Construction method for blasting and demolishing prestressed concrete continuous box girder bridge

Abstract

The present application relates to the technical field of blasting demolition, and discloses a construction method for blasting demolition of a prestressed concrete continuous box girder bridge, comprising the following steps: S1, hole opening; S2, installation of both-side anti-falling parts; S3, explosive pre-burying; S4, installation of an ignition device; S5, laying of a bottom buffer layer; and S6, ignition of the explosive and removal of the broken stones after the bridge is ignited. In the present application, the explosive pre-burying holes are distributed in a matrix manner on the top of the bridge, so that the whole top of the bridge can be blasted by the point-by-point blasting method. In addition, the inclination of the sinking holes helps the quick separation of the top of the bridge after the top is blasted, and the explosive pre-burying holes in the same group are composed of four sinking holes, so that the top of the bridge is easily separated in the form of a circular truncated cone after blasting.

Description

Technical Field

[0001] This invention relates to the field of demolition by blasting, and in particular to a construction method for demolishing a prestressed concrete continuous box girder bridge by blasting. Background Technology

[0002] A bridge is a structure built to allow roads to cross natural or man-made obstacles. It spans rivers, lakes, and seas, enabling vehicles and pedestrians to pass smoothly. A bridge generally consists of a superstructure, a substructure, and ancillary structures. The superstructure mainly refers to the bridge span structure and bearing system; the substructure includes abutments, piers, and foundations; and ancillary structures include approach slabs, tapered slopes, revetments, and diversion works.

[0003] Bridges need to be demolished after reaching their service life. The existing demolition method is mainly by blasting. In the blasting process, blasting holes are opened on the top of the bridge and explosives are installed in the blasting holes. However, there are the following problems after the blasting: the impact force of the vertically set blasting holes acts horizontally on the inside of the bridge after the explosives detonate, which makes it difficult to separate the bridge as a whole. In addition, the existing blasting process does not have a splash protection device for debris such as gravel, resulting in a wide area affected by the blasting, which is not conducive to subsequent collection and disposal. Summary of the Invention

[0004] The purpose of this invention is to solve the problems in the prior art where the impact force of vertically set blasting holes acts horizontally inside the bridge after the detonation of explosives, making it difficult to separate the bridge as a whole. Furthermore, the existing blasting process does not have anti-splash devices for gravel and other debris, resulting in a wide area affected by the blast and making subsequent collection and processing difficult. Therefore, this invention proposes a construction method for the blasting demolition of prestressed concrete continuous box girder bridges.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A method for the demolition of a prestressed concrete continuous box girder bridge by blasting includes the following steps: S1. Opening: Multiple sets of explosive pre-embedded holes are opened at equal intervals in an M*N arrangement on the top of the bridge deck. Each set of explosive pre-embedded holes consists of four sinking holes. The entrances of the four sinking holes are located on the same outer perimeter of the circle, and the entrances of two opposite sinking holes are perpendicular to the entrances of the other two opposite sinking holes. Each sinking hole is inclined at 30°-60°. S2. Installation of anti-fall devices on both sides: Install peripheral anti-splash plates on both sides of the bridge deck. The peripheral anti-splash plates are made of steel plates and are installed on the sides of the bridge deck at both ends of the same row of explosive pre-embedded holes. The tops of the two peripheral anti-splash plates in the same row are connected by a buffer zipper. S3. Explosive pre-embedding: The explosive is loaded from the inlet of the sinkhole and pre-embedded at the bottom of the sinkhole. S4. Detonation device installation: By connecting the leads in series, the explosives in multiple sets of pre-embedded holes are triggered synchronously. S5. Laying of bottom buffer layer: Laying a buffer layer at the bottom of the bridge to buffer the severe damage to the bottom surface of the bridge at any time after blasting; S6. Detonate the explosives and clear away the debris from the bridge after the explosion.

[0006] Preferably, in S1, the sinkhole is set at a 45° angle to the top of the bridge deck, and the bottom of the sinkhole is located at the center of the bridge deck thickness.

[0007] Preferably, in S1, the sinkhole is set at an angle of 30°-45° to the top of the bridge deck, and the bottom of the sinkhole is lower than the center of the bridge deck thickness.

[0008] Preferably, in S1, the sinkhole is set at an angle of 45°-60° to the top of the bridge deck, and the bottom of the sinkhole is lower than the center of the bridge deck thickness.

[0009] Preferably, in S2, the buffer zipper is formed by two connecting chains, with multiple branches connected to the two connecting chains, and the branches at corresponding positions on the two connecting chains are connected together at the ends furthest from the connecting chains.

[0010] Preferably, in S3, the pre-embedding depth of the explosive in the sinkhole is greater than half the height of the sinkhole.

[0011] Preferably, in S5, the laying width of the bottom buffer layer is widened to between 3m and 5m on each side relative to the width of the bridge.

[0012] The beneficial effects of this invention are as follows: In this invention, the explosive pre-embedded holes are distributed in a matrix on the top of the bridge deck. This allows for point-by-point blasting, which helps to blast the entire bridge deck and top. In addition, the inclined setting of the sinking holes helps to quickly separate the bridge deck and top after blasting. Furthermore, since the group of explosive pre-embedded holes consists of four sinking holes, the bridge deck and top can easily separate into a frustum shape after blasting.

[0013] This invention also includes peripheral splash guards installed on both sides of the bridge deck. This prevents debris such as gravel from splashing outwards after blasting, helps the debris settle centrally, reduces the impact on the surrounding area beneath the bridge deck, and facilitates subsequent collection and processing. Furthermore, the buffer zipper of this invention consists of multiple branch chains connecting two main chains (connecting chains). After blasting, the explosive force is absorbed by the breaking of the branch chains, further reducing the outward splashing of debris such as gravel. Attached Figure Description

[0014] Figure 1 This is a flowchart of a construction method for the blasting demolition of a prestressed concrete continuous box girder bridge proposed in this invention; Figure 2 This invention provides a construction method for the blasting demolition of a prestressed concrete continuous box girder bridge, including a diagram showing the distribution of pre-embedded holes for explosives and the installation diagram of anti-fall devices on both sides. Figure 3 This is a diagram showing the inclination state of the sinkhole in a construction method for the blasting demolition of a prestressed concrete continuous box girder bridge proposed in this invention. Figure 4 This is a structural diagram of the buffer zipper in the construction method for the blasting demolition of a prestressed concrete continuous box girder bridge proposed in this invention. Detailed Implementation

[0015] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0017] Reference Figure 1-4 A construction method for the demolition of a prestressed concrete continuous box girder bridge by blasting includes the following steps: S1. Opening: Multiple sets of explosive pre-embedded holes are opened at equal intervals in an M*N arrangement on the top of the bridge deck. Each set of explosive pre-embedded holes consists of four sinking holes. The entrances of the four sinking holes are located on the same outer perimeter of the circle, and the entrances of two opposite sinking holes are perpendicular to the entrances of the other two opposite sinking holes. Each sinking hole is set at an inclination of 30°-60°. The setting of sinking holes in the same group helps the bridge deck to be removed after blasting.

[0018] Reference Figure 3When the sinkhole is set at a 45° angle to the top of the bridge deck, and the bottom of the sinkhole is located at the center of the bridge deck thickness, this helps the explosive to detonate at the same point above and below the bridge deck, thus facilitating the demolition of the bridge deck. When the sinkhole is set at a 30°-45° angle to the top of the bridge deck, and the bottom of the sinkhole is lower than the center of the bridge deck thickness, this helps the explosive to detonate below the bridge deck. Similarly, when the sinkhole is set at a 45°-60° angle to the top of the bridge deck, and the bottom of the sinkhole is also lower than the center of the bridge deck thickness.

[0019] S2. Installation of anti-fall devices on both sides: Install peripheral splash guards on both sides of the bridge deck. The peripheral splash guards are made of steel plates and are installed on the sides of the bridge deck at both ends of the same row of explosive pre-embedded holes. The tops of the two peripheral splash guards in the same row are connected by a buffer zipper.

[0020] Reference Figure 4 The buffer zipper is composed of two connecting chains, and multiple branches are connected to the two connecting chains. The branches at corresponding positions on the two connecting chains are connected together at the ends away from the connecting chains. In this invention, the buffer zipper is composed of multiple branches connecting two main chains (connecting chains). After the explosion, the explosive force is broken by the branches, thereby achieving the buffering effect.

[0021] In this invention, the splash guard is made of steel plate and can be installed on both sides of the bridge deck by bolts or clips. S3. Explosive pre-embedding: The explosive is loaded from the inlet of the sinkhole and pre-embedded at the bottom of the sinkhole. The pre-embedding depth of the explosive in the sinkhole is greater than half the height of the sinkhole, which helps to make full use of the explosive.

[0022] S4. Detonation device installation: By connecting the leads in series, the explosives in multiple sets of pre-embedded holes are triggered synchronously. S5. Bottom Buffer Layer Laying: A buffer layer is laid at the bottom of the bridge to buffer against severe damage to the bottom surface of the bridge after blasting; the laying width of the bottom buffer layer is increased to between 3m and 5m on each side relative to the width of the bridge.

[0023] S6. Detonate the explosives and clear away the debris from the bridge after the explosion.

[0024] In this invention, the explosive pre-embedded holes are distributed in a matrix on the top of the bridge deck. This allows for point-by-point blasting, which helps to blast the entire bridge deck and top. In addition, the inclined setting of the sinking holes helps to quickly separate the bridge deck and top after blasting. Furthermore, since the group of explosive pre-embedded holes consists of four sinking holes, the bridge deck and top can easily separate into a frustum shape after blasting.

[0025] This invention also includes peripheral splash guards installed on both sides of the bridge deck. This prevents debris such as gravel from splashing outwards after blasting, helps the debris settle centrally, reduces the impact on the surrounding area beneath the bridge deck, and facilitates subsequent collection and processing. Furthermore, the buffer zipper of this invention consists of multiple branch chains connecting two main chains (connecting chains). After blasting, the explosive force is absorbed by the breaking of the branch chains, further reducing the outward splashing of debris such as gravel.

[0026] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A construction method for the demolition of a prestressed concrete continuous box girder bridge by blasting, characterized in that, Includes the following steps: S1. Opening: Multiple sets of explosive pre-embedded holes are opened at equal intervals in an M*N arrangement on the top of the bridge deck. Each set of explosive pre-embedded holes consists of four sinking holes. The entrances of the four sinking holes are located on the same outer perimeter of the circle, and the entrances of two opposite sinking holes are perpendicular to the entrances of the other two opposite sinking holes. The sinking holes are set at a 45° angle to the top of the bridge deck, and the bottom of the sinking holes is located at the center of the thickness of the bridge deck. S2. Installation of anti-fall devices on both sides: Install peripheral anti-splash plates on both sides of the bridge deck. The peripheral anti-splash plates are made of steel plates and are installed on the sides of the bridge deck at both ends of the same row of explosive pre-embedded holes. The tops of the two peripheral anti-splash plates in the same row are connected by a buffer zipper. S3. Explosive pre-embedding: The explosive is loaded from the entrance of the sinkhole and pre-embedded at the bottom of the sinkhole. The pre-embedding depth of the explosive in the sinkhole is greater than half the height of the sinkhole. S4. Detonation device installation: By connecting the leads in series, the explosives in multiple sets of pre-embedded holes are triggered synchronously. S5. Laying of bottom buffer layer: Laying a buffer layer at the bottom of the bridge to buffer the severe damage to the bottom surface of the bridge at any time after blasting; S6. Detonate the explosives and clear away the debris from the bridge after the explosion.

2. The construction method for the blasting demolition of a prestressed concrete continuous box girder bridge according to claim 1, characterized in that, In S2, the buffer zipper is composed of two connecting chains, with multiple branches connected to the two connecting chains. The branches at corresponding positions on the two connecting chains are connected together at the ends furthest from the connecting chains.

3. The construction method for the blasting demolition of a prestressed concrete continuous box girder bridge according to claim 1, characterized in that, In S5, the width of the bottom buffer layer is increased to between 3m and 5m on each side relative to the width of the bridge.

Images