Split type super-long distance pipe jacking high-precision construction method in narrow space

Abstract

This invention relates to the field of municipal engineering construction technology and discloses a high-precision construction method for split-type ultra-long-distance pipe jacking in narrow spaces. The method includes the following steps: determining the design route of the jacking pipeline; installing a pipe jacking cylinder in the receiving shaft, installing the jacking main unit in the working shaft, arranging a hydraulic power module outside the working shaft, and connecting the hydraulic power module to the jacking main unit via hydraulic connection pipelines; connecting the guide drill rod to the guide drill bit and the jacking main unit, installing a probe and a dual-frequency receiver at the end of the guide drill rod, and establishing a data link between the dual-frequency receiver and a ground-based handheld receiver. This invention, by installing the jacking main unit inside the working shaft, arranging the hydraulic power module outside the working shaft, and connecting the hydraulic power module to the jacking main unit via hydraulic connection pipelines, can reduce the space requirements of the working shaft. The minimum size of the working shaft can be compressed, reducing space requirements and making it suitable for narrow space conditions such as dense urban areas, residential areas, and under overpasses.

Description

Technical Field

[0001] This invention relates to the field of municipal engineering construction technology, and in particular to a high-precision construction method for split-type ultra-long-distance pipe jacking in narrow spaces. Background Technology

[0002] Currently, trenchless construction techniques are widely used in the construction of water supply and drainage pipelines in municipal engineering projects to reduce road occupation and alleviate traffic congestion. Traditional pipeline construction often employs micro-jacking techniques using earth pressure balance and slurry balance methods in a single construction phase.

[0003] However, the aforementioned traditional construction techniques still have shortcomings in practical applications. Traditional integrated jacking equipment is limited by the size of the working shaft, resulting in a low power density of the jacking device, which makes it difficult to meet the power requirements of ultra-long-distance pipe jacking. The effective jacking distance in a single operation is usually no more than 200m.

[0004] Traditional laser guidance systems also face the problem of difficulty in controlling guidance accuracy during ultra-long pipeline construction. As the jacking distance increases, the laser beam is prone to divergence and attenuation, resulting in a shorter effective accuracy distance. Significant deviations can easily occur during jacking up to 600m, making it difficult to achieve high-precision control.

[0005] Meanwhile, controlling earth pressure and slurry pressure in traditional construction techniques is quite difficult. If not controlled properly, it can easily lead to ground heave or subsidence, especially under shallow burial and complex soil conditions, where the problem is more prominent.

[0006] In addition, traditional integrated equipment requires a large working well space, usually requiring a working well size of no less than 4m×4m, which is difficult to implement in narrow spaces such as dense urban areas, residential areas, and under overpasses.

[0007] Furthermore, traditional processes have limited effective jacking distance per run, require frequent intermediate working wells, and involve long equipment relocation times. Pipeline construction speed is typically only 3-5 m / h, resulting in low overall construction efficiency. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-precision construction method for split-type ultra-long-distance pipe jacking in narrow spaces.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A high-precision construction method for split-type ultra-long-distance pipe jacking in confined spaces includes the following steps:

[0011] S1. Determine the design route of the jacking pipeline;

[0012] S2. Install the pipe jacking cylinder in the receiving well, install the jacking host in the working well, arrange the hydraulic power module outside the working well, and connect the hydraulic power module to the jacking host through the hydraulic connection pipeline.

[0013] S3. Connect the guide drill rod to the guide drill bit and the jacking host, install the probe and dual-frequency receiver at the end of the guide drill rod, and establish a data link between the dual-frequency receiver and the ground-based handheld receiver.

[0014] S4. Start the hydraulic power module to drive the jacking host, so that the guide drill rod is jacked in sections according to the design route, and the travel status of the guide drill rod is monitored in real time through the probe.

[0015] S5. Based on the guidance data obtained from the probe and dual-frequency receiver, the direction of travel of the guide drill pipe is corrected so that the guide drill pipe is pushed into the receiving well.

[0016] S6. After the guide drill pipe reaches the receiving well, remove the guide drill bit, connect the tapered reamer to the guide drill pipe, and connect the pipe puller to the tapered reamer.

[0017] S7. Connect the first section of pipe to the pipe pulling head, start the pipe jacking cylinder to make the first section of pipe fit with the pipe pulling head, and then drive the jacking host to reverse through the hydraulic power module to pull back the guide drill rod, so that the guide drill rod drives the tapered reamer to rotate and cut the hole along the jacking path of the guide drill rod, and then the pipe pulling head drives the pipe to be laid along the channel after the hole is expanded.

[0018] Preferably, in step S2, the jacking host and the hydraulic power module are connected through a flange-type hydraulic quick-connect system, and the pressure resistance of the flange-type hydraulic quick-connect system is 36MPa.

[0019] Preferably, in step S5, the guiding data obtained by the probe and the dual-frequency receiver is processed using an adaptive algorithm, the deviation amount is calculated based on the deviation between the guiding data and the designed route, and the jacking direction of the guide drill rod is controlled based on the deviation amount.

[0020] Preferably, in step S5, the travel direction of the guide drill bit is corrected by controlling the push-pull control valve and the rotary control valve.

[0021] Preferably, in step S5, a threshold alarm is triggered when the guide deviation is greater than 20mm, and the travel direction of the guide drill rod is controlled in conjunction with the handheld receiver.

[0022] Preferably, after the guide drill rod is pushed into the receiving well and before the conical reamer is installed, the three-dimensional position, orientation, elevation, and slope of the hole formed after the guide drill rod is pushed in are checked and measured; when the check measurement results meet the design requirements, the conical reamer is installed and the hole is reamed; when the check measurement results do not meet the design requirements, the guide drill rod is pushed in again.

[0023] Preferably, in step S7, when the tapered reamer rotates to cut and expand the hole, water is injected through the mud injection port at the end of the tapered reamer to reduce drilling resistance.

[0024] Preferably, during the laying of the pipeline along the enlarged channel, the water injection pressure at the mud injection port gradually increases with the increase of the number of pipe sections to reduce the friction between the pipe sections and the soil layer, and the mud pressure formed during the pull-back stage is dynamically adjusted to 0.8~1.2MPa.

[0025] Preferably, the pipe sections adopt a socket joint, and the gap of the socket joint is no more than 1mm.

[0026] Preferably, synchronous grouting is performed during the laying of the pipeline along the enlarged channel. The synchronous grouting uses bentonite grout to reduce the frictional resistance between the pipe section and the soil layer.

[0027] The beneficial effects of this invention are as follows:

[0028] This invention reduces the space requirements of the working shaft by installing a jacking main unit inside the working shaft, arranging a hydraulic power module outside the working shaft, and connecting the hydraulic power module to the jacking main unit through hydraulic connection pipelines. The minimum size of the working shaft can be reduced to 2.7m × 3.2m, reducing space requirements by 60%, making it suitable for narrow space conditions such as dense urban areas, residential areas, and under overpasses.

[0029] This invention, by installing a probe and a dual-frequency receiver at the end of the guide drill rod and establishing a data link between the dual-frequency receiver and a handheld receiver on the ground, enables real-time monitoring of the guide drill rod's movement and allows for correction of its direction based on the guidance data. The wireless dynamic guidance system achieves construction accuracy control of ±15mm, a 40% improvement over traditional laser guidance, and reduces the correction response time from 8 seconds to less than 3 seconds, a reduction of 62.5%.

[0030] This invention utilizes a directional drilling method, where a guide drill rod is advanced in sections along a designed route. After the guide drill rod reaches the receiving well, a conical reamer is connected to it, and a pipe-pulling head is connected to the conical reamer. The guide drill rod drives the conical reamer to rotate and cut along the jacking path of the guide drill rod, thus enlarging the borehole. The pipe-pulling head then drives the pipe to be laid along the enlarged channel, enabling coordinated construction of directional drilling and borehole enlargement. Through a two-stage pressure balance method and dynamic mud pressure regulation, surface settlement can be stabilized within 3.2mm, below the allowable value of 10mm, preventing ground heave or subsidence from impacting the surrounding environment.

[0031] This invention, by adopting a split power arrangement and a guide drill rod pullback and hole enlargement pipe laying method, can break through the bottleneck of ultra-long-distance jacking, with a single effective jacking distance exceeding 600m. Compared with the traditional process limit of 200m, it reduces the number of intermediate working wells and thus reduces project costs.

[0032] This invention improves construction efficiency through the modular arrangement of the jacking main unit, hydraulic power module, and guiding equipment, as well as the coordinated construction of sectional jacking of the guide drill rod, rotary cutting and reaming of the borehole with a conical reamer, and pipeline pullback and laying. Pipeline construction speed can reach 12 m / h, compared to 3-5 m / h with traditional methods; borehole reaming speed can reach 5 m / min, compared to 3 m / min with traditional methods; significantly improving construction efficiency. Equipment transfer time is reduced from 12 hours to 4 hours, and the efficiency of the jacking head recovery is increased by 3 times.

[0033] This invention injects water through a mud injection port at the end of a conical reamer. During the pipeline laying process along the reamed channel, the water injection pressure at the mud injection port gradually increases with the number of pipe sections, reducing friction between the pipe sections and the soil layer and minimizing pipeline wear. After construction, there is no ground heave or settlement, minimizing impact on the land and meeting green construction requirements. Furthermore, the mud pressure is controllable during construction, resulting in a high rate of soil removal during cutting and minimal waste discharge, demonstrating significant environmental benefits. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the segmented jacking structure of the guide drill rod in this invention;

[0035] Figure 2 This is a schematic diagram of the split-type ultra-long-distance pipe jacking construction structure in a narrow space according to the present invention. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0037] A high-precision construction method for split-type ultra-long-distance pipe jacking in confined spaces includes the following steps:

[0038] S1. Carry out construction preparation. Determine the design route of the jacking pipeline based on the design drawings, construction plan, geological survey results, pipeline axis control piles, elevation piles and temporary leveling points, and set pipeline control points at the working shaft and receiving shaft.

[0039] S2. Construction working shaft and receiving shaft. Install pipe jacking cylinder in the receiving shaft, install jacking host in the working shaft, arrange hydraulic power module outside the working shaft, and connect hydraulic power module to jacking host through hydraulic connection pipeline.

[0040] S3. Connect the guide drill rod to the guide drill bit and the jacking host, install the probe and dual-frequency receiver at the end of the guide drill rod, and establish a data link between the dual-frequency receiver and the ground-based handheld receiver.

[0041] S4. Start the hydraulic power module to drive the jacking host, so that the guide drill rod is jacked in sections according to the design route, and the travel status of the guide drill rod is monitored in real time through the probe.

[0042] S5. Based on the guidance data obtained from the probe and dual-frequency receiver, the direction of travel of the guide drill pipe is corrected so that the guide drill pipe is pushed into the receiving well.

[0043] S6. After the guide drill pipe reaches the receiving well, remove the guide drill bit, connect the tapered reamer to the guide drill pipe, and connect the pipe puller to the tapered reamer.

[0044] S7. Connect the first pipe section to the pipe pulling head, start the pipe jacking cylinder to make the first pipe section fit with the pipe pulling head, and then drive the jacking host to reverse the action through the hydraulic power module to pull back the guide drill rod, so that the guide drill rod drives the conical reamer to rotate and cut the hole along the jacking path of the guide drill rod, and the pipe pulling head drives the pipe to be laid along the channel after the hole is expanded. The pipe jacking cylinder pushes the subsequent pipe sections in sequence.

[0045] The jacking machine, hydraulic power module, and guiding equipment all adopt a modular structure and can be disassembled and assembled.

[0046] In a preferred embodiment of the present invention, in step S2, the jacking host and the hydraulic power module are connected through a flange-type hydraulic quick-connect system, the flange-type hydraulic quick-connect system having a pressure resistance of 36MPa.

[0047] In a preferred embodiment of the present invention, the minimum planar dimensions of the working well are 2.7m × 3.2m.

[0048] In a preferred embodiment of the present invention, in step S3, the guide drill rod is a Φ90mm high-strength guide drill rod, and the yield strength of the guide drill rod is not less than 550MPa.

[0049] In a preferred embodiment of the present invention, in step S3, the accuracy of the probe is 0.01°, and the operating frequencies of the dual-frequency receiver include 2.4 GHz and 5.8 GHz.

[0050] In a preferred embodiment of the present invention, in step S4, when the guide drill rod is pushed forward in sections, the drilling speed is controlled to be 5~8cm / s.

[0051] In a preferred embodiment of the present invention, in step S4, the earth pressure during the jacking stage of the guide drill rod is controlled to be no greater than 0.8γh, where γ is the weight of the soil and h is the burial depth.

[0052] In a preferred embodiment of the present invention, in step S5, the guiding data obtained by the probe and the dual-frequency receiver is processed by an adaptive algorithm, the deviation amount is calculated based on the deviation between the guiding data and the designed route, and the jacking direction of the guide drill rod is controlled based on the deviation amount.

[0053] In a preferred embodiment of the present invention, in step S5, the travel direction of the guide drill bit is corrected by controlling the push-pull control valve and the rotary control valve.

[0054] In a preferred embodiment of the present invention, in step S5, when the guide deviation is greater than 20mm, a threshold alarm is triggered, and the direction of travel of the guide drill rod is controlled in conjunction with the handheld receiver.

[0055] In a preferred embodiment of the present invention, after the guide drill rod is pushed into the receiving well and before the conical reamer is installed, the three-dimensional position, orientation, elevation and slope of the hole formed after the guide drill rod is pushed in are checked and measured; when the check measurement results meet the design requirements, the conical reamer is installed and the hole is reamed; when the check measurement results do not meet the design requirements, the guide drill rod is pushed in again.

[0056] In a preferred embodiment of the present invention, in step S7, when the conical reamer rotates to cut and expand the hole, water is injected through the mud injection port at the end of the conical reamer to form a mud-water mixture, so as to reduce drilling resistance and dynamically adjust its pressure to 0.8~1.2MPa.

[0057] In a preferred embodiment of the present invention, in step S7, the taper of the tapered reamer is 12°, and the reaming speed of the tapered reamer is 3~5m / min.

[0058] In a preferred embodiment of the present invention, during the laying of the pipeline along the enlarged channel, the water injection pressure at the mud injection port gradually increases with the increase of the number of pipe sections, so as to reduce the friction between the pipe sections and the soil layer.

[0059] In a preferred embodiment of the present invention, the pipe section adopts a socket joint, and the gap of the socket joint is no more than 1 mm.

[0060] In a preferred embodiment of the present invention, synchronous grouting is performed during the laying of the pipeline along the enlarged channel. The synchronous grouting uses bentonite slurry to reduce the frictional resistance between the pipe section and the soil layer. The bentonite concentration of the bentonite slurry is 6% to 8%.

[0061] In a preferred embodiment of the present invention, in step S7, after the first section of pipe is connected to the pipe pulling head, the pipe jacking cylinder is activated to make the first section of pipe fit with the pipe pulling head. The first section of pipe advances along the channel after the borehole is enlarged under the drive of the guide drill rod until the first section of pipe is completely entered into the channel after the borehole is enlarged. After the first section of pipe is completely entered into the channel after the borehole is enlarged, the guide drill rod is pulled back, and at the same time, the back-expansion excavation and pipe jacking are carried out, and other pipe sections are continued to be jacked in by the pipe jacking cylinder.

[0062] In a preferred embodiment of the present invention, in step S2, a C20 precast reinforced concrete back plate is provided behind the jacking cylinder. The C20 precast reinforced concrete back plate is used to withstand the counter-thrust force during the jacking process. The C20 precast reinforced concrete back plate has a thickness of 50cm, a height of 0.5m, and is 0.3m below the bottom of the pit. The compressive strength of the C20 precast reinforced concrete back plate is not less than 20MPa.

[0063] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0064] Example 1: This example includes the following construction process: construction preparation, construction of working well and receiving well, installation of micro-jacking equipment, sectional jacking of guide drill rod, accuracy verification measurement, hole enlargement with special reamer, jacking and pulling of the first section of pipe, and pipe pullback.

[0065] During the construction preparation phase, refer to the design drawings and construction plan to understand the specific length, burial depth, design and structural requirements of the pipe jacking project, and understand the underground soil conditions based on the geological survey results. Formulate corresponding technical measures for each process to ensure construction quality and efficiency.

[0066] Before construction, the actual situation of the site topography, landforms, buildings, underground pipelines and obstacles along the pipeline jacking route should be understood, and the site should be leveled according to the area requirements of the working well, receiving well, soil piling area and material storage area.

[0067] Before construction, the site of the jacking pipeline is measured based on temporary benchmarks, pipeline axis control piles, and elevation piles. Pipeline control points are set and extended to the working shaft and receiving shaft. After the shaft is excavated, the control points are extended from the ground to the underground, and the design route of the jacking pipeline is determined according to the direction of the jacking.

[0068] During the construction phase of the working and receiving wells, working and receiving wells were installed at both ends of the main shaft. The working well was used to install the jacking machine, and the receiving well was used for mud discharge and pipeline laying. Steel sheet piles were driven around the construction perimeter to ensure the stability of the road slope, based on the locations of the working and receiving wells determined by surveying and setting out. Excavators were used to excavate the foundation pit, and the excavated soil was stockpiled on-site for subsequent backfilling. During excavation, damage to existing pipelines was avoided, and the impact on the surrounding environment was minimized.

[0069] The caisson's cutting edge formwork is constructed by laying a thin film on the concrete foundation. The caisson's planar position is precisely measured and marked on the plain concrete foundation according to the designed caisson location, ensuring the cutting edge's bevel is flat. The caisson wall formwork uses 30mm thick wooden formwork; the inner formwork is erected first, followed by the outer formwork. The formwork and reinforcing steel are tied in coordination. After the formwork and support structures are completed, C30 concrete is poured for the first section of the caisson wall. Caisson sinking must proceed after the concrete strength reaches the design requirements, with the first section reaching 100% strength and the second section reaching 70% strength. A drainage and excavation sinking process is then used for caisson sinking.

[0070] When the caisson sinks to 0.2-0.3m below the design elevation, excavation should be stopped, allowing the caisson to sink to the design elevation under its own weight. When the caisson is ready to sink to the predetermined position, C20 grade concrete should be poured to seal the bottom. After the excavation of the working and receiving shafts is completed, retaining structures should be immediately installed, and warning signs should be set up to ensure the safety of personnel and vehicles. A 0.3m x 0.3m drainage ditch should be constructed around the bottom of the pit to prevent construction wastewater or other water from flowing into the pit, ensuring the working pit remains dry.

[0071] During the micro-jacking equipment installation phase, after the working shaft is excavated, a crane is driven into the construction site to hoist the high-precision split-type ultra-long shallow buried micro-jacking construction equipment and materials transported to the site into the working shaft and receiving shaft according to their functions, and the jacking host connecting the guide drill rod is hoisted into the working shaft.

[0072] The hydraulic power module is positioned outside the working shaft, with the specific distance determined based on the on-site construction conditions. It is connected to the jacking main unit via hydraulic connection pipelines. After the receiving shaft is excavated, jacking cylinders are installed inside. A 50cm thick C20 precast reinforced concrete backing plate is installed behind the cylinders. The C20 precast reinforced concrete backing plate is 0.5m high and 0.3m below the pit bottom to withstand the counter-thrust force during the jacking process, ensuring a tight fit between pipe sections during the pipe section pullback and laying construction.

[0073] After the jacking main unit and hydraulic power module are installed, the guiding equipment is installed. The guide drill rod is a Φ90mm high-strength drill rod with a yield strength of not less than 550MPa. The guide drill rod is connected to the guide drill bit and the jacking main unit, with the connection direction aligned with the main shaft direction of the jacking main unit. A probe and a dual-frequency receiver are installed at the end of the guide drill rod. The dual-frequency receiver operates at frequencies of 2.4GHz and 5.8GHz, and a data link is established between the dual-frequency receiver and a handheld receiver on the ground. Cables, signal lines, and oil pipes are connected, and the entire equipment and its components are debugged to ensure stable operation during formal construction.

[0074] During the sectional jacking stage of the guide drill pipe, after the high-precision split-type ultra-long shallow-buried micro-jacking equipment is installed, the hydraulic power module is started to drive the jacking host, so that the guide drill pipe is jacked sectionally according to the designed route; at the same time, the guide drill bit begins to rotate and jack. After the first section of the guide drill pipe is jacked, the next section of the guide drill pipe is installed manually until the guide drill bit and guide drill pipe reach the receiving well, and the drilling speed is controlled at 5~8cm / s.

[0075] During the jacking process of the guide drill rod, its movement is monitored in real time using probes, and a monitoring remote display device also monitors the guide drill rod in real time via probes installed inside the guide drill rod. Based on the guidance data obtained from the probes and the dual-frequency receiver, the direction of travel of the guide drill rod is corrected; specifically, the direction of travel of the guide drill bit is corrected by controlling the push-pull control valve and the rotation control valve to ensure that the accuracy of the pipeline trajectory meets the design requirements.

[0076] After the guide rail drilling is completed, the three-dimensional position, orientation, elevation, and slope of the hole formed by the guide drill rod are checked and measured, and compared with the accuracy required by the design. If the verification measurement results meet the specifications and drawing requirements, the next construction process is carried out; if the verification measurement results do not meet the design requirements, the guide drill rod is jacked up again.

[0077] During the reaming stage using a dedicated reamer, after the guide drill bit and guide drill rod reach the receiving well, the guide drill bit is manually removed, and the tapered reamer is connected to the guide drill rod, along with the pipe puller head. Rotating the guide drill rod drives the tapered reamer to rotate and cut the soil, simultaneously expanding and displacing the surrounding soil. While the tapered reamer rotates and cuts the hole, water is injected through the mud injection port at the end of the tapered reamer to reduce drilling resistance.

[0078] During the reaming process, the guide drill rod is slowly pulled in the working well to provide forward power for the conical reamer. The cut soil is carried to the working well and discharged in a timely manner. The reaming speed of the conical reamer is 3~5m / min. After the reaming is completed, the pipe opening dimensions of the receiving well and the working well are measured. After confirming that they meet the design requirements, the next step of construction is carried out.

[0079] During the first section of pipe jacking, after the guide drill rod is connected to the tapered reamer and the pipe pulling head, the first section of pipe is aligned with the pipe pulling head. The jacking cylinder is then activated to bring the first section of pipe into contact with the pipe pulling head. Subsequently, the hydraulic power module drives the jacking main unit to reverse, pulling back the guide drill rod. This causes the guide drill rod to rotate and cut the reamer along the jacking path of the guide drill rod, and the pipe pulling head then drives the first section of pipe to slowly advance along the reamed channel until the first section of pipe is completely inside the reamed channel.

[0080] During the pipe pullback phase, after the first pipe section has fully entered the reamed channel, the hydraulic power module continues to drive the jacking main unit in reverse to pull back the guide drill rod. The guide drill rod then drives the conical reamer to perform reaming excavation, and the pipe pulling head pulls the pipe along the reamed channel. Simultaneously, the pipe jacking cylinder continues to jack up other pipe sections, allowing subsequent pipe sections to enter the reamed channel in sequence.

[0081] During the pipeline laying along the reamed borehole channel, the water injection pressure at the mud injection port at the end of the conical reamer gradually increases with the number of pipe sections to reduce friction between the pipe sections and the soil layer, minimize pipeline wear, and achieve rapid and high-precision pipeline laying. The pipe sections use socket joints with a gap of no more than 1mm. Simultaneous grouting is performed during the pipeline laying along the reamed borehole channel to further reduce frictional resistance between the pipe sections and the soil layer.

[0082] The high-precision construction method for split-type ultra-long-distance pipe jacking in confined spaces provided by this invention can be applied to the construction of municipal water supply networks, drainage networks, and stormwater and sewage pipelines, and is especially suitable for ultra-long-distance pipeline laying under limited construction site conditions. The application of this invention will be further explained below with reference to specific engineering projects.

[0083] Application Example 1: This construction method was applied to the Fuyang No. 3 Water Plant Phase II and Pipeline Zone Metering and Monitoring System Project (Supporting Pipeline Project Section 2). During the construction process, the DN300~1000 water supply pipeline network of 19 roads in the urban area was updated and renovated. The main construction contents included trench and pit excavation, pipe and fitting installation, caisson construction, pipe jacking construction, pipe bridge construction, foundation treatment and backfilling, valve well construction, and other supporting construction.

[0084] In this application example, a high-precision construction method for split-type ultra-long-distance pipe jacking in narrow spaces was used to construct a municipal supporting project drainage pipe network. The construction length of the pipe network was 2820m using this construction method.

[0085] During construction, a pipe-jacking cylinder is installed inside the receiving shaft, a jacking main unit is installed inside the working shaft, and a hydraulic power module is deployed outside the working shaft. The hydraulic power module is connected to the jacking main unit via hydraulic connection pipelines; the jacking main unit and the hydraulic power module are connected via a flange-type hydraulic quick-connect system. A split architecture of "in-shaft jacking + external power" is adopted. By separating the in-shaft jacking device and the external power station, the integrated jacking equipment is adjusted to have the jacking main unit inside the shaft and the hydraulic power module deployed outside, so that the power output is not limited by the construction site.

[0086] During construction, a wireless dynamic guidance system was established using probes, dual-frequency receivers, and handheld receivers on the ground to monitor the jacking status of the guide drill rod in real time. Based on the guidance data obtained from the probes and dual-frequency receivers, the direction of travel of the guide drill rod was corrected, ensuring that the guide drill rod was jacked in sections according to the designed route. This wireless dynamic guidance system achieved construction accuracy control of ±15mm, with fast correction response and high guidance stability.

[0087] After the guide drill rod reaches the receiving well, the guide drill bit is removed, and the tapered reamer is connected to the guide drill rod, and the pipe puller is connected to the tapered reamer. Then, the hydraulic power module drives the jacking host to reverse, so as to pull back the guide drill rod. This causes the guide drill rod to drive the tapered reamer to rotate and cut the hole along the jacking path of the guide drill rod. The pipe puller then drives the pipeline to be laid along the reamed hole, thus achieving rapid and high-precision construction of the drainage network.

[0088] After adopting this construction method, construction is no longer limited by narrow sites, construction costs are reduced, the scope of application of construction is broadened, the construction period is reduced by 18 days, and the overall cost is reduced by 684,000 yuan, which has good economic, social and environmental benefits.

[0089] Application Example 2: This construction method was applied to the first phase of the Anhui Medical University New Medical Center (New Campus) project. The project has a frame structure, a total building area of ​​150,768.67 m², of which the underground building area is 39,194.07 m². The municipal ancillary works started on December 27, 2021, and were completed on November 11, 2022. The total project cost was 38,046,392 yuan.

[0090] In this project, the high-precision construction method of split-type ultra-long-distance pipe jacking in narrow spaces was applied to the construction of rainwater and sewage pipelines in municipal ancillary projects. The method was used to complete the construction of 2450m of pipeline network.

[0091] During construction, a two-stage pressure balancing method of "first orientation, then reaming" was adopted. Precise positioning was achieved using a guide drill rod, and a conical reamer with a taper of 12° was used for reaming. After the guide drill rod was used to form the guiding path, the conical reamer was then used to ream the hole, reducing the soil pressure on the front and stabilizing surface settlement, thus improving the overall reaming efficiency by 3 times.

[0092] Meanwhile, the equipment adopts a modular design, which requires less construction site area and has high efficiency in equipment relocation and recycling. During construction, the elevation error is controlled within ±15mm, and the pipe section connection accuracy is high, ensuring the progress of pipeline construction and the smooth flow of ground traffic.

[0093] Through engineering application, this method has saved 15 days of construction time and 592,000 yuan in costs, demonstrating good economic and social benefits.

[0094] This invention addresses the problems in existing technologies, such as limited layout of pipe jacking equipment in narrow spaces, insufficient power for ultra-long-distance jacking, difficulty in controlling guiding accuracy, difficulty in controlling ground settlement, and low construction efficiency. It proposes a high-precision construction method for split-type ultra-long-distance pipe jacking in narrow spaces.

[0095] This invention employs a split architecture of "in-well jacking + external power," disassembling the traditional integrated jacking equipment into a jacking main unit housed inside the working shaft and a hydraulic power module located outside the working shaft. The jacking main unit and the hydraulic power module are connected via a flange-type hydraulic quick-connect system, which has a pressure resistance of 36 MPa. This split architecture reduces the minimum size of the working shaft from 4m × 4m to 2.7m × 3.2m, improving spatial adaptability by 40%. Simultaneously, it increases the jacking power density by 2.3 times, achieving a single effective jacking distance exceeding 600m.

[0096] In this invention, a wireless dynamic guidance system is used to monitor and correct the jacking status of the guide drill rod. The wireless dynamic guidance system includes a probe, a dual-frequency receiver, and a ground-based handheld receiver. The probe is installed at the end of the guide drill rod and has an accuracy of 0.01°. The dual-frequency receiver operates at frequencies of 2.4 GHz and 5.8 GHz and establishes a data link with the ground-based handheld receiver. Based on the guidance data obtained from the probe and the dual-frequency receiver, an adaptive algorithm is used for processing, and the correction amount is calculated based on the deviation signal to control the jacking direction of the guide drill rod. Using this wireless dynamic guidance system, the dynamic accuracy can reach ±15 mm during a 600m jacking operation, the correction response time is no more than 3 seconds, the signal attenuation rate in complex electromagnetic environments is no more than 0.5 dB, and the guidance stability is 5 times better than laser technology.

[0097] This invention employs a directional-reaming co-process. In the guiding stage, a Φ90mm high-strength guide drill rod is advanced in sections along the designed route. The yield strength of the guide drill rod is not less than 550MPa. The earth pressure during the guiding stage is controlled to be no greater than 0.8γh, where γ is the soil weight and h is the burial depth, to prevent surface heave. In the pullback stage, after the guide drill rod reaches the receiving well, the guide drill bit is removed, and a tapered reamer is connected to the guide drill rod, along with a pipe puller. The hydraulic power module drives the jacking unit to reverse, pulling back the guide drill rod. This causes the guide drill rod to rotate and ream the tapered reamer along the jacking route of the guide drill rod, and the pipe puller then drives the pipeline to be laid along the reamed channel. The tapered reamer has a taper of 12°. During the pullback stage, the mud pressure is dynamically adjusted to 0.8~1.2MPa, which improves the efficiency of removing cut soil (cutting soil removal rate not less than 95%). The above-mentioned directional-reaming synergistic process can reduce the frontal soil pressure by 38%, stabilize the surface settlement within 3.2 mm, and enable the reaming speed of the conical reamer to reach 5 m / min.

[0098] In this invention, the jacking main unit, hydraulic power module, and guiding equipment adopt a modular design and can be quickly assembled and disassembled. Through this modular design, the equipment transfer time can be reduced from 12 hours to 4 hours, and the head recovery efficiency is increased by 3 times. During construction, the elevation error is controlled within ±15mm and the pipe section misalignment is no more than 2mm through a three-stage "push-pull-stabilize" control, and the pipeline construction speed reaches 12m / h.

[0099] In this invention, a threshold alarm mechanism is set up. When the guiding deviation exceeds 20mm, a threshold alarm is triggered. This is combined with a ground-based handheld receiver to control the direction of the guide drill rod, thereby achieving millimeter-level correction of ±10mm / 100m. The pipe sections adopt a socket-type interface, with a gap of no more than 1mm. The jacking reaction force is borne by a C20 prefabricated backing, whose compressive strength is no less than 20MPa. During the laying of the pipe along the enlarged channel, synchronous grouting is performed. The synchronous grouting uses bentonite slurry with a bentonite concentration of 6%~8% to reduce the frictional resistance between the pipe section and the soil layer.

[0100] This method combines the advantages of horizontal directional jacking construction technology and underground working shaft jacking technology. By separating the in-shaft jacking device from the external power station, the traditional integrated jacking equipment is modified to have a jacking main unit inside the working shaft and a hydraulic power module outside. The hydraulic power module is connected to the jacking main unit via hydraulic pipelines. The jacking main unit and the hydraulic power module are connected through a flange-type hydraulic quick-connect system with a pressure resistance of 36MPa. This allows power output to be unrestricted by the construction site and reduces the minimum size of the working shaft from the traditional 4m×4m to 2.7m×3.2m, increasing the jacking power density to 2.3kW / m³.

[0101] This method constructs a closed-loop guidance system using a probe, a dual-frequency receiver, and an adaptive algorithm. The probe has an accuracy of 0.01°, and the dual-frequency receiver operates at frequencies of 2.4 GHz and 5.8 GHz. The probe and dual-frequency receiver are installed at the end of the guide drill rod. The dual-frequency receiver establishes a data link with a ground-based handheld receiver. Based on the guidance data obtained from the probe and dual-frequency receiver, an adaptive algorithm is used for processing, and the correction amount is calculated based on the deviation between the guidance data and the designed route to control the jacking direction of the guide drill rod. This closed-loop guidance system achieves a dynamic accuracy of ±15 mm during 600m jacking. The dual-frequency receiver has an IP68 protection rating, making it suitable for complex electromagnetic environments. When the guidance deviation exceeds 20 mm, a threshold alarm is triggered, and the ground-based handheld receiver controls the direction of the guide drill rod, achieving millimeter-level correction of ±10 mm / 100m.

[0102] After the modular equipment is installed, this method uses a wireless dynamic guidance system and a ground-based handheld receiver to control the 90mm high-strength guide drill rod to be jacked in sections according to the designed route. The yield strength of the guide drill rod is not less than 550MPa. The earth pressure during the jacking stage of the guide drill rod is controlled to be no more than 0.8γh, where γ is the soil weight and h is the burial depth, to prevent surface heave.

[0103] After the jacking drill pipe reaches the receiving well, the jacking bit is removed, and the tapered reamer is connected to the jacking drill pipe. The pipe puller is then connected to the tapered reamer. The first pipe section is connected to the pipe puller, and the jacking cylinder is activated to bring the first pipe section into contact with the pipe puller. Subsequently, the hydraulic power module drives the jacking main unit to reverse, pulling back the jacking drill pipe. This causes the jacking drill pipe to rotate and cut the hole along the jacking path of the jacking drill pipe, and the pipe puller then pulls the pipe along the reamed hole channel for laying.

[0104] During the pullback and reaming process, the tapered reamer has a taper of 12° and cuts the soil through it. During the pullback stage, the mud pressure is dynamically adjusted to 0.8~1.2MPa, the soil removal rate is not less than 95%, and the surface settlement is stabilized within 3.2mm.

[0105] The pipe sections employ socket-type interfaces, with a gap of no more than 1 mm. The jacking reaction force is supported by a C20 precast backing, whose compressive strength is no less than 20 MPa. Simultaneous grouting is performed during the pipe laying process along the reamed-out channel, using bentonite grout with a bentonite concentration of 6%–8% to reduce frictional resistance between the pipe sections and the soil layer. The remaining pipe sections are then sequentially placed and pulled back along the reamed-out channel in the receiving well, ensuring precise laying of the entire pipeline.

[0106] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-precision construction method for split-type super-long distance pipe jacking in a narrow space, characterized in that, Includes the following steps: S1. Determine the design route of the jacking pipeline; S2. Install the pipe jacking cylinder in the receiving well, install the jacking host in the working well, arrange the hydraulic power module outside the working well, and connect the hydraulic power module to the jacking host through the hydraulic connection pipeline. S3. Connect the guide drill rod to the guide drill bit and the jacking host, install the probe and dual-frequency receiver at the end of the guide drill rod, and establish a data link between the dual-frequency receiver and the ground-based handheld receiver. S4. Start the hydraulic power module to drive the jacking host, so that the guide drill rod is jacked in sections according to the design route, and the travel status of the guide drill rod is monitored in real time through the probe. S5. Based on the guidance data obtained from the probe and dual-frequency receiver, the direction of travel of the guide drill pipe is corrected so that the guide drill pipe is pushed into the receiving well. S6. After the guide drill pipe reaches the receiving well, remove the guide drill bit, connect the tapered reamer to the guide drill pipe, and connect the pipe puller to the tapered reamer. S7. Connect the first section of pipe to the pipe pulling head, start the pipe jacking cylinder to make the first section of pipe fit with the pipe pulling head, and then drive the jacking host to reverse through the hydraulic power module to pull back the guide drill rod, so that the guide drill rod drives the tapered reamer to rotate and cut the hole along the jacking path of the guide drill rod, and then the pipe pulling head drives the pipe to be laid along the channel after the hole is expanded.

2. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, In step S2, the jacking host and the hydraulic power module are connected through a flange-type hydraulic quick-connect system.

3. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, In step S5, the guidance data obtained by the probe and dual-frequency receiver is processed using an adaptive algorithm. The correction amount is calculated based on the deviation between the guidance data and the designed route, and the jacking direction of the guide drill rod is controlled according to the correction amount.

4. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, In step S5, the travel direction of the guide drill bit is corrected by controlling the push-pull control valve and the rotation control valve.

5. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, In step S5, when the guide deviation is greater than 20mm, a threshold alarm is triggered, and the direction of travel of the guide drill rod is controlled in conjunction with the handheld receiver.

6. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, After the guide drill rod is pushed into the receiving well and before the conical reamer is installed, the three-dimensional position, orientation, elevation, and slope of the hole formed after the guide drill rod is pushed in are checked and measured. When the check measurement results meet the design requirements, the conical reamer is installed and the hole is reamed. When the check measurement results do not meet the design requirements, the guide drill rod is pushed in again.

7. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, In step S7, when the conical reamer rotates to cut and expand the hole, water is injected through the mud injection port at the end of the conical reamer.

8. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 7, characterized in that, During the laying of the pipeline along the enlarged channel, the water injection pressure at the mud injection port gradually increases with the increase in the number of pipe sections.

9. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, The pipe sections adopt a socket joint, and the gap of the socket joint is no more than 1mm.

10. The high-precision construction method for split-type ultra-long-distance pipe jacking in a narrow space according to claim 1, characterized in that, Grouting is performed simultaneously during the laying of the pipeline along the enlarged channel.

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