Method for steel box girder web plane simple approximate lofting and material preparation of steel structure bridge

Abstract

The present application relates to steel structure bridge, especially a kind of steel structure bridge steel box girder web plane simple approximate lofting method of material drawing. Including the following steps: S1, draw the web center line of left steel box girder and right steel box girder;S2, the material drawing web is divided into multiple web units;S3, web unit length determination;S4, according to the vertical curve parameters provided by original design, longitudinal slope and steel box girder pre-camber;S5, copy steel box girder vertical curve "curve SQ", establish coordinate system;S6, determine web geometry by vertical curve "curve S1Q1";S7, determine web unit hypotenuse length;S8, determine the maximum length of web unit;S9, determine the maximum width of a certain web unit;S10, determine the width and length of web unit material drawing steel plate.The present application is short in time, more than twice the efficiency of three-dimensional modeling again unfolding web, meet the accuracy requirement, cost is in the controllable, acceptable range, can significantly shorten the manufacturing cycle of steel structure bridge.

Description

Technical Field

[0001] This invention relates to steel structure bridges, and in particular to a method for simple approximate layout and material lifting of the web plate of a steel box girder in a steel structure bridge. Background Technology

[0002] Steel structure bridges mainly consist of a top slab, web, bottom slab, diaphragms, transverse and longitudinal stiffeners, and transverse connecting beams. Among these, the web layout and material selection for determining steel plate specifications is the most complex, as it requires consideration of factors such as the bridge's transverse and longitudinal slopes, horizontal and vertical curves, and the pre-camber. After considering these factors, a three-dimensional model of the steel box girder web, composed of several web units (irregular geometric shapes), is created. Each web unit is then unfolded and laid out to finally determine the width and length of the ordered steel plates. While this method provides high accuracy in creating the three-dimensional model, it is time-consuming. Summary of the Invention

[0003] The present invention aims to solve the above-mentioned technical problems, thereby providing a simple approximate layout and material lifting method for the web of steel box girder of steel structure bridge, which is time-saving and meets the ordering requirements.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows: A simplified approximate layout and material extraction method for the web of a steel box girder in a steel structure bridge includes the following steps: S1. Draw the center lines of the webs of the left and right steel box girders. Using the road centerline "curve ZX" as a reference in the plan view, and according to the cross-sectional dimensions of the steel box girder, offset to the left and right by a certain distance respectively to obtain the web centerlines of the left and right steel box girders; S2. Divide the lifting web into multiple web units. The webs of the multi-span continuous left and right steel box girders are divided into several web units by the radial line where the web splicing position is located during manufacturing. The webs of the steel box girder are all spliced ​​together from multiple web units. S3. Determination of web element length The web centerline length L1 of a certain web element of the left and right steel box girders is obtained by querying and measuring on the plan view; S4. Based on the vertical curve parameters, longitudinal slope and pre-camber of the steel box girder provided in the original design, the vertical curve "Curve SQ" of the steel box girder corresponding to the road design centerline is calculated and drawn. S5. Copy the vertical curve "Curve SQ" of the steel box girder, establish a coordinate system, rotate "Curve SQ" by 90° to obtain "Curve S1Q1", and align the left and right endpoints of "Curve S1Q1" with the left and right endpoints of the road design centerline "Curve ZX" respectively. S6. Determine the web geometry using the vertical curve "curve S1Q1". Based on the height values ​​of the webs of the left and right steel box girders, draw the equidistant curve "Curve S1Q1"; take the intersection of the road design centerline "Curve ZX" and the radial line where the web splicing position is located as the reference point, draw a vertical line downwards to obtain the intersection with "Curve S1Q1" and its equidistant curve, and then obtain the geometric figure composed of two curve segments and a vertical line segment of a certain web unit. S7. Determine the hypotenuse length of the web element. Rotate the geometric figure in step S6 so that the two endpoints of the equidistant curve segment are on the same horizontal line. At this time, the vertical segment of the geometric figure becomes an inclined oblique segment. Measure the horizontal distance of this oblique segment as L2. S8. Determine the maximum length of the web element. The length of the web centerline L1 plus the horizontal distance L2 of the oblique line segment is the maximum length of a certain web element. S9. Determine the maximum width of a web element. The maximum width of the geometry after rotation in step S7 is the maximum width of a certain web element. S10. Determine the width and length of the lifting steel plate for the web unit. According to the manufacturing process requirements, add △W in the maximum width direction and △L in the maximum length direction of the web unit. This gives the procurement dimensions of the steel plate corresponding to the web unit.

[0005] Compared with the prior art, the present invention, which adopts the above technical solution, has the following beneficial effects: It is less time-consuming, more than twice as efficient as 3D modeling and web unfolding, meets accuracy requirements, and keeps costs within a controllable and acceptable range, which can significantly shorten the manufacturing cycle of steel structure bridges. Attached Figure Description

[0006] Figure 1 This is a diagram showing the road design centerline and stationing according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the pre-camber of the steel box girder according to an embodiment of the present invention; Figure 3 This is a diagram showing the vertical curve parameters of the steel box girder according to an embodiment of the present invention; Figure 4 This is a design cross-sectional view of the steel box girder according to an embodiment of the present invention; Figure 5 This is an overall view of the web centerline of the steel box girder according to an embodiment of the present invention; Figure 6 This is a partial view of the web centerline of a steel box girder according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the web unit splicing of a steel box girder according to an embodiment of the present invention; Figure 8 A schematic diagram of the centerlines of the YFFB1-15 and YFFB2-15 segment elements of the web. Figure 9 A schematic diagram of the vertical curve "SQ" of the steel box girder; Figure 10 Create a schematic diagram of the coordinate system; Figure 11 This is a schematic diagram of "Curve S1Q1" and the road centerline "Curve ZX"; Figure 12 This is a schematic diagram of the web section height; Figure 13 This is a schematic diagram of the web geometry; Figure 14 A schematic diagram for extracting the geometry of the web plate; Figure 15 This is a schematic diagram showing the length of the hypotenuse of the web. Figure 16 This is a schematic diagram showing the maximum width of the web. Figure 17 for Figure 16 A magnified view of the midpoint Y; Figure 18 for Figure 16 A magnified view of the Y' point in the middle; Figure 19 Dimension diagram for ordering steel plates for material delivery.

[0007] In the diagram: left steel box girder 1; left outer web plate ZFFB1; left inner web plate ZFFB2; right steel box girder 2; right inner web plate YFFB1; right outer web plate YFFB2; top plate 3; bottom plate 4. Detailed Implementation

[0008] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0009] This embodiment is applied to a certain interchange project. The second section of ramp E (hereinafter referred to as E2 section) of the project is a three-span continuous steel box girder of (57+59+57)m, from chainage EK0+683.000 to EK0+856.000 (axis lines 16 to 19). The road design centerline is "curve ZX" (…). Figure 1 As shown), the pre-camber values ​​at mid-span of the three spans of the steel box girder are 111mm, 53mm, and 112mm, respectively. Figure 2 As shown). The original design vertical curve parameters were R=2000, T=43, E=0.462, the slope change point station number was EK0+845.045, the slope change elevation was 44.095, the front slope was 0.3%, and the back slope was -4%. Figure 3 (As shown). The center height of both the left steel box girder 1 and the right steel box girder 2 is 2450mm. Figure 4As shown), the web of the left steel box girder 1 consists of a left outer web ZFFB1 and a left inner web ZFFB2, and the web of the right steel box girder 2 consists of a right inner web YFFB1 and a right outer web YFFB2. The left outer web ZFFB1 of the left steel box girder 1 and the right inner web YFFB1 of the right steel box girder 2 are at the same height, and the left inner web ZFFB2 of the left steel box girder 1 and the right outer web YFFB2 of the right steel box girder 2 are at the same height. The web thickness of both the left steel box girder 1 and the right steel box girder 2 is 16mm. The thickness of the top plate 3 is 25mm in the non-thickened area and 50mm in the thickened area. The thickness of the bottom plate 4 is 20mm in the non-thickened area and 40mm in the thickened area. The center distance of the thickness of the left inner web plate ZFFB2 of the left steel box girder and the right inner web plate YFFB1 of the right steel box girder is 1158mm from the road design centerline. The center distance of the thickness of the left outer web plate ZFFB1 of the left steel box girder 1 and the right outer web plate YFFB2 of the right steel box girder 2 is 3642mm from the road design centerline. The cross slope of the steel box girder structure is i=4%.

[0010] The above-mentioned simplified approximate layout and material collection method for the web plane of steel box girder of steel structure bridge is carried out according to the following steps: S1. Draw the center lines of the webs of the left and right steel box girders. See Figure 5 , Figure 6 In the plan view, using the road centerline "curve ZX" as the reference, and according to the cross-sectional dimensions of the steel box girder, offset 3642mm to the left to obtain the centerline of the left outer web plate ZFFB1 of the left steel box girder 1. Using the road design centerline "curve ZX" as the reference line, offset 1158mm to the left to obtain the centerline of the left inner web plate ZFFB2 of the left steel box girder 1. Using the road design centerline "curve ZX" as the reference line, offset 1158mm to the right to obtain the centerline of the right inner web plate YFFB1 of the right steel box girder 2. Using the road design centerline "curve ZX" as the reference line, offset 3642mm to the right to obtain the centerline of the right outer web plate YFFB2 of the right steel box girder 2. S2. Divide the lifting web into multiple web units. Taking into account factors such as cost, transportation, manufacturing process, and installation plan, the left steel box girder 1 and right steel box girder 2 of the E2 series were each divided into 8 segments and transported to the project site. During manufacturing, the webs of the multi-span continuous left steel box girder 1 and right steel box girder 2 were divided into several web units along the radial line where the web splicing positions were located. In this embodiment, the left outer web ZFFB1, left inner web ZFFB2, right inner web YFFB1, and right outer web YFFB2 of both steel box girders are each composed of 16 web units. Specifically, the web of the right steel box girder 2 of segment 8 in the E2 series is composed of YFFB1-15 segment units spliced ​​with YFFB1-16 segment units, and YFFB2-15 segment units spliced ​​with YFFB2-16 segment units, respectively. This embodiment uses YFFB1-15 segment units and YFFB2-15 segment units as examples for illustration. Figure 7 (as shown) S3. Determination of web element length The centerline lengths of the YFFB1-15 and YFFB1-16 segments of the right steel box girder 2 were obtained by checking and measuring on the plan view. Figure 7 In the measurement, the length of the web segment YFFB1-15 is defined by curve MN, where M and N are the intersections of the radial lines KM and BL where the two webs are joined, and the right inner web YFFB1. The curve length between points M and N is 12066 mm. The length of the web segment YFFB2-15 is defined by curve KL, where K and L are the intersections of the radial lines KM and BL where the two webs are joined, and the right outer web YFFB2. The curve length between points K and L is 12208 mm. Measurement method ( Figure 8 (As shown): Cut "curve MN" and "curve KL" with straight lines AK and BL to obtain the centerline length L corresponding to the YFFB1-15 and YFFB2-15 web elements. 1-YFFB1-15、 L 1-YFFB2-15 The length of the centerline is the length of the web. Point A is the intersection of the road design centerline "curve ZX" and straight line KM, and straight line KM is the radial line where the web segment units YFFB1-15 and YFFB1-16, and YFFB2-15 and YFFB2-16 are spliced; Point B is the intersection of the road design centerline "curve ZX" and straight line BL, and straight line BL is the radial line where the web splicing position is located. S4. Based on the vertical curve parameters, longitudinal slope, and pre-camber of the steel box girder provided in the original design, the vertical curve "Curve SQ" of the steel box girder corresponding to the road design centerline was calculated and drawn. Figure 9 (as shown); S5. Copy the vertical curve "Curve SQ" of the steel box girder and establish a coordinate system. Figure 10As shown in the diagram, in this coordinate system, the vertical curve "Curve SQ" of the steel box girder is rotated by 90° to obtain "Curve S1Q1". On the plan view, the left endpoint Q1 of "Curve S1Q1" is aligned with the left endpoint X of the road design centerline "Curve ZX", and the right endpoint S1 is aligned with the right endpoint Z of the road design centerline "Curve ZX". Figure 11 (as shown); S6. Determine the web geometry using the vertical curve "curve S1Q1". Based on the height values ​​of the left steel box girder 1 and the right steel box girder web 2, draw the equidistant curve "Curve S1Q1"; take the intersection of the road design centerline "Curve ZX" and the radial line where the web splicing position is located as the reference point, draw a vertical line downward to obtain the intersection point with "Curve S1Q1" and its equidistant curve, and then obtain the geometric figure composed of the two curve segments and the vertical line segment of the web unit. Web plate segments YFFB1-15 and YFFB2-15 are located in the non-thickened area of ​​the steel box girder. In the cross-section, the top plate 3 has a thickness of 25mm, the bottom plate 4 has a thickness of 20mm, and the web plate has a thickness of 16mm. From the cross-section, the height of web plate segment YFFB1 is 2355mm, and the height of web plate segment YFFB2 is 2455mm. Figure 12 , Figure 13 (as shown); Will Figure 11 Copy the curve "S1Q1" down one line to get S. 11 Q 11 and obtain Figure 13 The curves "CG" and "EP" in the diagram; the left endpoint X of the road design centerline "Curve ZX", the left endpoint Q1 of "Curve CG", and the left endpoint Q of "Curve EP". 11 The points are on the same vertical line; Draw a perpendicular line downwards from point A, intersecting curve CG at point C, curve DH at point D, curve EP at point E, and curve FJ at point F; draw a perpendicular line downwards from point B, intersecting curve CG at point G, curve DH at point H, curve EP at point P, and curve FJ at point J. "Curve CG" and "Curve DH" are equidistant curves 2355mm apart, and "Curve EP" and "Curve FJ" are equidistant curves 2455mm apart. 2355mm and 2455mm represent the web height of web segment YFFB1-15 and web segment YFFB2-15, respectively. S7. Determine the hypotenuse length of the web element. Rotate the geometric figure in step S6 so that the two endpoints of the equidistant curve segments are on the same horizontal line. At this point, the perpendicular segment of the geometric figure becomes an inclined segment. Measure the horizontal distance of this inclined segment as L. 2； Figure 13 The geometric figures formed by midpoints C, D, H, and G (shaded areas) and points E, F, J, and P (shaded areas) respectively represent the YFFB1-15 segment element and the YFFB2-15 segment element of the web of the right-side steel box girder. Figure 14 As shown), rotate the geometric figure (shaded area) so that points D and H are on the horizontal line, and points F and J are on the horizontal line. Measure the horizontal distance L between points H and G on the hypotenuse segment HG. 2-YFFB1-15 The horizontal distance L between points J and P on the hypotenuse segment JP is 47mm. 2-YFFB2-15 49mm ( Figure 14 , Figure 15 (as shown) S8. Determine the maximum length of the web element. The length L of the web YFFB1-15 segment element in step S3 1-YFFB1-15 (12066mm) plus the length L of the hypotenuse segment HG of the web YFFB1-15 segment element in step S7. 2-YFFB1-15 (47mm), the maximum length of the web YFFB1-15 segment element is obtained as 12113mm; the length L of the web YFFB2-15 segment element in step S3 is... 1-YFFB2-15 (12208mm) plus the length L of the hypotenuse segment JP of the YFFB2-15 segment of the web plate in step S7. 2-YFFB2-15 (49mm), the maximum length of the YFFB2-15 segment unit of the web is 12257mm; S9. Determine the maximum width of a web element. Figure 15 In the middle, connect point D and point H of the web element YFFB1-15 to obtain the horizontal line segment DH, and take its midpoint Y. Draw a perpendicular line through point Y to intersect curve CG and point Y'. The length of the perpendicular line segment YY' is measured to be 2369mm, which is the maximum width of the web element YFFB1-15. Using the same method, the maximum width of the web element YFFB2-15 is obtained as 2469mm. Figure 16 , Figure 17 , Figure 18 (as shown) S10. Determine the width and length of the lifting steel plate for the web unit. According to the manufacturing process requirements, add △W in the maximum width direction and △L in the maximum length direction of the web unit. This gives the procurement dimensions of the steel plate corresponding to the web unit.

[0011] In this embodiment, the width and length of the steel plates ordered for other web plate units are carried out according to the steps described above.

[0012] The maximum length of the unfolded web element YFFB1-15, drawn using the 3D model, is 12109 mm, and the maximum length of the web element YFFB2-15 is 12253 mm. The maximum length deviation for this web element using this method is +4 mm, which is within the cost control range and fully meets the requirements. The maximum width of the unfolded web element YFFB1-15, drawn using the 3D model, is 2369 mm, and the maximum width of the web element YFFB2-15 is 2469 mm. The maximum width deviation for this web element using this method is ±0 mm.

[0013] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent structural changes made based on the description and drawings of the present invention are included within the scope of the present invention.

Claims

1. A method for simple approximate layout and material extraction of the web plate of a steel box girder in a steel structure bridge, comprising the following steps: S1. Draw the center lines of the webs of the left and right steel box girders. Using the road centerline "curve ZX" as a reference in the plan view, and according to the cross-sectional dimensions of the steel box girder, offset to the left and right by a certain distance respectively to obtain the web centerlines of the left and right steel box girders; S2. Divide the lifting web into multiple web units. The webs of the multi-span continuous left and right steel box girders are divided into several web units by the radial line where the web splicing position is located during manufacturing. The webs of the steel box girder are all spliced ​​together from multiple web units. S3. Determination of web element length The web centerline length L1 of a certain web element of the left and right steel box girders is obtained by querying and measuring on the plan view; S4. Based on the vertical curve parameters, longitudinal slope and pre-camber of the steel box girder provided in the original design, the vertical curve "Curve SQ" of the steel box girder corresponding to the road design centerline is calculated and drawn. S5. Copy the vertical curve "Curve SQ" of the steel box girder, establish a coordinate system, rotate "Curve SQ" by 90° to obtain "Curve S1Q1", and align the left and right endpoints of "Curve S1Q1" with the left and right endpoints of the road design centerline "Curve ZX" respectively. S6. Determine the web geometry using the vertical curve "curve S1Q1". Based on the height values ​​of the webs of the left and right steel box girders, draw the equidistant curve "Curve S1Q1"; take the intersection of the road design centerline "Curve ZX" and the radial line where the web splicing position is located as the reference point, draw a vertical line downwards to obtain the intersection with "Curve S1Q1" and its equidistant curve, and then obtain the geometric figure composed of two curve segments and a vertical line segment of a certain web unit. S7. Determine the hypotenuse length of the web element. Rotate the geometric figure in step S6 so that the two endpoints of the equidistant curve segment are on the same horizontal line. At this time, the vertical segment of the geometric figure becomes an inclined oblique segment. Measure the horizontal distance of this oblique segment as L2. S8. Determine the maximum length of the web element. The length of the web centerline L1 plus the horizontal distance L2 of the oblique line segment is the maximum length of a certain web element. S9. Determine the maximum width of a web element. The maximum width of the geometry after rotation in step S7 is the maximum width of a certain web element. S10. Determine the width and length of the lifting steel plate for the web unit. According to the manufacturing process requirements, add △W in the maximum width direction and △L in the maximum length direction of the web unit. This gives the procurement dimensions of the steel plate corresponding to the web unit.

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