Method for continuous removal of launching nose before incremental launching construction

Abstract

The application discloses a method for continuously removing a leading beam before incremental launching construction, which installs a hanger fixing device and a hanger structure on a bent cap as a fixing base of a jacking equipment and a counterforce support portal, so that the jacking equipment and the counterforce portal can form supports at the bottoms of two different leading beam sections respectively, when the leading beam is removed, the first leading beam section at the front end is jacked up to the top of the second leading beam section at the rear end by the jacking equipment, then the first leading beam section is pulled to slide along the second leading beam section to the rear end by a sliding mode, so that the leading beam is removed section by section while the incremental launching is performed; the application can effectively reduce high-altitude operation in the leading beam removal work to reduce the construction safety risk, and realizes the continuous segmented removal of the leading beam to improve the construction efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of bridge engineering construction technology, in particular to a method for continuous removal of a launching nose before incremental launching construction. BACKGROUND

[0002] Incremental launching construction is a construction method in which prefabricated bridge segments are slid down or pushed horizontally along the piers by jacks and other equipment until the entire bridge is assembled. Incremental launching construction has the advantages of fast construction speed, little impact on traffic under the bridge, and low construction cost. In order to increase the bridge span applicable to incremental launching construction, a launching nose is often used in incremental launching construction. The launching nose, which is arranged at the front end of the main girder, reduces the maximum cantilever length of the main girder, thereby reducing the internal force of the front end of the main girder during incremental launching construction and serving as a guide. After the completion of incremental launching construction, the construction temporary measure launching nose arranged at the frontmost end of the girder must be removed. The existing removal method often uses a large crane to hoist and remove the launching nose in segments. Since the removal work is performed at a high altitude, there is a high safety risk, and the construction cost is high and the construction efficiency is low.

[0003] Chinese patent application No. CN118880757A discloses a foldable launching nose and a construction method. The technical solution includes two launching noses. Each launching nose includes a front segment and a rear segment. The front segment is connected with a front segment connecting node, and the rear segment is connected with a rear segment connecting node. The front segment connecting node and the rear segment connecting node are connected by a preset hinge. A supporting truss is hinged to the top of the rear segment connecting node. A control pulley is connected to the top of the supporting truss. The front segment and the rear segment are connected to the control pulley by a steel strand. A telescopic oil cylinder mechanism is connected between the front segment and the rear segment.

[0004] The technical solution of the above-mentioned patent uses the telescopic oil cylinder mechanism, the control pulley on the supporting truss, and the steel strand to fold and recover the launching nose. However, the launching nose still needs to be hoisted and removed as a whole by a large crane, which still has a high risk of hoisting operation. The construction cost is high and the construction efficiency is low, which cannot be solved by using a crane. SUMMARY

[0005] The present application solves the technical problem of providing a method for continuous removal of a launching nose before incremental launching construction, which can effectively reduce the difficulty of removing the launching nose and improve the construction efficiency of removing the launching nose.

[0006] To solve the above technical problems, the technical solution adopted by the present application is a method for continuous removal of a launching nose before incremental launching construction, comprising the following steps:

[0007] Step S1, install a fixed hanger fixing device on the bent cap, install a hanger structure on the hanger fixing device, and install a jacking device and a counterforce support gantry on the hanger structure;

[0008] Step S2, push construction, push the guide beam to the connection point between the adjacent first guide beam segment and the second guide beam segment, and the connection point is located in the middle of the bent cap, support the jacking device on the bottom of the first guide beam segment, and support the counterforce support gantry on the bottom of the second guide beam segment;

[0009] Step S3, jacking the first guide beam segment by the jacking device, so that the bottom of the first guide beam segment is consistent with the top of the second guide beam segment in elevation;

[0010] Step S4, pulling the first guide beam segment by the pulling device, so that the first guide beam segment moves to the top of the second guide beam segment and then slides to the rear along the extension direction of the second guide beam segment;

[0011] Step S5, reset the jacking device, and repeat steps S2 to S4 until the guide beam is completely removed.

[0012] As an improvement of the above scheme: in the step S1, the hanger fixing device includes two connection parts fixedly connected with the two ends of the bent cap respectively, the hanger structure includes two main beams arranged in parallel outside the two ends of the bent cap, the main beams are fixedly connected through three cross beams, and the jacking device and the counterforce support gantry are fixedly arranged at the intersection of the cross beams and the main beams; the bottom of the connection part of the hanger fixing device is provided with a limiting groove in gap cooperation with the main beam, the main beam passes through the corresponding limiting groove and forms a rotatable connection with the connection part through a pin shaft.

[0013] As an improvement of the above scheme: in the step S1, a plurality of jacking devices are installed on the hanger structure, and the spacing of the jacking devices along the length direction of the first guide beam segment is less than half of the length of the first guide beam segment, and the spacing of the jacking devices from the center of the bent cap is less than half of the length of the first guide beam segment.

[0014] As an improvement of the above scheme: a distribution beam is installed on the top of the jacking device, and the distribution beam is connected with the top of at least two jacking devices in the width direction of the first guide beam segment.

[0015] As an improvement of the above scheme: in the step S4, at least one sliding convex strip extending in the length direction is arranged on the top of the first guide beam segment and the second guide beam segment, and at least one sliding concave groove extending in the length direction is arranged on the bottom of the first guide beam segment and the second guide beam segment, and the sliding convex strip and the sliding concave groove are in sliding cooperation.

[0016] As an improvement of the above scheme: the jacking device adopts a jack, and the pulling device adopts a winch.

[0017] The beneficial effects of the present application are: the present application installs the hanger fixing device and the hanger structure on the bent cap as the fixing base of the jacking equipment and the counterforce support gantry, so that the jacking equipment and the counterforce gantry can form supports at the bottom of two different guide beam segments respectively, when disassembling, the first guide beam segment at the front end is lifted to the top of the second guide beam segment at the rear end by jacking, and then the first guide beam segment is pulled to slide along the second guide beam segment to the rear end by sliding, so that the guide beam is disassembled segment by segment while being jacked; the present application can effectively reduce the high-altitude operation in the guide beam disassembly work to reduce the construction safety risk, and realize the continuous segmented disassembly of the guide beam to improve the construction efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structure schematic diagram of the hanger fixing device and the hanger structure after being installed with the bent cap;

[0019] Figure 2 is a schematic diagram of the guide beam supported by the jacking equipment and the counterforce support gantry;

[0020] Figure 3 is a schematic diagram of the guide beam disassembled by the present application;

[0021] Figure 4 is a schematic diagram of the end structure of the guide beam segment.

[0022] In the drawings, 100 is the bent cap, 200 is the hanger fixing device, 210 is the connecting part, 220 is the pin shaft, 300 is the hanger structure, 310 is the main beam, 320 is the cross beam, 400 is the jacking equipment, 500 is the counterforce support gantry, 610 is the first guide beam segment, 620 is the second guide beam segment, 630 is the distribution beam, 640 is the sliding convex strip, 650 is the sliding groove, and 700 is the pulling equipment. DETAILED DESCRIPTION

[0023] In order to facilitate the understanding of the present application, the present application will be further described below in combination with the drawings.

[0024] In the description of the present application, it should be noted that the terms "front", "rear", "left", "right", "upper", "lower", "inner", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of description, and do not indicate or imply that the devices or parts must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application.

[0025] The disclosed method for continuous removal of the leading beam before the incremental launching construction adopts the hanger fixing device 200, the hanger structure 300, the jacking equipment 400 and the counterforce support portal 500 to realize the segmented removal of the leading beam. The hanger fixing device 200 is used as a relay component between the hanger structure 300 and the bent cap 100 to form a stable installation support base on the bent cap 100. The hanger structure 300 is used as a direct fixing base of the jacking equipment 400 and the counterforce support portal 500 to install the jacking equipment 400 and the counterforce support portal 500. The jacking equipment 400 is used to support and jack the leading beam segment at the front end, and the counterforce support portal 500 is used to support the leading beam segment at the rear end.

[0026] Specifically, as shown in the drawings, Figures 1 to 3 The hanger fixing device 200 includes two connecting parts 210, which are fixedly connected to the two sides of the bent cap 100, respectively. The hanger structure 300 is composed of two main beams 310 and three cross beams 320. The two main beams 310 are arranged on the two sides of the bent cap 100, and the hanger structure 300 is connected and fixed with the hanger fixing device 200 through the two main beams 310. A limiting groove is arranged at the bottom of the connecting part 210 of the hanger fixing device 200, which is gap-fitted with the main beam 310 to form a clamping connection. The main beam 310 passes through the limiting groove at the bottom of the corresponding connecting part 210, and is connected with the connecting part 210 through the pin shaft 220, so that the hanger fixing device 200 and the hanger structure 300 form a relatively rotatable connection and fitting relationship. Three cross beams 320 are arranged in the hanger structure 300, which are spaced apart and arranged in parallel between the two main beams 310. The cross beam 320 is fixedly connected with the main beam 310 to form a longitudinal and transverse intersecting frame structure of the hanger structure 300. The cross beam 320 connects the two main beams 310 and reinforces the whole hanger structure 300.

[0027] Specifically, the jacking equipment 400 and the counterforce support gantry 500 are installed on the suspension structure 300. The number of the jacking equipment 400 is set to be multiple, and the jacking equipment 400 is uniformly arranged on the suspension structure 300. Since the jacking equipment 400 is used for jacking the first girder segment 610 at the front end, the jacking equipment 400 is arranged in the corresponding range of the first girder segment 610. Considering the stress balance of the suspension structure 300, the arrangement position of the jacking equipment 400 is preferably the intersection of the cross beam 320 and the main beam 310. The specific embodiment of the jacking equipment 400 is not limited, and as long as the equipment capable of realizing the jacking function can be selected, for example, a hydraulic cylinder, an air cylinder, and the like. In the present application, a more conventional jack is used as the jacking equipment 400. The counterforce support gantry 500 is a simple support frame structure, which is composed of two vertical rods fixed on the suspension structure 300 and a horizontal rod vertically connected between the two vertical rods. When the counterforce support gantry 500 supports the second girder segment 620, the weight of the suspension structure 300 is used to apply a reverse support to the suspension structure 300 in the process of jacking the first girder segment 610 by the jacking equipment 400, so that the jacking equipment 400 can jack the first girder segment 610 to a suitable elevation.

[0028] Further, the arrangement mode of the jacking equipment 400 is limited in the present application, so that the spacing of the jacking equipment 400 along the length direction of the first girder segment 610 is less than half of the length of the first girder segment 610, and the spacing of the jacking equipment 400 from the center of the deck 100 is less than half of the length of the first girder segment 610, so as to ensure that the first girder segment 610 will not be deflected in the process of jacking the first girder segment 610 by the jacking equipment 400, and ensure that the horizontal state can be maintained to reach a suitable elevation for traction.

[0029] In order to make the first girder segment 610 bear force uniformly when the jacking equipment 400 jacks the first girder segment 610, and avoid the deflection of the first girder segment 610 in the jacking process due to the uneven distribution of the jacking force on the first girder segment 610, as shown in Figure 1 The distribution beam 630 is further installed on the jacking equipment 400 in the present application, the distribution beam 630 is installed and fixed on the top of the jacking equipment 400, and the distribution beam 630 is connected with the top of at least two jacking equipment 400 in the width direction of the first girder segment 610. The jacking force applied on the first girder segment 610 by the jacking equipment 400 is distributed by arranging the distribution beam 630, so that the jacking force can be uniformly dispersed on the first girder segment 610.

[0030] After jacking the first girder segment 610, the first girder segment 610 is moved to the rear by sliding.Figure 4 As shown, the sliding movement of the first girder segment 610 is realized by the sliding convex strip 640 and the sliding groove 650, the sliding convex strip 640 is arranged on the top of the first girder segment 610 and the second girder segment 620 and extends along the length direction, the sliding groove 650 is arranged on the bottom of the first girder segment 610 and the second girder segment 620 and extends along the length direction, and the sliding convex strip 640 is in sliding fit with the sliding groove 650; when the jacking device 400 jacks up the bottom of the first girder segment 610 to be flush with the top of the second girder segment 620, the sliding groove 650 on the bottom of the first girder segment 610 is aligned with the sliding convex strip 640 on the top of the second girder segment 620, the sliding convex strip 640 is inserted into the sliding groove 650 by pulling the first girder segment 610 by the pulling device 700, so that the first girder segment 610 can slide along the second girder segment 620 to the rear by the sliding fit of the sliding convex strip 640 and the sliding groove 650. The pulling device 700 for pulling the first girder segment 610 is a winch.

[0031] The method for continuously removing the front girder before the incremental launching construction disclosed in the application is constructed according to the following steps when the girder is removed:

[0032] Step S1, installing the fixed hanger fixing device 200 on the bent cap 100, installing the hanger structure 300 on the hanger fixing device 200, and installing the jacking device 400 and the counterforce support portal frame 500 on the hanger structure 300;

[0033] Step S2, incremental launching construction, pushing the girder to the connection point between the adjacent first girder segment 610 and the second girder segment 620, which is located in the middle of the bent cap 100, supporting the jacking device 400 on the bottom of the first girder segment 610, and supporting the counterforce support portal frame 500 on the bottom of the second girder segment 620;

[0034] Step S3, jacking up the first girder segment 610 by the jacking device 400, so that the bottom of the first girder segment 610 is flush with the top of the second girder segment 620;

[0035] Step S4, pulling the first girder segment 610 by the pulling device 700, so that the first girder segment 610 moves to the top of the second girder segment 620 and then slides to the rear along the extension direction of the second girder segment 620;

[0036] Step S5, resetting the jacking device 400, repeating steps S2 to S4, and removing the girder by incremental launching and segmented removal, until the girder is completely removed.

Claims

1. A method for continuous removal of a front guide beam before incremental launching construction, characterized in that: The method comprises the following steps: Step S1, installing a fixed hanger fixing device (200) on the bent cap (100), installing a hanger structure (300) on the hanger fixing device (200), and installing a jacking device (400) and a counterforce support gantry (500) on the hanger structure (300); Step S2, pushing construction, pushing the guide beam to the connection point between the adjacent first guide beam segment (610) and the second guide beam segment (620) located in the middle of the bent cap (100), supporting the jacking device (400) on the bottom of the first guide beam segment (610), and supporting the counterforce support gantry (500) on the bottom of the second guide beam segment (620); Step S3, jacking the first guide beam segment (610) by the jacking device (400) to make the bottom of the first guide beam segment (610) consistent with the top of the second guide beam segment (620) in elevation; Step S4, pulling the first guide beam segment (610) by a pulling device (700) to make the first guide beam segment (610) move to the top of the second guide beam segment (620) and then slide to the rear along the extension direction of the second guide beam segment (620); Step S5, resetting the jacking device (400) and repeating steps S2 to S4 until the guide beam is completely removed.

2. The incremental launching nose girder continuous removal method of claim 1, wherein: In the step S1, the hanger fixing device (200) comprises two connection parts (210) fixedly connected with the two ends of the bent cap (100) respectively, the hanger structure (300) comprises two main beams (310) arranged in parallel outside the two ends of the bent cap (100), the main beams (310) are fixedly connected by three cross beams (320), and the jacking device (400) and the counterforce support gantry (500) are fixedly arranged at the intersection of the cross beams (320) and the main beams (310); the bottom of the connection part (210) of the hanger fixing device (200) is provided with a limiting groove in gap cooperation with the main beam (310), the main beam (310) passes through the corresponding limiting groove and forms a rotatable connection with the connection part (210) through a pin shaft (220).

3. The incremental launching nose girder continuous removal method of claim 1, wherein: In the step S1, a plurality of jacking devices (400) are installed on the hanger structure (300), and the spacing of the jacking devices (400) along the length direction of the first guide beam segment (610) is less than half of the length of the first guide beam segment (610), and the spacing of the jacking devices (400) from the center of the bent cap (100) is less than half of the length of the first guide beam segment (610).

4. The incremental launching nose girder continuous removal method of claim 3, wherein: A distribution beam (630) is installed on the top of the jacking device (400), and the distribution beam (630) is connected with the top of at least two jacking devices (400) in the width direction of the first guide beam segment (610).

5. The incremental launching nose girder continuous removal method of claim 1, wherein: In the step S4, at least one sliding convex strip (640) extending in the length direction is arranged on the top of the first guide beam segment (610) and the second guide beam segment (620), and at least one sliding concave groove (650) extending in the length direction is arranged on the bottom of the first guide beam segment (610) and the second guide beam segment (620), and the sliding convex strip (640) and the sliding concave groove (650) are in sliding cooperation.

6. The incremental launching nose girder continuous removal method of claim 1, wherein: The jacking device (400) adopts a jack, and the traction device (700) adopts a winch.

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