Overpass drainage separation protection modular dismantling construction method

Abstract

The application provides a modularized dismantling construction method for a cross-line bridge drainage separation protection, comprising: construction preparation, middle strip protection support erection, traffic drainage organization, beam plate modularized dismantling, middle strip bridge pier dismantling, site cleaning, and traffic recovery. In the whole dismantling operation, reliable drainage separation protection and modularized dismantling concentrated crushing are adopted, only the traffic is temporarily closed when the beam plate is unloaded, the traffic is not affected at other times, continuous uninterrupted dismantling is realized, and the work efficiency is greatly improved. The dismantling method is efficient and safe, the traffic influence is negligible, and has the value of popularization and application.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of demolition construction, in particular to a modularized demolition construction method for drainage separation and protection of a cross-line bridge. BACKGROUND

[0002] The cross-line bridge is usually arranged at a place where pedestrians and vehicles cross a highway and a first-class highway, especially a place where traffic flow conflicts are serious, and is usually in a simply supported form and has two spans. With the rapid development of national highway construction, many highways need to be reconstructed and widened, and the cross-line bridge needs to be removed first. Since the demolition project has great risks, the section where the cross-line bridge is located has great daytime traffic pressure, so the demolition work is usually carried out at night when the traffic is less (22:00-5:00) to close the traffic, but when there is a large amount of vehicle accumulation, the work needs to be stopped immediately, the site needs to be cleaned, and the traffic needs to be restored, which greatly reduces the demolition efficiency. The cross-line bridge can be demolished after the road is widened and reconstructed, and the demolition speed directly affects the final completion and opening to traffic of the project. SUMMARY

[0003] To solve the above problems, the present application discloses a modularized demolition construction method for drainage separation and protection of a cross-line bridge. In the whole demolition operation, reliable drainage separation and protection and modularized demolition centralized crushing are used, only the traffic is temporarily closed when the beam slab is unloaded, and the traffic is not affected at other times, continuous and uninterrupted demolition is realized, and the work efficiency is greatly improved. The demolition method is efficient and safe, has negligible traffic impact, and has popularization and application value.

[0004] The specific scheme is as follows:

[0005] A modularized demolition construction method for drainage separation and protection of a cross-line bridge, characterized in that it comprises: construction preparation, middle strip protection support erection, traffic drainage organization, beam slab modularized demolition, middle strip bridge pier demolition, site cleaning, and traffic restoration.

[0006] As a further improvement of the present application, the construction preparation comprises: safety technology briefing, preparation of materials and equipment, investigation of various pipelines in the construction area, traffic drainage measures, and other preparation measures.

[0007] As a further improvement of the application, the safety technology disclosure includes: 1) the design profile and current situation of the overpass bridge body, pier column, etc.; 2) the construction sequence and construction method; 3) the maximum cutting height of the standard boom rock drill in the process; 4) the organization and personnel instruction receiving object and method during the bridge demolition construction; 5) the stationing of various construction machinery and personnel and the division of tasks; 6) the safety operation content of temporary power supply, high-altitude operation, and mechanical crushing operation; 7) the safety protection measures and matters needing attention in the middle strip; the material and equipment preparation includes: before the bridge demolition, according to the provided material and equipment list, the materials and equipment are timely organized to enter the site to meet the needs of the start of the bridge demolition construction. The mechanical equipment is guaranteed to have good working performance; the investigation of various pipelines in the construction area includes: before the bridge demolition, the pipelines in the bridge demolition range are investigated, and the property right units are contacted in time for relocation; the traffic diversion measures include: 1) communicate with the traffic police, road administration and other departments to complete the traffic diversion declaration and approval work in advance; 2) improve the production and procurement of relevant signs, signs and lighting facilities; 3) remove the middle strip along the highway and the wave-shaped guardrails on both sides within 50m in the bridge operation range in advance, and replace them with water horses combined with sandbags as temporary protection, the distance between sandbags is not greater than 5m, and the vehicles are protected; 4) the professional traffic protection team uses cone barrels, anti-collision barrels and other to complete the highway diversion work, and improves the relevant signs, signs and warning facilities; the other preparation measures include: 1) complete the construction of the temporary road on both sides of the highway in advance, so that the equipment and vehicles can smoothly enter the operation site during the demolition operation; 2) prepare steel plates for road protection in advance and store them at the side of the temporary road; 3) close the two sides of the overpass in advance, and prohibit personnel from going on the bridge during the bridge demolition construction.

[0008] As a further improvement of the application, the middle strip protection support erection includes: diverting the existing traffic to the outermost lane of the highway, and installing the safety protection scaffold in the middle strip; using steel pipe protection frame + dense mesh net to separate and protect the vehicles on both sides of the pier, the protection frame is arranged in the middle strip, longitudinally, and perpendicular to the two rows of protection frames, the distance from the pier is not less than 5m, and the protection frame parallel to the road is not less than 0.4m from the pier, the dense mesh net needs to cover the entire protection frame to prevent concrete fragments from splashing into the adjacent traffic lane during the bridge demolition process, and the size of the scaffold safety protection is determined according to the actual situation on site; the portal frame extends from one end to the other end, changes the erection direction layer by layer, and cannot be opposite, and the horizontal and vertical degrees are checked and adjusted immediately after one step of erection is completed.

[0009] As a further improvement of the application, the traffic diversion organization includes: traffic conversion instructions and traffic diversion arrangement requirements.

[0010] As a further improvement of the present application, the traffic conversion instruction comprises: firstly, diverting the traffic flow to the right lane of the two-way traffic, and removing the left lane bridge module; then diverting the traffic flow to the left lane of the two-way traffic, and removing the right lane bridge module and the pier column in the middle strip for excavation; and intermittently temporarily blocking the traffic during the removal of the beam plate and the pier column.

[0011] As a further improvement of the present application, the traffic diversion arrangement comprises:

[0012] 1) Warning area S

[0013] Function: To prompt the road construction ahead, so that the driver can pay attention to the traffic changes and take timely measures.

[0014] The length of the warning area is 2000m. Before this section, a construction advance sign should be set up to inform the driver of the road traffic blockage and detour, so that the driver has time to adjust the driving speed. The construction advance sign is set up in a fixed way on the right side of the driving direction in a prominent place. In the warning area, relevant signs should be set up at certain intervals. The distance between the first warning sign and the next sign should not exceed 500m. The distance between the last sign and the first channeling device of the front gradual change area should not be less than 150m, and the distance between the rest of the signs should be between 200-500m.

[0015] In the warning area, "construction ahead" signs, "no overtaking" signs, "narrow lane ahead" signs, "no passing" signs, "direction" signs and "speed limit" signs should be set up uniformly. The speed limit in this area is 60km / h.

[0016] 2) Upstream transition area LS

[0017] Function: To guide the flow of vehicles to change the driving direction and change lanes.

[0018] The length of this area is about 300m. When the vehicle drives to the front gradual change area, the driving speed should be less than 40km / h. "Direction" signs should be set up before the front gradual change area.

[0019] 3) Buffer area H

[0020] Function: To guide the traffic flow to move in an orderly manner.

[0021] The length of the buffer area is about 200m. Roadblocks, concrete isolation piers or conical traffic signs should be set up in the buffer area.

[0022] 4) Work area G

[0023] Function: Isolation devices must be set up between the lane and the work area, and the work area should also provide a safe entrance and exit for engineering vehicles.

[0024] Throughout this area, traffic cones and water-filled barriers are used to separate the roadway from the traffic lanes. Where one half of the road is closed and the other half has two lanes for two-way traffic, enhanced safety measures should be implemented in the median of the detour section, using medium-sized water-filled barriers continuously deployed to guide vehicles to their respective lanes. Sandbag barriers are used at lane change entrances and exits, along with comprehensive safety signs and protective facilities.

[0025] 5) Downstream transition zone LX

[0026] Function: It serves to guide traffic, directing vehicles to change direction, switch lanes, and enter the normal driving lane.

[0027] The length of this area is set at approximately 30 meters. After vehicles pass through the construction area, a gradual transition zone should be set up using traffic cones to guide vehicles into the normal lane.

[0028] 6) Termination region Z

[0029] Function: Indicates the end of the construction zone and the lifting of construction restrictions; located at the end of the construction zone. The length of the termination zone is approximately 30m, and a speed limit lifting sign is placed at the end of the termination zone.

[0030] As a further improvement of the present invention, the modular dismantling of the beam slab includes: before modular dismantling the beam slab, firstly cutting off the wet joints of the beam slab and the connection between it and the expansion joint. Then, rock drills are placed on both sides of the left (right) span of the bridge, with one rock drill on each side of each span simultaneously and symmetrically breaking the concrete of the beam slab from top to bottom, forming a "V-shaped" cut on the web, with a cut depth of 2 / 3 of the beam height, ensuring that the main reinforcement of the bottom slab of the beam is cut off. The cut position is 1m longitudinally away from the median pier, and the rock drill is used to press the modular beam down. Simultaneously, a 2cm steel plate is laid on the existing highway pavement to reduce damage to the existing asphalt concrete pavement of the highway when the beam slab falls. Considering the safety of traffic on the other side during construction, traffic is temporarily and intermittently closed during the entire process from breaking to unloading each beam slab. Finally, the dismantled beam slab is moved to a temporary breaking area for further breaking. The demolition area should be staffed by designated personnel, and unauthorized personnel, vehicles, and machinery are strictly prohibited from entering the work area. During the demolition process, a mist cannon was used to spray dust at the demolition site every 5 minutes to ensure a good working environment.

[0031] As a further improvement of the present application, the middle strip bridge pier removal comprises: the middle strip bridge pier removal needs to close the right lane, the vehicles are guided to the left lane for bidirectional traffic, before the chiseling, the pier cap is connected with the anti-collision wall of one side abutment by using a 40m steel wire rope (with a diameter of 2cm) to ensure that the pier column does not overturn into the unsealed traffic lane during the chiseling process. In order to reduce the damage to the existing highway pavement during the overturning process of the pier column and the pier cap and facilitate the chiseling construction of the rock drill, the pier column is chiseled in sections, and the height of each section is controlled to be less than 3m. The traffic of the passing lane is temporarily closed during the chiseling and overturning process to ensure the safe driving of the passing vehicles.

[0032] As a further improvement of the present application, the site cleaning and traffic recovery comprises: after the removal is completed, the site is cleaned by the operating personnel and the machinery, the concrete blocks are transported to the outside of the line by the excavator and the muck car, the road surface steel plate is lifted, and the machinery is withdrawn from the site. Finally, the road surface is washed by using a water sprinkler, and the traffic is recovered after the site cleaning is completed and the safety facilities are recovered.

[0033] The present application has the following advantages:

[0034] 1. By using reliable drainage separation protection measures, the influence on the traffic is greatly reduced, and the removal time can be selected in the daytime, which is more efficient than the previous stage closure of the traffic at night to avoid heavy traffic, and is more conducive to construction organization.

[0035] 2. The bridge plate of the overpass bridge is removed in a modular manner and is broken in a concentrated manner in a breaking site, the breaking occupies the road for a short time, the waste material is prevented from splashing and causing injury, the breaking machinery is continuously operated, and the cost is reduced.

[0036] 3. By using the drainage separation protection modular removal, the construction period of each overpass bridge can be shortened by 1 / 3-2 / 3, the construction process is simple, the equipment requirement is not high, and the application is easy to popularize. DETAILED DESCRIPTION

[0037] Figure 1 The flowchart of the present application.

[0038] Figure 2 The drawing of the protection frame for closing one lane of the left and right lanes.

[0039] Figure 3 The side view of the safety protection of the middle strip.

[0040] Figure 4 The cross section view of the safety protection of the middle strip.

[0041] Figure 5 The drawing of guiding the traffic to the right lane and removing the bridge of the left lane.

[0042] Figure 6 The drawing of guiding the traffic to the left lane and removing the bridge of the right lane.

[0043] Figure 7 Traffic diversion schematic diagram.

[0044] Figure 8 Positioning diagram for V-shaped notch.

[0045] Figure 9 Protection diagram for middle strip not to overturn inwardly.

[0046] Figure 10 Segmented removal diagram for middle strip pier. Embodiment

[0047] The present application is further illustrated below in conjunction with the accompanying drawings and specific embodiments, and it should be understood that the following specific embodiments are only used to illustrate the present application and are not used to limit the scope of the present application.

[0048] As shown in Figure 1 A modular removal construction method for cross-line bridge diversion and separation protection, comprising: construction preparation, middle strip protection support erection, traffic diversion organization, beam plate modular removal, middle strip pier removal and site cleaning, and traffic recovery.

[0049] In the embodiment, the construction preparation comprises: safety technical briefing, material and equipment preparation, investigation of various pipelines in the construction area, traffic diversion measures, and other preparation measures.

[0050] In the embodiment, the safety technology disclosure includes: 1) the design profile and the current situation of the overpass bridge body and the pier column; 2) the construction sequence and the construction method; 3) the maximum cutting height of the rock drilling machine standard movable arm in the process; 4) the organization and the personnel instruction receiving object and the way during the bridge demolition construction; 5) the station and the task division of each construction machinery and personnel; 6) the temporary power supply safety operation content, the high-altitude operation safety content, the mechanical crushing operation safety content and the like; 7) the safety protection measures and the matters needing attention of the middle strip; the material and equipment preparation includes: before the bridge demolition, according to the provided material and equipment list, the materials and equipment are timely organized to enter the site, so as to meet the starting needs of the bridge demolition construction. The mechanical equipment is guaranteed to have good working performance; the investigation of various pipelines in the construction area includes: before the bridge demolition, the pipelines in the bridge demolition range are investigated, and the property right unit is timely contacted for relocation; the traffic diversion measures include: 1) the communication with the traffic police, the road administration and the like, the reporting and the approval work of the traffic diversion is completed in advance; 2) the production and the purchase of the related signs, the signboards and the lighting facilities are improved; 3) the overpass operation range of the middle strip and the two sides of each 50m wave-shaped guardrail are removed in advance, and are replaced by the water horse combined with the sand bag as the temporary protection, the sand bag spacing is not greater than 5m, and the vehicle is protected; 4) the professional traffic protection team uses the cone barrel, the anti-collision barrel and the like to complete the highway diversion work, and improves the related signs, the signboards and the warning facilities; the other preparation measures include: 1) the construction work of the temporary road on the two sides of the highway is completed in advance, so that the equipment and the vehicle can smoothly enter the operation site during the demolition operation; 2) the steel plate for the road surface protection is prepared in advance and is stored at the temporary road side; 3) the closure measures of the overpass on the two sides are prepared in advance, and the personnel are prohibited to go up the bridge during the bridge demolition construction.

[0051] In the embodiment, the middle strip protection support erection includes: the existing traffic is respectively diverted to the outermost lane of the highway, the installation of the safety protection scaffold is carried out at the middle strip, Figure 2 ; the steel pipe protection frame + dense mesh net is used on the two sides of the pier to separate and protect the vehicle, the protection frame is arranged in the middle strip, is arranged longitudinally and is perpendicular to the two rows of protection frames of the road, the distance between the protection frame and the pier is not less than 5m, the protection frame parallel to the road is not less than 0.4m from the pier, the dense mesh net needs to fully cover the entire protection frame, so as to prevent the concrete fragments from splashing to the adjacent traffic lane in the process of the bridge drilling, and the safety protection size of the scaffold is determined according to the actual situation of the site, such as Figure 3 and 4 ; the portal is installed to extend from one end to the other end, the erection direction is changed layer by layer, and the portal cannot be relatively erected, and the horizontal and vertical degrees of the portal are checked and adjusted immediately after the portal is erected.

[0052] In the embodiment, the traffic diversion organization includes: the traffic conversion instruction, the traffic diversion arrangement requirement

[0053] In this embodiment, the traffic conversion instruction includes: first, divert the traffic to the right lane of the two-way traffic, remove the left lane of the bridge module, such as Figure 5 ; then divert the traffic to the left lane of the two-way traffic, remove the right lane of the bridge module and the pier column in the middle strip for excavation, such as Figure 6 ; during the removal of the beam slab and pier column, the traffic is intermittently temporarily blocked.

[0054] In this embodiment, the traffic diversion arrangement requires Figure 7 including:

[0055] 1) warning area S

[0056] Function: prompt the road construction ahead, make the driver pay attention to the traffic change, so as to take timely measures.

[0057] The length of the warning area is 2000m. Before this section, construction warning signs should be set up to inform the driver of the road traffic blockage and detour, so that the driver has time to adjust the driving speed. The construction warning signs are set up in a fixed way on the right side of the driving direction in a conspicuous place. In the warning area, relevant signs should be set up at certain intervals. The distance between the first warning sign and the next sign should not exceed 500m. The distance between the last sign and the first channeling device of the front gradual change area should not be less than 150m, and the distance between the rest of the signs should be between 200-500m.

[0058] In the warning area, "construction ahead" signs, "no overtaking" signs, "narrow lane ahead" signs, "no passing" signs, "direction" signs and "speed limit" signs are uniformly set up. The speed limit in this area is 60km / h.

[0059] 2) upstream transition area LS

[0060] Function: guide the flow, guide the vehicle to change the driving direction and change the lane.

[0061] The length of this area is about 300m. When the vehicle drives to the front gradual change area, the driving speed should be less than 40km / h. "Direction" signs should be set up before the front gradual change area.

[0062] 3) buffer area H

[0063] Function: guide the traffic to orderly travel.

[0064] The length of the buffer area is about 200m. Roadblocks, concrete isolation piers or conical traffic signs should be set up in the buffer area.

[0065] 4) working area G

[0066] Function: isolation devices must be set up between the lane and the working area, and the working area should also provide safe access for engineering vehicles.

[0067] The whole area is isolated from the traffic lane by conical traffic signs and anti-collision buckets. When half of the road is closed and the other half is two-lane traffic, the middle of the road should be strengthened to set up safety facilities in the detour section. The middle separation uses medium water horses, which are continuously laid out to guide vehicles to their respective lanes. Sand buckets are used to isolate the entrance and exit positions of the lane change, and complete safety signs and protective facilities are set up.

[0068] 5) Downstream transition zone LX

[0069] Function: It plays a guiding role and guides vehicles to change driving direction, change lanes, and enter normal driving lanes.

[0070] The length of this area is set to about 30m. After the vehicle passes through the construction area, a gradual change area should be set up using conical traffic signs to guide the vehicle into the normal lane.

[0071] 6) Termination zone Z

[0072] Function: It indicates the end of the construction area and the removal of construction restrictions, located at the end of the construction area. The length of the termination zone is greater than 30m, and the end of the termination zone is provided with a speed limit removal sign.

[0073] In this embodiment, the beam plate modular demolition includes: before the beam plate is modularly demolished, the connection between the beam plate wet joint and the expansion joint is first cut off. Then a rock drill is placed on both sides of the left (right) span bridge, and 1 rock breaker is arranged on each side of the single span to simultaneously and symmetrically crush the concrete of the beam plate from top to bottom, forming a "V-shaped" notch on the web, with a notch depth of 2 / 3 of the beam height, ensuring that the bottom plate main reinforcement of the cut beam is cut off. As shown in Figure 8 , the longitudinal distance between the notch position and the mid-division belt pier column is 1m, and the rock drill is used to press and drop the module beam. At the same time, 2cm steel plates are laid on the existing highway surface to reduce the damage to the existing highway asphalt concrete surface when the beam plate falls. Considering the safety of traffic on the other side during construction, the traffic is temporarily and intermittently closed during the entire process from crushing to unloading of each piece of beam plate. Finally, the demolished beam plate is moved to the temporary crushing area for crushing. The drilling area should be manned, and non-related personnel, vehicles and machinery are strictly prohibited from entering the work area. During the demolition process, a fog cannon is used to spray dust every 5 minutes to ensure the working environment of the site.

[0074] In this embodiment, the mid-division belt pier demolition includes: the right span needs to be closed for the demolition of the mid-division belt pier, and the vehicles are diverted to the left span for two-way traffic. Before drilling, a 40m steel wire rope (2cm in diameter) is used to connect the pier cap with the anti-collision wall of one side of the abutment to ensure that the pier column does not overturn into the unsealed traffic lane during drilling, as shown in Figure 9To reduce the damage to the existing highway pavement during the process of the pier column and pier cap falling and facilitate the rock drill to remove the construction, the pier column is removed in sections, each section is controlled within 3m, such as Figure 10 The traffic of the passing lane is temporarily closed during the process of removal and pulling down to ensure the safe driving of the passing vehicles.

[0075] In the embodiment, the site cleaning and traffic recovery include: immediately after the completion of the removal, the site is cleaned by the operating personnel and the machinery, the concrete blocks are transported to the outside of the line by the excavator and the muck truck, the road steel plate is lifted and removed, and the machinery is withdrawn from the site. Finally, the road is washed by the water sprinkler, and the traffic is recovered after the site is cleaned and the safety facilities are recovered.

[0076] The principle of the method is to realize the removal of the overpass bridge without interrupting the traffic by draining the vehicles. First, the overpass bridge is divided into modules, and each piece of beam is taken as a module. Before the construction, 2cm-thick steel plates are laid on the road surface to protect the existing highway pavement. Then, the crushing machinery is placed on the left (right) side of the bridge, and 1 crushing machine is arranged on each side of the single span. The beam plate is symmetrically crushed from top to bottom, a V-shaped notch is formed on the web, the notch depth is 2 / 3 of the beam height, and the width is 5cm, which can ensure the cutting of the main steel bar connection inside. The longitudinal distance between the notch position and the middle pier column is 1m, and the rock drill is used to press and drop the module beam. After the module beam is dropped, it is transported to the temporary removal site on the roadside for small removal and destruction. Finally, the crushed slag is transported to the waste slag field. In this way, the time of occupying the road by the machinery can be reduced, and the construction period can be effectively shortened. At the same time, the method can realize the removal of the bridge without interrupting the traffic, and has less impact on the traffic. Therefore, in order to achieve the purpose of protecting the traffic safety of the vehicles, the traffic flow is guided and protected in the non-construction section, mainly using ton bags, anti-collision barrels and related traffic facilities to guide the upstream and downstream traffic flow, so that the vehicles can pass through the construction section safely and orderly. In the construction section, the middle pier bridge is protected by the protection frame to ensure the safety of the operating personnel. After ensuring the safety of the vehicle traffic, the daytime construction can be selected to avoid the night operation, which can better organize the construction. Through the guidance of the vehicles, each half of the bridge is removed, that is, the vehicles are divided into left and right directions, the right half of the bridge is removed, and the left half of the bridge is removed in the same way.

[0077] The quality control of the application is as follows:

[0078] 1. Engineering quality control standard

[0079] Highway Maintenance Safety Operation Regulations DB34 / T2196-2014

[0080] Technical Code for Construction of Highway Bridges and Culverts (JTG / TF50-2011)

[0081] Safety Regulations for Highway Maintenance Operation (JTGH30-2015)

[0082] Technical Code for Safety of Building Demolition (JGJ147-2016)

[0083] Technical Code for Safety of Building Demolition (JGJ147-2016)

[0084] 2 Quality Control Measures

[0085] 2.1 Steel wire rope is used to bundle the beam body during the demolition process, and one end is connected to the abutment position. Thus, the stability of the beam body is ensured, and overturning is prevented.

[0086] 2.2 The connection of the wet joint needs to be cut off before construction, so that the beam bodies will not form a whole during demolition, thus ensuring that the beam body falling will not cause serious damage to the road surface.

[0087] 2.3 The personnel on site need to have similar bridge demolition experience, and the person in charge of the demolition site needs to be familiar with the principles of this method to ensure the quality of the bridge demolition.

[0088] 2.4 The embedded depth of the pier is checked in time before the pier is demolished to ensure the integrity of the pier demolition.

[0089] 2.5 When there are 2 pieces of beam slab left, use the excavator on the other side to support and prevent vibration from causing beam slab instability.

[0090] The safety measures of the present application are as follows:

[0091] 1. The on-site command personnel and traffic diversion personnel use intercom to communicate, ensuring that the on-site bridge demolition and traffic diversion are coordinated, and if any abnormalities are found, traffic is closed immediately, and passing vehicles are guided to prevent entering the construction area.

[0092] 2. Safety helmets and reflective vests must be worn when entering the construction site, and safety belts must be worn for high-altitude work. Hard-soled shoes and slippers are not allowed.

[0093] 3. The mechanical equipment used on site must strictly follow the operation procedures and specifications, and must be maintained by a dedicated person. The key parts are checked frequently, the drill rig cab must be equipped with a splash-proof device to protect the operator, and the splash radius should be closed during the bridge breaking process. No one is allowed to approach the construction area.

[0094] 4. The temporary electrical equipment on the construction site must have good insulation, the metal shell should be protected by zero, the line must be erected neatly according to the specification, the distribution box on site should be set with a fence and a clear safety warning sign, and good rain protection measures should be taken.

[0095] 5. All construction information signs, speed limit signs, turning signs and other safety signs on the expressway are fixed firmly, and special personnel are arranged to maintain them to prevent them from falling, tilting or mispositioning. During the process of segmentally cutting the pier column, the expressway is temporarily blocked intermittently until the pier column is completely laid down.

[0096] 6. The temporary demolition site is surveyed in advance. If there are trenches, the trenches should be filled with soil, paved and rammed in advance.

[0097] The environmental protection measures of the present application are as follows:

[0098] 1. The safety management department is mainly responsible for the environmental protection inspection and supervision of the project, and the construction team is responsible for the specific implementation.

[0099] 2. The demolition waste should not be placed randomly, but should be transported to the designated site for stacking according to the requirements, and the smooth passage of construction vehicles and machinery should be ensured.

[0100] 3. During the construction period, the construction area should be treated by spraying water with a water spraying vehicle and a fog gun to reduce dust.

[0101] 4. Vehicles with good condition and tight sealing should be selected for cleaning the waste to prevent running, escaping, dripping and leaking during the cleaning and transportation process. The outside and wheels of the waste cleaning vehicles should be washed successively to prevent the soil from being carried out, and the construction machinery should be washed.

[0102] 5. After the construction is completed, the construction site and the surrounding area should be cleaned and washed in time to remove the floating dust and soil on the ground.

[0103] 6. During the construction process, dangerous waste such as waste engine oil and waste paint should not be disposed of randomly, but should be disposed of by a qualified unit, and the procedures for transferring the dangerous waste should be handled in accordance with the law.

[0104] The benefit analysis of the present application is as follows:

[0105] 1. Economic benefit

[0106] Compared with the traditional method of in-situ demolition of the overpass bridge, the present application optimizes the demolition process by reliable flow separation protection and modular demolition, centralized crushing, mechanized and streamlined operation, improves the utilization efficiency by 30%, and at the same time, the entire demolition process is not affected by traffic, and the demolition speed is accelerated by 20% compared with the traditional method, the demolition period of each bridge is saved by 1 day, and the demolition efficiency is greatly improved. Taking the Nanjing-Hefei National Expressway Zhangdian Hub to Chuhe Bridge Expressway Expansion Project and Nanjing Jiangbei Avenue Quickening Reconstruction Investment and Construction (BT Project) JBDD-11 Section as an example, 5 overpass bridges are demolished by using the present application, and the comprehensive construction cost is saved by 270,000 yuan through cost accounting.

[0107] 2. Social benefit

[0108] The method has proper drainage protection measures, and the temporary interruption of traffic flow when the beam module is unloaded has negligible impact on traffic. Daytime demolition can also ensure the safe and smooth passage of main line traffic, which is safer and more secure than the traditional nighttime demolition. Meanwhile, the transportation and demolition greatly reduce the impact of broken dust on driving and personnel, and is worth popularizing and applying.

[0109] Application examples of the invention:

[0110] 1. A highway expansion project

[0111] The total length of the project road is 5.119 kilometers. There are two overline bridge demolitions in the bid section. The bridge is a 2*16m prefabricated reinforced concrete hollow slab, with a beam height of 80cm and a beam width of 99cm. The bridge deck of 1# overline bridge is 9.08m wide, with 9 hollow slab beams per hole. The bridge deck of 2# overline bridge is 6m wide, with 6 hollow slab beams per hole.

[0112] The project adopted the "overline bridge drainage separation protection modular demolition construction method", successfully realized traffic demolition operation, and completed the demolition work of each bridge from 7am to 13pm, with a total demolition time of only 6 hours. Four rock drills and one excavator were used throughout the construction, and no mechanical downtime occurred. No traffic accidents occurred throughout the process, and traffic flow was smooth without congestion. At the same time, nighttime construction was avoided, costs were reduced, and the safety of workers was ensured. The related technology of this method is advanced, and the economic benefits are significant.

[0113] 2. A widening reconstruction project

[0114] The project is located in a certain street and is a widening reconstruction project of an old road with a total length of 4.447 kilometers. It is a widening reconstruction of the existing certain ferry connecting line. There are three bridge demolitions in the bid section. The bridge superstructure is a 1-union 2-span prestressed hollow slab beam, with 10 slab beams per span, a total of 40 slab beams. The lower part is a cylindrical pier and a gravity type abutment, with a total demolition volume of 284m3.

[0115] Each bridge realized daytime operation, and the demolition operation time was shortened by 1 / 2 compared to traditional nighttime phased traffic closure demolition. Mechanical operation did not stop and wait, greatly improving the efficiency of mechanical operation. At the same time, the vehicles passed smoothly, and there was no large-scale congestion or traffic accidents.

[0116] The technical means disclosed in the present application are not limited to the technical means disclosed in the above embodiments, and include technical solutions composed of any combination of the above technical features. It should be noted that, for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements are also considered within the scope of protection of the present application.

Claims

1. A method for modular demolition construction of a bridge over a waterway with drainage separation protection, characterized in that, The application relates to a construction method for a middle-divided bridge. The method comprises the following steps: construction preparation, middle-divided protection support erection, traffic diversion organization, beam and slab modularization removal, middle-divided pier removal and site cleaning, and traffic recovery. The traffic diversion organization comprises traffic conversion instructions and traffic diversion arrangement requirements; the traffic conversion instructions comprise the following steps: first, diverting the traffic flow to the right lane for bidirectional traffic, and removing the left lane bridge module; then, diverting the traffic flow to the left lane for bidirectional traffic, and removing the right lane bridge module and the middle-divided pier column for chiseling; intermittently temporarily blocking the traffic during the removal of the beam and slab and the pier column; the beam and slab modularization removal comprises the following steps: before the modularization removal of the beam and slab, first, cutting the connection between the beam and slab wet joint and the expansion joint; then, placing a rock drill on the left / right lane of the bridge, and symmetrically and simultaneously removing the beam and slab from top to bottom by using a crusher, so as to form a "V-shaped" cut on the web, the cut depth is 2 / 3 of the beam height, and the bottom plate main reinforcement of the cut beam is ensured; the cut position is 1m away from the middle-divided pier column in the longitudinal direction, and the rock drill is used to press and drop the module beam; meanwhile, laying a 2cm steel plate on the existing highway pavement to reduce the damage to the existing highway asphalt concrete pavement when the beam and slab drop; considering the safety of the traffic on the other side during the construction process, the traffic is temporarily and intermittently blocked during the removal and dropping of each piece of beam and slab; finally, removing the removed beam and slab to a temporary crushing area for crushing; a person should be on duty in the chiseling area, and non-related personnel, vehicles and machines are strictly prohibited from entering the operation area; during the removal process, a fog gun is used to spray dust at the removal position every 5 minutes to ensure the operation environment of the site; the middle-divided pier removal comprises the following steps: the middle-divided pier removal needs to close the right lane, the vehicles are diverted to the left lane for bidirectional traffic, a 40m steel wire rope is used to connect the pier cap and the anti-collision wall of one side of the abutment before chiseling, so as to ensure that the pier column does not overturn into the unsealed traffic lane during the chiseling process; in order to reduce the damage to the existing highway pavement during the overturning of the pier column and the pier cap and facilitate the chiseling construction of the rock drill, the pier column is chiseled in sections, the height of each section is controlled to be less than 3m, and the traffic of the traffic lane is temporarily blocked during the chiseling and overturning process, so as to ensure the safe driving of the passing vehicles.

2. The method of claim 1, wherein The construction preparation comprises the following steps: safety technical briefing, material and equipment preparation, investigation of various pipelines in the construction area, traffic diversion measures and other preparation measures.

3. The method of claim 2, wherein The safety technology disclosure includes: 1) the design profile and current situation of the overpass bridge body and pier column; 2) the construction sequence and construction method; 3) the maximum cutting height of the standard boom rock drill during the process; 4) the organization and personnel instruction receiving object and method during the bridge demolition construction; 5) the station and task division of various construction machinery and personnel; 6) the safety operation content of temporary power supply, high-altitude operation and mechanical crushing operation; 7) the safety protection measures and matters needing attention of the middle strip; the material and equipment preparation includes: before the bridge demolition, the materials and equipment are organized in time according to the provided material and equipment list to meet the needs of the bridge demolition construction; the mechanical equipment is guaranteed to have good working performance; the investigation of various pipelines in the construction area includes: before the bridge demolition, the pipelines in the bridge demolition range are investigated, and the property right units are contacted in time for relocation; the traffic diversion measures include: 1) communicate with the traffic police and road administration departments to complete the traffic diversion declaration and approval work in advance; 2) improve the production and procurement of relevant signs, signs and lighting facilities; 3) remove the middle strip along the highway and the wave-shaped guardrails on both sides of the bridge operation range in advance, and replace them with water horses combined with sand bags as temporary protection, with a sand bag spacing of not more than 5m to protect the vehicles; 4) the professional traffic protection team uses conical barrels and anti-collision barrels to complete the highway diversion work and improve the relevant signs, signs and warning facilities; the other preparation measures include: 1) complete the construction of temporary roads on both sides of the highway in advance to facilitate the smooth entry of equipment and vehicles into the construction site during the demolition operation; 2) prepare steel plates for road protection in advance and store them at the side of the temporary road; 3) close the two sides of the overpass bridge in advance, and prohibit personnel from going on the bridge during the bridge demolition construction.

4. The method of claim 1, wherein The middle strip protection support erection includes: the existing traffic is respectively diverted to the outermost lane of the highway, and the installation of the safety protection scaffold is carried out at the middle strip; steel pipe protection frame + dense mesh net is used on both sides of the pier to separate and protect the vehicles, the protection frame is arranged in the middle strip, longitudinally and perpendicular to the road, the distance between the two rows of protection frames from the pier is not less than 5m, the distance between the row of protection frames parallel to the road from the pier is not less than 0.4m, the dense mesh net needs to cover the entire protection frame to prevent concrete fragments from splashing into the adjacent traffic lane during the bridge demolition process, and the size of the scaffold safety protection is determined according to the actual situation on site; the portal frame extends from one end to the other end, changes the erection direction layer by layer, and cannot be relative, and the horizontal and vertical degrees are checked and adjusted immediately after one step of erection is completed.

5. The method of claim 1, wherein The traffic diversion arrangement requirements include: 1) warning area S Function: prompt the road construction in front, make the driver pay attention to the traffic change, so as to take measures in time; Warning zone length is 2000m; before this section, construction notice signs should be set up to inform the road traffic blockage and detour, so that the drivers have time to adjust their driving speed; construction notice signs are set up in a fixed way on the right side of the driving direction in a prominent place; in the warning zone, relevant signs should be set up at certain intervals, the distance between the first warning sign and the next sign should not exceed 500m; the distance between the last sign and the first channelization device of the front transition zone should not be less than 150m, and the distance between the rest of the signs should be between 200-500m; In the warning zone, "construction ahead" signs, "no overtaking" signs, "narrow lane ahead" signs, "no passing" signs, "direction" signs and "speed limit" signs should be set up uniformly; the speed limit in this area is 60km / h; 2) Upstream transition zone LS Function: to guide the flow of vehicles to change direction and lane; The length of this zone is about 300m; when vehicles drive to the front transition zone, the driving speed should be less than 40km / h; "direction" signs should be set up before the front transition zone; 3) Buffer zone H Function: to guide the orderly flow of vehicles; The length of the buffer zone is about 200m; roadblocks, concrete barriers or conical traffic signs should be used to separate the buffer zone; 4) Work zone G Function: isolation devices must be set up between the lane and the work zone, and the work zone should also provide safe access for engineering vehicles; In this area, conical traffic signs and anti-collision buckets are used to separate the passing lane; when half of the road is closed and the other half is a two-lane two-way road, the middle safety facilities in the road section should be strengthened, the middle separation should use medium-sized water horses, and the vehicles should be guided to their respective lanes; sand barrels should be used to separate the entrance and exit positions of lane changing, and complete safety signs and protective facilities should be set up; 5) Downstream transition zone LX Function: to guide the flow of vehicles to change direction and lane, and enter the normal driving lane; The length of this zone is about 30m; after vehicles drive through the construction zone, a rear transition zone should be set up using conical traffic signs to guide vehicles into the normal lane; 6) Termination zone Z Function: to indicate the end of the construction zone and the removal of construction restrictions, located at the end of the construction zone; the length of the termination zone is greater than 30m, and the end of the termination zone is set up with a speed limit removal sign.

6. The method of claim 1, wherein The site cleaning and traffic restoration includes: immediately after completion, organizing workers and machinery to clean the site, using excavators and dump trucks to transport concrete blocks to the outside of the line, lifting the road steel plates, and organizing machinery to withdraw from the site; finally, using a water truck to wash the road, and restoring traffic after the site is cleaned and the traffic facilities are restored.

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