A method for installing a steel box girder across an existing expressway with short-time traffic interruption

Abstract

The present application relates to the field of high-speed construction technology, in particular to a kind of short-time interruption traffic implementation steel box girder installation construction method across existing high-speed, comprising the following steps: S1, before steel box girder processing and manufacturing, the construction site is strictly investigated, measurement, especially for the plane position and width of the existing high-speed central separation zone, the plane position of the road both sides wave guardrail, topographic elevation;S2, according to the measured data, steel box girder bridge is divided into steel box girder longitudinal section, and numbered arrangement;S3, after steel box girder longitudinal section division is determined, each section is decomposed into several transverse unit body, and numbered arrangement;S4, install temporary support at the central separation zone of existing highway;S5, according to erection sequence (section division sequence) hole installation half-width steel box girder unit body across high-speed. The present application can reduce the influence on the existing high-speed normal traffic by the above method, simple process, easy to implement, compared with integral hoisting mode, reduce construction cost.

Description

Technical Field

[0001] This invention relates to the field of high-speed construction technology, specifically a method for installing steel box girders across existing highways during short-term traffic interruptions. Background Technology

[0002] When constructing steel structure bridges across existing highways, in order to minimize the impact on traffic on the existing highways, construction is usually carried out by closing one side of the road. However, the construction permit process is cumbersome and time-consuming, and it seriously affects the normal travel of other vehicles. Alternatively, traffic diversion measures such as using borrowed lanes may be adopted, but these pose significant traffic safety risks. Another option is to use the steel box girder launching method, which is complicated, has a long construction period, is not suitable for ramp bridges with small curve radii, and also creates a psychological burden on drivers, posing certain safety risks. Summary of the Invention

[0003] The purpose of this invention is to provide a method for installing steel box girders across existing highways during short-term traffic interruptions.

[0004] The above-mentioned objective of this invention is achieved through the following technical solution: a method for installing steel box girders across existing highways with short-term traffic interruption, comprising the following steps: S1. Before the steel box girder is processed and manufactured, a thorough investigation and measurement of the construction site is carried out, especially the planar position and width of the existing highway central divider, the planar position of the corrugated guardrails on both sides of the road, and the terrain elevation. S2. Based on the measured data, use finite element analysis software to analyze the overall structural characteristics and stress characteristics of the bridge, and combine the transportation restrictions of steel structures to divide the steel box girder bridge into longitudinal segments and number them. S3. After the longitudinal segments of the steel box girder are determined, each segment is further decomposed into several transverse units and numbered and arranged. S4. Install temporary supports at the median strip of the existing highway: occupy the overtaking lanes on both sides of the median strip of the existing highway as the construction area, and set up various traffic channelization facilities according to the requirements of the highway traffic police and road administration units to ensure construction safety and driving safety. The traffic channelization facilities can be removed after the installation is completed. S5. Install the half-width steel box girder unit across the highway one span at a time according to the erection sequence (segment division sequence).

[0005] By adopting the above technical solution, step S2 is used to construct a temporary support system only in the original median strip of the highway, while the temporary support systems for the remaining sections are located outside the original road.

[0006] The present invention is further configured such that step S5 includes the following steps: A1. Implement half-width traffic channelization on existing highways. Place signs indicating "Construction Ahead," "Slow Down," and "Road Narrowing" at intervals of 3km, 2km, 1.5km, 1km, 500m, and 300m ahead of oncoming traffic in the construction area, along with speed limit signs. Improve the traffic channelization area using cones, water-filled barriers, solar-powered flashing lights, and guide lights. Sufficient personnel should be deployed for traffic control and monitoring. A2. Preparations before steel box girder hoisting: (Construction site restrictions outside existing expressways): Large hoisting equipment (≥260t truck crane) will be used at the central median of the existing expressway, and a traffic channelization area will be set up by occupying the overtaking lanes in both directions on the original road. The steel box girder units will be transported by transport vehicles, which will enter the construction area in the order of erection from the direction of oncoming traffic. Before the formal hoisting, the existing road will be open to traffic. The transport vehicles and hoisting equipment will be prepared for hoisting. Two windproof hemp ropes will be tied to the steel box girder unit. After the steel wire ropes used for hoisting are firmly connected to the four hoisting points set on the steel box girder unit, the safety officer will inspect and accept it. After passing the inspection, the hoisting commander will direct the operators to slowly lift the steel girder about 10cm away from the transport vehicle and then stand by. (The construction site outside the existing expressway is in good condition): Large lifting equipment (≥300t truck crane) is used and located outside the existing expressway corrugated guardrail. The crane station must be leveled as necessary. The transport vehicle is located outside the cross-line and can cooperate with the lifting. Optionally, the transport vehicle can occupy the emergency lane of the existing expressway. Ensure that the traffic channelization facilities in the direction of oncoming traffic in the construction area meet the requirements. After the lifting preparation work is completed, the crane slowly lifts and rotates the boom to the existing expressway corrugated guardrail and waits. The purpose is mainly to reduce the temporary road closure time and ensure that the steel beam is quickly installed in place. After the traffic police and road administration personnel issue the road closure signal and the vehicle has completely left the construction area, the lifting operation will officially begin. A3. Formal hoisting (brief traffic interruption) After the hoisting preparations are completed, traffic police and road administration personnel will temporarily close the road at least 300 meters away from the construction area in the direction of oncoming traffic. After the construction personnel receive the road closure signal and wait for the vehicles to completely leave the construction area, the hoisting operation will officially begin. A4. Installation of the first steel beam unit The crane slowly lifts and rotates the boom to the predetermined installation position. Then, it slowly lowers the hook to lower the beam segment to 10cm above the temporary support. The steel beam is then manually positioned according to the pre-marked bottom edge line and center line of the steel beam. At this point, traffic police and road administration staff can be notified to open the road. A5. Detailed and precise adjustments After the initial positioning of the steel beam is completed, the crane continues to lower the hook to the installation position for detailed and precise adjustments. At the same time, one end of the beam segment is temporarily welded and fixed to the finished installation segment using a board or similar material, and the other end is temporarily welded and fixed to the temporary support system. A6. Installation of the second steel beam unit Based on the actual traffic flow and following the instructions of traffic police and road administration personnel, the second steel beam was installed using the same method as the first steel beam unit. A7. Temporary welding fixation After the initial installation and positioning of the second steel beam unit is completed, the two ends of the two steel beam units are temporarily welded and fixed to open traffic as soon as possible. Then, workers enter the steel beam box chamber and use fireproof membrane to cover the longitudinal joints of the two steel beams to prevent sparks and weld slag from falling when the top plate of the steel beam is temporarily fixed laterally.

[0007] The present invention is further configured such that: step S3 generally divides the steel box girder of the double-box girder into 3 transverse units; the steel box girder of the three-box girder is generally divided into 4 transverse units; the number of units to be decomposed must take into account factors such as the length of the beam segment and the lifting weight.

[0008] The present invention is further configured such that the unit body includes: a bottom plate unit, a web plate unit, a top plate unit, an internal partition plate unit, a cantilever unit (beam edge), etc., which have been assembled and welded together.

[0009] In summary, the beneficial technical effects of the present invention are as follows: 1. The invention solves the problems of high economic cost of constructing auxiliary roads, large social impact of closing traffic, and high safety risks of using the road for passage by means of the above method. It shortens the cycle operation time of the steel box girder hoisting process, which not only improves the construction efficiency of steel box girder hoisting, but also reduces the construction and traffic safety risks, and at the same time reduces the impact of construction on the normal traffic of the existing expressway. 2. The invention utilizes the above-mentioned method to divide the steel box girder into longitudinal segments and transverse units. This allows for the installation of a set of temporary supports at the central median of the existing highway, with the remaining temporary supports located outside the existing highway. Before the steel box girder is hoisted, traffic police and road administration departments cooperate to temporarily close half of the existing road for about 10 minutes to complete the process from hoisting the steel girder unit to its basic placement. After that, traffic can be reopened. This achieves the technical objective of simultaneous construction and vehicle traffic (with temporary traffic closure for some construction procedures), improving the efficiency of steel box girder hoisting, reducing construction and traffic safety risks, and minimizing the impact on normal traffic flow on the existing highway. 3. The above-mentioned method of this invention shortens the cycle time of the hoisting process, with an average hoisting operation every 1.5 hours, improving the construction efficiency of the steel box girder hoisting. Compared with the construction of auxiliary roads for the construction of cross-line bridges, it reduces economic costs and saves temporary land. Compared with the construction of cross-line bridges with traffic closure measures, it reduces the difficulty of construction permit approval procedures and reduces the social impact caused by road construction. Compared with the construction of cross-line bridges with detour measures, it reduces construction and traffic safety risks. Compared with the overall hoisting construction of steel box girders, the segmented hoisting method requires less mechanical equipment investment, saves costs, has a fast construction speed, is applicable to different terrain conditions, and can be located on the existing highway surface without affecting vehicle traffic when the construction site is limited. Detailed Implementation

[0010] The present invention will be further described in detail below with reference to the embodiments.

[0011] This invention discloses a method for installing steel box girders across existing highways during short-term traffic disruptions, characterized by the following steps: S1. Before the steel box girder is processed and manufactured, a thorough investigation and measurement of the construction site is carried out, especially the planar position and width of the existing highway central divider, the planar position of the corrugated guardrails on both sides of the road, and the terrain elevation. S2. Based on the measured data, use finite element analysis software to analyze the overall structural characteristics and stress characteristics of the bridge, and combine the transportation restrictions of steel structures to divide the steel box girder bridge into longitudinal segments and number them. S3. After the longitudinal segments of the steel box girder are determined, each segment is further decomposed into several transverse units and numbered and arranged. S4. Install temporary supports at the median strip of the existing highway: occupy the overtaking lanes on both sides of the median strip of the existing highway as the construction area, and set up various traffic channelization facilities according to the requirements of the highway traffic police and road administration units to ensure construction safety and driving safety. The traffic channelization facilities can be removed after the installation is completed. S5. Install the half-width steel box girder unit across the highway one span at a time according to the erection sequence (segment division sequence).

[0012] By adopting the above technical solution, step S2 is used to construct a temporary support system only in the original median strip of the highway, while the temporary support systems for the remaining sections are located outside the original road.

[0013] Step S5 includes the following steps: A1. Implement half-width traffic channelization on existing highways. Place signs indicating "Construction Ahead," "Slow Down," and "Road Narrowing" at intervals of 3km, 2km, 1.5km, 1km, 500m, and 300m ahead of oncoming traffic in the construction area, along with speed limit signs. Improve the traffic channelization area using cones, water-filled barriers, solar-powered flashing lights, and guide lights. Sufficient personnel should be deployed for traffic control and monitoring. A2. Preparations before steel box girder hoisting: (Construction site restrictions outside existing expressways): Large hoisting equipment (≥260t truck crane) will be used at the central median of the existing expressway, and a traffic channelization area will be set up by occupying the overtaking lanes in both directions on the original road. The steel box girder units will be transported by transport vehicles, which will enter the construction area in the order of erection from the direction of oncoming traffic. Before the formal hoisting, the existing road will be open to traffic. The transport vehicles and hoisting equipment will be prepared for hoisting. Two windproof hemp ropes will be tied to the steel box girder unit. After the steel wire ropes used for hoisting are firmly connected to the four hoisting points set on the steel box girder unit, the safety officer will inspect and accept it. After passing the inspection, the hoisting commander will direct the operators to slowly lift the steel girder about 10cm away from the transport vehicle and then stand by. (The construction site outside the existing expressway is in good condition): Large lifting equipment (≥300t truck crane) is used and located outside the existing expressway corrugated guardrail. The crane station must be leveled as necessary. The transport vehicle is located outside the cross-line and can cooperate with the lifting. Optionally, the transport vehicle can occupy the emergency lane of the existing expressway. Ensure that the traffic channelization facilities in the direction of oncoming traffic in the construction area meet the requirements. After the lifting preparation work is completed, the crane slowly lifts and rotates the boom to the existing expressway corrugated guardrail and waits. The purpose is mainly to reduce the temporary road closure time and ensure that the steel beam is quickly installed in place. After the traffic police and road administration personnel issue the road closure signal and the vehicle has completely left the construction area, the lifting operation will officially begin. A3. Formal hoisting (short-term traffic interruption): After the hoisting preparation work is completed, traffic police and road administration personnel will implement temporary traffic closure at a distance of no less than 300m in front of the construction area in the direction of oncoming traffic. After the construction personnel receive the road closure signal and wait for the vehicles to completely leave the construction area, the hoisting operation will begin. A4. The crane slowly lifts the first steel beam unit and rotates the boom to the predetermined installation position. Then, it slowly lowers the hook to lower the beam segment to 10cm above the temporary support. Then, the steel beam is initially positioned by manual labor according to the pre-marked edge line and center line of the steel beam bottom plate. At this time, traffic police and road administration staff can be notified to open the road. A5. After the initial positioning of the steel beam is completed, the crane continues to lower the hook to the installation position for detailed and precise adjustments. At the same time, one end of the beam segment is temporarily welded and fixed to the finished installation segment using a board or similar material, and the other end is temporarily welded and fixed to the temporary support system. A6. The second steel beam unit shall be installed according to the actual traffic flow and the instructions of the traffic police and road administration personnel, following the same method as the first steel beam unit. A7. Temporary welding and fixing: After the initial installation and positioning of the second steel beam unit is completed, the two ends of the two steel beam units are temporarily welded and fixed to open traffic as soon as possible. Then, workers enter the steel beam box chamber and use fireproof membrane to cover the longitudinal joints of the two steel beams to prevent sparks and weld slag from falling when the top plate of the steel beam is temporarily fixed laterally.

[0014] In step S3, the steel box girder with two compartments is generally divided into 3 transverse units; the steel box girder with three compartments is generally divided into 4 transverse units. The number of units to be decomposed must take into account factors such as the length of the beam segment and the lifting weight.

[0015] The unit body includes: bottom plate unit, web plate unit, top plate unit, box girder unit, cantilever unit (beam edge), etc., which are assembled and welded unit bodies.

[0016] 1. The invention solves the problems of high economic cost of constructing auxiliary roads, large social impact of closing traffic, and high safety risks of using the road for passage by means of the above method. It shortens the cycle operation time of the steel box girder hoisting process, which not only improves the construction efficiency of steel box girder hoisting, but also reduces the construction and traffic safety risks, and at the same time reduces the impact of construction on the normal traffic of the existing expressway. The invention utilizes the aforementioned method to divide the steel box girder into longitudinal segments and transverse units. This allows for the installation of a set of temporary supports at the central median of the existing highway, with the remaining temporary supports located outside the existing highway. Before the steel box girder is hoisted, traffic police and road administration departments cooperate to temporarily close half of the existing road for about 10 minutes to complete the process from lifting the steel girder unit to its basic placement. Afterward, traffic can be reopened. This achieves the technical objective of simultaneous construction and vehicle traffic (with temporary traffic closure for some construction procedures), improving the efficiency of steel box girder hoisting, reducing construction and traffic safety risks, and minimizing the impact on normal traffic flow on the existing highway. The method described in this invention shortens the cycle time of the hoisting process, allowing for an average hoisting operation every 1.5 hours. This improves the efficiency of hoisting steel box girders across the line. Compared to constructing auxiliary roads for overpass construction, it reduces economic costs and saves temporary land. Compared to closing traffic to overpass construction, it reduces the difficulty of obtaining construction permits and mitigates the social impact of road-related construction. Compared to using alternative routes for overpass construction, it reduces construction and traffic safety risks. Compared to hoisting the entire steel box girder, the segmented hoisting method requires less mechanical equipment, saves costs, and allows for faster construction. It is applicable to various terrain conditions, and even in situations where the construction site is limited, the hoisting equipment can be located on the existing highway surface without affecting vehicle traffic.

[0017] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for installing steel box girders across existing highways during short-term traffic disruptions, characterized in that... This includes the following steps: S1. Before the steel box girder is fabricated, a thorough investigation and measurement are conducted on the plan position and width of the existing highway central divider, the plan position of the corrugated guardrails on both sides of the road, and the terrain elevation at the construction site. S2. Based on the measured data, the overall structural characteristics and stress characteristics of the bridge are analyzed using finite element analysis software. In conjunction with the transportation restrictions of steel structures, the steel box girder bridge is divided into longitudinal segments and numbered. This ensures that only the original median strip of the highway is used for temporary support systems, while the temporary support systems for the remaining segments are located outside the original road. S3. After the longitudinal segments of the steel box girder are determined, each segment is further decomposed into several transverse units, which are then numbered and arranged. S4. Install temporary supports at the median strip of the existing highway: occupy the overtaking lanes on both sides of the median strip of the existing highway as the construction area, and set up various traffic channelization facilities according to the requirements of the highway traffic police and road administration units to ensure construction safety and driving safety. The traffic channelization facilities can be removed after the installation is completed. S5. Install the half-width steel box girder units spanning the highway one span at a time according to the erection sequence; After the hoisting preparations are completed, traffic police and road administration personnel will temporarily close the road at least 300 meters in front of the construction area in the direction of oncoming traffic. Construction workers will begin hoisting operations only after receiving the road closure signal and after all vehicles have completely left the construction area. The crane slowly lifts and rotates its boom to the predetermined installation position. Then, it slowly lowers the hook to lower the beam segment to 10cm above the temporary support. The beam is then manually positioned according to the pre-marked bottom edge and center line of the steel beam. At this point, traffic police and road administration personnel can be notified to open the road to traffic. After the initial positioning of the steel beam is completed, the crane continues to lower the hook to the installation position for detailed and precise adjustments. At the same time, one end of the beam segment is temporarily welded to the finished installation segment using a support plate, and the other end is temporarily welded to the temporary support system.

2. The method for installing steel box girders across existing highways with short-term traffic interruption as described in claim 1, characterized in that... Step S3 divides the double-chamber steel box girder into 3 transverse units; the triple-chamber steel box girder into 4 transverse units; the number of units to be decomposed must take into account the length of the beam segments and the lifting weight.

3. The method for installing steel box girders across existing highways with short-term traffic interruption as described in claim 2, characterized in that... The unit body comprises: a base plate unit, a web plate unit, a top plate unit, an internal partition plate unit, and a cantilever unit, which are assembled and welded together.