Deviation rectifying method for large-section long-distance rectangular jacking pipe

Abstract

The invention provides a large-section long-distance rectangular jacking pipe deviation rectifying method, which relates to the technical field of jacking pipe construction and comprises the steps of soil body improvement, posture monitoring and deviation rectifying, real-time monitoring and early warning and the like. Through the synergistic effect of soil body improvement, multi-dimensional deviation rectification control and real-time monitoring, precise regulation and control of the pipe jacking posture can be achieved, and the construction precision and safety are improved.

Description

Technical Field

[0001] This invention relates to the field of pipe jacking construction technology, specifically a method for correcting the deviation of large-section, long-distance rectangular pipe jacking. Background Technology

[0002] In the development of urban underground space, rectangular pipe jacking technology is widely used in underground tunnel construction due to its advantages such as high cross-sectional utilization and minimal impact on the surrounding environment. However, for rectangular pipe jacking projects with large cross-sections (such as 11.35m × 7.5m and above) and long distances (over 200m), especially when traversing complex geological conditions such as silt layers and silt-soil interbedded with silt layers, the control of the pipe jacking posture faces many challenges.

[0003] In existing technologies, single correction methods (such as relying solely on articulated hydraulic cylinders or soil improvement) are insufficient to cope with disturbances in complex strata, which can easily lead to deviations of the pipe jacking axis exceeding the design allowable range, and even cause safety problems such as piping and settlement of surrounding buildings.

[0004] Furthermore, traditional monitoring systems lack sufficient accuracy and real-time performance, failing to provide timely and accurate data support for dynamic correction, thus making it difficult to guarantee construction accuracy. Therefore, there is an urgent need for an integrated, high-precision correction method to solve the posture control problem in the construction of large-section, long-distance rectangular pipe jacking projects. Summary of the Invention

[0005] In response to the aforementioned existing technologies, this invention proposes a method for correcting the deviation of large-section, long-distance rectangular pipe jacking. Through the synergistic effect of soil improvement, multi-dimensional deviation control, and real-time monitoring, the method can achieve precise control of the pipe jacking posture, thereby improving construction accuracy and safety.

[0006] This invention provides a method for correcting the deviation of large-section, long-distance rectangular pipe jacking, comprising the following steps: Step 1, Soil Improvement: Soil improvement is carried out using a mixed slurry of sodium-based bentonite and CMC. The mixed slurry is evenly injected through several injection holes set on the breast plate and cutterhead to control the slump of the excavated soil at 10-15cm and the permeability coefficient <1×10⁻. 5 cm / s; Step 2, Attitude Monitoring and Correction: Multi-dimensional correction is achieved by using cutterhead rotation, articulated hydraulics, screw conveyor soil discharge control and mud injection assistance. The articulated hydraulic correction cylinder can achieve a correction angle of ±1° up and down and ±1° left and right, with a single correction amount ≤5mm. Step 3, Real-time monitoring and early warning: A three-level alarm mechanism is established through dual measurement using a laser theodolite and a total station, and corresponding correction measures are initiated sequentially according to the deviation value.

[0007] Preferably, in step 1, the specific ratio of the mixed slurry includes: water: Klein bentonite: CMC = 100: 8: 0.5, injection rate 15%; or water: Jianping high-viscosity bentonite: CMC = 100: 8: 0.5, injection rate 20%; or water: Klein bentonite: Jianping high-viscosity bentonite: CMC = 100: 4: 4: 0.5, injection rate 20%.

[0008] Preferably, in step 1, several evenly distributed first injection holes are set on the breast plate; several second injection holes are set on the cutter head and the spokes of the cutter head, and the improved slurry and the soil are fully mixed by the agitation of the cutter head.

[0009] Preferably, in step 2, the correction cylinder consists of multiple φ310 / 210-200 cylinders, which adjust the posture by extending and retracting in groups to achieve upward tilting, downward tilting, leftward tilting, and rightward tilting.

[0010] Preferably, in step 3, laser-guided measurement: a laser theodolite is set up in the starting well, and several laser targets are set on the jacking machine partition to monitor the axis, level, and torsional deviations in real time. Each pipe section is measured 1-3 times during jacking. Manual re-measurement: manual re-measurement is carried out daily using a total station. Axis deviation: ±25mm, blue warning; ±35mm, yellow warning; ±40mm, red warning; Angle deviation: ±0.1°, blue warning; ±0.2°, yellow warning; ±0.3°, red warning. When a warning is triggered, the corresponding correction measures are activated in sequence, namely cutterhead rotation → hinge correction → mud injection correction.

[0011] Compared to existing technologies, the beneficial effects of this invention are as follows: The large-section, long-distance rectangular pipe jacking correction method proposed in this invention solves the problem of pipe jacking attitude control under complex geological conditions through the integrated application of a soil improvement system (mixing slurry ratio and injection hole arrangement), a pipe jacking correction system (cutterhead rotation, articulated hydraulics, screw conveyor soil removal, mud injection assistance), and a real-time monitoring system (laser guidance, three-level alarm). This method achieves synergistic control of the plasticity and permeability of the excavated soil. Through precise regulation of multi-dimensional correction methods, combined with dual measurement and graded early warning mechanisms, the axial deviation is controlled within ±40mm, and the angular deviation is controlled within ±0.3°. It is suitable for rectangular pipe jacking projects with cross-sectional dimensions ≥10m×6m and jacking length ≥200m, providing an efficient and reliable correction solution for similar projects. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the arrangement of the first injection hole in an embodiment of the present invention.

[0013] Figure 2 This is a schematic diagram of the arrangement of the second injection hole in an embodiment of the present invention.

[0014] Figure 3This is a schematic diagram showing the arrangement of the correction cylinders in an embodiment of the present invention.

[0015] Figure 4 This is a schematic diagram of the structure of the screw conveyor for removing soil in an embodiment of the present invention.

[0016] Figure 5 This is a schematic diagram of the arrangement of the laser target and the laser theodolite in an embodiment of the present invention.

[0017] In the diagram, 1-front and rear shells of the pipe jacking machine; 2-breast plate; 3-first injection hole; 4-second injection hole; 5-cutter head; 6-correction cylinder; 7-screw excavator; 8-laser target; 9-pipe section; 10-laser theodolite; 11-jack. Detailed Implementation

[0018] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0019] Example: Figure 1-5 The method for correcting the deviation of a large-section, long-distance rectangular pipe jacking project, as shown, includes the following steps: Step 1, Soil Improvement: Soil improvement is carried out using a mixed slurry of sodium-based bentonite and CMC. The mixed slurry is evenly injected through several injection holes set on the breast plate 2 and cutterhead 5 to control the slump of the excavated soil at 10-15cm and the permeability coefficient <1×10⁻. 5 cm / s; The specific proportions of the mixed slurry include: water: Klein bentonite: CMC = 100:8:0.5, injection rate 15%; or water: Jianping high-viscosity bentonite: CMC = 100:8:0.5, injection rate 20%; or water: Klein bentonite: Jianping high-viscosity bentonite: CMC = 100:4:4:0.5, injection rate 20%. Twelve 2-inch first injection holes 3 are set on the breast plate 2, evenly distributed to enhance the workability of the soil in the soil chamber; 21 second injection holes 4 are set on the cutter head 5 and the spokes of the cutter head 5, and the improved slurry and the soil are fully mixed by the agitation of the cutter head 5. During the jacking process, the injection rate of the modified slurry is dynamically adjusted based on the current of the cutterhead 5 (normal range 150-200A) and the soil discharge status of the screw conveyor 7. When the current exceeds 200A, the injection volume of Jianping high-viscosity bentonite-CMC mixed slurry is increased by 15% to ensure that the slump of the excavated soil is maintained at 10-15cm and the permeability coefficient is <1×10⁻. 5 cm / s.

[0020] Step 2, Attitude Monitoring and Correction: Multi-dimensional correction is achieved by using cutterhead rotation, articulated hydraulics, screw conveyor soil discharge control and mud injection assistance. Among them, the articulated hydraulic correction cylinder 6 can achieve a correction angle of ±1° up and down and ±1° left and right, with a single correction amount ≤5mm. Among them, the horizontal tilt angle sensor of the pipe jacking machine is used to monitor the rolling posture in real time. When the rolling deviation reaches the warning value, the pipe jacking torque balance is adjusted by the forward and reverse rotation of the cutter head 5 to achieve the rolling angle correction. The single correction amount is ≤5mm. Twenty-four φ310 / 210-200 hydraulic cylinders 6 are installed between the front and rear housings of the pipe jacking machine. The maximum correction force is 6340T, and it can achieve a correction angle of ±1° vertically and ±1° horizontally. The specific correction logic is as follows: Upward correction: The lower, left, and right hydraulic cylinders extend simultaneously, or the upper, left, and right hydraulic cylinders retract simultaneously; Downward correction: The upper, left, and right hydraulic cylinders extend simultaneously, or the lower, left, and right hydraulic cylinders retract simultaneously; Left deviation correction: The right, upper, and lower hydraulic cylinders extend simultaneously, or the left, upper, and lower hydraulic cylinders retract simultaneously; Right deviation correction: The left, upper, and lower hydraulic cylinders extend simultaneously, or the right, upper, and lower hydraulic cylinders retract simultaneously; The auger excavator 7 adopts a double-auger design. By adjusting the speed of the left and right augers (difference ≤ 10%), the pressure difference between the left and right sides of the soil chamber (difference ≤ 5 kPa) is controlled. When the jacking pipe deviates horizontally, the excavation volume of the auger on the opposite side of the deviation is increased to balance the pressure of the soil chamber and achieve deviation correction.

[0021] Step 3, Real-time monitoring and early warning: A three-level alarm mechanism is established through dual measurement using a laser theodolite 10 and a total station, and corresponding correction measures are initiated sequentially according to the deviation value; Among them, laser-guided measurement: a laser theodolite 10 is set at the starting well, and three laser targets 8 are set on the jacking machine partition to monitor the axis, level, and torsional deviations in real time. Each pipe section 9 is measured 1-3 times during jacking. Manual re-measurement: manual re-measurement is carried out daily using a total station. When passing through cultural relics buildings, the frequency is increased to once every 4 hours. If necessary, 24-hour tracking and monitoring are carried out. Axis deviation: ±25mm, blue warning; ±35mm, yellow warning; ±40mm, red warning; Angle deviation: ±0.1°, blue warning; ±0.2°, yellow warning; ±0.3°, red warning. When a warning is triggered, the corresponding correction measures are activated in sequence, namely cutterhead rotation → hinge correction → mud injection correction. When the laser target 8 detects an axial deviation of 10mm, the cutterhead 5 is started to rotate forward and backward (with a speed difference of ±5r / min) for pre-correction. If the deviation continues to increase to 25mm (blue warning), the correction cylinder 6 is activated in groups. For example, when deviating to the left, the right, upper, and lower cylinders extend by 5mm simultaneously, while the left tie rod is loosened. When the deviation exceeds 35mm (yellow warning), the right screw conveyor speed is increased (difference 10%) in conjunction with the adjustment of the soil output of the screw conveyor, and the soil output of the right side is reduced. If the deviation reaches 40mm (red warning), correction mud with a viscosity of 50s is injected through the mud-drilling holes of the shield body, with 0.5m³ of mud injected into each hole to form a pressure wedge on the left side. This, combined with the hinged correction, brings the deviation back to within 20mm. When passing through cultural relics buildings, the monitoring frequency is increased to once every 4 hours. When the angle deviation reaches 0.1°, the cutterhead 5 is immediately started to rotate in the opposite direction (speed 10r / min), while the correction cylinder 6 is finely adjusted (extension 3mm) to ensure that the angle deviation is controlled within 0.2°. Every day, we organize the laser measurement and manual re-measurement data, draw a comparison diagram between the jacking route and the design axis, and when the cumulative deviation exceeds 50mm, we optimize the correction parameters of the next pipe section 9, such as increasing the modified grout injection rate by 5% or adjusting the hydraulic cylinder extension and retraction by 2mm.

[0022] Before construction, geotechnical tests were conducted on the natural soil of the crossing layer to determine parameters such as particle size distribution (uniformity coefficient 120, curvature coefficient 0.008), permeability coefficient (1.36×10⁻³cm / s), and slump (0), verifying the applicability of the improved material mix ratio. The improved system, including the breast plate 2, cutter head 5, and their injection holes, was installed according to design requirements, and the stirring rod speed was adjusted (15-20 r / min). The correction cylinder 6 was installed, and its extension stroke (200 mm) and correction force (6340 T) were tested. The accuracy of the horizontal tilt sensor was calibrated (±0.05°). A laser theodolite 10 (emission power ≥50 mW) and a laser target 8 were deployed, and the laser beam was adjusted to be parallel to the design axis, with a deviation ≤5 mm / 100 m.

[0023] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent solutions made using the contents of the present invention specification, whether directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of the present invention.

Claims

1. A method for correcting the deviation of large-section, long-distance rectangular pipe jacking, characterized in that, Includes the following steps: Step 1, Soil Improvement: Soil improvement is carried out using a mixed slurry of sodium-based bentonite and CMC. The mixed slurry is evenly injected through several injection holes set on the breast plate and cutterhead to control the slump of the excavated soil at 10-15cm and the permeability coefficient <1×10⁻. 5 cm / s; Step 2, Attitude Monitoring and Correction: Multi-dimensional correction is achieved by using cutterhead rotation, articulated hydraulics, screw conveyor soil discharge control and mud injection assistance. The articulated hydraulic correction cylinder can achieve a correction angle of ±1° up and down and ±1° left and right, with a single correction amount ≤5mm. Step 3, Real-time monitoring and early warning: A three-level alarm mechanism is established through dual measurement using a laser theodolite and a total station, and corresponding correction measures are initiated sequentially according to the deviation value.

2. The method for correcting deviation of large-section, long-distance rectangular pipe jacking as described in claim 1, characterized in that, In step 1, the specific proportions of the mixed slurry include: water: Klein bentonite: CMC = 100: 8: 0.5, injection rate 15%; or water: Jianping high-viscosity bentonite: CMC = 100: 8: 0.5, injection rate 20%; or water: Klein bentonite: Jianping high-viscosity bentonite: CMC = 100: 4: 4: 0.5, injection rate 20%.

3. The method for correcting deviation of large-section, long-distance rectangular pipe jacking as described in claim 1 or 2, characterized in that, In step 1, several evenly distributed first injection holes are set on the breast plate; several second injection holes are set on the cutter head and the spokes of the cutter head, and the improved slurry and soil are fully mixed by the agitation of the cutter head.

4. The method for correcting the deviation of large-section, long-distance rectangular pipe jacking as described in claim 1 or 2, characterized in that, In step 2, the correction cylinder consists of multiple φ310 / 210-200 cylinders, which adjust the posture by tilting up, tilting down, veering left, and veering right through group extension and retraction.

5. The method for correcting the deviation of large-section, long-distance rectangular pipe jacking as described in claim 1 or 2, characterized in that, In step 3, laser-guided measurement: A laser theodolite is set up in the starting well, and several laser targets are set on the jacking machine partition to monitor the axis, horizontal, and torsional deviations in real time. Each pipe section is measured 1-3 times during jacking. Manual re-measurement: Manual re-measurement is carried out daily using a total station. Axis deviation: ±25mm, blue warning; ±35mm, yellow warning; ±40mm, red warning; Angle deviation: ±0.1°, blue warning; ±0.2°, yellow warning; ±0.3°, red warning. When a warning is triggered, the corresponding correction measures are activated in sequence, namely cutterhead rotation → articulation correction → mud injection correction.

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