CN113802474A

CN113802474A - Half-width bridge beam-slab stabilizing device and construction method for keeping bridge open in half width

Info

Publication number: CN113802474A
Application number: CN202111012258.XA
Authority: CN
Inventors: 张立兵; 吴昊聪; 张洪铭; 欧阳禄龙; 唐智昶; 窦照金
Original assignee: China Construction Civil Engineering Co Ltd
Current assignee: China Construction Civil Engineering Co Ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2021-12-17
Anticipated expiration: 2041-08-31
Also published as: CN113802474B

Abstract

The invention relates to the technical field of bridge renovation construction, and provides a bridge half-width traffic protection construction method for performing half-width traffic protection construction operation on a bridge with a bridge deck formed by transversely splicing a plurality of beam plates. Firstly, removing one side of a lane of an old bridge and recording as a removal half width, and keeping the other side of the lane of the old bridge still and recording as a communication-keeping half width; then applying inward extrusion stress from the left side and the right side of the half-width bridge floor; then, constructing the half width of the new bridge in the original position of removing the half width, and removing the extrusion stress on the half width of the bridge floor after the half width lane of the new bridge is communicated; and finally, removing the half of the reserved half of the old bridge, and constructing the other half of the new bridge at the original site. Meanwhile, the invention also provides a half-width bridge beam plate stabilizing device matched with the applied extrusion stress. The scheme of the invention can keep the traffic passing capability of the road in the whole bridge construction process. And the dangerous condition caused by instability of the communication protection part of the old bridge is avoided.

Description

Half-width bridge beam-slab stabilizing device and construction method for keeping bridge open in half width

Technical Field

The invention relates to the technical field of bridge renovation construction, in particular to a construction method for performing half-width maintenance on an old bridge and a matched stabilizing device for a half-width bridge beam plate.

Background

The turnover cover for repairing the bridge on the original road is different from bridge construction on a brand-new road, and a certain traffic capacity of the original bridge during the repair period is maintained in many times. At this time, one side lane, namely, the half lane is firstly removed, and then the other half lane keeps the traffic capacity, so that all the original vehicles enter the reserved half lane to traffic.

However, many old bridges needing to be rebuilt with heavy covers are different from the existing integrated box girder bridges, and a plurality of beam plates are transversely spliced into a bridge deck, namely in the left-right direction. Demolish half bridge floor and concentrate on the vehicle in addition half to keep the vehicle unblocked promptly and keep leading to half a construction, the traffic flow grow, lead to producing great moment of flexure on the beam slab of bridge easily, perhaps vehicle start emergency brake causes the wet seam stress of beam slab to ftracture under the condition that exerts great reaction force to the bridge floor, and whole beam slab takes place the translation even. The safety of the communicated half-width bridge is difficult to guarantee during construction.

In the prior art, the general coping method is to directly fix the beam plates of the traffic-securing half-width bridge into a whole by using the steel plates, and the steel plates are fixed by expansion bolts, but the main structure of the traffic-securing half-width bridge is just broken, so that irreversible damage is easily caused to the traffic-securing half-width bridge, and the traffic-securing half-width normal traffic is influenced. The device can only be installed on the bottom surface of a bridge, the installation and construction are very difficult to hoist and mount by personnel, and the device is not easy to dismantle in the later period.

Disclosure of Invention

The invention relates to a half-width construction method for bridge protection.

The technical problem to be solved is that: some old bridges with a plurality of beam plates spliced into a bridge deck left and right are subjected to renovation construction, and when certain traffic capacity is maintained to perform half-width traffic maintenance construction, the half-width bridge beam plates which are maintained to be communicated are unstable, connecting joints between the beam plates are easy to crack or even the beam plates slide, and bridge safety is influenced.

In order to solve the technical problem, the half-width construction method for keeping the bridge open adopts the following scheme.

A half-width construction method for protecting a bridge is used for performing half-width construction operation on the bridge with a bridge deck formed by transversely splicing a plurality of beam plates, and comprises the following steps:

the method comprises the following steps: removing one side of the old bridge and recording as a removal half-width, and keeping the other side of the old bridge as a traffic-keeping half-width;

step two: applying inward extrusion stress from the left side and the right side of the communicated half-width bridge deck;

step three: constructing the half lane of the new bridge in the original position of half-removed;

step four: after the half lane of the new bridge is communicated with the vehicle, the extrusion stress applied to the communication-maintaining half lane of the old bridge is removed;

step five: and removing the half of the reserved opening of the old bridge, and building the other half of the driveway of the new bridge in the original position.

Preferably, in the second step, a beam plate stabilizing device is adopted for loading the extrusion stress, and a plurality of beam plate stabilizing devices are arranged at intervals in the length direction of the beam plate; the beam slab stabilizing device comprises two fixing clamps which can be respectively fixed on the left side and the right side of a bridge deck communicated with a half width, wherein the fixing clamps are connected through a tightening mechanism, the tightening mechanism is arranged below the beam slab, the tightening mechanism is tightened for two, and inward extrusion stress can be applied to the communicated half width through the fixing clamps.

Preferably, in the second step, the bridge deck at the position of the fixing clip, which is kept through by half width, is trimmed, so that the fixing clip and the bridge deck are stressed uniformly.

Preferably, in the step one, the dismantling operation of the beam plate of the bridge is sequentially performed from the side close to the edge of the dismantling half width to the side close to the opening step by step; and before the dismantling operation of the beam plates, the asphalt pavement with the half bridge deck to be dismantled is cut and separated, and the asphalt pavement is cut along the splicing seams between the beam plates.

Preferably, before the cutting and separating operation of the asphalt pavement in the first step, the asphalt pavement with the half-width removed and two ends thereof is planed to be exposed out of the splicing seams of the beam slabs; and marking the positions of the beam plate splicing seams on the asphalt pavement according to the side edges of the bridge deck and the positions of the exposed bridge splicing seams, and then cutting and separating the asphalt pavement along the marked lines.

Preferably, in step three, a gap is left between the new bridge and the old bridge in the half-width of the communication between the new bridge and the old bridge, and the range of the gap is not less than 10cm, which can be determined according to the actual design condition. So as to avoid the direct contact between the new bridge and the through-guard half-width.

Preferably, in the fifth step, the pier which is kept through by half is dismantled from top to bottom.

Meanwhile, the invention also provides a half-bridge beam plate stabilizing device for specially reinforcing the beam plate of the communicated half-bridge, and the following scheme is adopted.

A half-width bridge beam plate stabilizing device is used for applying extrusion stress inwards to beam plates of a bridge which is transversely spliced by a plurality of beam plates when the bridge deck is subjected to half-width penetration construction operation,

the beam slab stabilizing device comprises two fixing clips which can be fixed on the side edge of the bridge floor and are connected through a tightening mechanism,

two fixing clips are respectively installed on the left side and the right side of the bridge protection half-width, a tightening mechanism is located below the bridge and is connected at the two ends of the bridge respectively to protect the fixing clips on the two sides of the half-width, and the tightening mechanism can extend and contract to adjust the distance between the two fixing clips and further apply inward extrusion stress to the bridge floor protecting the half-width.

Preferably, the fixing clip is U-shaped and is fit with the left side and the right side of the half-width of the bridge opening, and the inner edge of the fixing clip is provided with anti-skid textures; one side of the fixing clip on one side of the edge is clamped in a flowing water hole of the bridge floor, or a groove is formed in the bridge guardrail, one side of the fixing clip is clamped in the groove, and the guardrail is arranged on the fixing clip on the other side of the fixing clip.

Preferably, the tightening mechanism is a steel wire rope with a rope tightening device, the rope tightening device is arranged on one side of the bridge edge, two ends of the steel wire rope are fixed on a fixing clamp on one side of the bridge edge, a pulley is arranged on the lower portion of the fixing clamp on the other side of the bridge edge, and the steel wire rope bypasses the pulley.

Compared with the prior art, the half-width construction method for keeping the bridge open has the following beneficial effects:

the bridge with the bridge deck formed by transversely splicing the plurality of beam plates left and right is provided with the blocking structures on the left and right sides of the supporting structure, the beam plates on the outermost side are prevented from moving outwards, and then the beam plates in the middle of the whole bridge deck are restrained by the beam plates on the two sides to keep the positions of all the beam plates of the whole bridge deck fixed. At present, half-width protection construction is carried out on the bridge, half-width bridges are dismantled, beam plates exposed on the outermost side lose the restraint of original beam plates at the moment, and the movement is inevitable under the condition of large stress.

According to the invention, after the half-width bridge is dismantled, inward pressurizing stress is applied to the left side and the right side of the reserved bridge deck of the half-width bridge, and the exposed beam plates after the half-width bridge is dismantled can be subjected to the action force of extrusion, so that the beam plates are prevented from moving.

For the whole construction process, firstly, a half of the bridge is dismantled, the rest of the bridge is generally reserved as a pass-through half-width, the pass-through half-width is reinforced in a mode of applying extrusion stress, and meanwhile, vehicles are guided onto the pass-through half-width to keep certain traffic capacity of the road. And then, in order to align the roads at the two ends, constructing the half width of the new bridge road at the original position, and after the half width of the new bridge road can be communicated after the construction is finished, guiding the vehicles to the half width bridge of the new bridge road which is already constructed. The force applied to the break-through half-width is then removed and the break-through half-width of the old bridge is removed. And constructing the other half of the new bridge. Therefore, the basic traffic capacity of the original road is always kept in the construction process of the whole bridge. The road is prevented from being directly blocked to influence traffic.

Meanwhile, the invention also provides a half-width bridge beam plate stabilizing device, which changes the original installation mode that a steel plate is fixed on a beam plate through expansion bolts after crossing the joint of the beam plate. The mode that two fixing clamps that can block in the bridge floor both sides are connected to the adoption tightening mechanism, only need be connected to two fixing clamps and protect the both sides of leading to half a width, then let two fixing clamps of tightening means take-up and can let all roof beams board gather together as an organic whole. The beam plate exposed at the outermost side is prevented from translating under the action of external force such as braking. At the same time, in order to avoid the tightening device from affecting the vehicles on the deck, the tightening device is thus arranged below the deck. Because the tightening device is not connected with the bridge deck, the device is only required to be lifted to the lower surface position of the bridge plate from the left side and the right side of the bridge by using ropes and then connected with the fixed card. Or directly lifting the whole beam plate fixing device from the lower part of the bridge, then installing the fixing clip on the side edge of the through half-width, and tensioning the tightening device.

This scheme sets up simply, and easy dismounting has avoided the influence that the operation of punching on the bridge slab caused the structure of bridge, has also avoided the inconvenient problem of operation on the bridge lower surface simultaneously.

Drawings

FIG. 1 is a cross-sectional view of a half bridge beam and slab stabilization device of the present invention after installation;

FIG. 2 is a schematic view of the retainer clip and tensioner portion of the adjacent side of FIG. 1;

FIG. 3 is an enlarged view at A in FIG. 2;

fig. 4 is a schematic view of the position of the other side fixing clip in fig. 1.

Description of reference numerals: the device comprises a beam plate 1, a fixing clamp 2, a tightening mechanism 3, a steel wire rope 3a and a rope tightener 3 b.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

In the present invention, the use of the directional terms such as "upper, lower, left, right" generally means upper, lower, left, right as shown in reference to fig. 1, unless otherwise specified; "inner and outer" refer to the inner and outer relative to the profile of the components themselves. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

In order to solve the problems that old bridges with a plurality of beam plates 1 spliced into a bridge deck are subjected to overhaul construction, and when certain traffic capacity is required to be maintained and half-width traffic protection construction is carried out, the half-width bridge beam plates 1 which are in traffic protection are unstable, connecting joints among the beam plates 1 are easy to crack, even the beam plates 1 slide, and the safety of the bridge is influenced.

The invention provides a bridge half-width traffic protection construction method which is specially used for carrying out half-width traffic protection construction operation on a bridge with a bridge deck formed by transversely splicing a plurality of beam plates 1, and comprises the following steps:

step three: constructing the half width of the new bridge in the original position of dismantling the half width,

step four: after the half lane of the new bridge is communicated, the extrusion stress on the half bridge floor which is kept communicated is removed;

step five: and removing the half of the old bridge to ensure the communication, and constructing the other half of the new bridge at the original site.

The removal half-width and the opening-keeping half-width are only definitions made by expressing a party, and do not represent that in actual construction, a certain side of a bridge is necessarily the removal half-width or the opening-keeping half-width, and which side is removed first and is reserved can be determined according to actual conditions. Then the first side is the half-width to be removed, and the other side is the half-width to be kept open. After the half-width bridge is removed, all vehicles and pedestrians passing through the bridge are guided to the traffic-guaranteeing half-width bridge, and the basic traffic capacity of the bridge is kept.

Immediately after the beam panel 1 from which the half is removed, compressive stress is applied to both sides of the remaining half. The extrusion stress can be applied to the side face of the beam plate 1 exposed after the half beam plate 1 is removed by using a jack or a wedge block and the like on the reserved half beam plate in the direction of keeping through the half beam plate, and then the original blocking structure on the side edge of the bridge applies a reaction force to finish the whole target of applying the extrusion stress inwards from two sides. However, in many cases, the half-width side is removed without providing a device such as a jack. The two sides of the security half-web are clamped simultaneously by one and the same device, which is then pressed inwards, and likewise a compressive stress can be applied to the security half-web.

Then in three steps, the new bridge can be reconnected with the original road, so that the half of the new bridge is built at the original site where the half is removed. The new bridge design should employ two half-width individually supported structures.

And in the fourth step, after the half width of the new bridge is connected with the road and the vehicle is communicated, the function of ensuring the communication of the half width of the old bridge on the road is transferred to the half width of the new bridge which is communicated with the vehicle. Then the through-protection half-width of the old bridge can be removed, and then the construction of the other half-width of the new bridge is carried out on the original address of the removed through-protection half-width.

Specifically, in the second step, a beam plate stabilizing device is adopted to load the extrusion stress, and a plurality of beam plate stabilizing devices are arranged at intervals in the length direction of the beam plate 1;

the beam slab stabilizing device comprises two fixing clamps 2 which can be respectively fixed on the left side and the right side of a bridge deck communicated with a half width, wherein the two fixing clamps 2 are connected through a tightening mechanism 3, the tightening mechanism 3 is arranged below the beam slab 1, and the tightening mechanism 3 tightens the two fixing clamps 2 to apply inward extrusion stress on the communicated half width. This tightening device may be a tensioning mechanism for the wire rope 3a and the wire rope 3a in the drawings, or a double-headed screw or the like may be used as long as it is a device capable of expanding and contracting.

Preferably, the bridge floor which is kept through by half width at the position of the fixing clip 2 is trimmed, so that the fixing clip 2 and the bridge floor are stressed uniformly. The fixing clip 2 is determined according to the specific situation of the position to be installed of the bridge and needs to be matched with the bridge deck. However, concrete residues exist on wet joints of splicing seams of the asphalt pavement or the beam slab 1 on the bridge deck, and the installation and the stress of the fixing clip 2 and the bridge deck are influenced.

In the first step, the dismantling operation of the beam plate 1 of the bridge is sequentially carried out from the side close to the edge of the dismantling half width to the side for keeping open gradually; and before the dismantling operation of the beam plates 1, the asphalt pavement with the half bridge deck to be dismantled is cut and separated, and the asphalt pavement is cut along the splicing seams between the beam plates 1. Because the left half bridge and the right half bridge of the lanes on the two sides of the old bridge are connected into a whole, the asphalt pavement is also bonded into a whole. The asphalt pavement is cut from the middle in order to avoid affecting the asphalt pavement on the opening half. Meanwhile, the asphalt pavement is cut along the splicing seams of the beam plates 1 so as to be convenient for dismantling the beam plates 1, and the beam plates 1 are thoroughly separated. Specifically, before the cutting and separating operation in the first step, the asphalt pavement at two ends of the removed half width is planed to expose the position of the splicing seam of the beam slab 1; and marking the splicing seam position of the beam plate 1 on the asphalt pavement according to the side edge of the bridge deck and the exposed splicing seam position of the bridge, and then cutting and separating the asphalt pavement along the marked line.

In the third step, a gap is reserved between the new bridge and the through-keeping half-width of the old bridge to avoid the direct contact between the new bridge and the through-keeping half-width. The interference collision between the half-width of the protection opening of the old bridge and the half-width of the construction of the new bridge is avoided, the structural safety of the half-width of the protection opening is influenced, and meanwhile, the influence on the half-width construction of the new bridge is avoided. In the fifth step, the other half of the new bridge is preferably separated from the half constructed in the third step in advance, and a separated bridge structure is adopted.

And fifthly, removing the half bridge piers from top to bottom to avoid overturning of the bridge piers.

Wherein need confirm according to the actual conditions of old bridge when three kinds are to carrying out the pier demolishment with regard to dismantling half a width of bridge in step, the pier of old bridge beam generally has three kinds of forms:

1. an independent pier supports the left and right half bridge decks simultaneously. At this time, the piers of the old bridge need to be reserved, and only the repeatedly dismantled beam plates 1 are removed, so that the piers continue to support and keep full width by half. Preferably, after the half removed beam slab 1 is removed, half of the upper surface of the pier is exposed, and one end of the exposed upper surface of the pier near the half removed is removed downwards, so that the influence on the new bridge caused by interference with construction of the beam slab 1, the capping beam and other parts of the new bridge is avoided.

2. The two independent piers support the left and right half beam plates 1 respectively, the situation is easy to process, and only the support piers which are dismantled in half are needed to be directly dismantled, and then new bridge construction is carried out. Then, the half bridge piers are kept through without treatment.

3. The three piers support the left and right half-width beam plates 1 of the left and right bridges. In this case, it is rare that the treatment method combines the first two methods, the pier on the outermost side of the demolished half width is demolished, the pier which is positioned in the middle and supports the left and right half width simultaneously is retained, the pier in the middle and the pier which is communicated with the half width are retained, and after the beam slab 1 which is demolished the half width is removed, the exposed part of the pier in the middle is demolished downwards for a certain distance.

The invention provides a half-width bridge beam plate stabilizing device which is matched with the step two and applies inward extrusion stress to the half-width of the bridge floor.

When the device is used for half-width penetration-maintaining construction operation of a bridge with a bridge deck formed by transversely splicing a plurality of beam plates 1, the beam plates 1 of the half-width penetration-maintaining bridge are internally stressed in an extrusion manner, the beam plate stabilizing device comprises two fixing clamps 2 which can be fixed on the side edge of the bridge deck, the two fixing clamps 2 are connected through a tightening mechanism 3,

two fixing clips 2 are installed respectively in the bridge and are protected the left and right sides that leads to half a width of cloth, and tightening mechanism 3 is located bridge below and both ends and connects respectively and protects fixing clip 2 that leads to half a width of cloth both sides, tightening mechanism 3 can extend and contract and then exert inside compressive stress to the bridge floor of protecting the half a width of cloth with the interval of adjusting two fixing clips 2.

Meanwhile, the invention also provides a half-bridge beam plate stabilizing device, which changes the original installation mode that a steel plate is fixed on the beam plate 1 through expansion bolts after crossing the joint of the beam plate 1. Adopt to connect two can block the mode at the fixing clip 2 of bridge floor both sides on the tightening mechanism 3, only need be connected to two fixing clips 2 and protect the both sides of leading to half a width, then let two fixing clips 2 of tightening means take-up and can let all roof beam slabs 1 gather together as an organic whole. The beam plate 1 exposed at the outermost side is prevented from translating under the action of external force such as braking. At the same time, in order to avoid the tightening device from affecting the vehicles on the deck, the tightening device is thus arranged below the deck. Because the tightening device is not connected with the bridge deck, the setting only needs to be lifted to the lower surface position of the bridge plate 1 from the left side and the right side of the bridge by using ropes, and then the tightening device is connected with the fixing clip 2. Or directly lifting the whole beam plate 1 fixing device from the bridge, and then installing the fixing clip 2 on the side edge of the through half-width, and tensioning the tightening device.

Specifically, the fixing clip 2 can be clipped on the side of the bridge deck or the beam slab 1, and then when applying an inward external force to the fixing clip, the fixing clip 2 can conduct the external force to the beam slab 1 of the bridge, and is not limited by a concrete expression form. The external force of the fixing clips 2 is applied through the tightening mechanism 3, and the tightening mechanism 3 applies acting force towards the inner side of the bridge to the two fixing clips 2 simultaneously during contraction movement. The tightening mechanism 3 is a mechanism capable of contracting and expanding while applying a tensile force in a contracted state and maintaining the tensile force. The screw rod or the hydraulic mechanism can be used, but the screw rod or the hydraulic mechanism is heavy and high in cost and is not a use occasion of the invention. Therefore, the steel wire rope 3a with the rope tightener 3b is preferably adopted in the invention, the rope tightener 3b can enable the steel wire rope 3a to contract or extend, the steel wire rope 3a directly applies tension to the two fixing clamps 2, the rope tightener 3b is directly arranged on the steel wire rope 3a and can be a hand-operated take-up device as shown in fig. 2, and then a ratchet wheel is used for fixing and maintaining the tension, or can be any steel wire rope 3a rope tightener 3b, and the operation only needs to tighten and fix the steel wire rope 3 a. Preferably for convenient operation, euphroe 3b sets up and faces limit one side at the bridge, and further preferably, wire rope 3 a's both ends are fixed on the fixing clip 2 that the limit one side was faced to the bridge, and the pulley is installed to the lower part of the fixing clip 2 of opposite side, and wire rope 3a walks around the pulley. Alternatively, as shown in fig. 2, one or more steel wires may be used, and both ends of the steel wire rope 3a are directly connected to the two fixing clips 2. It is preferable that the rope tensioner 3b is fixed to the fixing clip 2 according to the kind of the selected rope tensioner 3b, and then one end of the wire rope 3a is connected to the rope tensioner 3b and the other end is connected to the other fixing clip 2.

The fixing clip 2 is U-shaped and is fit with the left side and the right side of the bridge opening half-width, and the inner edge of the fixing clip 2 is provided with anti-skid textures; the anti-slip texture prevents the fixing clip 2 from falling off. One side of the fixing clip 2 on the side close to the edge is clipped in a flowing water hole of the bridge floor, or one side of the fixing clip 2 with a slot is clipped in the slot on the bridge guardrail, or as shown in figure 2, under the condition that the guardrail of the bridge is firmer, the fixing clip 2 on the side close to the edge can also be directly fixed on the guardrail. The other side is simpler, as shown in fig. 3, and it is only necessary to directly clip on the exposed beam plate 1.

As shown in fig. 2, the fixing clip 2 is provided with a mounting seat, and the mounting seat is used as a mounting base of the guardrail. The guardrail provides the safety guarantee for one side that the bridge exposes simultaneously.

Because the steel wire ropes 3a are difficult to avoid bending on the beam plate 1, the steel wire ropes 3a are padded with backing plates at the broken lines of the beam plate 1 to disperse the pressure of the steel wire ropes on the beam plate.

The fixing clip 2 is U-shaped and comprises an upper plate, a lower plate and a side plate, wherein the upper end and the lower end of the side plate are respectively connected with the side edges of the upper plate and the lower plate; the fixing clip 2 is made of metal.

The above-mentioned embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solution of the present invention by those skilled in the art should fall within the protection scope defined by the claims of the present invention without departing from the spirit of the present invention.

Claims

1. A half-width construction method for protecting a bridge is used for performing half-width construction operation on the bridge with a bridge deck formed by transversely splicing a plurality of beam plates (1), and comprises the following steps:

2. The construction method for half-width opening protection of the bridge according to claim 1, wherein in the second step, a beam plate stabilizing device is adopted for loading extrusion stress, and a plurality of beam plate stabilizing devices are arranged at intervals in the length direction of the beam plate (1);

the beam slab stabilizing device comprises two fixing clamps (2) which can be respectively fixed on the left side and the right side of a bridge deck communicated with a half width, the fixing clamps (2) are connected through a tightening mechanism (3), the tightening mechanism (3) is arranged below the beam slab (1), the tightening mechanism (3) is tightened for two, and the fixing clamps (2) can apply inward extrusion stress on the communicated half width.

3. The half-width opening maintaining construction method of the bridge according to claim 2, characterized in that in the second step, the half-width opening maintaining bridge surface at the position of the fixing clip (2) is trimmed so that the fixing clip (2) and the bridge surface are stressed uniformly.

4. The construction method for protecting the half width of the bridge according to claim 1, wherein in the first step, the dismantling operation of the beam plates (1) of the bridge is carried out from the side adjacent to the dismantling half width to the side for protecting the half width gradually;

and before the dismantling operation of the beam plates (1), the asphalt pavement with a half bridge deck to be dismantled is cut and separated, and the asphalt pavement is cut along the splicing seams between the beam plates (1).

5. The half-width construction method for protecting the bridge according to claim 4, wherein before the cutting and separating operation of the asphalt pavement in the first step, the asphalt pavement at two ends of the removed half-width is planed to expose the splicing seam of the beam slab (1); and marking the splicing seam position of the beam plate (1) on the asphalt pavement according to the side edge of the bridge deck and the exposed splicing seam position of the bridge, and then cutting and separating the asphalt pavement along the marked line.

6. The method according to claim 1, wherein a gap is left between the new bridge and the through-cut half of the old bridge in step three to prevent the new bridge from directly contacting the through-cut half.

7. The half width opening maintaining construction method of the bridge according to claim 1, wherein in the fifth step, the pier for maintaining the half width opening is dismantled from top to bottom.

8. A half-width bridge beam plate stabilizing device is used for applying extrusion stress inwards to a half-width beam plate (1) for bridge opening when a bridge with a bridge deck formed by transversely splicing a plurality of beam plates (1) is subjected to half-width opening construction operation,

the beam plate stabilizing device comprises two fixing clamps (2) which can be fixed on the side edge of the bridge deck, the two fixing clamps (2) are connected through a tightening mechanism (3),

two fixing clips (2) are installed respectively in the bridge and are protected the left and right sides of leading to half a width of cloth, tightening mechanism (3) are located beam slab (1) below and both ends are connected respectively and are protected leading to half a width of cloth fixing clips (2), tightening mechanism (3) can extend and contract in order to adjust two the interval of fixing clips (2) and then applys inward extrusion stress to the bridge floor of protecting leading to half a width of cloth.

9. The half-width bridge beam and plate stabilizing device is characterized in that the fixing clips (2) are U-shaped and are matched with the left side edge and the right side edge of the communicated half-width of the bridge, and the inner edges of the fixing clips (2) contacting with the bridge deck are provided with anti-skidding textures;

one side of the fixing clip (2) on the side close to the edge is clipped in a running water hole of the bridge floor, or a groove is formed on the bridge guardrail, and one side of the fixing clip (2) is clipped in the groove.

10. The half bridge beam panel stabilizing device according to claim 8, wherein the tightening mechanism (3) is a wire rope (3 a) with a rope tensioner (3 b),

euphroe (3 b) sets up and faces limit one side at the bridge, the both ends of wire rope (3 a) are fixed and are faced limit one side at the bridge on fixing clip (2), the opposite side the pulley is installed to the lower part of fixing clip (2), wire rope (3 a) are walked around the pulley.