A rapid design method for shield segment K block

Abstract

The application provides a kind of shield segment K block quick design method, comprising the following steps: step 1: with segment ring center as origin, establish Cartesian coordinate system, the direction of its Z axis is the axial direction of segment ring, the positive direction of Y axis is perpendicular to K block;Step 2: obtain the preset parameter of K block;Step 3: the preset parameter of K block is brought into Cartesian coordinate system, the X coordinate value of K block small end outer arc surface point and K block assembly position inner arc surface point is calculated;Then calculate the assembly gap of K block;Step 4: whether the assembly gap of K block meets the construction requirement of segment ring, if not meet the construction requirement, adjust the preset parameter of K block, repeat step 3, until the assembly gap of K block that meets the construction requirement is calculated.The core parameters of K block are analyzed by geometric tools, the relationship between parameters is found by mathematical method, and the assembly gap of K block can be quickly solved according to the core parameters of K block, which greatly improves the design efficiency.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of shield tunnel design, and particularly relates to a kind of shield segment K block rapid design method. BACKGROUND

[0002] Shield segment is the core content of shield tunnel design, and flat plate type segment is the most commonly used type, which is generally divided into one top block, two adjacent blocks and a plurality of standard blocks, as shown in Figure 1 and Figure 2 The top block is the key to the design, also known as K block. K block is the last block assembled in the segment ring, and there are two assembly ideas, one is longitudinal wedge, i.e. one end is large and the other end is small, and the other is radial wedge, i.e. the outer arc surface of K block is smaller than the inner arc surface. In practical application, the two ideas are combined. K block is overlapped by a certain length to reduce the stroke of the shield jacks; the longitudinal large and small ends are realized by offset, and the size of the outer arc surface is adjusted by the deflection of the radial angle, which is convenient for assembly and avoids the sliding caused by the outer arc surface of K block being smaller than the inner arc surface. The conventional K block design is to preset the relevant parameters, and then to determine the K block assembly gap by entity section to verify whether the design is reasonable, but the efficiency is low. SUMMARY

[0003] The present application provides a kind of shield segment K block rapid design method to solve the technical problems existing in the prior art, which quickly solves the assembly gap of K block according to the core parameters of K block, greatly improving the design efficiency.

[0004] The technical scheme adopted by the present application is as follows: a kind of shield segment K block rapid design method, comprising the following steps:

[0005] Step 1: a Cartesian coordinate system is established with the center of the segment ring as the origin, the direction of the Z axis is the axial direction of the segment ring, and the positive direction of the Y axis is perpendicular to the K block;

[0006] Step 2: obtain the preset parameters of K block, including segment inner diameter, segment thickness, segment width, K block radial angle, offset value, rotation angle and K block longitudinal overlap value;

[0007] Step 3: bring the preset parameters of K block into the Cartesian coordinate system, calculate the X coordinate value of the K block small end outer arc surface point, and the X coordinate value of the K block assembly position inner arc surface point corresponding thereto; then calculate the K block assembly gap;

[0008] Step 4: determine whether the K block assembly gap meets the construction requirements of the segment ring, if not, adjust the preset parameters of K block, repeat step 3 until the K block assembly gap that meets the construction requirements is calculated.

[0009] Further, in step 3,

[0010] According to the formula

[0011]

[0012] Calculate x=P x1 ,

[0013] Wherein, x, y indicate the coordinates (x, y) of any point P on the segment ring, r is the inner diameter of the segment, d is the thickness of the segment, o is the offset value, alpha is the rotation angle, theta=(pi-A) / 2, A is the radial angle of the K block, P x1 X coordinate value of the outer arc surface point of the small end of the K block;

[0014] According to the formula

[0015]

[0016] Calculate x=P x2 ,

[0017] Wherein, o' is the offset value corresponding to the K block longitudinal lap value l, P x2 X coordinate value of the inner arc surface point of the K block assembly position;

[0018] Finally, calculate the assembly gap of the K block delta=P x1 -P x2 .

[0019] Further, take zero lap (0, -o) and full-width lap (B, o) as boundary conditions, find the linear relationship equation of the lap amount and the offset value, and then calculate the offset value o' corresponding to the K block longitudinal lap value l, B is the width of the segment, and l is the K block longitudinal lap value.

[0020] Compared with the prior art, the present application has the beneficial effects that: the present application analyzes the core parameters of the K block through geometric tools, finds the relationship between the parameters by mathematical method, and can quickly solve the assembly gap of the K block according to the core parameters of the K block, improves the speed of judging whether the assembly gap of the K block meets the construction requirements of the segment ring, and greatly improves the design efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 It is a structural diagram of the prior art shield segment ring;

[0022] Figure 2 It is a planar projection diagram of the prior art shield segment ring;

[0023] Figure 3 It is a flowchart of the embodiment of the present application;

[0024] Figure 4 It is a section line equation relationship diagram of the embodiment of the present application;

[0025] Figure 5A K block plane schematic diagram of an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order for those skilled in the art to better understand the technical solutions of the present application, the present application will be described in detail below in combination with the drawings and specific embodiments.

[0027] An embodiment of the present application provides a shield segment K block rapid design method, as shown in Figure 3 , which comprises the following steps:

[0028] Step 1: Establish a Cartesian coordinate system with the segment ring center as the origin, the direction of the Z axis as the axial direction of the segment ring, and the positive direction of the Y axis perpendicular to the K block. Obtain the segment ring equation x 2 +y 2 =ri 2 . Wherein x, y refers to the coordinates (x, y) of any point P on the segment ring, r i refers to the radius of the circular ring.

[0029] Step 2: Obtain the preset parameters of the K block, including the segment inner diameter, segment thickness, segment width, K block radial angle, offset value, rotation angle and K block longitudinal lap value.

[0030] Step 3: Bring the preset parameters of the K block into the Cartesian coordinate system, wherein r is the segment inner diameter, d is the segment thickness, B is the segment width, A is the K block radial angle, o is the offset value, α is the rotation angle, and l is the K block longitudinal lap value.

[0031] Step 3.1: Calculate the X coordinate value P x1 of the K block small end outer arc surface point.

[0032] The cross-section line equation relationship diagram is shown in Figure 4 , and the cross-section line equation is a straight line equation formed by rotating and then offsetting the radial line.

[0033] The straight line equation of the radial line through the center of the circle is y=tanθx, wherein θ=(π-A) / 2.

[0034] Rotate the above radial line by an angle α along its intersection point (x1, y1) with the outer arc surface to obtain

[0035]

[0036] After sorting, it is: y=tan(θ+α)x+y1-tan(θ+α)x1.

[0037] In the above formula, let m=tan(θ+α), c=y1-tan(θ+α)x1,

[0038] Then the equation is simplified as y=mx+c.

[0039] Then offset o, so c' = o*cos -1 (θ + β).

[0040] Let h = c + c', then y = mx + h is the equation of the rotated and offset straight line.

[0041] With the segment ring equation, the formula is expanded to get

[0042]

[0043] The known parameter values are brought in, and the X coordinate value P of the small end outer arc surface point of the K block can be calculated. x1 .

[0044] Step 3.2: Calculate the X coordinate value P of the inner arc surface point of the K block assembly position. x2 .

[0045] Through similar calculation process can get,

[0046]

[0047] Where o' is the offset value corresponding to the K block longitudinal lap value l.

[0048] Take zero lap (0, -o) and full-width lap (B, o) as boundary conditions to find the linear relationship equation of lap amount and offset value.

[0049] The boundary conditions are brought in Get

[0050] The calculation gets y = (2o / B)x - o.

[0051] The K block longitudinal lap value l is brought into the above formula, and the corresponding offset value o' = (2o / B)l - o can be obtained.

[0052] The known parameter values are brought in, and the X coordinate value P of the small end outer arc surface point of the K block can be calculated. x2 .

[0053] Step 3.3: Finally calculate the assembly gap δ = P x1 -P x2 .

[0054] Figure 5 The K block plane diagram, in which P1 is the small end outer arc surface point of the K block, and P2 is the inner arc surface point of the K block assembly position.

[0055] Step 4: Determine whether the assembly gap of the K block meets the construction requirements of the segment ring. If it does not meet the construction requirements, adjust the preset parameters of the K block, repeat step 3, until the assembly gap of the K block that meets the construction requirements is calculated.

[0056] The construction requirement of the assembling gap of the K block is determined according to the actual situation of the project, and is determined according to multiple conditions such as geological conditions, structure buried depth and pipe piece inner diameter through structure calculation. When the calculated assembling gap of the K block does not meet the construction requirement of the pipe piece ring, one or more preset parameters of the K block are selected for adjustment.

[0057] Taking the shield pipe piece parameters in the following table as an example, the gap of the K block assembling is calculated according to the above method content.

[0058] Table 1 Shield pipe piece parameters

[0059] Item Value Inner diameter of pipe segment 2750mm Thickness of pipe segment 350mm Width of pipe segment 1200mm Number of pipe segment blocks 6 Radial angle of K-block 21.5° Offset value 85mm Rotation angle 2.75° Longitudinal overlap value of K-block 650mm

[0060] Calculate the X coordinate value P of the small end outer arc surface point of the K block x1 .

[0061] θ=(180-21.5°) / 2=79.25°, α=2.75°;

[0062] θ+α=79.25°+2.75°=82°;

[0063] m=tan(θ+α)=tan82°=7.1154;

[0064] y1=r×sinθ=2701.7386, x1=r×cosθ=512.9411;

[0065] c=y1=-tan(θ+α)x1=2701.7386-7.1154*512.9411=-948.0270;

[0066] c′=o·cos -1 (θ+α)=85×7.1853=610.7502;

[0067] h=c+c′=-948.0270+610.7502=-337.2768;

[0068] y=mx+h=7.1154x-337.2768.

[0069]

[0070] Take the effective value in the first quadrant, and calculate P x1 =477.8682.

[0071] Calculate the X coordinate value P of the inner arc surface point of the K block assembling position x2 .

[0072] The linear relationship equation of the lap length and the offset value is solved with zero lap and full width lap as boundary conditions.

[0073] The boundary condition is brought in Get

[0074] y = 17x / 120-85.0. When the lap value is 650mm, the corresponding offset value is y = 17*650 / 120-85 = 7.0833. That is o' = 7.0833.

[0075] θ = (180-21.5°) / 2 = 79.25°, α = 2.75°;

[0076] θ + α = 79.25° + 2.75° = 82°;

[0077] m = tan(θ + α) = tan82° = 7.1154;

[0078] y1 = r × sinθ = 2701.7386, x1 = r × cosθ = 512.9411;

[0079] c = y1 = -tan(θ + α)x1 = 2701.7386-7.1154*512.9411 = -948.0270;

[0080] c' = o' · cos -1 (θ + α) = 7.0833 × 7.1853 = 50.8956;

[0081] h = c + c' = -948.0270 + 50.8956 = -897.1314;

[0082] y = mx + h = 7.1154x-897.1314.

[0083]

[0084] Take the effective value in the first quadrant, and calculate P x2 = 505.9707.

[0085] The assembly gap δ of the K block is P x1 -P x2 = 28.1025mm.

[0086] The assembly gap of the K block that meets the construction requirements of the pipe piece ring is 20mm-30mm, so the preset parameters of the K block meet the construction requirements.

[0087] The application is described in detail above by way of examples, but the content described is only exemplary embodiments of the application and cannot be considered to limit the implementation scope of the application. The protection scope of the application is defined by the claims. Any similar technical solutions that utilize the technical solutions described in the application or are inspired by the technical solutions of the application within the spirit and protection scope of the application, and achieve the above technical effects, or equivalent changes and improvements to the application scope, should still belong to the patent protection scope of the application.

Claims

1. A method for rapid design of a shield segment K-block, characterized in that: The method comprises the following steps: Step 1: A Cartesian coordinate system is established with the segment ring center as the origin, the Z-axis direction of the Cartesian coordinate system is the axial direction of the segment ring, and the positive direction of the Y-axis is perpendicular to the K block; Step 2: The preset parameters of the K block are obtained, and the preset parameters comprise a segment inner diameter, a segment thickness, a segment width, a K block radial angle, an offset value, a rotation angle and a K block longitudinal lap value; Step 3: The preset parameters of the K block are brought into the Cartesian coordinate system, the X coordinate value of a K block small-end outer arc surface point and the X coordinate value of a K block assembling position inner arc surface point corresponding to the K block small-end outer arc surface point are calculated, and then the K block assembling gap is calculated; Step 4: Whether the K block assembling gap meets the construction requirements of the segment ring is judged, if the K block assembling gap does not meet the construction requirements, the preset parameters of the K block are adjusted, and step 3 is repeated until the K block assembling gap meeting the construction requirements is calculated; In step 3, according to the formula ； calculated , Wherein, x, y indicate the coordinates (x, y) of any point P on the pipe piece ring, r is the inner diameter of the pipe piece, d is the thickness of the pipe piece, and o is an offset value, is a rotation angle, , A is a K block radial angle, is the X coordinate value of the outer arc surface point of the small end of the K block; According to the formula ； calculated , wherein, is the offset value corresponding to the K-block longitudinal lap value l, is the X coordinate value of the inner arc surface point in the K-block assembly position; Finally, the assembling gap of K blocks is calculated ; The zero lap (0, -o) and the full-width lap (B, o) are taken as boundary conditions, a linear relationship equation of the lap amount and the offset value is solved, the offset value o' corresponding to the K block longitudinal lap value l is calculated, and B is the segment width.

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