Line adjusting method for shield method station and interval line connection under shaft-free condition

Abstract

The invention discloses a line adjusting method for joining a shield station and an interval line under a shaft-free condition. The method comprises the following steps: determining various center lines and boundaries of the station and a tunnel; taking the point A as a starting point, taking the minimum turning radius D of the shield after expanding excavation as an arc AB, enabling the tangent line of the point A to be overlapped with the center line of the station, and enabling a terminal point B to be located on the original shield center line; drawing an inner contour of the tunnel after expanding excavation by taking AB as a center line, adjusting the position of the point B until no conflict with the driving boundary, and determining as an expanding excavation starting point; b is used as a starting point, the minimum turning radius d of the shield before expanding excavation is used as an arc BC, an end point C is required to be located on the center line of the original shield, the tangent line of the point B and the point C coincides with the line, and the maximum deviation does not exceed 30 cm; if not, moving forward a point B; and drawing the inner contour of the tunnel before expanding excavation by taking the BC as a center line, adjusting the point C until no conflict exists, and confirming the point C as a line adjustment starting point. According to the method, line sequential connection before and after shield expanding excavation is achieved through accurate arc line adjustment, vertical shaft construction is avoided, efficiency is improved, and cost and risks are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shield tunnel construction, in particular to a method for connecting a shield tunnel and a section line under the condition of no vertical shaft. BACKGROUND

[0002] When a station and a section tunnel are connected, the attitude of a shield tunnel is often adjusted after the shield tunnel is expanded to meet the construction requirements of the station. Currently, a secondary shield starting well is usually constructed, but this method has high requirements for the construction environment. If there are important buildings in the construction influence range of the receiving well, the attitude adjustment measures will be extremely complex, and a large amount of manpower and material resources will be required to handle the shield attitude adjustment problem, which significantly increases the engineering cost and construction period. SUMMARY

[0003] In order to solve the above technical problems, the present application provides a method for connecting a shield tunnel and a section line under the condition of no vertical shaft, which can realize the connection of the lines before and after the expansion of the shield tunnel without constructing a vertical shaft, and meet the construction requirements of the station.

[0004] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: a method for connecting a shield tunnel and a section line under the condition of no vertical shaft is provided, which comprises the following steps:

[0005] S1, the station starting point mileage line, the station center line, the driving center line, the driving boundary and the original shield center line are determined;

[0006] S2, the intersection of the station starting point mileage line and the station center line is recorded as point A, a circular arc AB is drawn with point A as the starting point and the minimum turning radius D of the shield after expansion as the radius, the tangent of the circular arc AB at point A overlaps the station center line, and the terminal point B of the circular arc AB is located on the original shield center line;

[0007] S3, the tunnel inner contour after expansion is drawn with the circular arc AB as the shield center line after expansion, and it is determined whether a conflict occurs between the tunnel inner contour and the driving center line and the driving boundary; if no conflict occurs, the point B is taken as the expansion starting point; if a conflict exists, the point B is moved along the original shield center line towards the shield, and it is ensured that the radius of the circular arc AB is not less than the minimum turning radius D of the shield after expansion, until the tunnel inner contour after expansion has no conflict with the driving center line and the driving boundary, and finally the point B is determined as the expansion starting point;

[0008] S4, a circular arc BC is drawn with the point B as the starting point and the minimum turning radius d of the shield before expansion as the radius, the terminal point C of the circular arc BC is located on the original shield center line, the tangents of the circular arc BC at points B and C are tangent to and coincide with the lines before and after the expansion, and the offset of the highest point of the arch of the circular arc BC from the original shield center line is not more than 30 cm;

[0009] S5, if the arc BC cannot meet all the conditions in step S4 at the same time, the B point is moved along the original shield center line to the shield, and it is ensured that the radius of the arc BC is not less than the minimum turning radius d of the shield before expansion, until all the conditions in step S4 are met at the same time;

[0010] S6, draw the tunnel inner contour before expansion with the arc BC as the shield center line before expansion, judge whether it conflicts with the driving center line and the driving boundary, if not, the C point is taken as the starting point of the line adjustment, if there is a conflict, the C point is moved along the original shield center line to the shield, and it is ensured that the radius of the arc BC is not less than the minimum turning radius d of the shield before expansion, until the tunnel inner contour before expansion has no conflict with the driving center line and the driving boundary, and finally the C point is determined as the starting point of the line adjustment;

[0011] S7, the line connection is realized and the line adjustment is completed with the C point as the starting point of the line adjustment, the arc BC as the shield center line before expansion, and the B point as the expansion starting point, and the arc AB as the shield center line after expansion.

[0012] As a further improvement of the application, the minimum turning radius D of the shield after expansion is 1000m.

[0013] As a further improvement of the application, the minimum turning radius D of the shield before expansion is 450m.

[0014] As a further improvement of the application, the diameter of the tunnel inner contour after expansion is equal to the diameter of the segment after expansion.

[0015] As a further improvement of the application, the diameter of the tunnel inner contour after expansion is 11.1m.

[0016] As a further improvement of the application, the diameter of the tunnel inner contour before expansion is equal to the diameter of the segment before expansion.

[0017] As a further improvement of the application, the diameter of the tunnel inner contour before expansion is 8.5m.

[0018] The beneficial effects of the application are: the method realizes the line connection before and after the shield expansion through the accurate arc line adjustment, so that the attitude adjustment of the shield machine after expansion is not needed by excavating the shaft, thereby effectively improving the construction efficiency, shortening the construction period, reducing the construction risk and saving the engineering cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a schematic diagram of station, driving, shield boundary and center line;

[0020] Figure 2 It is a schematic diagram of the arc AB;

[0021] Figure 3 It is a schematic diagram of the tunnel inner contour after expansion;

[0022] Figure 4 Draw a schematic diagram for the arc BC;

[0023] Figure 5 This is a schematic diagram of the tunnel's internal outline before widening. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0025] Referring to the figure, a method for adjusting the alignment of a shield tunneling station and a section of track under shaftless conditions includes the following steps:

[0026] S1, such as Figure 1 As shown, the station's starting mileage line, station centerline, train centerline, train boundary, original shield tunnel centerline, segment diameter before excavation, and segment diameter after excavation are clearly defined. These conditions can be confirmed through original design documents, survey data, etc. The train boundary is the area formed by extending 1.65m outwards from the train centerline on both sides.

[0027] S2, such as Figure 2 As shown, the intersection of the station's starting mileage line and the station's centerline is marked as point A. Using point A as the starting point of the arc, and with a radius of 1000 meters (the minimum turning radius of the tunnel boring machine after widening), an arc AB is drawn towards the direction of the tunnel boring machine. When drawing, it is essential to ensure that the tangent of this arc at point A completely coincides with the station's centerline. The endpoint B of arc AB is located on the original tunnel boring machine's centerline. Thus, the arc AB is preliminarily determined.

[0028] S3, such as Figure 3 As shown, using the initially determined arc AB as the shield tunnel centerline after widening, and based on the widened segment diameter of 11.1 meters, expand outward by 5.55 meters (i.e., 11.1 / 2) to draw the inner contour of the widened tunnel. Check whether this inner contour conflicts with the traffic centerline and traffic boundary.

[0029] No conflict: If the check is correct, then the current point B is confirmed as the starting point for the excavation.

[0030] Conflicts may occur: If the inner contour of the tunnel after widening conflicts with the traffic boundary, point B needs to be moved along the original shield centerline towards the shield's direction. Each time point B is moved, a new arc must be drawn starting from point A, with a radius not less than the minimum turning radius D of the widened shield, and ending at the new point B. The newly generated inner contour of the tunnel is then checked again. This process is iterated until the first point B location is found that completely prevents the inner contour of the widened tunnel from encroaching on the traffic boundary. This point B is then ultimately confirmed as the starting point of the widening. Moving point B essentially increases the turning radius, making the curve smoother and thus avoiding conflicts.

[0031] S4, such asFigure 4 As shown, starting from the final determined point B, and with the minimum turning radius of the tunnel boring machine before widening the tunnel as d = 450 meters, an arc BC is drawn towards the direction of the tunnel boring machine. This arc must meet three strict conditions:

[0032] 1. The endpoint C of the arc must fall on the centerline of the original shield tunnel in the original section.

[0033] 2. The tangent of the arc at point B must coincide with the tangent of the AB arc at point B as determined in step S3; at the same time, the tangent of the arc at point C must coincide with the direction of the original shield tunnel centerline at point C to ensure a smooth connection of the line.

[0034] 3. The horizontal offset between the highest point of the arch of the arc BC and the centerline of the original shield tunnel in the original section shall not exceed 30cm.

[0035] S5. If the initially drawn arc BC cannot simultaneously meet the above three conditions, for example, if the tangent direction at point C is mismatched or the offset exceeds the limit, then point B needs to be finely adjusted again along the original shield centerline towards the shield. After adjustment, using the new point B as the starting point, redraw the arc BC with a radius no less than the minimum turning radius d of the shield before widening, and re-verify all conditions. This process is repeated until a definite position of point B is found, until all conditions in step S4 are simultaneously met.

[0036] S6, such as Figure 5 As shown, the arc BC determined in the previous step, which satisfies all conditions, is used as the shield centerline before widening. Based on the segment diameter of 8.5 meters before widening, it is widened outward by 4.25 meters (i.e., 8.5 / 2) to draw the inner contour of the tunnel before widening. Check whether this inner contour conflicts with the traffic centerline and traffic boundary.

[0037] No conflict: then confirm that the current point C is the starting point for line adjustment.

[0038] If there is a conflict: then point C will be moved along the original shield centerline toward the shield direction. During the movement, ensure that the radius of the arc BC is not less than the minimum turning radius d of the shield before the excavation, until there is no conflict between the inner contour of the tunnel before the excavation and the centerline and boundary of the traffic. Finally, point C will be determined as the starting point for the alignment adjustment.

[0039] S7. Finally, one or more tunneling routes for the tunnel boring machine (TBM) can be selected, and the alignment is adjusted. Taking point C as the starting point for alignment adjustment, the TBM tunnels along the arc BC (the centerline of the TBM before widening), and after reaching point B (the starting point of widening), it widens the TBM and then enters the arc AB (the centerline of the TBM after widening) for tunneling. Finally, it enters the station section with a perfect horizontal posture, realizing the smooth connection of the line and completing the alignment adjustment.

[0040] Through the above-mentioned accurate adjustment method, the smooth and safe transition of the shield tunnel from the small section of the interval to the large section of the station is realized without the need to build expensive and time-consuming shafts. The method significantly improves the construction efficiency, shortens the overall construction period, reduces the engineering risk and cost, and has great engineering application value.

[0041] The above-mentioned embodiments are only used to facilitate the illustration of the present application, and any person with ordinary knowledge in the art can make equivalent embodiments by making partial changes or modifications within the scope of the technical features disclosed in the present application without departing from the technical features of the present application.

Claims

1. A method for adjusting a line in a shield method station and a section line under the condition of no shaft, characterized in that The method comprises the following steps: S1, determining the station starting mileage line, the station center line, the driving center line, the driving boundary and the original shield center line; S2, recording the intersection of the station starting mileage line and the station center line as point A, taking point A as the starting point and the minimum turning radius D of the post-expansion shield as the radius to draw a circular arc AB, the tangent of the circular arc AB at point A overlaps the station center line, and the terminal point B of the circular arc AB is located on the original shield center line; S3, drawing the post-expansion tunnel inner contour with the circular arc AB as the post-expansion shield center line, and judging whether the post-expansion tunnel inner contour conflicts with the driving center line and the driving boundary; if there is no conflict, taking point B as the expansion starting point; if there is a conflict, moving point B along the original shield center line towards the shield direction, and ensuring that the radius of the circular arc AB is not less than the minimum turning radius D of the post-expansion shield, until the post-expansion tunnel inner contour does not conflict with the driving center line and the driving boundary, and finally determining point B as the expansion starting point; S4, taking point B as the starting point and the minimum turning radius d of the pre-expansion shield as the radius to draw a circular arc BC, the terminal point C of the circular arc BC is located on the original shield center line, the tangents of the circular arc BC at points B and C are tangent to the front and rear lines and coincide with each other, and the offset of the highest point of the arch of the circular arc BC from the original shield center line is not more than 30 cm; S5, if the circular arc BC cannot simultaneously satisfy all the conditions in step S4, moving point B along the original shield center line towards the shield direction, and ensuring that the radius of the circular arc BC is not less than the minimum turning radius d of the pre-expansion shield, until all the conditions in step S4 are simultaneously satisfied; S6, drawing the pre-expansion tunnel inner contour with the circular arc BC as the pre-expansion shield center line, and judging whether the pre-expansion tunnel inner contour conflicts with the driving center line and the driving boundary; if there is no conflict, taking point C as the line adjustment starting point; if there is a conflict, moving point C along the original shield center line towards the shield direction, and ensuring that the radius of the circular arc BC is not less than the minimum turning radius d of the pre-expansion shield, until the pre-expansion tunnel inner contour does not conflict with the driving center line and the driving boundary, and finally determining point C as the line adjustment starting point; S7, taking point C as the line adjustment starting point, taking the circular arc BC as the pre-expansion shield center line, taking point B as the expansion starting point, and taking the circular arc AB as the post-expansion shield center line to realize the line connection and complete the line adjustment.

2. The method according to claim 1, wherein the method is characterized in that: The minimum turning radius D of the post-expansion shield is 1000 m.

3. The method of claim 1, wherein the method is characterized by: The minimum turning radius D of the pre-expansion shield is 450 m.

4. The method of claim 1, wherein the method is characterized by: The diameter of the post-expansion tunnel inner contour is equal to the diameter of the post-expansion segment.

5. The method according to claim 4, wherein the method is characterized in that: The diameter of the post-expansion tunnel inner contour is 11.1 m.

6. The method of claim 1, wherein the method is characterized by: The diameter of the pre-expansion tunnel inner contour is equal to the diameter of the pre-expansion segment.

7. The method of claim 6, wherein the method further comprises: determining a first tunneling direction of the first shield tunneling machine; and determining a second tunneling direction of the second shield tunneling machine. The diameter of the pre-expansion tunnel inner contour is 8.5 m.

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