Double-rocker-arm derrick field load test loading method for power transmission line tower assembly

Abstract

The invention discloses a field load test loading method of a double-rocker-arm derrick for tower assembly of a power transmission line, belongs to the field of tests of double-rocker-arm derricks for tower assembly, and aims to solve the problem of unbalanced bending moment overrun caused by different loading at two ends of a suspension arm. According to the unbalance loading bending moment design value of the main holding pole, the total balance weight for the test is grouped and divided into N levels of balance weights, a rocker arm lifts a first-level right balance weight block in a horizontal state, and then lifts a first-level left balance weight block; the rocker arm is vertically rotated to a second test angle, a second-stage right balancing weight is lifted, and then a second-stage left balancing weight is lifted; repeating the steps until the last stage of counterweight hoisting is completed; and the rocker arm is vertically rotated to the horizontal direction to perform a rotation test in the horizontal plane. According to the invention, the counterweight for test is divided into several graded counterweight blocks according to the bearing capacity of the holding pole, the load loaded each time is reduced in a graded loading mode along with graded loading of each stage of loading counterweight when the rocker arm is at different angles, the problem of unbalanced bending moment overrun is avoided, and the requirements of test loading and equipment testing are met.

Description

Technical Field

[0001] The invention relates to the technical field of double rocker arm bracket test for tower assembly, and in particular to a loading method for an on-site load test of a double rocker arm bracket for tower assembly of a transmission line. Background Art

[0002] The double rocker arm is one of the commonly used tools for assembling towers for power transmission lines. It has the characteristics of light weight, low power requirements, and easy installation. It is widely used in high-voltage iron tower assembly. According to the requirements of relevant national standards, the double rocker arm bracket needs to be tested for bearing capacity parameters before it is used in production. Because the cross-section of the equipment column is small, the unbalanced bending moment is mainly borne by the guy wire fixed at the root of the rocker arm and the waist ring of the body. In the test factory, by accurately controlling the rocker arm angle and the length of the lifting rope, it is basically possible to achieve simultaneous lifting of the counterweight load at both ends of the rocker arm. However, in the field, it is difficult to achieve simultaneous loading at both ends of the boom due to factors such as climatic conditions, the degree of slackness of the loading rope, and the control of the test loading speed. The loading of the ends of the two booms at different times often causes excessive unbalanced bending moments and equipment damage. Summary of the invention

[0003] The purpose of the present invention is to provide a method for loading a double rocker arm on-site load test for a transmission line tower assembly, so as to solve the problem of excessive unbalanced bending moment caused by loading at both ends of the boom at different times.

[0004] The technical solution adopted by the present invention is: a method for loading a double rocker arm on-site load test for a transmission line tower assembly, comprising the following steps: Step 1: Assemble the rocker arm and the main pole to the required height, and install the left counterweight between the top of the main pole and the outer end of the rocker arm; Step 2: Assemble the tower body and install the tower waist ring; Step 3: The top of the pole-holding wire is fixed to the main pole, and the bottom is fixed to the tower waist ring at the top of the tower body. The angle between the pole-holding wire and the central axis of the main pole is β, 60°≤β≤70°; Step 4: Divide the rocker arm test angle at position M according to the design value of the eccentric load bending moment of the main pole, where the rocker arm test angle is the angle α between the rocker arm and the horizontal plane; The total counterweight for the test is divided into N levels of counterweights according to the design value of the eccentric load bending moment of the main pole. Each level of counterweights includes a right counterweight block located on the right side of the main pole and a left counterweight block located on the left side. N=M, and the rocker arm test angles at M are test angle 1, test angle 2, test angle 3, and so on from small to large. The N-level counterweights correspond to the rocker arm test angles one by one, which are the first-level counterweights, the second-level counterweights, the third-level counterweights, and so on. Step 5: Lift the first-stage right counterweight with the rocker in the horizontal state and conduct a rotation test in the horizontal plane; then lift the first-stage left counterweight and conduct a rotation test in the horizontal plane. Step 6: Vertically rotate the rocker with the first-stage counterweight to the test angle two, lift the second-stage right counterweight and conduct a rotation test in the horizontal plane; then lift the second-stage left counterweight and conduct a rotation test in the horizontal plane. Step 7: Repeat Step 6 until the lifting of the last-stage counterweight is completed. Step 8: Vertically rotate the rocker to the horizontal direction and maintain for a time period t; then, conduct a rotation test in the horizontal plane. Step 9: Unload the counterweights in sequence.

[0005] Further, after lifting the corresponding counterweight each time, maintain for a time period t and then conduct a rotation test in the horizontal plane.

[0006] Further, the rotation test in the horizontal plane includes the following steps: First, rotate the rocker 90° in the horizontal plane; then, maintain for a time period t; finally, rotate 90° in the reverse direction in the horizontal plane to reset.

[0007] Further, the right and left counterweights of each stage are respectively arranged directly below the suspension points corresponding to the test angles of each rocker.

[0008] Further, a rope for lifting the next counterweight is fixed at the bottom end of each counterweight, and the length of the rope is adapted to the horizontal distance between adjacent two counterweights.

[0009] Further, the test angle of the rocker and the counterweight weight meet the following requirements: (FL - FR) × L × cosα < M; where: FL is the weight of the left counterweight; FR is the weight of the right counterweight; L is the length of the rocker; α is the angle between the rocker and the horizontal plane; M is the offset moment of the rocker and the pole.

[0010] Further, the specific operation of unloading the counterweights in sequence in Step 9 is as follows: Vertically rotate the rocker to the nearest counterweight angle and lower the corresponding right and left counterweights in sequence from near to far.

[0011] The beneficial effects of the present invention are as follows: In the present invention, the test counterweights are divided into several graded counterweight blocks according to the load-bearing capacity of the pole. As the rocker is at different angles, each stage of the counterweight is loaded in a graded manner. The graded loading method reduces the load applied each time, avoids the problem of exceeding the limit of the unbalanced moment, and meets the requirements of test loading and equipment testing.

[0012] The test method disclosed in the present invention adopts graded loading, which makes it easy to control the eccentric load bending moment during loading and unloading, and can achieve full load test under all loading conditions. At the same time, this test method breaks through the limitation of 60° between the conventional rocker arm bracket cable and the horizontal plane, and has a wider range of applications, especially in steep mountainous areas where it is impossible to set external cable.

[0013] During the graded loading process, loading is performed according to the rocker arm test angle from small to large. As the rocker arm test angle increases, the horizontal distance between the hanging point and the main arm decreases, which reduces the change in the bending moment of each load level, thereby reducing the eccentric load bending moment and helping to avoid the problem of excessive unbalanced bending moment.

[0014] Moreover, during each level of loading, a rotation test is carried out in the horizontal plane for each load change, making the test closer to the actual construction status of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a loading diagram when the rocker arm is at the test angle position one; Figure 2 It is a loading diagram when the rocker arm is in the second test angle position.

[0016] In the figure, there are tower body 1, main holding pole 2, tower body waist ring 3, holding pole cable 4, rocker arm 5, control rope 6, lifting rope 7, first-stage right counterweight 81, second-stage right counterweight 82, third-stage right counterweight 83, first-stage left counterweight 91, second-stage left counterweight 92, and third-stage left counterweight 93. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] The terms "vertical", "up", "down", "left", "right", etc., which indicate directions in the present invention, are based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] The method for loading a double rocker arm on-site load test for a transmission line tower assembly includes the following steps: Step 1: Assemble the rocker arm 5 and the main pole 2 to the required height, and install the rotation control rope 6 between the top of the main pole 2 and the outer end of the rocker arm 5. Figure 1 and Figure 2 As shown, the inner end of the rocker arm 5 is rotatably mounted on the main boom 2, and the other end opposite to the inner end is the outer end. The rotation control rope 6 acts on the outer end of the rocker arm 5, and the rocker arm 5 can be controlled to rotate around the main boom 2 with the main boom 2 as the rotating axis, that is, the rotation in the horizontal plane described later. The rocker arm 5 can also be controlled to rotate up and down with the inner end of the rocker arm 5 as the fulcrum to adjust the angle between the rocker arm 5 and the horizontal plane. The angle between the rocker arm 5 and the horizontal plane is α, also known as the rocker arm test angle. After the rocker arm 5 and the main boom 2 are assembled in place, a no-load test needs to be performed. The main boom 2 is assembled to a certain height by a mast or a crane. The rocker arm 5 is lifted by the main boom 2.

[0020] After the rocker arm 5 and the main holding rod 2 are assembled, the second step is to assemble the tower body 1 and install the tower body waist ring 3. The specific operation is: as the height of the tower body 1 increases, waist rings are installed within the range of 8-12m, and fixed to the tower body 1 through the tower body waist ring cable, and each section of the tower body 1 is hoisted for test verification.

[0021] When the tower body 1 is assembled to the specified position, proceed to step 3. The top of the pole cable 4 is fixed to the main pole 2, and the bottom is fixed to the tower waist ring 3 at the top of the tower body 1. The angle between the pole cable 4 and the central axis of the main pole 2 is β, 60°≤β≤70°. The rocker arms 5 on both sides are placed in the horizontal direction, the rocker arms and lifting equipment are adjusted, and a no-load test is performed. The tower waist ring 3 transmits the load on the main pole 2 to the tower body 1, and cooperates with the main pole 2 and the tower body 1 to bear the force.

[0022] Step 4: divide the rocker arm test angle at position M according to the design value of the eccentric load bending moment of the main holding pole 2, where the rocker arm test angle is the angle between the rocker arm 5 and the horizontal plane, denoted as α; The total counterweight for the test is divided into N levels of counterweights according to the design value of the eccentric load bending moment of the main pole 2. Each level of counterweights includes a right counterweight block located on the right side of the main pole 2 and a left counterweight block located on the left side. N=M, and the rocker arm test angles at M are test angle 1, test angle 2, and test angle 3 from small to large; The N-level counterweights correspond to the rocker arm test angles one by one, namely the first-level counterweight, the second-level counterweight, and the third-level counterweight.

[0023] The rocker arm test angle at position M is the angle between the rocker arm 5 and the horizontal plane when the rocker arm 5 is vertically rotated to different positions, and is defined as test angle 1, test angle 2, test angle 3 ... test angle M from small to large. Among them, test angle 1 is 0°, that is, the rocker arm 5 is in a horizontal position. The first-level counterweight includes the first-level right counterweight block 81 and the first-level left counterweight block 91; the first-level counterweight includes the second-level right counterweight block 82 and the second-level left counterweight block 92; the third-level counterweight includes the third-level right counterweight block 83 and the third-level left counterweight block 93, and so on, until the Nth level counterweight. N-level counterweights correspond to the rocker arm test angles one by one, which means that in the state of test angle 1, the first-level counterweight is loaded, that is, the first-level right counterweight block 81 is loaded on the right rocker arm 5, and the first-level left counterweight block 91 is loaded on the left rocker arm 5; in the state of test angle 1, the second-level counterweight is loaded, that is, the second-level right counterweight block 82 is loaded on the right rocker arm 5, and the second-level left counterweight block 92 is loaded on the left rocker arm 5, and so on. For the convenience of description, in the present invention, N=M=3, in fact, the number of N and M is determined according to the actual situation and is not limited to 3.

[0024] Step 5: When the rocker arm 5 is in a horizontal state, the first-stage right counterweight 81 is lifted to perform a rotation test in the horizontal plane; then the first-stage left counterweight 91 is lifted to perform a rotation test in the horizontal plane.

[0025] Step 6: Vertically rotate the rocker arm 5 with the first-stage counterweight to the test angle 2, lift the second-stage right counterweight 82 to perform a rotation test in the horizontal plane; then lift the second-stage left counterweight 92 to perform a rotation test in the horizontal plane. That is, in the state of the test angle 2, the first-stage right counterweight 81 and the second-stage right counterweight 82 are finally hoisted on the right rocker arm 5, and the first-stage left counterweight 91 and the second-stage left counterweight 92 are finally hoisted on the left rocker arm 5.

[0026] Step 7, repeat step 6 until the last level of counterweight lifting is completed. That is, after the second level of counterweight loading is completed, the rocker arm 5 is vertically rotated from the test angle 2 to the test angle 3, and at the test angle 3 position, the right rocker arm 5 lifts the third level right counterweight block 83 to perform a rotation test in the horizontal plane; then the left rocker arm 5 lifts the third level left counterweight block 93 to perform a rotation test in the horizontal plane. That is, in the state of test angle 3, the first level right counterweight block 81, the second level right counterweight block 82 and the third level right counterweight block 83 are finally hoisted on the right rocker arm 5, and the first level left counterweight block 91, the second level left counterweight block 92 and the third level left counterweight block 93 are finally hoisted on the left rocker arm 5.

[0027] Step 8: Rotate the rocker arm 5 vertically to the horizontal direction and maintain for a period of time t; then, perform a rotation test in the horizontal plane. In step 8, after the N-level counterweight is loaded, the rocker arm 5 is rotated from the test angle M to the test angle 1, that is, the rocker arm 5 is rotated to the horizontal direction. At this time, at the test angle 1 position, the N-level counterweight is completely hoisted on the rocker arm 5.

[0028] During the entire loading and testing process, the deformation of the main boom 2 and the rocker arm 5 is observed using measuring equipment such as a total station, and load changes are monitored and recorded using force transmitters, strain gauges, etc., to finally complete the test.

[0029] Step 9. Unload the counterweights one by one.

[0030] Preferably, after each lifting of the corresponding counterweight block, the time period t is maintained, and then a rotation test in the horizontal plane is performed.

[0031] Where t is the time it takes for the structure to stabilize, usually 3 minutes. The structure will generally stabilize within 3 minutes.

[0032] A rotation test in the horizontal plane is required for each loading and also for the full load, which effectively simulates the working requirement of horizontal rotation of double rocker arm bracket for transmission line tower assembly in actual engineering, tests the load-bearing performance of the main bracket in two directions, and makes the test more accurate and reliable.

[0033] The rotation test in the horizontal plane includes the following steps: first, the rocker arm 5 rotates 90° in the horizontal plane; then, it is maintained for a time period t; and finally, it is reversely rotated 90° in the horizontal plane and reset.

[0034] Preferably, the right counterweights and left counterweights of each level are respectively arranged directly below the hanging points corresponding to the rocker arm test angles. That is, when the rocker arm 5 is in the test angle 1 state, the first-level right counterweight 81 is located directly below the hanging point of the right rocker arm 5, and the first-level left counterweight 91 is located directly below the hanging point of the left rocker arm 5; when the rocker arm 5 is in the test angle 2 state, the second-level right counterweight 82 is located directly below the hanging point of the right rocker arm 5, and the second-level left counterweight 92 is located directly below the hanging point of the left rocker arm 5; when the rocker arm 5 is in the test angle 3 state, the third-level right counterweight 83 is located directly below the hanging point of the right rocker arm 5, and the third-level left counterweight 93 is located directly below the hanging point of the left rocker arm 5, and so on. The hanging points of the left rocker arm 5 and the right rocker arm 5 are both tied with lifting ropes 7.

[0035] A rope for lifting the next counterweight is fixed to the bottom end of each counterweight, and the length of the rope is adapted to the horizontal distance between two adjacent counterweights. That is, the top end of the first-stage right counterweight 81 is connected to the end of the lifting rope 7, and a rope is connected to the bottom end of the first-stage right counterweight 81. The end of this rope is used to connect to the top end of the second-stage right counterweight 82. The length of the rope suspended from the bottom end of the first-stage right counterweight 81 is almost equal to the horizontal distance between the first-stage right counterweight 81 and the second-stage right counterweight 82 on the ground; a rope is connected to the bottom end of the second-stage right counterweight 82. The end of this rope is used to connect to the top end of the third-stage right counterweight 83. The length of the rope suspended from the bottom end of the second-stage right counterweight 82 is almost equal to the horizontal distance between the second-stage right counterweight 82 and the third-stage right counterweight 83 on the ground; the same applies to the counterweights at each level on the left side.

[0036] Each right counterweight and left counterweight are respectively arranged directly below the suspension points corresponding to the test boom angles, so that the lifting rope 7 suspends the corresponding counterweight at the corresponding position, and the arrangement of the ropes at the bottom ends of the counterweights enables that when the suspended counterweights leave the ground, only the rotation of the boom needs to be controlled, without the need to operate the lifting rope 7. The swinging arc of the lifting rope 7 is small, and the impact force on the boom 5 and the main holding rod 2 is small.

[0037] Preferably, the test boom angle and the counterweight weight meet the following requirements: (FL - FR) × L × cosα < M; where: FL is the weight of the left counterweight; FR is the weight of the right counterweight; L is the length of the boom; α is the angle between the boom and the horizontal plane; M is the offset moment of the boom holding rod.

[0038] Preferably, the specific operation of unloading the counterweights in step nine is as follows: Rotate the boom 5 vertically to the nearest counterweight angle, and lower the corresponding right counterweights and left counterweights in sequence from near to far. That is, when rotating vertically to the position of test angle three, lower the third-stage right counterweight 83 and the third-stage left counterweight 93; then, when rotating vertically to the position of test angle two, lower the second-stage right counterweight 82 and the second-stage left counterweight 92; finally, when rotating the boom 5 to the position of test angle one, lower the first-stage right counterweight 81 and the first-stage left counterweight 91. From near to far is determined according to the distance of each counterweight from the tower body 1.

[0039] In the present invention, the test counterweights are divided into several graded counterweights according to the load-bearing capacity of the holding rod. As the boom is at different angles, each level of the counterweights is loaded in a graded manner. This graded loading method reduces the load applied each time, avoids the problem of exceeding the limit of the unbalanced moment, and meets the requirements of test loading and equipment testing.

[0040] During the graded loading process, loading is performed according to the rocker arm test angle from small to large. As the rocker arm test angle increases, the horizontal distance between the hanging point and the main boom 2 decreases, which reduces the change in the load bending moment at each level, thereby reducing the eccentric load bending moment and helping to avoid the problem of excessive unbalanced bending moment.

[0041] Moreover, during each level of loading, a rotation test is performed in the horizontal plane for each load change, making the test more accurate.

[0042] It should be noted that, in this article, relational terms such as "first", "second", "third" and "fourth" are only used to distinguish one component or operation from another component or operation, and do not necessarily require or imply any such actual relationship or order between these components or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

Claims

1. The on-site load test method of double rocker arm bracket for transmission line tower assembly is characterized by: It includes the following steps: Step 1: Erect the rocker arm (5) and the main hoist boom (2) to the required height, and install the left counterweight (6) between the top of the main hoist boom (2) and the outer end of the rocker arm (5); Step 2: Erect the tower body (1) and install the tower body waist ring (3); Step 3: Fix the top end of the hoist boom guy wire (4) to the main hoist boom (2), and fix the bottom end to the tower body waist ring (3) at the top of the tower body (1). The included angle between the hoist boom guy wire (4) and the central axis of the main hoist boom (2) is β, and 60° ≤ β ≤ 70°; Step 4: Divide the rocker arm test angles at M according to the design value of the eccentric load moment of the main hoist boom (2). The rocker arm test angle is the included angle α between the rocker arm (5) and the horizontal plane; Group the total test counterweights according to the design value of the eccentric load moment of the main hoist boom (2) into N - level counterweights. Each level of counterweight includes a right counterweight block on the right side of the main hoist boom (2) and a left counterweight block on the left side; N = M, and the rocker arm test angles at M are, in ascending order, test angle one, test angle two, test angle three... test angle M; The N - level counterweights correspond one - to - one with the rocker arm test angles, and are, in turn, the first - level counterweight, the second - level counterweight, the third - level counterweight... the N - level counterweight; Step 5: Lift the first - level right counterweight block (81) with the rocker arm (5) in the horizontal state and conduct a rotation test in the horizontal plane; then lift the first - level left counterweight block (91) and conduct a rotation test in the horizontal plane; Step 6: Vertically rotate the rocker arm (5) with the first - level counterweight to test angle two, lift the second - level right counterweight block (82) and conduct a rotation test in the horizontal plane; then lift the second - level left counterweight block (92) and conduct a rotation test in the horizontal plane; Step 7: Repeat Step 6 until the hoisting of the last - level counterweight is completed; Step 8: Vertically rotate the rocker arm (5) to the horizontal direction and maintain for a time period t; then, conduct a rotation test in the horizontal plane; Step 9: Unload the counterweights in sequence.

2. The method for loading a double rocker arm on-site load test for a transmission line tower assembly as claimed in claim 1, characterized in that: After each hoisting of the corresponding counterweight block, maintain for a time period t, and then conduct a rotation test in the horizontal plane.

3. The method for loading a double rocker arm on-site load test for a transmission line tower assembly as claimed in claim 1 or 2, characterized in that: The rotation test in the horizontal plane includes the following steps: First, rotate the rocker arm (5) 90° in the horizontal plane; then, maintain for a time period t; finally, rotate 90° in the reverse direction in the horizontal plane to reset.

4. The method for loading a double rocker arm on-site load test for a transmission line tower assembly according to claim 1 or 2, characterized in that: The right counterweight blocks and left counterweight blocks at each level are respectively arranged directly below the suspension points corresponding to the respective rocker arm test angles.

5. The method for loading a double rocker arm on-site load test for a transmission line tower assembly as claimed in claim 4, characterized in that: A rope for hoisting the next counterweight block is fixed to the bottom end of each counterweight block, and the length of the rope is adapted to the horizontal distance between adjacent two counterweight blocks.

6. The method for loading a double rocker arm on-site load test for a transmission line tower assembly according to claim 1 or 2, characterized in that: The rocker arm test angle and the counterweight weight meet the following requirements: (FL - FR)×L×cosα < M; where, FL is the weight of the left - side counterweight; FR is the weight of the right - side counterweight; L is the length of the rocker arm; α is the included angle between the rocker arm and the horizontal plane; M is the eccentric load moment of the rocker arm and hoist boom.

7. The method for loading a double rocker arm on-site load test for a transmission line tower assembly according to claim 1 or 2, characterized in that: The specific operation of unloading the counterweights in sequence in Step 9 is as follows: Vertically rotate the rocker arm (5) to the nearest counterweight angle, and sequentially lower the corresponding right counterweight block and left counterweight block from near to far.

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