A method for determining the assembly overlap distance of a shield segment capping block and a shield segment capping block assembly device

Abstract

The application provides a method for determining the splicing overlap distance of a shield segment top sealing block, which comprises the following steps: establishing a three-dimensional rectangular coordinate system with the intersection point of the axis of a segment ring and one side end surface O in the axial direction of the segment ring as the origin, taking the up-down direction as the Z axis and the axial direction as the Y axis; obtaining the expression of the top sealing block overlap surface of the central angle, the expression of the top sealing block overlap surface considering the insertion angle, and the expression of the top sealing block overlap surface considering the joint angle according to the geometric parameters of the top sealing block and the segment ring; the X axis coordinate value of the intersection point of the top sealing block overlap surface considering the joint angle and the outer surface of the segment ring and the other side end surface O' in the axial direction of the segment ring is recorded as L1, the X axis coordinate value of the point on the intersection line of the top sealing block overlap surface considering the insertion angle and the inner surface of the segment ring is recorded as L2, the axial coordinate value is recorded as d, and when L1=L2, d is the maximum overlap distance of the top sealing block along the axial direction and the segment ring.

Description

Technical Field

[0001] This invention relates to the field of shield tunnel segment design technology, specifically to a method for determining the stacking distance of shield tunnel segment capping blocks and a shield tunnel segment capping block assembly device. Background Technology

[0002] Shield tunneling offers significant advantages such as high construction speed, high construction quality, minimal construction disturbance, and improved construction safety, and has been widely applied in the construction of large-scale underground space projects such as integrated utility tunnels, subway stations, and mountain tunnels. Shield tunnel segments not only provide initial support in shield tunnels but also serve as permanent structures, bearing the loads during construction and the water and soil pressures during normal use.

[0003] Currently, precast reinforced concrete segments are widely used in shield tunneling construction both domestically and internationally. These precast segments are assembled into a segment ring, which typically consists of several standard blocks, two adjacent blocks, and a capping block. The capping block is generally assembled using a radial (or vertical) insertion followed by an axial insertion method. This method ensures a certain overlap while reliably preventing the capping block from falling off. Therefore, this radial-to-axial insertion method has been widely applied in shield tunneling projects in China. However, radial insertion occupies the hydraulic cylinder's stroke space. Due to the capping block's design, the arc length and chord length on the soil-facing side are greater than those on the back side. If the hydraulic cylinder's retraction stroke is insufficient, and the overlap length between the capping block and the segment ring is large, the segment may not be able to be inserted radially. Increasing the hydraulic cylinder's retraction stroke also increases the cylinder size, encroaching on the assembly space and affecting the assembly operation. Therefore, finding a method for calculating the assembly space of the shield tunnel segment capping block is crucial. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for determining the stacking distance of shield tunnel segment capping blocks and a shield tunnel segment capping block assembly device. This method can quickly determine the geometric dimension parameters of the segment capping blocks and the matching degree of the shield equipment assembly space under specific engineering backgrounds, thereby improving the design efficiency of the segment structure and shield equipment.

[0005] According to a first aspect of the present invention, a method for determining the stacking distance of shield tunnel segment capping blocks is provided, comprising the following steps: Step 1: Establish a three-dimensional rectangular coordinate system with the intersection of the axis of the segment ring and one end face O in the axial direction of the segment ring as the origin, with the up and down direction as the Z-axis and the axial direction of the segment ring as the Y-axis; Step 2: Based on the geometric parameters of the capping block and the segment ring, calculate the expression of the capping block mating surface considering the central angle, then further calculate the expression of the capping block mating surface considering the insertion angle, and then further calculate the expression of the capping block mating surface considering the joint angle. Step 3: The X-axis coordinate value of the intersection point of the sealing block overlapping surface considering the joint angle with the outer surface of the segment ring and the other end face O' of the segment ring in the axial direction is recorded as L1. The X-axis coordinate value of the point on the intersection line of the sealing block overlapping surface considering the insertion angle with the inner surface of the segment ring is recorded as L2, and the axial coordinate value is recorded as d. When L1=L2, d is the maximum overlapping distance between the sealing block and the segment ring in the axial direction.

[0006] like Figure 1 As shown, when the capping block is assembled using vertical or radial insertion, the capping block and the segment ring are not completely overlapped axially. After being offset by a certain distance axially, they are first inserted radially or vertically, and then inserted axially. The overlap distance between the capping ring and the segment ring should meet the following condition: the chord length of the arc where the small end face of the capping block intersects the outer circular surface of the segment ring is less than the chord length of the inner circular arc of the segment ring corresponding to the small end face of the capping block at the radial insertion position. This is the critical state, that is, the construction gap is 0, corresponding to the maximum assembly overlap distance.

[0007] The aforementioned segment ring consists of several standard blocks, two adjacent blocks, and a capping block, with space between the two adjacent blocks for the capping block to be inserted.

[0008] Preferably, in step 2, the geometric parameters of the capping block include at least one of the following: central angle 2θ, insertion angle α, joint angle β, segment ring width L, segment inner diameter R1, or segment outer diameter R2. It is understood that the inner diameter, outer diameter, and width of the segment ring are also R1, R2, and L, respectively.

[0009] Preferably, in step 2, the overlapping surface of the capping block considering the central angle is denoted as surface ABCD, which intersects the end face O at the line segment formed by points A and B, and intersects the other end face O' in the axial direction of the segment ring at the line segment formed by points C and D.

[0010] Preferably, in step 2, the overlapping surface of the capping block considering the insertion angle is obtained by: dividing surface ABCD into... With α as the axis, after rotating counterclockwise by α, it intersects the end face O' at the line segment formed by points C' and D', denoted as face ABC'D'.

[0011] Preferably, in step 2, the overlapping surface of the capping block considering the joint angle is obtained by: dividing surface ABC'D into... Let be the axis, and after rotation by β, let AB'C'D'' intersect the end face O at point B' and D'' respectively.

[0012] Preferably, face ABC'D is... The direction of rotation around the axis is either clockwise or counterclockwise.

[0013] Preferably, in step 2, the expression for the superimposed surface of the capping block considering the central angle includes the point-normal form equation of surface ABCD, the expression for the superimposed surface of the capping block considering the insertion angle includes the point-normal form equation of surface ABC'D', and the expression for the superimposed surface of the capping block considering the joint angle includes the point-normal form equation of surface AB'C'D''.

[0014] Preferably, in step 3, L1 is obtained by the following method: by combining the point-normal equation of the surface AB'C'D'' and the intersection line of the outer surface of the segment ring and the end face O' into a system of equations, the X-axis coordinate value of D'' is calculated, which is L1.

[0015] Preferably, in step 3, L2 is obtained by the following method: solving a system of equations by combining the point-normal equation of the surface ABC'D' and the intersection line of the inner surface of the segment ring and the end face O', calculating the coordinates of C', and the X-axis coordinate value of the point on line segment AC' is L2.

[0016] This invention first calculates the equation of the overlapping surface ABCD of the capping block considering the central angle. Based on the preset insertion angle α, the overlapping surface ABCD is rotated around the AB axis to obtain the equation of the overlapping surface ABC'D' of the capping block considering the insertion angle α, and the coordinates of the intersection point C' of the overlapping surface ABC'D' and the back soil surface of the segment are calculated. Based on the preset joint angle β, the overlapping surface ABC'D' of the capping block considering the insertion angle α is rotated around the AC' axis to obtain the equation of the overlapping surface AB'C'D'' of the capping block considering the joint angle β. The coordinates of D'' are calculated based on the equation of AB'C'D'', and the equation of the chord length L1 of the small end surface of the capping block can be obtained according to the geometric relationship. Then, the expression of the chord length L2 of each arc along the Y-axis (axial direction) of the inner surface of the capping block is calculated according to the geometric relationship. When L1 is less than L2, the capping block can be inserted in the radial or vertical direction. When L1=L2, the overlapping distance between the capping block and the segment ring is the maximum assembly overlapping distance.

[0017] According to a second aspect of the invention, a jack is used to axially insert a capping block between two adjacent blocks, the travel distance of which is the difference between the tail shield assembly space and the circumference of the capping block segment, the tail shield assembly space being determined by the method described in the first aspect of the invention.

[0018] According to one embodiment of the present invention, at least the following beneficial effects are achieved: This invention proposes a method for calculating the assembly space of shield tunnel segment capping blocks. Based on the geometric dimensions of the capping blocks, it can quickly calculate the stacking distance of the capping segments under specific engineering conditions, determine whether the segment design and the tail assembly space design of the shield are compatible, and provide a reference for the design of segment parameters and shield equipment parameters. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram showing the overlap distance between the capping block and the adjacent block of the present invention; Figure 2 A schematic diagram of the overlapping surface of the capping block considering the central angle in this invention; Figure 3 This is a schematic diagram of another angle of the overlapping surface of the capping block considering the central angle in this invention; Figure 4 A schematic diagram of the overlapping surface of the capping block considering the insertion angle in this invention; Figure 5 A schematic diagram of the overlapping surface of the capping block considering the joint angle in this invention; Figure 6 This is a three-dimensional schematic diagram of the overlapping surface of the capping block of the present invention; Figure 7 This is a schematic diagram of the space for assembling the shield tail. Detailed Implementation

[0020] The following will describe the concept and technical effects of the present invention clearly and completely with reference to the embodiments, so as to fully understand the purpose, features and effects of the present invention.

[0021] This embodiment proposes a method for determining the overlapping distance of shield tunnel segment capping blocks. First, the point-normal equation of the capping block overlapping surface ABCD, considering only the central angle, is calculated. Based on this, the point-normal equation of the capping block overlapping surface ABC'D', considering the central angle and insertion angle, is calculated. Then, the point-normal equation of the capping block overlapping surface AB'C'D'', considering the central angle, insertion angle, and joint angle, is further calculated. At this point, surface AB'C'D'' is the side surface of the capping block with the central angle, insertion angle, and joint angle as characteristic parameters (also the overlapping surface of the capping block after it is assembled with adjacent blocks). When the capping block is inserted into the space between two adjacent blocks in the vertical or radial direction, the chord length L1 of the outer surface of the small end of the capping block (i.e., the length of the soil-facing surface of the small end of the capping block along the X-axis) should be less than or equal to the chord length L2 of the arc between the back soil surfaces of the two adjacent blocks along the X-axis (since the shape of the capping block corresponds to the space between the two adjacent blocks, L2 is actually also the chord length of the arc on the inner surface of the capping block in the Y-axis direction / axial direction equal to the overlap distance). Based on geometric relationships, the expressions for L1 and L2 are calculated respectively. When L1 = L2, the overlap distance between the capping block and the segment ring in the axial direction corresponding to this insertion position is the maximum assembly overlap distance, corresponding to the minimum assembly space required by the shield tunnel segment capping block assembly equipment when assembling the capping block.

[0022] The above process specifically includes the following steps: Step 1: Calculate the overlapping surface of the capping blocks at the central corner. Given that the inner surface radius of the segment ring is R1, the outer surface radius is R2, the width of the segment ring is L, and the central angle corresponding to the arc length of the capping block is 2θ, a three-dimensional coordinate system is established with the intersection of the segment ring axis and one end face O as the origin. The segment ring extends along the positive Y-axis, and the capping block is located at the center position directly above the segment ring in the XZ coordinate plane. The other end face of the segment ring is O', and the Z-axis passes through the center line of the capping block. In this embodiment, the radial direction of the capping block insertion is either the up-down direction or the Z-axis direction, and the axial direction is the Y-axis direction.

[0023] like Figure 2 As shown, let the overlapping surface of the longitudinal joint of the capping block be surface (ABCD), where points A and B are located on the end face O of the segment ring, and points C and D are located on the end face O' of the segment ring. Surface (ABCD) is parallel to the Y-axis, and its normal vector is... , The starting point is the origin of the coordinate system, and the ending point is located on the intersection of the XZ coordinate plane and the inner circle of the segment ring. We will now analyze the quarter-segment ring located in the first quadrant of the coordinate system.

[0024] Based on the above conditions, the equation of the inner circle of the segment ring is: ; The equation for the outer circle of the segment ring is: ; The coordinates of point A are (R1sinθ, 0, R1cosθ), the coordinates of point B are (R2sinθ, 0, R2cosθ), the coordinates of point C are (R1sinθ, L, R1cosθ), and the coordinates of point D are (R2sinθ, L, R2cosθ).

[0025] but: The coordinates are ((R2-R1)sinθ, 0, (R2-R1)cosθ), and the normal vector of plane ABCD is... The coordinates are (-cosθ, 0, sinθ). Since the plane (ABCD) passes through point A and its normal vector is... Then the point-normal form equation of plane (ABCD) is: .

[0026] Step 2: Calculate the C' coordinate when considering the overlapping surface of the inserted corner capping block. Face (ABCD) Rotate counterclockwise by α, with the capping block inserted at an angle of α, to form a surface (ABC'D'), where... Let be the unit vector along the AB axis. = (sinθ, 0, cosθ), points A and B are located on the end face O of the segment ring, and points C' and D' are located on the end face O' of the segment ring. According to general engineering experience, in this coordinate system, points C' and D' are both located in the first quadrant, therefore, α < 90°. Simultaneously around Rotational α formation , Let be the normal vector of the plane (ABC'D'). Then, according to Rodriguez's formula, = ·cosα+( × sinα+ ( · (1-cosα), Substitute , Coordinates: The coordinates are ( , , The point-normal form equation of the plane (ABC'D') can be obtained as follows: .

[0027] To find the coordinates of point C', let the coordinates of point C' be ( , , Solve the system of equations by combining the equations of the surface (ABC'D') and the intersection line of the inner circle of the segment ring with the end face O': ; Solving for: .

[0028] Step 3: Calculate the overlapping surface of the joint corner capping block. Face (ABC'D') Rotate clockwise by β, with the capping block joint angle as β, to form the surface (AB'C'D''). In this embodiment, the joint angle β is assumed to rotate outward (clockwise), which ensures that the upper arc chord length of the capping block at the same position is greater than the lower arc chord length. The joint angle can also rotate inward (counterclockwise), but it must satisfy... At this point, it can still be guaranteed that the upper arc chord length of the capping block at the same position is greater than the lower arc chord length, and β should be taken as a positive value when calculating.

[0029] Points A and B' are located on the end face O of the segment ring, and points C' and D'' are located on the end face O' of the segment ring. Since β < 90°, points B', C', and D'' are all located in the first quadrant in this coordinate system. Simultaneously around Rotate β to form , Let be the normal vector of the surface (AB'C'D''), then: , ⊥ , and The included angle is β.

[0030] Let AC' be the unit vector of the AC' axis. = ( According to the Rodriguez rotation formula, we can calculate: , Will , Substituting the coordinates into the above formula, we can calculate... coordinates ( , , )for: , The point-normal form equation of the surface (AB'C'D'') is: .

[0031] Let the coordinates of point D'' be ( , , Solve the system of equations by combining the equations of the surface (AB'C'D'') and the intersection line between the outer circle of the segment ring and the end face O': , The calculation yields: , Where M=sinθsinβ-cosαcosθcosβ, N=1-sin 2 αcos 2 β, P=sinθcosαcosβ+cosθsinβ, Q = R1sinβ + Lsinαcosβ.

[0032] Step 4: Calculation of critical state overlap distance Based on the above calculation results and geometric relationships: The distance L1 between D'' on the outer surface of the tube segment and the YZ plane is = .

[0033] According to geometric relationships, point C is... Using the axis as an axis, after rotating counterclockwise by α, the coordinates of the new point C' are (R1sinθ-Lcosθsinα, Lcosα, R1cosθ+Lsinθsinα). Then, the coordinates of the direction vector of line AC' are: ( , , Therefore, the equation of line AC' is: , Point E is a point on line AC', and L2 is the distance from point E to the YZ plane. (In this invention, the values ​​of the insertion angle α and the connector angle β must ensure that D'' is located between A and C' in the X-axis direction. These values ​​can be parameters of a specific capping block, optional parameters during capping block production, or parameters determined by other methods.) When L1 = L2, that is... = When the capping block can be inserted radially along the segment ring, the limiting state is given by substituting into the equation of line AC', which gives the limiting state as follows: .

[0034] It can be seen that when the axial overlap distance between the capping block and the segment ring is less than At this time, the capping block can be inserted radially (or vertically) along the segment ring. In this embodiment, the parameters of the capping block are as follows:

[0035] Substituting the central angle, insertion angle, joint angle, segment ring width, segment inner diameter, and segment outer diameter into the above formula, we can calculate that under the critical state (when the gap is 0, corresponding to the maximum assembly overlap distance), the overlap distance of the capping block is 424mm. That is, under the critical state, when the overlap distance of the capping block is 424mm, the capping block can be inserted radially (or vertically). At this time, the minimum space for the shield tail assembly is the segment ring width + (segment ring width - overlap distance), which is 676mm.

[0036] As can be seen, the present invention can quickly calculate the minimum space required for shield tail assembly to meet construction requirements based on the parameters of the capping block, providing an effective reference for equipment design and manufacturing.

[0037] In some embodiments of the present invention, see Figure 2-5 The segment ring includes several standard blocks, two adjacent blocks located at both ends of the standard blocks, and a capping block located between the two adjacent blocks. During installation, the capping block is installed last. The capping block is first moved radially approximately along the XZ plane or vertically to adjust its height, and then inserted axially to complete the assembly.

[0038] See Figure 2 , 5 AC' is obtained by rotating AC counterclockwise around AB. Therefore, for points on the line AC', the X-axis coordinate value gradually decreases along the direction from A to C' (i.e., gradually approaches the YZ plane). Similarly, although B'D'' has rotated clockwise around AC' to a certain extent, the X-axis coordinate value of points on the line B'D'' also gradually decreases along the direction from B' to D''.

[0039] Therefore, when the installation is complete, the point at the upper right corner of the capping block needs to coincide with or approximately coincide with point D'', so that their X-axis coordinates are equal or approximately equal.

[0040] Because a certain rotation angle was chosen, the X-axis coordinate of D'' lies between points A and C'. Therefore, between points A and C', there must exist a point E whose X-axis coordinate is equal to that of point D''. Thus, before moving the capping block radially or vertically, the Y-coordinate of the upper right corner of the capping block must be equal to the Y-coordinate of point E. At this point, the assembly overlap distance can be calculated. If the overlap distance is too large, the capping block cannot be inserted radially or vertically; if the overlap distance is too small, the axial insertion distance increases, resulting in a larger stroke for the jack.

[0041] When the upper right corner of the capping block moves radially or vertically, it needs to pass through or approximately pass through point E, and finally stop moving vertically when the Z coordinate of the upper right corner is equal to the Z coordinate of D''. Then, it is then... Figure 7The jacks in the middle push the capping block along the Y-axis.

[0042] according to Figure 7 Initially, on the Y-axis, the capping block extends a certain distance to the left beyond the segment ring; this distance is denoted as the extension distance. Since the width of the capping block on the Y-axis is... Figure 7 Since the widths of the assembled segments (or segment rings) are equal, the extension distance is the difference between the segment ring width and the assembly overlap distance. Therefore, the initial position of the jack that axially pushes the capping block is also greater than or equal to the extension distance from the left end of the assembled segment.

[0043] During assembly, the lifting device is first used to move the top panel to be assembled to a suitable position along the radial or vertical direction, and then the jacks push the top panel along the Y-axis. Figure 2-7 From this, we can deduce that the effective distance the jack can push the capping block in the Y-axis direction is, or approximately, the extension distance. Therefore, the effective stroke of the jack needs to be designed with reference to the extension distance.

[0044] In some embodiments, the jack's stroke is 1-10 times the extension distance. For example, it can be 1-2 times the extension distance, or 1.1-5 times the extension distance. The specific value needs to be determined based on the jack's parameters and market price. The jack's stroke cannot be less than the extension distance, otherwise the capping block cannot be pushed into place. Similarly, the jack's stroke should not be excessively greater than the extension distance, as this would result in wasted space or performance, leading to increased costs.

[0045] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A method for determining the overlapping distance of shield tunnel segment capping blocks, characterized in that, Includes the following steps: Step 1: Establish a three-dimensional rectangular coordinate system with the intersection of the axis of the segment ring and one end face O in the axial direction of the segment ring as the origin, with the up and down direction as the Z-axis and the axial direction of the segment ring as the Y-axis; Step 2: Based on the geometric parameters of the capping block and the segment ring, calculate the expression of the capping block mating surface considering the central angle, then further calculate the expression of the capping block mating surface considering the insertion angle, and then further calculate the expression of the capping block mating surface considering the joint angle. Step 3: The X-axis coordinate value of the intersection point of the sealing block overlapping surface considering the joint angle with the outer surface of the segment ring and the other end face O' of the segment ring in the axial direction is recorded as L1. The X-axis coordinate value of the point on the intersection line of the sealing block overlapping surface considering the insertion angle with the inner surface of the segment ring is recorded as L2, and the axial coordinate value is recorded as d. When L1=L2, d is the maximum overlapping distance between the sealing block and the segment ring in the axial direction.

2. The determination method according to claim 1, characterized in that, In step 2, the geometric parameters of the capping block include at least one of the following: central angle 2θ, insertion angle α, joint angle β, segment ring width L, segment inner diameter R1, or segment outer diameter R2.

3. The determination method according to claim 2, characterized in that, In step 2, the overlapping surface of the capping block considering the central angle is denoted as surface ABCD. It intersects the end face O at the line segment formed by points A and B, and intersects the other end face O' in the axial direction of the segment ring at the line segment formed by points C and D.

4. The determination method according to claim 3, characterized in that, In step 2, the overlapping surface of the capping block considering the insertion angle is obtained in the following way: Surface ABCD is... With α as the axis, after rotating counterclockwise by α, it intersects the end face O' at the line segment formed by points C' and D', denoted as face ABC'D'.

5. The determination method according to claim 4, characterized in that, In step 2, the overlapping surface of the capping block considering the joint angle is obtained in the following way: Surface ABC'D is... Let be the axis, and after rotation by β, let AB'C'D'' intersect the end face O at point B' and D'' respectively.

6. The determination method according to claim 5, characterized in that, Faces ABC'D The direction of rotation around the axis is either clockwise or counterclockwise.

7. The determination method according to claim 5, characterized in that, In step 2, the expression for the superimposed surface of the capping block considering the central angle includes the point normal form equation of surface ABCD, the expression for the superimposed surface of the capping block considering the insertion angle includes the point normal form equation of surface ABC'D', and the expression for the superimposed surface of the capping block considering the joint angle includes the point normal form equation of surface AB'C'D''.

8. The determination method according to claim 7, characterized in that, In step 3, L1 is obtained by the following method: the point-normal equation of the surface AB'C'D'' and the intersection line of the outer surface of the segment ring and the end face O' are combined into a system of equations, and the X-axis coordinate value of D'' is calculated as L1.

9. The determination method according to claim 7, characterized in that, In step 3, L2 is obtained by the following method: the point-normal equation of the surface ABC'D' and the intersection line of the inner surface of the segment ring and the end face O' are combined into a system of equations to calculate the coordinates of C'. The X-axis coordinate value of the point on line segment AC' is L2.

10. A shield tunnel segment capping block assembly device, comprising jacks for axially inserting the capping block between two adjacent blocks, characterized in that, The stroke of the jack is greater than or equal to the difference between the ring width of the capping block and the overlapping distance, wherein the overlapping distance is determined by the method according to any one of claims 1-9.

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