Shield tunneling method capable of avoiding slab staggering

Abstract

The invention relates to the technical field of shield tunneling, in particular to a shield tunneling method capable of avoiding slab staggering, which comprises the following steps: the stroke difference value of thrust cylinders of a shield tunneling machine is monitored in real time, and the stroke difference value comprises the stroke difference of left and right thrust cylinders and / or the stroke difference of upper and lower thrust cylinders; dynamically adjusting the oil pressure of a thrust cylinder of the corresponding partition based on the stroke difference value, so that the absolute value of the stroke difference between the shield tunneling machine and the assembled tunnel segment is not greater than the parallel state corresponding to the maximum allowable value; wherein the absolute value of the stroke difference value is controlled not to exceed the maximum allowable value determined based on the outer diameter of the duct piece, according to the shield tunneling method capable of avoiding slab staggering, by calculating the stroke difference value of the thrust oil cylinder, control over the shield posture relative to the duct piece posture in the propelling process is conducted, and therefore the effect of avoiding slab staggering is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunneling, in particular to a shield tunneling method for avoiding misalignment. Background Art

[0002] Currently, the traditional shield tunneling method relies on the current shield axis posture (the XY coordinates of the nose and tail, requiring tunneling to be controlled within a ±50mm deviation from the theoretical value). Based on the existing shield-tail clearance and the current axis conditions, workers set hydraulic pressure control values ​​for each zone. For example, the upper zone oil pressure is 70 bar, the lower zone is 230 bar, the left zone is 150 bar, and the right zone is approximately 180 bar.

[0003] During shield tunneling, segment misalignment is a common quality defect. Segments that are assembled without misalignment often misalign as soon as the shield tail is pushed out. Misalignment can also lead to segment breakage and water seepage. Therefore, preventing segment misalignment is a crucial aspect of shield construction quality management. To address this issue, there is an urgent need to develop a shield tunneling method that avoids misalignment to overcome the shortcomings of current practical applications. Summary of the Invention

[0004] The object of the present invention is to provide a shield tunneling method that avoids misalignment, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions: A shield tunneling method for avoiding misalignment includes the following steps: Real-time monitoring of the stroke difference of the shield machine's propulsion cylinders, the stroke difference including the left and right propulsion cylinder stroke difference and / or the upper and lower propulsion cylinder stroke difference; Dynamically adjusting the oil pressure of the corresponding zone propulsion cylinder based on the stroke difference so that the absolute value of the stroke difference between the shield machine and the assembled tunnel segments is no greater than the parallel state corresponding to the maximum allowable value; The absolute value of the stroke difference is controlled not to exceed a maximum allowable value determined based on the outer diameter of the segment and the shield tail gap.

[0006] As a further solution of the present invention: the stroke difference between the left and right propulsion cylinders is the difference between the stroke of the left partition propulsion cylinder and the stroke of the right partition propulsion cylinder; The stroke difference between the upper and lower propulsion cylinders is the difference between the stroke of the upper propulsion cylinder and the stroke of the lower propulsion cylinder.

[0007] As a further solution of the present invention: when a standard annular segment without a wedge amount is advanced, the stroke difference between the left and right thrust cylinders and the stroke difference between the upper and lower thrust cylinders are controlled to approach zero.

[0008] As a further solution of the present invention: when advancing a universal annular segment with a wedge amount, the stroke increment of the propulsion cylinder located at the capping block is controlled to be half of the wedge amount, and the strokes of the other partitioned propulsion cylinders are shortened proportionally.

[0009] As a further solution of the present invention: the maximum stroke increment of the capping block position advancing cylinder does not exceed (wedge amount / 2+maximum allowable value) mm.

[0010] As a further solution of the present invention, it also includes: in the synchronous grouting construction, by shortening the slurry solidification time or injecting double liquid slurry into the top of the pipe segment at intervals of 3-5 rings, the up and down misalignment caused by the buoyancy of the slurry is suppressed.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. Completely avoid segment misalignment: By controlling the stroke difference of the propulsion cylinder to ≤ the maximum allowable value (the standard ring is close to 0, and the universal ring is controlled according to the wedge amount ratio), ensure that the shield and the segment are parallel (the angle is 0), and eliminate the cause of misalignment from the root; 2. Significantly reduce the risk of segment damage and water seepage: Simultaneously suppress segment breakage and water seepage caused by misalignment; 3. Realize real-time and precise control of shield machine attitude: Dynamically adjust oil pressure based on stroke difference (rather than traditional axis deviation monitoring). Deviation of attitude can be detected every 200mm of advancement, allowing timely correction to avoid urgent adjustments after the entire ring is pushed. 4. Optimization of universal segment misalignment suppression: capping block cylinder stroke increment = wedge amount / 2 (e.g. 48mm wedge amount → 24mm), and the remaining cylinders are shortened proportionally to ensure that the trapezoidal segment is parallel to the shield; The upper limit of the stroke difference increment is ≤ (wedge amount / 2 + maximum allowable value) mm, providing a tolerance safety margin; 5. Eliminate misalignment caused by slurry buoyancy: By shortening the slurry solidification time or injecting double-liquid slurry at intervals of 3-5 rings, the up-down misalignment caused by synchronous grouting can be specifically suppressed; 6. Measurement reliability guarantee: Manual calibration of the propulsion cylinder stroke meter is performed every shift to avoid misjudgment due to equipment errors; BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Schematic diagram of the control of the shield tunneling method for avoiding misalignment in an embodiment of the present invention.

[0013] Figure 2 It is a schematic structural diagram of the cooperation between the shield and the segments in an embodiment of the present invention.

[0014] Figure 3 Schematic diagram of the offset between pipe segments at the construction site.

[0015] Figure 4Schematic diagram of the relative positions of the oil cylinder and pipe segments at the construction site.

[0016] Figure 5 This is a schematic diagram of a formed tunnel with less segment misalignment after adopting the excavation method of the present invention.

[0017] In the figure: 1-shield, 2-thrust cylinder, 3-shield tail protection platform, 4-lining shoe plate, 5-segment, 6-staggered part, 7-piston rod, 8-cutter disc. DETAILED DESCRIPTION

[0018] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] The specific implementation of the present invention is described in detail below with reference to specific embodiments.

[0020] See also Figure 1-Figure 5 The present invention provides a shield tunneling method for avoiding misalignment. The method uses the calculated stroke difference of the propulsion cylinder 2 to control the shield posture relative to the posture of the segment 5 during the propulsion process, thereby achieving the effect of avoiding misalignment. The specific contents are as follows: During shield operation, when the stroke differences of the upper and lower and left and right thrust cylinders 2 are all zero (the stroke difference of thrust cylinder 2 is divided into the left and right thrust cylinder stroke difference (i.e., the thrust length of the left thrust cylinder minus the thrust length of the right thrust cylinder) and the upper and lower thrust cylinder stroke difference (i.e., the thrust length of the upper thrust cylinder minus the thrust length of the lower thrust cylinder), when both stroke differences are zero, the segment 5 and the shield are considered parallel (or nearly parallel), and the angle between the shield machine and the tunnel segment 5 is zero, resulting in no misalignment. After assembly, the misalignment caused during assembly will not change (neither worsen nor improve) during the advancement of the next few rings.

[0021] When tunneling is required, a stroke correction command is issued. This command is proportional to the width of the tunneling segment 5. For example, the left-side thrust cylinder should be extended 15mm more than the right-side thrust cylinder. The stroke difference between the upper and lower cylinders is controlled similarly. Traditional methods simply issue thrust pressure or similar commands that only require the axis deviation to be within a range (e.g., within ±50mm).

[0022] The new travel error correction tunneling command can quickly determine (for example, after advancing 200mm) whether the shield axis is operating according to the intended posture. If the posture control is not proportional, appropriate measures can be taken immediately. For example, the left side should have lengthened by 1mm for every 200mm of advancement, but it actually shortened by 1mm instead of lengthening. This method effectively controls the shield posture in a timely manner (keeping the machine and the segment posture as parallel as possible), preventing the situation where the axis deviation is discovered after a full tunnel has been pushed. Forcible correction can cause segment 5 to misalign and break.

[0023] The correction instructions for excavation are obtained according to the advance amount of each ring of the three-dimensional coordinates of the tunnel axis, so as to control the direction of the shield axis.

[0024] The process of the shield tunneling method is as follows: according to the three-dimensional coordinates, the direction control correction amount of the lower ring propulsion (that is, the stroke difference control amount of the propulsion cylinder 2; how much longer the left is than the right, and how much longer the top is than the bottom) is obtained, and the staff increases or decreases the shield propulsion oil pressure according to the stroke difference control amount (during the entire propulsion process, the staff cannot always pay attention to the axis display value of the measurement system, but need to focus on the change in the stroke difference, so as to quickly discover whether the shield posture is out of control and take timely measures), so that the ideal stroke difference correction amount is achieved at the end of the propulsion. In order to eliminate the measurement error of the stroke meter of the propulsion cylinder 2, manual calibration is required before each shift.

[0025] like Figure 2 As shown, the structure of the existing shield and pipe segments is coordinated, wherein the shield shell 1 constitutes the main shell of the shield machine, and a cutter head 8 is installed at its front end; the cylinder body of the thrust cylinder 2 is fixed to the inner wall of the shield shell 1, and the end of its piston rod 7 is connected to the lining shoe plate 4; the lining shoe plate 4 directly pushes the end face of the assembled pipe segment 5; the shield tail protection platform 3 is an annular protrusion structure at the tail end of the shield shell 1, and a shield tail gap is formed between it and the outer wall of the pipe segment 5 (the design value is 30mm); when the stroke difference of the thrust cylinder 2 in the upper and lower partitions is greater than the maximum allowable value (i.e., the stroke difference: BC>maximum allowable value mm), a misalignment portion 6 will be generated between the pipe segments 5, and if the stroke difference is too large, serious misalignment will occur at the misalignment portion 6.

[0026] During the entire excavation process of each ring, the stroke difference must be strictly controlled. For the 5-segment design type such as the standard ring and the left and right turning rings (the standard ring is rectangular when viewed from above), when advancing the standard ring, since it is a rectangular segment, the left and right or up and down stroke difference of 0 is the ideal control state; or controlling the stroke difference to less than the maximum allowable value (mm) is the only way to avoid misalignment.

[0027] For universal ring segment 5 designs (this type of segment 5 appears as an isosceles trapezoid when viewed from above, designed with the capping block as the shortest side), the propulsion cylinder 2 at the capping block should be extended by half the wedge amount during advancement. For example, for a universal ring with a wedge amount of 48mm, the cylinder at the capping block should be extended by 24mm compared to the cylinder directly opposite the capping block. This ensures that segment 5 is parallel to the shield, preventing misalignment. Because segment 5 and the shield are rigid bodies, as long as the maximum travel difference at the capping block is controlled, the cylinder lengths at other locations will adapt automatically. Since zero deviation is unattainable, the maximum extension of the cylinder at the capping block is controlled to no more than 44mm.

[0028] In addition to the shield tail pulling on segment 5 and causing misalignment, the buoyancy of the synchronous slurry can also cause misalignment (only vertical misalignment, not horizontal misalignment). In this case, the influence of buoyancy can be eliminated by shortening the slurry setting time or injecting dual-liquid slurry into the top area of ​​segment 5 every 3-5 rings for localized solidification.

[0029] like Figure 1 As shown, the left thrust cylinder can be represented by displacement group C, representing a thrust length of 1264mm, while the right thrust cylinder can be represented by displacement group A, representing a thrust length of 1208mm. Thus, the left-right stroke difference = 1264-1208 = 56mm. Similarly, the vertical stroke difference = 1237-1270 = -33mm. Both 56 and 33 (the absolute values ​​of which are greater than the required control value (or the maximum allowable value, in this case, 20mm)) result in misalignment. Once misalignment occurs, it cannot be corrected. Although no cracks may be visible on the inner side of segment 5, the outer side of the segment where it meets the shield shell has already cracked.

[0030] Example 1: Basic control process; Analysis of misalignment: During shield construction, misalignment is prone to occur when the shield tail is pushed out after the segments are assembled, resulting in segment breakage and water seepage. Preventing misalignment is a core goal of shield quality management.

[0031] Definition and monitoring of stroke difference: The left-right stroke difference is defined as the total stroke of the left propulsion cylinder - the total stroke of the right propulsion cylinder (unit: mm); the up-down stroke difference is defined as the total stroke of the upper propulsion cylinder - the total stroke of the lower propulsion cylinder (unit: mm); Real-time monitoring of two types of travel differences (such as Figure 1 In the example shown: left travel difference = 1264-1208 = 56 mm; upper travel difference = 1237-1270 = -33 mm).

[0032] Dynamic deviation correction control: When tunneling is required, the staff issues a stroke difference correction instruction (for example, the left zone cylinder advances 15mm more than the right zone); the shield driver adjusts the zone oil pressure according to the instruction to achieve the target stroke difference at the end of advancement.

[0033] Control target: absolute value of stroke difference ≤ maximum allowable value (20mm in this example); Parallel state determination: When the left and right and up and down stroke differences are all 0, it is determined that the shield is parallel to segment 5 (the angle is 0), and the misalignment is completely suppressed.

[0034] Example 2: Segment 5 type adaptive control; Standard ring segment control: Segment 5 is rectangular in design. Ideal control state: left-right travel difference = 0, up-down travel difference = 0; allowable deviation: absolute value of travel difference ≤ maximum allowable value 20mm (this 20mm is based on segment 5 with an outer diameter of 6200mm and a shield tail gap of 30mm. For larger diameters, such as 10-meter segments and shield tail gaps, the value will be increased accordingly, such as 35mm). Universal ring segment control: Segment 5 is designed as an isosceles trapezoid, with the capping block as the shortest side; capping block position cylinder: stroke increment control is wedge amount / 2 (for example, when the wedge amount is 48mm, the increment = 24mm); other partition cylinders: the stroke is shortened proportionally; maximum increment limit: capping block cylinder stroke increment ≤ (wedge amount / 2 + maximum allowable value) mm (for example: ≤24+20=44mm, in this case the maximum allowable value is 20mm).

[0035] Example 3: Suppression of other misalignment-inducing factors; Slurry buoyancy control: The vertical misalignment caused by synchronous grouting can be suppressed by any of the following methods: (a) shortening the slurry setting time; (b) injecting double-liquid slurry into the top of the segment 5 for local solidification every 3-5 rings; Elimination of measurement errors: Before each shift, the stroke measuring device of the propulsion cylinder 2 is manually calibrated.

[0036] like Figure 1 As shown, the left travel difference is 56mm (Group C 1264mm - Group A 1208mm), and the upper travel difference is -33mm (measured value 1237mm - 1270mm). Since the absolute values ​​are all greater than 20mm, it is easy to cause misalignment.

[0037] It should be noted that, in the present invention, unless otherwise expressly specified or limited, the terms "sliding," "rotating," "fixed," and "provided with," etc., should be understood in a broad sense. For example, they may refer to welded connections, bolted connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise expressly specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0038] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A shield tunneling method for avoiding misalignment, characterized in that: The following steps are involved: Real-time monitoring of the stroke difference of the shield machine's propulsion cylinders, the stroke difference including the left and right propulsion cylinder stroke difference and / or the upper and lower propulsion cylinder stroke difference; Dynamically adjusting the oil pressure of the corresponding zone propulsion cylinder based on the stroke difference so that the absolute value of the stroke difference between the shield machine and the assembled tunnel segments is no greater than the parallel state corresponding to the maximum allowable value; The absolute value of the stroke difference is controlled not to exceed a maximum allowable value determined based on the outer diameter of the segment and the shield tail gap.

2. The shield tunneling method for avoiding misalignment according to claim 1, characterized in that: The stroke difference between the left and right propulsion cylinders is the difference between the stroke of the left partition propulsion cylinder and the stroke of the right partition propulsion cylinder; The stroke difference between the upper and lower propulsion cylinders is the difference between the stroke of the upper propulsion cylinder and the stroke of the lower propulsion cylinder.

3. The shield tunneling method for avoiding misalignment according to claim 1 or 2, characterized in that: When a standard annular segment without a wedge amount is pushed forward, the stroke difference between the left and right thrust cylinders and the stroke difference between the upper and lower thrust cylinders are controlled to approach zero.

4. The shield tunneling method for avoiding misalignment according to claim 1 or 2, characterized in that: When advancing a universal annular segment with a wedge amount, the stroke increment of the advancing cylinder at the capping block is controlled to be half of the wedge amount, and the strokes of the advancing cylinders in the remaining partitions are shortened proportionally.

5. The shield tunneling method for avoiding misalignment according to claim 4, characterized in that: The maximum stroke increment of the thrust cylinder at the capping block position shall not exceed (wedge amount / 2+maximum allowable value) mm.

6. The shield tunneling method for avoiding misalignment according to claim 1, characterized in that: Also includes: During the synchronous grouting construction, the slurry setting time is shortened or double liquid slurry is injected into the top of the segment at intervals of 3-5 rings to suppress the up and down misalignment caused by the buoyancy of the slurry.

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