Jacking and flat-turning dismantling method for overline continuous beam bridge

Abstract

The invention relates to an over-line continuous beam bridge jacking and horizontal rotating dismantling method which comprises the steps that rotary disc supports are erected around two main piers of a main span beam respectively, jacking supports are erected on the two sides of one rotary disc support, and jacks are arranged on the jacking supports; the midspan closure section and the two-side span closure section are cut off through a rope saw, and the main span beam is divided into two sections; a jacking support and a rotating disc support are alternately lifted to jack one section of main beam to be higher than the beam bottom and the beam surface of the other section of main beam, and then the two sections of main beams are horizontally rotated to the two sides of a road correspondingly to be dismantled. Smooth horizontal rotation of the main span beam body can be achieved without breaking and dismantling the midspan closure section during overall dismantling, so that the risks that the bridge collapses and fragments fall off the bridge in the bridge dismantling process are avoided, and construction safety is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, relates to a demolition construction of an old bridge, and specifically relates to a method for demolishing a cross-line continuous beam bridge by lifting and rotating it horizontally. Background Art

[0002] During the construction of a continuous beam bridge across a line, in order not to affect the normal passage of the existing line below, a horizontal rotation construction process is often used. The two T-structures of the main span are cantilevered and cast on both sides of the existing line, and then the two T-structures are rotated and joined above the existing line. Similarly, when dismantling the old bridge in the reconstruction and expansion project of a continuous beam bridge across a line, in order not to affect the traffic under the bridge, the horizontal rotation demolition method can also be used. First, the joint sections of the middle span and the side span are dismantled to form two T-structures, and then the two T-structures are horizontally rotated to both sides of the existing line and then dismantled in sections. However, when a bridge is newly built, in order to avoid mutual interference between the joint ends of the two T-structures during horizontal rotation, the joint section is usually set longer, so the weight of the joint section is also heavier. During demolition, if the joint section is cut and removed as a whole, because the lifting and transportation equipment can only operate on the cantilever of the T-structure, and the bearing capacity of the T-structure cantilever is not as good as when the bridge was built, there is a risk of collapse; if the joint section is dismantled by crushing, not only is the construction efficiency low, but it is also easy to drop fragments and affect the traffic safety of the line below. Summary of the invention

[0003] The purpose of the present invention is to provide a method for lifting and rotating the dismantling of a continuous beam bridge across a line in view of the above-mentioned problems. Only a gap is cut in the middle of the mid-span joint section. First, the beam on one side is lifted as a whole to a height where the bottom of the beam is higher than the height of the beam surface on the other side. Then, the two beams are rotated to the outside of the existing line for dismantling.

[0004] The technical solution of the present invention is as follows:

[0005] A method for dismantling a cross-line continuous beam bridge by lifting and horizontal rotation, wherein the cross-line continuous beam bridge comprises two main piers, a main span beam, two side span piers and a side span beam, and a traffic line is located in the middle and lower part of the main span. The method is characterized in that the method comprises the following steps:

[0006] (1) Set up No. 1 turntable bracket and No. 2 turntable bracket around No. 1 main pier and No. 2 main pier respectively to support the bottom of the beam, and the turntable bracket is provided with a turntable; set up jacking brackets on both sides of No. 1 turntable bracket, and set up jacks on the jacking brackets;

[0007] Side span brackets are set up on both sides of the two side span piers to support the side span beams;

[0008] (2) Use a rope saw to cut the middle section of the span from the middle, and then use a rope saw to cut the sections of the two side spans, so that the main span forms two T structures;

[0009] When cutting the side span joint section, determine the cutting line of the side span joint section according to the weight of the joint section in the middle of the other end of the main span beam, so that the weight of the joint sections at both ends of the main span beam is equal to ensure the balance of the cantilevers at both ends of the T-structure;

[0010] (3) Use a crawler crane to remove all sections of the side span beam and the side span brackets;

[0011] (4) Release the vertical constraints between the tops of the two main piers and the beam body, so that the weight of the beam body is completely borne by the turntable bracket;

[0012] Start the jack on the jacking bracket to first jack up the beam above the No. 1 main pier, then raise the No. 1 turntable bracket to the bottom of the supporting beam, then retract the jacking jack to raise the jacking bracket; use the jack to jack up the beam again, raise the turntable bracket, and raise the jacking bracket and turntable bracket alternately in this way, and jack up the beam above the No. 1 pier to a beam bottom higher than the beam surface of the beam above the No. 2 main pier; finally, retract the jack to let the beam fall onto the No. 1 turntable bracket;

[0013] (5) Remove the lifting support;

[0014] (6) The two main beams are moved horizontally to both sides of the road for removal.

[0015] The present invention can realize smooth horizontal rotation of the main span beam without overall demolition or broken demolition of the mid-span joint section, thereby avoiding the risk of bridge collapse and fragments falling under the bridge during bridge demolition and ensuring construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a construction flow chart of the present invention;

[0017] Figure 2 It is a structural diagram of a cross-line continuous beam bridge;

[0018] Figure 3 This is a schematic diagram of the status after the turntable bracket, jacking bracket and side span bracket are installed;

[0019] Figure 4 It is a schematic diagram of the state of the mid-span closure section and the side span closure section after cutting;

[0020] Figure 5 This is a schematic diagram of the main span beam on one side after being lifted;

[0021] Figure 6 This is a schematic diagram of the status after the main beam is rotated horizontally. DETAILED DESCRIPTION

[0022] Figure 2The figure shows a schematic diagram of the structure of a cross-line continuous beam bridge, including a No. 1 main pier 1 and a No. 2 main pier 2, a main span beam 3 on the two main piers, two side span piers 4 and a side span beam 5 at both ends of the main span beam 3, and a passageway 6 at the middle and lower part of the main span beam 3. The method for lifting, rotating and dismantling the cross-line continuous beam bridge of the present invention is as follows:

[0023] (1) Figure 3 As shown, around the No. 1 main pier 1 and the No. 2 main pier 2, a No. 1 turntable bracket 7 and a No. 2 turntable bracket 8 are respectively set up to support the bottom of the main span beam, and a turntable is provided on the turntable bracket; a jacking bracket 9 is set up on both sides of the No. 1 turntable bracket 7, and a jack 10 is provided on the jacking bracket 9;

[0024] Side span brackets 11 are respectively set up on both sides of the side span piers 4 to support the side span beams 5;

[0025] (2) Figure 4 As shown, the middle span joint section of the main span beam 3 is cut from the middle by a rope saw, so that the main span beam is divided into two sections; and then the joint sections of the two side spans are cut by a rope saw, so that the main span forms two T structures;

[0026] When cutting the side span joint section, determine the cutting line of the side span joint section according to the weight of the joint section in the middle of the other end of the main span beam, so that the weight of the joint sections at both ends of the main span beam is equal to ensure the balance of the cantilevers at both ends of the T-structure;

[0027] (3) Using a crawler crane to dismantle all sections of the side span beam 5 and the side span bracket 11;

[0028] (4) Figure 5 As shown, the vertical constraints between the tops of the two main piers and the beam body are released, and the pier top supports are removed, so that the weight of the beam body is completely borne by the turntable bracket;

[0029] Start the jack 10 on the jacking bracket 9 to first jack up the main span beam above the No. 1 main pier, then raise the No. 1 turntable bracket 7 to the bottom of the supporting beam, then retract the jacking jack 10 to raise the jacking bracket 9; use the jack to jack up the beam again, raise the turntable bracket 7, and the jacking bracket 9 and the turntable bracket 7 are raised alternately in this way, and the beam 3 above the No. 1 pier is jacked up to the beam bottom higher than the beam surface of the beam 3 above the No. 2 main pier; finally, the jack is retracted to make the beam fall onto the No. 1 turntable bracket;

[0030] (5) Remove the lifting support;

[0031] (6) The two sections of the main span beam 3 are respectively rotated to the two sides of the road 6 for removal. The state of the main span beam after rotation is as follows: Figure 6 shown.

Claims

1. A method for dismantling a continuous beam bridge by lifting and horizontal rotation, wherein the continuous beam bridge comprises two main piers, a main span beam, two side span piers and a side span beam, and the main span is located in the middle and lower part of the main span, and is characterized in that: The following steps are involved: (1) Set up No. 1 turntable bracket and No. 2 turntable bracket around No. 1 main pier and No. 2 main pier respectively to support the bottom of the beam, and the turntable bracket is provided with a turntable; set up jacking brackets on both sides of No. 1 turntable bracket, and set up jacks on the jacking brackets; Side span brackets are set up on both sides of the two side span piers to support the side span beams; (2) Use a rope saw to cut the middle section of the span from the middle, and then use a rope saw to cut the sections of the two side spans, so that the main span forms two T structures; When cutting the side span joint section, determine the cutting line of the side span joint section according to the weight of the joint section in the middle of the other end of the main span beam, so that the weight of the joint sections at both ends of the main span beam is equal to ensure the balance of the cantilevers at both ends of the T-structure; (3) Use a crawler crane to remove all sections of the side span beam and the side span brackets; (4) Release the vertical constraints between the tops of the two main piers and the beam body, so that the weight of the beam body is completely borne by the turntable bracket; Start the jack on the jacking bracket to first jack up the beam above the No. 1 main pier, then raise the No. 1 turntable bracket to the bottom of the supporting beam, then retract the jacking jack to raise the jacking bracket; use the jack to jack up the beam again, raise the turntable bracket, and raise the jacking bracket and turntable bracket alternately in this way, and jack up the beam above the No. 1 pier to a beam bottom higher than the beam surface of the beam above the No. 2 main pier; finally, retract the jack to let the beam fall onto the No. 1 turntable bracket; (5) Remove the lifting support; (6) The two main beams are moved horizontally to both sides of the road for removal.

Images