A planning method for a double-layer framed pier of a skew railway line

Abstract

The present invention discloses a planning method for a double-layer frame pier of a railway skew line, comprising the following steps: determining the loads of the upper and lower box girders; determining the positions where the loads of the upper and lower box girders act; determining the resultant force action points of the upper and lower railway box girders; determining the center line position of the cross beam of the double-layer frame pier; determining the minimum width of the cross beam of the frame pier; and completing the design of the skew line. The planning method for the double-layer frame pier of the railway skew line proposed by the present invention can make the out-of-plane actions of the upper and lower skew railways on the double-layer frame pier basically symmetric, reducing the torsional force of the structure. The planning method for the double-layer frame pier of the railway skew line proposed by the present invention can reduce the cross beam width of the double-layer frame pier of the skew railway or avoid setting tooth blocks, facilitating construction and saving investment.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge structure construction, and particularly relates to a planning method for a double-layer frame pier of a railway skew line. Background Art

[0002] In the construction of railway bridges, in some areas, due to the intricate existing and newly planned road pipelines, the double-layer frame pier scheme of railways is increasingly used. When arranging railway frame piers, the method of making the center line of the railway line perpendicular to the center line of the cross beam is often adopted. However, when the upper and lower railway lines are skew, the arrangement of the frame pier becomes a difficult problem. If the method of making the center line of the cross beam perpendicular to one railway line is still adopted, it is easy to cause the cross beam to be too wide or additional tooth blocks to be added; and there is a large eccentricity of the resultant force of the upper and lower railway lines on the cross beam of the frame pier, resulting in torsional stress on the frame pier out of the plane, causing construction difficulties and increased project costs. Summary of the Invention

[0003] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a planning method for a double-layer frame pier of a railway skew line.

[0004] The technical solution of the present invention is: a planning method for a double-layer frame pier of a railway skew line, characterized by comprising the following steps:

[0005] A. Determine the loads of the upper-layer box girder and the lower-layer box girder;

[0006] B. Determine the acting positions of the loads of the upper-layer box girder and the lower-layer box girder;

[0007] C. Determine the resultant force acting points of the upper and lower railway box girders;

[0008] D. Determine the position of the center line of the cross beam of the double-layer frame pier;

[0009] E. Determine the minimum width of the cross beam of the frame pier;

[0010] F. Complete the design of the skew line.

[0011] Furthermore, in step A for determining the loads of the upper-layer box girder and the lower-layer box girder, the specific process is as follows:

[0012] First, determine the self-weights of the upper-layer box girder and the lower-layer box girder;

[0013] Then, determine the secondary dead loads on the upper-layer box girder and the lower-layer box girder;

[0014] Finally, determine the live loads of the trains.

[0015] Furthermore, in step B for determining the acting positions of the loads of the upper-layer box girder and the lower-layer box girder, the specific process is as follows:

[0016] First, the load is transferred to the cross beam of the frame pier through the bearing padstone.

[0017] Then, determine the acting position of the load according to the layout diagram of the railway line.

[0018] The layout diagram of the railway line is carried out first. When designing the frame pier, the positions of the railway line and the box girder have been determined.

[0019] Furthermore, step C determines the resultant force acting points of the upper and lower layer railway box girders. The specific process is as follows:

[0020] First, determine the resultant force acting point of the upper layer box girder;

[0021] Then, determine the resultant force acting point of the lower layer box girder;

[0022] Finally, obtain the resultant force acting points of the upper and lower layer box girders based on the resultant force acting point of the upper layer box girder and the resultant force acting point of the lower layer box girder.

[0023] Furthermore, step D determines the center line position of the double - layer frame pier cross beam. The specific process is as follows:

[0024] First, obtain the included angle between the upper and lower layer lines based on the upper layer line and the lower layer line;

[0025] Then, make the angular bisector of the included angle between the upper and lower layer lines to obtain the angular bisector of the included angle between the upper and lower layer lines;

[0026] Next, draw a perpendicular line from the resultant force acting points of the upper and lower layer box girders to the angular bisector of the included angle between the upper and lower layer lines, and save the obtained line segment;

[0027] Finally, this saved line segment is the center line of the cross beam.

[0028] Furthermore, step E determines the minimum width of the frame pier cross beam. The specific process is as follows:

[0029] First, determine the position of the upper layer bearing padstone according to the layout diagram of the upper layer box girder;

[0030] Then, determine the position of the lower layer bearing padstone according to the layout diagram of the lower layer box girder;

[0031] Finally, obtain the minimum width of the cross beam based on the upper layer bearing padstone and the lower layer bearing padstone.

[0032] Furthermore, the specific process of obtaining the minimum width of the cross beam is as follows:

[0033] First, obtain the minimum distances from the upper layer bearing padstone and the lower layer bearing padstone to the edge of the cross beam according to the design requirements;

[0034] Then, obtain the width of the padstone between the upper layer bearing padstones, and accumulate the double of the minimum distance and the width of the padstone to obtain the minimum width of the upper layer cross beam;

[0035] Finally, the width of the bearing pad between the lower bearing pads is obtained, and the minimum width of the lower cross beam is obtained by adding the double of the minimum distance and the width of the bearing pad.

[0036] The beneficial effects of the present invention are as follows:

[0037] The present invention provides a planning method for a double-layer frame pier of a railway skew line, which can make the out-of-plane actions of the upper and lower skew railways on the double-layer frame pier basically symmetrical, and reduce the torsional force of the structure.

[0038] The planning method for a double-layer frame pier of a railway skew line provided by the present invention can reduce the width of the cross beam of the double-layer frame pier of the skew railway, or avoid setting tooth blocks, which facilitates construction and saves investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the front view of the double-layer frame pier involved in the present invention;

[0040] Figure 2 is the side view of the double-layer frame pier involved in the present invention;

[0041] Figure 3 is the schematic diagram of the design scheme of the present invention;

[0042] Figure 4 is the plan view of the upper cross beam of the double-layer frame pier in the present invention;

[0043] Figure 5 is the plan view of the lower cross beam of the double-layer frame pier in the present invention;

[0044] Wherein:

[0045] 1 upper cross beam 2 lower cross beam

[0046] 3 pier column 4 upper box girder

[0047] 5 lower box girder 6 upper bearing pad

[0048] 7 lower bearing pad 8 cross beam center line

[0049] 9 upper box girder joint center line 10 lower box girder joint center line

[0050] 11 upper railway line center line 12 upper box girder resultant force action point

[0051] 13 lower railway line center line 14 lower box girder resultant force action point

[0052] 15 resultant force action points of the upper and lower box girders 16 included angle between the upper and lower lines

[0053] 17 Angle bisector of the upper and lower layer lines 18 Angle between the upper layer line and the cross beam

[0054] 19 Angle between the lower layer line and the cross beam. Specific implementation manner

[0055] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and embodiments:

[0056] As Figures 1 to 5 shown, a planning method for a double-layer frame pier of a railway skew line is characterized in that it includes the following steps:

[0057] A. Determine the loads of the upper and lower box girders;

[0058] B. Determine the load acting positions of the upper and lower box girders;

[0059] C. Determine the resultant force acting points of the upper and lower railway box girders;

[0060] D. Determine the center line position of the cross beam of the double-layer frame pier;

[0061] E. Determine the minimum width of the cross beam of the frame pier;

[0062] F. Complete the design of the skew line.

[0063] Step A determines the loads of the upper and lower box girders, and the specific process is as follows:

[0064] First, determine the self-weights of the upper and lower box girders;

[0065] Then, determine the secondary permanent loads on the upper and lower box girders;

[0066] Finally, determine the live loads of the trains.

[0067] Step B determines the load acting positions of the upper and lower box girders, and the specific process is as follows:

[0068] First, the loads are transmitted to the cross beam of the frame pier through the bearing pads;

[0069] Then, determine the acting positions of the loads according to the layout diagram of the railway line.

[0070] The layout diagram of the railway line is carried out first, and the positions of the railway line and the box girder have been determined during the design of the frame pier.

[0071] Step C determines the resultant force acting points of the upper and lower railway box girders, and the specific process is as follows:

[0072] First, determine the resultant force acting point of the upper box girder;

[0073] Then, determine the resultant force acting point of the lower box girder;

[0074] Finally, the resultant force action points 15 of the upper and lower box girders are obtained based on the resultant force action point of the upper box girder and the resultant force action point of the lower box girder.

[0075] Step D determines the center line position of the cross beam of the double-layer frame pier, and the specific process is as follows:

[0076] First, the included angle between the upper and lower lines is obtained based on the upper line and the lower line.

[0077] Then, the angular bisector of the included angle 16 between the upper and lower lines is made to obtain the angular bisector 17 of the included angle between the upper and lower lines.

[0078] Next, a perpendicular line to the angular bisector 17 of the included angle between the upper and lower lines is drawn through the resultant force action point 15 of the upper and lower box girders, and the obtained line segment is saved.

[0079] Finally, the saved line segment is the center line 8 of the cross beam.

[0080] Step E determines the minimum width of the cross beam of the frame pier, and the specific process is as follows:

[0081] First, according to the layout drawing of the upper box girder, the position of the upper bearing pad stone 6 is determined.

[0082] Then, according to the layout drawing of the lower box girder, the position of the lower bearing pad stone 7 is determined.

[0083] Finally, the minimum width of the cross beam is obtained based on the upper bearing pad stone 6 and the lower bearing pad stone 7.

[0084] The specific process of obtaining the minimum width of the cross beam is as follows:

[0085] First, the minimum distances from the upper bearing pad stone 6 and the lower bearing pad stone 7 to the edge of the cross beam are obtained according to the design requirements.

[0086] Then, the width of the pad stone between the upper bearing pad stones 6 is obtained, and the sum of twice the minimum distance and the width of the pad stone gives the minimum width of the upper cross beam.

[0087] Finally, the width of the pad stone between the lower bearing pad stones 7 is obtained, and the sum of twice the minimum distance and the width of the pad stone gives the minimum width of the lower cross beam.

[0088] Specifically, to determine the resultant force action point of the upper box girder, the specific process is as follows:

[0089] For the box girders erected on the same frame pier, the second-stage and live load forms are generally the same, but the spans of the box girders on the large and small mileage sides may be different, such as a 32m simply supported beam erected on one side and a 24m simply supported beam erected on the other side, etc.

[0090] When the spans of the large- and small-mileage side box girders erected on the upper-layer railway frame pier are the same, it can be considered that the intersection point of the center line 9 of the upper-layer box girder joint and the center line 11 of the upper-layer railway line is the resultant force action point 12 of the upper-layer box girder.

[0091] Specifically, to determine the resultant force action point of the lower-layer box girder, the specific process is as follows:

[0092] The confirmation method of the resultant force action point 14 of the lower-layer box girder is the same as that of the resultant force action point 12 of the upper-layer box girder above.

[0093] Specifically, to determine the resultant force action point 15 of the upper- and lower-layer box girders, the specific process is as follows:

[0094] In this process, not only may the spans of the upper- and lower-layer railway box girders be different, but also the secondary loads and live load forms may be different. The resultant force action point 15 of the upper- and lower-layer box girders can be determined according to the following formula:

[0095] D1 = F2 / (F1 + F2) × D

[0096] D2 = F1 / (F1 + F2) × D

[0097] D = D1 + D2

[0098] Among them, D is the longitudinal distance between the resultant force action point 12 of the upper-layer box girder and the resultant force action point 14 of the lower-layer box girder;

[0099] D1 is the distance from the resultant force action point 12 of the upper-layer box girder to the resultant force action point 15 of the upper- and lower-layer railway box girders;

[0100] D2 is the distance from the resultant force action point 14 of the lower-layer box girder to the resultant force action point 15 of the upper- and lower-layer railway box girders;

[0101] F1 is the vertical resultant force of the upper-layer box girder;

[0102] F2 is the vertical resultant force of the lower-layer box girder.

[0103] Specifically, the minimum distance is obtained from the "Code for Design of Railway Bridges and Culverts" (TB10002 - 2017).

[0104] Another embodiment

[0105] A planning method for a double-layer frame pier of a railway skew line, characterized by comprising the following steps:

[0106] A. Determine the loads of the upper-layer box girder and the lower-layer box girder;

[0107] B. Determine the load action positions of the upper-layer box girder and the lower-layer box girder;

[0108] C. Determine the resultant force action points of the upper- and lower-layer railway box girders;

[0109] D. Determine the center line position of the cross beam of the double - layer frame pier;

[0110] E. Determine the minimum width of the cross beam of the frame pier;

[0111] F. Complete the design of the skew line.

[0112] Step A determines the loads of the upper - layer box girder and the lower - layer box girder, and the specific process is as follows:

[0113] First, determine the self - weight of the upper - layer box girder and the lower - layer box girder;

[0114] Then, determine the secondary permanent load on the upper - layer box girder and the lower - layer box girder;

[0115] Finally, determine the live load of the train.

[0116] Step B determines the load acting positions of the upper - layer box girder and the lower - layer box girder, and the specific process is as follows:

[0117] First, the load is transmitted to the cross beam of the frame pier through the bearing padstone;

[0118] Then, determine the acting position of the load according to the layout plan of the railway line.

[0119] The layout plan of the railway line is carried out first. When designing the frame pier, the positions of the railway line and the box girder have been determined.

[0120] Step C determines the resultant force action point of the upper - and lower - layer railway box girders, and the specific process is as follows:

[0121] First, determine the resultant force action point of the upper - layer box girder;

[0122] Then, determine the resultant force action point of the lower - layer box girder;

[0123] Finally, obtain the resultant force action point of the upper - and lower - layer box girders 15 according to the resultant force action point of the upper - layer box girder and the resultant force action point of the lower - layer box girder.

[0124] Step D determines the center line position of the cross beam of the double - layer frame pier, and the specific process is as follows:

[0125] First, obtain the included angle between the upper - layer line and the lower - layer line according to the upper - layer line and the lower - layer line;

[0126] Then, make the angular bisector of the included angle 16 between the upper - layer line and the lower - layer line to obtain the angular bisector 17 of the included angle between the upper - layer line and the lower - layer line;

[0127] Next, draw a perpendicular line from the resultant force action point 15 of the upper - and lower - layer box girders to the angular bisector 17 of the included angle between the upper - layer line and the lower - layer line, and save the obtained line segment;

[0128] Finally, this saved line segment is the center line 8 of the cross beam.

[0129] Step E determines the minimum width of the cross beam of the frame pier, and the specific process is as follows:

[0130] First, according to the layout drawing of the upper box girder, determine the position of the upper bearing pad stone 6;

[0131] Then, according to the layout drawing of the lower box girder, determine the position of the lower bearing pad stone 7;

[0132] Finally, obtain the minimum width of the cross beam based on the upper bearing pad stone 6 and the lower bearing pad stone 7.

[0133] The specific process of obtaining the minimum width of the cross beam is as follows:

[0134] First, obtain the minimum distances from the upper bearing pad stone 6 and the lower bearing pad stone 7 to the edge of the cross beam according to the design requirements;

[0135] Then, obtain the width of the pad stone between the upper bearing pad stones 6, and the sum of twice the minimum distance and the width of the pad stone gives the minimum width of the upper cross beam;

[0136] Finally, obtain the width of the pad stone between the lower bearing pad stones 7, and the sum of twice the minimum distance and the width of the pad stone gives the minimum width of the lower cross beam.

[0137] Specifically, determine the resultant force action point of the upper box girder, and the specific process is as follows:

[0138] For the box girders erected on the same frame pier, the second-stage and live load forms are generally the same, but the spans of the box girders on the large and small mileage sides may be different. For example, a 32m simply supported beam is erected on one side and a 24m simply supported beam is erected on the other side, etc.

[0139] If the spans of the box girders on the large and small mileage sides of the upper railway frame pier are inconsistent, then the resultant force action point 12 of the upper box girder is located on the center line 11 of the upper railway line, but is biased towards the side of the box girder with a larger span, and is calculated according to the following formula:

[0140] d1 = f2 / (f1 + f2) × d

[0141] d2 = f1 / (f1 + f2) × d

[0142] d = d1 + d2

[0143] Where, d is the longitudinal distance between the centers of the bearings of the box girders on the large and small mileage sides of the upper railway;

[0144] d1 is the distance from the center of the bearing of the box girder on the small mileage side to the resultant force action point 12 of the upper box girder;

[0145] d2 is the distance from the center of the bearing of the box girder on the large mileage side to the resultant force action point 12 of the upper box girder;

[0146] f1 is the vertical load exerted by the box girder on the small mileage side on the frame pier;

[0147] $f_2$ is the vertical load exerted by the long - mileage box girder on the frame pier.

[0148] Specifically, to determine the resultant force action point of the lower - layer box girder, the specific process is as follows:

[0149] The confirmation method of the resultant force action point 14 of the lower - layer box girder is the same as that of the resultant force action point 12 of the upper - layer box girder mentioned above.

[0150] Specifically, to determine the resultant force action point 15 of the upper and lower - layer box girders, the specific process is as follows:

[0151] In this process, not only may the spans of the upper and lower - layer box girders of the railway be different, but also the secondary loads and live - load forms may be different. The resultant force action point 15 of the upper and lower - layer box girders can be determined according to the following formula:

[0152] $D_1=\frac{F_2}{F_1 + F_2}\times D$

[0153] $D_2=\frac{F_1}{F_1 + F_2}\times D$

[0154] $D = D_1+D_2$

[0155] Where, $D$ is the longitudinal distance along the bridge between the resultant force action point 12 of the upper - layer box girder and the resultant force action point 14 of the lower - layer box girder;

[0156] $D_1$ is the distance from the resultant force action point 12 of the upper - layer box girder to the resultant force action point 15 of the upper and lower - layer railway box girders;

[0157] $D_2$ is the distance from the resultant force action point 14 of the lower - layer box girder to the resultant force action point 15 of the upper and lower - layer railway box girders;

[0158] $F_1$ is the vertical resultant force of the upper - layer box girder;

[0159] $F_2$ is the vertical resultant force of the lower - layer box girder.

[0160] Specifically, the minimum distance from the bearing padstone to the edge of the cross - beam is obtained from the "Code for Design of Railway Bridges and Culverts" (TB10002 - 2017).

[0161] Specifically, the double - layer frame pier includes an upper - layer cross - beam 1, a lower - layer cross - beam 2, and a pier column 3. The upper - layer box girder 4 and the lower - layer box girder 5 are respectively placed through the upper - layer bearing padstone 6 and the lower - layer bearing padstone 7.

[0162] The center lines of the upper - layer cross - beam 1 and the lower - layer cross - beam 2 are the cross - beam center line 8.

[0163] The beam gaps between the upper - layer box girder 4 and the lower - layer box girder 5 are respectively the center line 9 of the upper - layer box - girder beam gap and the center line 10 of the lower - layer box - girder beam gap.

[0164] According to the layout scheme of the double-layer frame pier for the skew line made by this method, the included angle 18 between the upper line and the cross beam in the upper layer line is (90 + θ / 2)°, and the included angle 19 between the lower line and the cross beam in the lower layer line is (90 - θ / 2)°. The skew angle is reduced, which can reduce the width of the cross beam or avoid setting the tooth block.

[0165] The out-of-plane bending moment caused by the vertical resultant force F1 of the upper box girder on the frame pier is basically symmetrical with the out-of-plane bending moment caused by the vertical resultant force F2 of the lower box girder on the frame pier, reducing the torsional force on the structure.

[0166] The present invention proposes a planning method for the double-layer frame pier of the railway skew line, which can make the out-of-plane actions of the upper and lower skew railways on the double-layer frame pier basically symmetrical, reducing the torsional force on the structure.

[0167] The planning method for the double-layer frame pier of the railway skew line proposed by the present invention can reduce the width of the cross beam of the double-layer frame pier of the skew railway or avoid setting the tooth block, facilitating the construction and saving the investment.

Claims

1. A planning method for a double-layer frame pier of a skew railway line, characterized in that: It includes the following steps: (A)Determine the loads of the upper box girder and the lower box girder; (B)Determine the acting positions of the loads of the upper box girder and the lower box girder; (C)Determine the resultant force acting point of the upper and lower railway box girders; (D)Determine the center line position of the cross beam of the double-layer frame pier; (E)Determine the minimum width of the cross beam of the frame pier; (F)Complete the design of the skewed line; Step (C) determines the resultant force acting point of the upper and lower railway box girders. The specific process is as follows: First, determine the resultant force acting point of the upper box girder; Then, determine the resultant force acting point of the lower box girder; Finally, obtain the resultant force acting point (15) of the upper and lower box girders based on the resultant force acting point of the upper box girder and the resultant force acting point of the lower box girder; Step (D) determines the center line position of the cross beam of the double-layer frame pier. The specific process is as follows: First, obtain the included angle between the upper and lower lines according to the upper line and the lower line; Then, make the angular bisector of the included angle (16) between the upper and lower lines to obtain the angular bisector (17) of the included angle between the upper and lower lines; Next, draw a perpendicular line from the resultant force acting point (15) of the upper and lower box girders to the angular bisector (17) of the included angle between the upper and lower lines, and save the obtained line segment; Finally, this saved line segment is the center line (8) of the cross beam.

2. The planning method of a double-layer frame pier for a skew railway line according to claim 1, characterized in that: Step (A) determines the loads of the upper box girder and the lower box girder. The specific process is as follows: First, determine the self-weights of the upper box girder and the lower box girder; Then, determine the secondary dead loads on the upper box girder and the lower box girder; Finally, determine the live load of the train.

3. The planning method of a double-layer frame pier for a skew railway line according to claim 1, characterized in that: Step (B) determines the acting positions of the loads of the upper box girder and the lower box girder. The specific process is as follows: First, the load is transmitted to the cross beam of the frame pier through the bearing pad stone; Then, determine the acting position of the load according to the layout drawing of the railway line.

4. A planning method for a double-layer frame pier of a skew railway line according to claim 3, characterized in that: The layout drawing of the railway line is carried out first. When designing the frame pier, the positions of the railway line and the box girder have been determined.

5. A planning method for a double-layer frame pier of a skew railway line according to claim 1, characterized in that: Step (E) determines the minimum width of the cross beam of the frame pier. The specific process is as follows: First, determine the position of the upper bearing pad stone (6) according to the layout drawing of the upper box girder; Then, determine the position of the lower bearing pad stone (7) according to the layout drawing of the lower box girder; Finally, obtain the minimum width of the cross beam based on the upper bearing pad stone (6) and the lower bearing pad stone (7).

6. The planning method of a double-layer frame pier for a skew railway line according to claim 5, characterized in that: The specific process of obtaining the minimum width of the cross beam is as follows: First, obtain the minimum distance from the upper bearing pad stone (6) and the lower bearing pad stone (7) to the edge of the cross beam according to the design requirements; Then, obtain the width of the pad stone between the upper bearing pad stones (6). The sum of twice the minimum distance and the width of the pad stone gives the minimum width of the upper cross beam; Finally, obtain the width of the pad stone between the lower bearing pad stones (7). The sum of twice the minimum distance and the width of the pad stone gives the minimum width of the lower cross beam.

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