A main cable of a suspension bridge with split-span high-precision marking strands

Abstract

The present invention relates to a main cable of a suspension bridge with a split-span high-precision marking strand, and belongs to the technical field of bridge cables. It comprises a plurality of full-length strand units and a plurality of segmented marking strand units, wherein the two ends of the full-length strand units are respectively anchored to two loose cable saddles, and the main body continuously passes through a plurality of main cable saddles; any of the segmented marking strand units comprises a plurality of marking strands: two sections of side span marking strands and a plurality of sections of mid-span marking strands, wherein the side span marking strands are arranged between the loose cable saddle and the main cable saddle adjacent to the loose cable saddle, and the mid-span marking strands are arranged between two adjacent main cable saddles; the ends of the marking strands are anchored to the loose cable saddle or the main cable saddle. The present application can eliminate the marking error caused by the accumulation of errors within the full-length strands, and improve the accuracy of the marking strands.

Description

Technical Field

[0001] The invention relates to a main cable of a suspension bridge with split-span high-precision marked strands, belonging to the technical field of bridge cables. Background Art

[0002] The main cable is the lifeline of the suspension bridge. The line shape control of the empty cable and the uniform tension of the anchor span have a decisive influence on the line shape of the completed bridge. Compared with the two-tower suspension bridge, the line shape of the main cable must not only meet the requirements of consistency between the upstream and downstream, but also meet the requirements of consistency between the two main spans, with higher precision requirements and greater construction difficulty.

[0003] The adjustment after the erection of the main cable PPWS is a key construction stage to control and ensure the linear shape of the main cable. my country adopts the method of erecting the main cable with prefabricated parallel steel wire strands, and two methods are applied on site at the same time: the marking method and the sag adjustment method. The sag control is divided into the control of the reference strand and the sag control of other strands. The monitoring attaches great importance to the reference strand and adopts the absolute value control. After the adjustment is in place, it is necessary to observe stably for a few days. During the erection of the main cable strand, the marking method is used during the day. The center marks of each saddle marked on the strand during factory manufacturing are used. During the erection, this mark is installed in correspondence with the midpoint of the saddle (with an offset); the sag adjustment method is used at night, that is, the sag of the erected strand is measured and adjusted by comparing it with the reference strand at night when the temperature is stable. The linear shape control of the main cable includes the linear shape control of the reference strand and the linear shape control of the general strand. Among them, the linear shape of the reference strand is the reference value, and the general strand is installed according to the relative height difference with the reference strand. Therefore, in the process of erecting the main cable of a large-span suspension bridge, the construction control of the reference strand is the key.

[0004] The verticality of the reference cable strand is mainly affected by the site span, tower deviation, tower height, construction temperature and other parameters. The absolute elevation method is generally used to adjust the verticality of the reference cable strand; the relative elevation method is generally used to adjust the verticality of the general cable strand. The verticality adjustment of the reference cable strand has relatively strict requirements on climatic conditions. First, it is carried out after the temperature is stable at night and the wind is small. The temperature stability requires that the temperature difference of the cable strand along the length direction is not more than 2°C, and the temperature difference in the cross-section direction of the main cable strand is not more than 1 degree. If the temperature is not stable, or the wind force is 12 m / s (level 6 wind), or there is rain and fog, it is necessary to wait until the conditions are ripe to adjust the reference cable strand. For marine environments or other conditions with harsh climatic conditions, the adjustment of the reference cable strand takes a long time and is difficult.

[0005] In order to solve the above problems, it is necessary to use the marking method to replace the traditional sag adjustment method to install the benchmark cables. However, this marking method for installing the benchmark cables requires the development of ultra-high precision marking cables (more than 1.5 times the length accuracy of the full-length cables) for the adjustment of the benchmark cables. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a main cable of a suspension bridge with a split-span high-precision marking strand in response to the above-mentioned prior art. The high-precision marking strand can eliminate the marking error caused by the accumulation of errors within the strands of the full-length strands (including the reference strands), thereby improving the accuracy of the marking strands.

[0007] The technical solution adopted by the present invention to solve the above-mentioned problem is: a main cable of a suspension bridge with a split-span high-precision marking cable strand, comprising a plurality of full-length cable strand units and a plurality of segmented marking cable strand units, wherein the two ends of the full-length cable strand units are respectively anchored to two loose cable saddles, and the main body continuously passes through the plurality of main cable saddles; any of the segmented marking cable strand units comprises a plurality of marking cable strands: two sections of side span marking cable strands and a plurality of sections of mid-span marking cable strands, wherein the side span marking cable strands are arranged between the loose cable saddle and the main cable saddle adjacent to the loose cable saddle, and the mid-span marking cable strands are arranged between two adjacent main cable saddles; and the ends of the marking cable strands are anchored to the loose cable saddle or the main cable saddle.

[0008] The marking cable strand comprises a plurality of standard wires, and a full-length marking coating is provided on one of the standard wires located at a corner of the cross section of the marking cable strand as the marking wire.

[0009] The number of the standard wires is no less than 19.

[0010] In the vertical direction of the main cable cross section, the segmented marker strand unit is located at the bottom of the full-length strand unit, and a plurality of the segmented marker strand units are respectively arranged at the lower left corner, lower right corner and bottom of the main cable cross section.

[0011] The side span marker strands and the mid span marker strands anchored on the same main saddle are staggered with each other.

[0012] The marking cable strand comprises a plurality of standard wires; the end of the marking cable strand is anchored to a loose cable saddle or a main cable saddle through a marking anchor; the marking anchor comprises an F-type upswept anchor, a steering pad is provided between the F-type upswept anchor and the main cable saddle or the loose cable saddle, and the steering pad is fixed to the side of the main cable saddle or the loose cable saddle; the F-type upswept anchor is provided with marking steel wire holes corresponding to the standard wires, the standard wires are sequentially passed through the corresponding marking steel wire holes, and the standard wires are headed so that the standard wires are anchored to the F-type upswept anchor; the F-type upswept anchor and the steering pad are provided with connecting holes respectively, screws are passed through the connecting holes, so that the F-type upswept anchor is fixedly connected to the steering pad.

[0013] The diameter of the marking wire hole is 1 to 1.1 times the diameter of the standard wire.

[0014] The cross-sectional shape of the marking strand located inside the F-shaped head anchor is either a rectangle or a rectangle with missing corners, and the cross-sectional shape of the marking strand located outside the F-shaped head anchor is a polygon.

[0015] Compared with the prior art, the advantages of the present invention are: a main cable of a suspension bridge with a high-precision split-span marking strand, when erected, the full-length strand is arranged on a plurality of segmented marking strand units, any segmented marking strand unit includes three or more segments of marking strands, the steel wires in each segment of marking strand are all high-precision standard wires, and the precision of the marking strand is improved; in addition, each segment of marking strand includes three marking points, wherein the intra-strand error of the starting marking point of each marking strand is zero, and due to segmented production and anchoring, the production length of each segment of marking strand will be shortened, therefore, except for the starting marking point, the accumulation of intra-strand errors at other marking point positions is also greatly reduced, thereby ensuring the precision of the entire marking strand. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a main cable of a suspension bridge with split-span high-precision marked strands according to an embodiment of the present invention;

[0017] Figure 2 for Figure 1 Schematic diagram of the cross section of the main cable;

[0018] Figure 3 The diagram is a schematic diagram of anchoring of the side span marker cable strand and the mid span marker cable strand;

[0019] Figure 4 for Figure 3 A magnified image of

[0020] Figure 5 for Figure 3 Side view of

[0021] Figure 6 for Figure 4 Schematic diagram of the F-type head anchor;

[0022] Figure 7 for Figure 4 Schematic diagram of the middle steering pad;

[0023] Figure 8 A schematic diagram of the cross section of the marked cable strands outside the main cable saddle or loose cable saddle;

[0024] Fig. 9 A schematic diagram of the cross section of the marked strands in the main cable saddle or loose cable saddle;

[0025] In the figure, 1 is the middle span marking strand, 2 is the main cable saddle, 3 is the side span marking strand, 4 is the loose cable saddle, 5 is the marking anchor, 5.1 is the F-type upsetting anchor, 5.2 is the steering pad, 5.3 is the screw rod, 5.4 is the marking wire hole, 6 is the full length cable strand unit, 7 is the standard wire, and 8 is the marking wire. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below with reference to the accompanying drawings.

[0027] like Figure 1 , 2 As shown, a main cable of a suspension bridge with a split-span high-precision marker strand in this embodiment includes a full-length strand unit 6, which runs through two loose cable saddles 4 and a plurality of main cable saddles 2. Segmented marker strand units are respectively provided at the lower left corner, the lower right corner and the middle of the bottom of the full-length strand unit 6. Any segmented marker strand unit includes several segments of marker strands: two segments of side span marker strands 3 and multiple segments of middle span marker strands 1. The side span marker strands 3 are provided between the loose cable saddle 4 and the adjacent main cable saddle 2, and the middle span marker strands 1 are provided between the two main cable saddles 2. Marking anchors 5 are respectively provided at both ends of any marker strand, and the marking anchors 5 are respectively provided on the outer sides of the main cable saddle 2 and the loose cable saddle 4. The marker strands are respectively anchored in the marking anchors 5 on the corresponding sides, and the side span marker strands 3 and the middle span marker strands 1 on the main cable saddle 2 are anchored alternately.

[0028] The marking cable strands include 19 (not less than 19) standard wires 7, each of which is made of steel wires with a diameter equal to the standard steel wire diameter and an elastic modulus equal to the standard elastic modulus, eliminating the errors caused by the deviation of the steel wire diameter and the elastic modulus, ensuring that the accuracy of the marking cable strands can basically reach the accuracy of the standard wires, and the manufacturing accuracy can reach more than 1 / 40000. In order to ensure that the marking cable strands are not twisted during the manufacturing process, a standard wire 7 in the upper right corner is sprayed with a red or blue obvious color coating throughout the length to form a marking coating, which serves as the marking wire 8.

[0029] The full-length cable strand unit 6 includes a plurality of full-length cable strands.

[0030] The cable strands above, to the left or to the right of the marked strands are all full-length strands. If the traditional anchoring method is used, the anchoring structure will interfere with the full-length strands. Therefore, segmented anchoring and eccentric anchoring are required.

[0031] like Figure 3 , 4 As shown in Figures 5, 6 and 7, the marking anchor 5 includes an F-type upset anchor 5.1, a steering pad 5.2 and a screw 5.3 for preventing eccentric overturning. A steering pad 5.2 is provided between the F-type upset anchor 5.1 and the main cable saddle 2 or the loose cable saddle 4. The steering pad 5.2 is welded to the side of the main cable saddle 2 or the loose cable saddle 4. A marking wire hole 5.4 corresponding to the standard wire 7 is provided at the upper end of the F-type upset anchor 5.1. The diameter of the marking wire hole 5.4 is 1 to 1.1d (d is the diameter of the standard wire). When anchoring the marking cable strands, the standard wires 7 need to be passed through the marking wire holes 5.4 one by one, and then the pier head is performed. The pier head diameter is not less than 1.4d, and the pier head height is not less than 1.0d. The anchoring of the standard wire is achieved by relying on the pier head. Connecting holes are respectively provided on the steering pad and the F-type upsetting anchor, and screws are passed through the connecting holes, which not only ensures that the F-type upsetting anchor is fixedly connected to the steering pad, but also the tension of the screws prevents the F-type upsetting anchor from tipping over after being eccentrically loaded.

[0032] like Figure 8 , 9 As shown, the cross-sectional shape of the marking cable strand outside the main cable saddle or the loose cable saddle is a regular hexagon. In order to keep consistent with the width of the full-length cable strand in the main cable saddle or the loose cable saddle, the marking cable strand is pre-deformed before entering the main cable saddle or the loose cable saddle, so that the cross-sectional shape of the marking cable strand inside the main cable saddle or the loose cable saddle is a rectangle or a rectangle with missing corners, and the width is basically consistent with the width of the full-length cable strand and the width of the saddle groove of the main cable saddle or the loose cable saddle. The preforming can be implemented in the factory or at the construction site.

[0033] As shown in the figure, the segmented marked strand unit consists of three segments of marked strands (for multi-tower suspension bridges, no less than three segments), including the side span marked strand on the left, the middle span marked strand and the side span marked strand on the right. Among them, the side span marked strand on the left includes three marks: anchor point, loose cable saddle point, and middle tower anchor point; the middle span marked strand includes three marking points: middle tower anchor point, main span center point, and middle tower anchor point; the right span marked strand includes three marking points: middle tower anchor point, loose cable saddle point, and anchor point. Due to the segmented production, the intra-strand error of the marked strands of one anchor point and two middle tower anchor points can be guaranteed to be zero. In addition, the accumulation of intra-strand errors of the marked strands of the marked points is also greatly reduced, thereby ensuring the accuracy of the marked strands.

[0034] Before installing the main cable strands, set up the marking strands in advance, measure, adjust and check each marking point. When the measurement results meet the requirements, use the marking strands as a reference to install other strands.

[0035] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. A main cable of a suspension bridge with split-span high-precision marked strands, characterized in that: It comprises a plurality of full-length cable strand units and a plurality of segmented marker cable strand units, wherein the two ends of the full-length cable strand units are respectively anchored to two loose cable saddles, and the main body continuously passes through a plurality of main cable saddles; any segmented marker cable strand unit comprises a plurality of segments of marker cable strands: two segments of side span marker cable strands and a plurality of segments of mid-span marker cable strands, wherein the side span marker cable strands are arranged between the loose cable saddle and the main cable saddle adjacent to the loose cable saddle, and the mid-span marker cable strands are arranged between two adjacent main cable saddles; and the ends of the marker cable strands are anchored to the loose cable saddle or the main cable saddle; The marking cable strand comprises a plurality of standard wires, and a full-length marking coating is provided on one of the standard wires located at a corner of the cross section of the marking cable strand, serving as the marking wire; In the vertical direction of the main cable cross section, the segmented marker strand unit is located at the bottom of the full-length strand unit, and a plurality of the segmented marker strand units are respectively arranged at the lower left corner, lower right corner and bottom of the main cable cross section.

2. A main cable of a suspension bridge with split-span high-precision marking strands according to claim 1, characterized in that: The number of the standard wires is no less than 19.

3. The main cable of a suspension bridge with split-span high-precision marking strands according to claim 1, characterized in that: The side span marker strands and the mid span marker strands anchored on the same main saddle are staggered with each other.

4. The main cable of a suspension bridge with split-span high-precision marking strands according to claim 1, characterized in that: The marking cable strand comprises a plurality of standard wires; the end of the marking cable strand is anchored to a loose cable saddle or a main cable saddle through a marking anchor; the marking anchor comprises an F-type upswept anchor, a steering pad is provided between the F-type upswept anchor and the main cable saddle or the loose cable saddle, and the steering pad is fixed to the side of the main cable saddle or the loose cable saddle; the F-type upswept anchor is provided with marking steel wire holes corresponding to the standard wires, the standard wires are sequentially passed through the corresponding marking steel wire holes, and the standard wires are headed so that the standard wires are anchored to the F-type upswept anchor; the F-type upswept anchor and the steering pad are provided with connecting holes respectively, screws are passed through the connecting holes, so that the F-type upswept anchor is fixedly connected to the steering pad.

5. A main cable of a suspension bridge with split-span high-precision marking strands according to claim 4, characterized in that: The diameter of the marking wire hole is 1 to 1.1 times the diameter of the standard wire.

6. A main cable of a suspension bridge with split-span high-precision marking strands according to claim 4, characterized in that: The cross-sectional shape of the marking cable strand located inside the F-shaped upsetting anchor is a rectangle or a rectangle with missing corners, and the cross-sectional shape of the marking cable strand located outside the F-shaped upsetting anchor is a polygon.

Images