Pedestrian overpass without main piers and assembly installation method thereof

Abstract

Bridge abutments are arranged above pile foundations, the bridge abutments on the same side are connected through bridge abutment inhaul cables, ladder ramps are installed on the bridge abutments, a main beam is installed on the inner sides of the ladder ramps on the two sides, and grounding ladder ramps are arranged behind the bridge abutments. The bridge abutment inhaul cables, the ladder ramps, the main beams and the grounding ladder ramps are all prefabricated in a factory and assembled on site. The whole bridge is not provided with piers, and the bridge abutments are only arranged at the four landing points, so that on one hand, the influence on traffic and surrounding environments during overbridge construction and operation is reduced, on the other hand, interference between the foundation and urban pipelines is avoided, and the construction speed is greatly increased. The bridge abutment inhaul cable bears the horizontal load generated by the load, and the lightweight design of the overbridge foundation can be helped to be achieved. In addition, the main-pier-free overbridge is good in space intervisibility under the overbridge, simple in modeling and good in landscape effect.

Description

Technical Field

[0001] This invention belongs to the field of municipal bridge engineering, specifically relating to a pierless pedestrian overpass and its assembly and installation method. Background Technology

[0002] Currently, urban infrastructure construction has gradually shifted from an incremental market to a stock market, and urban renewal and transformation to create a more convenient and superior living environment for residents has become the theme of construction in the new era.

[0003] With the continuous rise in urban population density, traffic flow during morning and evening rush hours often exceeds the road's capacity. The complex traffic situation is not only reflected in the weaving and congestion between motor vehicles, but also in the conflicts between different road users. At-grade intersections of pedestrian and motor vehicle lanes have become a key point exacerbating urban traffic congestion. Motor vehicles must slow down and yield, and frequent stopping and starting disrupts the smooth flow of traffic. Especially in densely populated areas such as schools, commercial districts, and hospitals, these intersections often become bottlenecks, reducing road efficiency and significantly increasing the risk of traffic accidents. Most cities have addressed this through systematic municipal road renovations, planning and setting up dedicated non-motorized vehicle lanes to physically separate fast-moving motor vehicles from slower-moving non-motorized vehicles and pedestrians, effectively separating fast and slow traffic systems and alleviating the chaotic road traffic situation to some extent. However, this solution has not completely eliminated traffic conflicts. The problem of interrupting motor vehicle traffic when pedestrians cross the street still exists, especially on sections with high traffic volume. The frequent switching of pedestrian crossing signals further reduces the efficiency of motor vehicle traffic, and the hidden danger of traffic congestion has not been completely eradicated. In addition, there are some expressways without pedestrian crossings for long stretches, requiring pedestrians to take long detours. As the main facility for realizing three-dimensional pedestrian crossings, the development and application of construction technology for pedestrian overpasses are particularly crucial. They are directly related to the overall efficiency of improving traffic efficiency, enhancing residents' travel experience, and optimizing urban space during the process of urban renewal and quality improvement.

[0004] Traditional pedestrian overpass construction technology has matured through long-term practice and can meet basic traffic needs. However, it has many limitations that cannot be ignored in adapting to the complex traffic environment and efficient construction requirements of modern cities. From the perspective of space occupation, the supporting structure of traditional pedestrian overpasses mainly relies on piers. The construction of these piers requires the installation of pile foundations, abutments, and columns in the center or on both sides of the road, which inevitably occupies part of the lanes or green belts. Occupying lanes directly reduces the space for motor vehicle traffic, especially in sections with a limited number of lanes, which can easily lead to a decrease in traffic capacity and exacerbate congestion during peak hours. Occupying green belts will damage the city's ecological landscape and green coverage, affecting the aesthetics and livability of the urban environment. From the perspective of construction impact, the construction of the main pier foundation requires large-scale excavation. To ensure construction safety and avoid greater interference with surrounding traffic, it is often necessary to temporarily close some lanes. This not only causes great inconvenience to passing vehicles and pedestrians, but may also cause regional traffic congestion, negatively impacting the normal traffic order of the city and the lives of residents. From the perspective of construction difficulty and cost control, urban underground pipelines are dense and diverse, including water supply, drainage, gas, electricity, and communications. Traditional pile foundation construction is prone to conflicts with these underground pipelines, increasing the technical difficulty of construction and potentially causing water, power, and gas outages due to pipeline damage, disrupting residents' daily lives. Furthermore, avoiding potential impacts on the structural safety of existing buildings and addressing the complex underground environment through pit support and underground pipeline relocation incurs significant additional costs. From the perspective of construction cycle and social benefits, traditional construction methods involve multiple complex stages, including pile foundations, abutments, piers, and bridge deck pouring, each requiring a certain construction period, resulting in a long overall construction cycle. During construction, prolonged traffic control, noise pollution, and dust pollution have a lasting impact on the quality of life of surrounding residents, business operations, and the overall urban environment, leading to poor social benefits. Furthermore, from the perspective of later maintenance, the main piers located in the middle of the road are exposed to the outdoor environment for a long time. On the one hand, they are easily damaged by accidental collisions with passing vehicles; on the other hand, natural factors such as rainwater erosion and atmospheric corrosion will also cause the pier structure to age. In order to ensure the safe use of the pedestrian overpass, a lot of manpower and resources are needed for regular inspection and maintenance, resulting in high maintenance costs. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a pierless pedestrian bridge and its prefabricated installation method. This invention rationally solves the core problems faced by traditional pedestrian bridges in design and construction, and meets the requirements of modern urban renewal and transformation for traffic efficiency, space utilization, and landscape integration. The structure described in this invention features easy prefabrication and assembly construction, good structural stability, outstanding landscape effect, and high construction efficiency. By using the cable force of the abutments to resist the horizontal thrust generated by the load, it avoids the problem of excessively large abutment pile foundations, making it suitable for constructing small-span pedestrian bridges in cities.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a pedestrian overpass structure without main piers, comprising pile foundations, abutments, abutment cables, stair ramps, a main beam, and grounding stair ramps. Abutments are set above the pile foundations, and abutments on the same side are connected by abutment cables. Stair ramps are installed on the two abutments on the same side, with the stair ramps located directly above the abutment cables. The main beam is installed inside the stair ramps on both sides, and the grounding stair ramps are set outside the abutments and connected to the stair ramps. No piers are set at the mid-span and both ends of the main beam. Overpass supports are set at the abutment connections.

[0007] As a further optimization, the bridge abutment cables, ramps, main beams, and grounding ramps are all prefabricated in the factory.

[0008] As a further optimization, the bridge abutment cables are connected to the abutment by hinges, and the grounding ladder ramp is fixed to the foundation by anchor bolts.

[0009] As a further optimization, no piers are set in the middle of the stair ramp, and abutments are set at the landing points at both ends of the stair ramp.

[0010] As a further optimization, the main beam and the ramp are connected by supports or fixed connections.

[0011] As a further optimization, the stair ramp can be in the form of a stairway or a stairway plus a ramp, and the stair ramp can adopt a steel-concrete composite structure or an ultra-high performance material structure.

[0012] As a further optimization, the main beam and the stair ramp are prefabricated using ultra-high performance materials; the grounding stair ramp uses a cavity structure prefabricated using ultra-high performance materials.

[0013] As a further optimization, guardrails and handrails are installed on both sides of the main beam, the stair ramp, and the grounding stair ramp.

[0014] On the other hand, the present invention provides a prefabricated construction method for the above-mentioned overpass structure, comprising the following steps: Step 1: Construct the pile foundations and abutments, and confirm the elevation; Step 2, install the bridge abutment cables; Step 3: Install the overpass supports and confirm their planar position and elevation; Step 4: Install the ladder ramp and simultaneously tension the bridge abutment cables; Step 5: Install the main beam and simultaneously adjust the cable tension of the bridge abutment. Step 6: Install the grounding ladder ramp; Step 7: Construct the ramp steps and bridge deck system, and install ancillary facilities; Step 8: readjust the tension of the bridge abutment cables so that the horizontal load generated by the dead load is entirely borne by the bridge abutment cables. Step 9: Complete the construction and maintenance.

[0015] Step 10: Complete construction and commence operation.

[0016] Furthermore, before starting step 4, ensure that the bridge abutment has reached its design strength.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: The main components of the pierless pedestrian bridge structure described in this application work together as a whole to bear external loads. The bridge abutment cables bear the horizontal thrust generated by the loads, and the foundation consisting of four abutments and pile foundations at the landing point provides vertical support. The structural system is novel. Eliminating the main pier reduces the impact on road traffic capacity after the bridge is completed, avoiding risks such as vehicle collisions. Furthermore, it significantly reduces the impact on traffic, underground pipelines, and surrounding structures during the construction of the main pier and foundation. The use of ultra-high-performance materials ensures that the structure is lightweight while meeting load-bearing requirements, improving the structural aesthetics while reducing... The reduced lifting weight lowers construction difficulty; the use of prefabricated hollow structures made of ultra-high-performance materials for the grounding ladder ramps greatly reduces the weight of components during transportation and lifting, further reducing construction difficulty; compared to ordinary pedestrian bridges, the main load-bearing components of the pierless pedestrian bridge have simple shapes, clear force transmission, and fewer components, which facilitates transportation, allows for prefabricated construction, minimizes the impact on the urban environment, reduces on-site connection procedures, is more conducive to construction control, and also reduces maintenance time; the pierless design greatly reduces construction interference factors, improves construction efficiency, reduces the impact of structural construction on the urban environment, and has excellent social benefits.

[0018] Furthermore, the use of hinged connections for the bridge abutment cables can release bending moments, improve the stress state of the cables, and prevent local stress concentration. The grounding ladder ramp is fixed with anchor bolts to ensure the reliability of the connection with the foundation and the overall stability, and can also provide a certain level of horizontal support to the bridge abutment.

[0019] Furthermore, the ramp does not have a mid-span pier, and its load is directly transferred to the abutments at both ends. The structure is simple, suitable for modular installation, reduces on-site construction work, reduces ground occupation, and reduces the impact of construction on urban traffic.

[0020] Furthermore, the main beam and the ramp are provided with either a support connection or a fixed connection. The support connection can accommodate deformation, while the fixed connection can enhance the overall integrity. The choice can be made according to the specific needs of the pedestrian bridge scale.

[0021] Furthermore, the use of ultra-high performance materials in the stair ramps can reduce the self-weight of the upper structure and reduce construction difficulty, while making the upper structure as lightweight as possible. This lays a good foundation for reducing the size of the lower structure and saving costs, thereby achieving the goal of improving the economic efficiency of structural construction.

[0022] Furthermore, the main beams and ramps are made of ultra-high performance materials, which can provide the structure with higher stiffness and strength, making it easier to achieve larger spans.

[0023] Furthermore, ultra-high performance materials have excellent corrosion resistance, which can reduce maintenance costs during the operation of the structure and greatly improve the economic efficiency of the structure throughout its entire life cycle.

[0024] Furthermore, guardrails and handrails are installed on both sides of all passage components as a safety measure to ensure the safety of pedestrians and meet the basic functional requirements of pedestrian overpasses. Attached Figure Description

[0025] Figure 1 This is a structural schematic diagram of a pedestrian overpass without a main pier.

[0026] Figure 2 This is a plan view of a pedestrian overpass without a main pier.

[0027] Figure 3 This is a side view of a pedestrian overpass without a main pier.

[0028] Figure 4 This is an elevation view of a pedestrian overpass without a main pier.

[0029] In the attached diagram: 1-Pile foundation; 2-Abutment; 3-Abutment cable; 4-Mount ramp; 5-Main beam; 6-Grounding ramp. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0031] Example 1, Reference Figure 1 A pedestrian bridge structure without main piers includes a pile foundation 1, abutments 2, abutment cables 3, ramps 4, a main beam 5, and a ground-level ramp 6. Abutments 2 are installed above the pile foundation 1, and abutments 2 on the same side are connected by abutment cables 3. Ramps 4 are installed on the two abutments 2 on the same side, located directly above the abutment cables 3. Ramps 4 are higher in the middle and lower at both ends, and are symmetrical about their own center plane. The two ends of the main beam 5 are connected to the inner sides of the ramps 4 on both sides. The ground-level ramp 6 is located on the outer side of the abutments 2. The abutment cables 3, ramps 4, main beam 5, and ground-level ramp 6 are all prefabricated components and assembled on site.

[0032] The ladder ramp 4 described in this application can provide shelter from the rain, and the space directly below the ladder bridge cable 3 can also provide space for public seating, providing a temporary rain shelter for pedestrians.

[0033] The bridge abutment cable 3 is connected to the bridge abutment 2 by a hinge, which can release part of the bending moment, improve the stress state of the cable, and prevent local stress concentration; the main beam 5 and the ramp 4 are connected by a support or a fixed connection.

[0034] The grounding ladder ramp 6 is fixed to the foundation with anchor bolts to ensure the reliability of the connection with the foundation and the overall stability.

[0035] The main components work together as a whole to bear external loads. The bridge abutment cables 3 bear the horizontal thrust generated by the loads, while the foundation consisting of the four abutments 2 and pile foundations at the landing points provides vertical support. This is a completely new structural system. The main beams 5 and ramps 4 of the pierless pedestrian bridge do not have foundations, thus not affecting road traffic capacity. Furthermore, it avoids the pipeline relocation work required for main pier foundation construction, saving costs while improving construction efficiency and reducing the impact of structural construction on the urban environment, resulting in excellent social benefits. Therefore, compared to ordinary pedestrian bridges, the pierless pedestrian bridge has simpler shapes and fewer components in its main load-bearing components. This facilitates transportation, allows for prefabricated construction with less impact on the urban environment, and reduces on-site connection procedures, making construction control more favorable. The bridge structure only requires foundations at the four landing points.

[0036] The ramp 4 can be in the form of a stairway or a stairway plus a ramp. The stairway plus ramp can allow pedestrians to pass through, as well as wheelchairs, electric vehicles and bicycles.

[0037] The main beam 5 and the ramp 4 adopt a steel-concrete composite structure or an ultra-high performance material (i.e., ultra-high performance concrete or ultra-high performance inorganic composite material) structure, or the whole adopts an aluminum alloy structure. Those skilled in the art are capable of selecting different structures and materials according to actual needs.

[0038] As an optional embodiment, the main beam 5 can also adopt a truss structure, and the components of the truss structure are made of aluminum alloy; to meet the requirements of stiffness and strength, while reducing its own weight.

[0039] Guardrails and handrails are installed on both sides of the main beam 5, the stair ramp 4, and the grounding stair ramp 6 as a safety measure to ensure the safety of pedestrians.

[0040] The bridge abutment cable 3 uses multiple steel strands or steel wire ropes. The outer surface of the bridge abutment cable 3 is coated with an anti-corrosion layer and encased in an outer shell to improve the service life of the bridge abutment cable 3.

[0041] The grounding ladder ramp 6 can be made of a cavity-shaped ultra-high performance material, which can reduce weight while meeting strength requirements.

[0042] Abutment 2 and pile foundation 1 are made of concrete. The lateral load is borne by the abutment cable 3. Abutment 2 and pile foundation 1 bear the vertical load and will not generate bending moment. Therefore, there is no need to use a steel-concrete structure.

[0043] Example 2, using the prefabricated construction method for the pedestrian bridge structure described in this invention, includes the following steps: Step 1: Construct pile foundation 1 and abutment 2, check the elevation, and ensure that the anchorage of the abutment cable 3 is below the ground elevation. Step 2, install bridge abutment cables 3; Step 3: Install the overpass supports and verify their planar position and elevation; Step 4: Install the ramp 4 and simultaneously tension the bridge abutment cables 3; Step 5: Install main beam 5 and simultaneously adjust the tension of bridge abutment cable 3; Step 6, install grounding ladder ramp 6; Step 7: Construct the ramp steps and bridge deck system, and install ancillary facilities; Step 8: readjust the tension of the bridge abutment cable 3 so that the horizontal load generated by the dead load is entirely borne by the bridge abutment cable. Step 9: Complete the construction and maintenance.

[0044] Step 10: Complete construction and commence operation.

[0045] Anti-slip layers can also be installed on the bridge deck, and warning strips can be placed on the stairways to clearly indicate the steps.

[0046] Since the bridge abutment cable 3 bears the horizontal thrust generated by the load, the bridge abutment 2 and pile foundation 1 only bear the vertical force, reducing the design and construction difficulty of the bridge abutment 2 and pile foundation 1. The pierless design reduces the impact on traffic and the environment, while avoiding interference between the construction of the overpass foundation and municipal pipelines, greatly accelerating the construction progress. In addition, the pierless overpass has good visibility under the bridge, a simple shape, and a good landscape effect.

[0047] After the bridge is completed, the distribution of internal forces in the structure can be changed by adjusting the tension of the three cables at the abutments, so as to ensure the rationality of the stress on the structure.

[0048] The bridge structure described in this invention forms a cohesive whole to bear external loads. The abutment cables 3 can withstand the horizontal thrust generated by the load, while the foundation consisting of the four abutments 2 and pile foundations 1 at the landing point provides vertical support, making it a completely new structural system.

[0049] Example 3: When there are sufficient bridge abutments 2 of a certain size and a number of pile foundations 1, i.e., multiple sets of bridge abutments 2 are symmetrically arranged on the same side to reduce or even eliminate the lateral load, the bridge abutment cables 3 can be eliminated. The foundation composed of bridge abutments 2 and pile foundations 1 jointly resists the horizontal and vertical forces, and the construction process does not require bridge abutment cables 3; that is, a pedestrian bridge structure without main piers, including pile foundations 1, bridge abutments 2, stair ramps 4, main beams 5, and grounded stair ramps 6; bridge abutments 2 are set above pile foundations 1, and stair ramps 4 are installed on multiple bridge abutments 2 on the same side. The stair ramps 4 are higher in the middle and lower at both ends, and the stair ramps 4 are symmetrical about their own central plane; the two ends of the main beam 5 are connected to the inner sides of the stair ramps 4 on both sides, and the grounded stair ramps 6 are set on the outer side of the bridge abutments 2. The stair ramps 4, main beams 5, and grounded stair ramps 6 are all prefabricated components in the factory and assembled on site for construction. Specifically, the following steps are included: Step 1: Construct pile foundation 1 and abutment 2, and verify the elevation; Step 2: Install the overpass supports and verify their planar position and elevation; Step 3, install the ladder ramp 4; Step 4, install the main beam 5; Step 5, install the grounding ladder ramp 6; Step 6: Construct the ramp steps and bridge deck system, and install ancillary facilities; Step 7: Complete the construction and maintenance.

[0050] Step 8: Complete construction and commence operation.

[0051] In summary, this invention discloses a pierless pedestrian overpass and its prefabricated installation method, comprising a pile foundation 1, abutments 2, abutment cables 3, ramps 4, a main beam 5, and grounding ramps 6. Abutments 2 are positioned above the pile foundation 1, with abutment cables 3 connecting two abutments 2 on the same side. Ramps 4 are installed on the two abutments 2 on the same side, directly above the abutment cables 3. The main beam 5 is installed inside the ramps 4 on both sides, and the grounding ramps 6 are located outside the abutments 2, connecting to the ramps 4. No piers are installed at the mid-span or both ends of the main beam 5. Overpass supports are installed at the connection points between the abutments 2 and the ramps 4. The abutment cables, ramps, main beam, and grounding ramps are all constructed using a factory prefabrication and on-site assembly method. The entire bridge has no piers, with abutments only at four landing points. This reduces the impact on traffic and the surrounding environment during construction and operation, avoids interference between the foundation and urban pipelines, and greatly accelerates the construction speed. The bridge abutment cables bear the horizontal loads generated by the load, which helps to achieve a lightweight design for the bridge foundation. The use of ultra-high-performance materials in the superstructure further contributes to the lightweight design, reducing construction difficulty while improving the overall economic efficiency of the structure. In addition, the pierless bridge offers good visibility under the bridge, has a simple design, and provides a pleasing aesthetic appeal.

[0052] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A pedestrian overpass structure without main piers, characterized in that: The structure includes a pile foundation (1), abutments (2), abutment cables (3), ramps (4), main beams (5), and ground ramps (6). Abutments (2) are set above the pile foundation (1). Abutment cables (3) are set between two abutments (2) on the same side. Ramps (4) are installed on two abutments (2) on the same side. Ramps (4) are located directly above the abutment cables (3). The main beam (5) is installed inside the ramps (4) on both sides. Ground ramps (6) are set outside the abutments (2) and are connected to ramps (4). No piers are set at the mid-span and both ends of the main beam (5). Overpass supports are set at the connection between the abutments (2) and ramps (4).

2. The pedestrian bridge structure without main piers according to claim 1, characterized in that: The bridge abutment cables (3), ladder ramps (4), main beams (5), and grounding ladder ramps (6) are all prefabricated in the factory.

3. The pedestrian bridge structure without main piers according to claim 1, characterized in that: The bridge abutment cable (3) is connected to the bridge abutment (2) by a hinge, and the ground ladder ramp (6) is fixed to the foundation by anchor bolts.

4. The pedestrian bridge structure without main piers according to claim 1, characterized in that: No piers are set in the middle of the ladder ramp (4), and the landing points at both ends of the ladder ramp (4) are bridge abutments (2).

5. The pierless pedestrian bridge structure according to claim 1, characterized in that: The main beam (5) and the ramp (4) are connected by supports or fixed connections.

6. The pierless pedestrian bridge structure according to claim 1, characterized in that: The ladder ramp (4) is a ladder or a ladder plus a ramp.

7. The pedestrian bridge structure without main piers according to claim 1, characterized in that: The main beam (5) and the ramp (4) are prefabricated using ultra-high performance materials; the ground ramp (6) is a cavity structure prefabricated using ultra-high performance materials.

8. The pedestrian bridge structure without main piers according to claim 1, characterized in that: Guardrails and handrails are installed on both sides of the main beam (5), the stair ramp (4), and the grounding stair ramp (6).

9. The prefabricated construction method for the pedestrian bridge structure as described in any one of claims 1-8, characterized in that: Includes the following steps: Step 1: Construct the pile foundation (1) and bridge abutment (2), and confirm the elevation; Step 2, install the bridge abutment cables (3); Step 3: Install the overpass supports and confirm their planar position and elevation; Step 4: Install the ladder ramp (4) and simultaneously tension the bridge abutment cables (3). Step 5: Install the main beam (5) and simultaneously adjust the tension of the bridge abutment cables (3); Step 6, install the grounding ladder ramp (6); Step 7: Construct the ramp steps and bridge deck system, and install ancillary facilities; Step 8, readjust the tension of the bridge abutment cable (3) so that the horizontal load generated by the dead load is entirely borne by the bridge abutment cable; Step 9: Complete the construction and maintenance.

10. The construction method according to claim 9, characterized in that: Before starting step 4, ensure that the bridge abutment (2) has reached the design strength.

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