.

2. The long distance pipe jacking construction process according to claim 1 is characterized in that: In step S1, the working well is a circular well made of reinforced concrete, and the working well is made of 60 cm thick C30 concrete, and the diameter of the working well is 11 m-14 m; The receiving well is a circular well made of reinforced concrete, and the receiving well uses 60cm thick C30 concrete. The diameter of the receiving well is 8m-11m.

3. The long distance pipe jacking construction process according to claim 1 is characterized in that: In the step S2, the soft stratum section needs to be pre-grouted and reinforced before the jacking construction of the jacking pipe (10); The grouting range is within 1.5m around the pipe wall. A crawler-type shallow hole drill is used to drill holes and insert grouting pipes for grouting.

4. The long distance pipe jacking construction process according to claim 1, characterized in that: In the step S3, after the working pit is excavated to the designed elevation, it is promptly leveled and the bottom slab concrete is poured, and then the back wall (2) of the top pipe (10) is constructed; The rear wall (2) is made of C30 reinforced concrete, and the surface of the rear wall (2) is flat and perpendicular to the axis of the pipeline's advancing direction.

5. The long distance pipe jacking construction process according to claim 4 is characterized in that: A downhole guide rail is arranged in the working well / receiving well to support the top pipe (10); The underground guide rail comprises: A plurality of cross beams (101) are located at the bottom and arranged at intervals, wherein the cross beams (101) are made of 200mm*200mm steel plates, and the spacing between adjacent cross beams (101) is 1000mm; and An I-beam guide rail (102) is welded and fixed to the upper part of the plurality of crossbeams (101), wherein the I-beam guide rail (102) is made of I20a I-beam, and a reinforcing rib (104) is welded and fixed between the outer side surface of the I-beam guide rail (102) and the crossbeam (101); Pre-buried steel bars (103) are welded and fixed on both sides of the cross beam (101) near both ends, and the diameter of the pre-buried steel bars (103) is 28 mm. The lower part of the pre-buried steel bars (103) is pre-buried underground, and the length of the exposed part of the pre-buried steel bars (103) is 20 cm.

6. The long distance pipe jacking construction process according to claim 1 or 4, characterized in that: A shim is arranged between the rear wall (2) and the pipe jacking machine, the shim (201) has a thickness of 20 mm, a size of 4000 mm*4000 mm, and the gap between the shim (201) and the rear wall (2) is filled with cement mortar (203); A 500mm*500mm*30mm steel plate (202) is arranged between the hydraulic cylinder of the pipe jacking machine and the washer (201).

7. The long distance pipe jacking construction process according to claim 6, characterized in that: When the jacking length of the jacking pipe (10) exceeds 100 m, a relay room is provided; The number of relay rooms is one relay room per 100m; 20 hydraulic jacks with a jacking force of 20t are arranged in the relay room, and the outer diameter of the relay room is consistent with that of the jacking pipe.

8. The long distance pipe jacking construction process according to claim 1, characterized in that: The measurement in step S7 is mainly carried out in two ways, namely: Measurement method 1: A laser target is installed at the center of the pipe jacking machine as a measurement target. The operator observes the situation inside the machine through the display on the console outside the machine and makes corrections based on the position of the laser point. Measurement method 2: Set an inclinometer on the head of the pipe jacking machine and perform correction according to the value displayed by the inclinometer on the background operating system.

9. The long distance pipe jacking construction process according to claim 1, characterized in that: In step S8, firstly, the openings at both ends of the pipeline between the working well and the receiving well of the designated jacking section are fully sealed with MU10 cement mortar bricks, and then cement slurry is injected between the pipeline and the outer soil through the grouting holes reserved in the pipeline to replace the mud, so as to reinforce the soil outside the pipe body; The grouting pressure of cement slurry is controlled at 0.3MPa-0.4MPa.

10. The long distance pipe jacking construction process according to claim 1, characterized in that: In step S9, after the mud replacement is completed, a water pressure test is required before the working well is closed; Before the water pressure test, seal both ends of the pipe, open a small opening at one end and fill it with water and install a pressure device; First, conduct a preliminary test, slowly raise the water pressure in the pipeline to the test pressure and maintain the pressure for 30 minutes. If the pressure drops during this period, water can be injected to replenish the pressure, but it must not be higher than the test pressure; Check whether there is any leakage or damage at the pipe joints and fittings; if there is any leakage or damage, stop the pressure test immediately, find out the cause and take corresponding measures before retesting the pressure; After completion, water injection and pressure replenishment should be stopped and stabilized for 30 minutes; when the pressure drop does not exceed 70% of the test pressure after 30 minutes, the pre-test is completed; Otherwise, refill water to replenish pressure and stabilize for 30 minutes before observing again, until the pressure drop does not exceed 70% of the test pressure after 30 minutes; After the preliminary test is passed, the main test is carried out. Stop water injection and pressure replenishment and stabilize for 15 minutes. When the pressure drop does not exceed 0.03MPa after 15 minutes, reduce the test pressure to the working pressure and maintain constant pressure for 30 minutes. Perform an appearance inspection. If there is no water leakage, the water pressure test is qualified.

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