Road structure of underneath passing bridge and construction method

Abstract

The invention provides a road structure of an underneath pass bridge and a construction method, belongs to the field of building construction, and aims to solve the problem of insufficient bearing capacity of a newly-built road caused by direct laying of a circular pipe culvert on a riverbed in the prior art. Through arrangement of a first high-pressure jet grouting pile, a steel sheet pile supporting retaining wall, a high-pressure jet grouting pile gravity retaining wall and callback lime soil in a foundation pit, it is ensured that a roadbed of a newly-built road is stable, and it is ensured that under the repeated action of vehicle loads, the newly-built road does not settle or deform; the round pipe culverts are arranged at the bottoms of the original road and the river, so that river water can be drained, and the situation that the new road is submerged by the river water in the flood season, and traffic jam is caused is avoided; in addition, the second high-pressure jet grouting piles are arranged on the left side and the rear side of the pier correspondingly, and it is ensured that the newly-built road cannot cause reduction of the bearing capacity of the pier.

Description

Technical Field

[0001] The invention belongs to the field of building construction, and in particular relates to a road structure passing under a bridge and a construction method. Background Art

[0002] In the field of transportation infrastructure construction, underpasses are crucial nodes that connect different regions and ensure smooth traffic flow. They not only facilitate daily traffic but also play a vital role in promoting regional economic exchange and improving urban operational efficiency. However, with the continued rapid development of cities and the dramatic increase in traffic volume, existing underpasses are increasingly unable to meet the growing traffic demand, making their widening and renovation a pressing issue.

[0003] In specific scenarios where there are piers between the road and the river below the existing bridge, laying a circular culvert directly on the riverbed and then building a new road over it presents drawbacks. First, flood season flows pose a serious threat to this approach. During flood season, large amounts of river water surge into the riverbed, exerting immense pressure and scouring forces on the circular culvert. If the circular culvert lacks strength and stability, it could be destroyed or displaced by the floodwaters, causing the newly constructed road to collapse, seriously impacting traffic safety. Second, the geological conditions of the riverbed are generally soft, making direct installation of the circular culvert unstable, making it difficult to provide a solid foundation. Under the repeated impact of vehicle loads, the newly constructed road, lacking sufficient bearing capacity, will experience varying degrees of settlement and deformation. Over time, the road surface deteriorates, developing cracks and potholes. This not only affects the road's aesthetics and comfort, but also significantly shortens its service life and increases future maintenance costs. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a road structure and construction method under the bridge, which is used to solve the problem of insufficient bearing capacity of the newly built road caused by directly laying circular culverts on the riverbed in the prior art.

[0005] To achieve the above-mentioned objectives and other related objectives, the present invention provides a road structure passing under a bridge, comprising: foundation pits are respectively arranged on the original road and the river, support retaining walls are respectively arranged on the left and right sides of the foundation pits, and a plurality of first high-pressure rotary jet piles are arranged at the bottom of the foundation pits; a plurality of second high-pressure rotary jet piles are respectively arranged on the left and right sides of the bridge piers between the original road and the river; the support retaining walls include steel sheet pile support retaining walls and high-pressure rotary jet pile gravity retaining walls, the steel sheet pile support retaining walls are located 5 meters outside the original bridge, and the high-pressure rotary jet pile gravity retaining walls are arranged within 5 meters of the original bridge; at least one circular culvert for diverting river water is arranged in each foundation pit, and 3-8% lime soil is backfilled to the bottom of the road structure; the road structure body is laid on the bottom of the road structure.

[0006] Optionally, anti-collision guardrails are provided on both sides of the bridge piers between the original road and the river.

[0007] Optionally, the road structure body includes a 10-15% lime soil cushion layer arranged on the bottom of the road structure, a 30-40 cm thick C30 concrete cushion layer laid on the lime soil cushion layer, and a 10-15 cm thick asphalt layer laid on the C30 concrete cushion layer.

[0008] Optionally, circular culvert fixing seats are respectively provided on the front and rear sides of the foundation pit.

[0009] Optionally, the circular pipe culvert fixing seat is made of C25 concrete.

[0010] On the other hand, a construction method of a road structure passing under a bridge is also provided, comprising the above-mentioned road structure passing under a bridge, and further comprising the following steps:

[0011] S1, intercepting the river, backfilling the river to the bottom height of the pavement structure, and excavating the original road to the bottom height of the pavement structure;

[0012] S2, excavation of foundation pit on the original road and river;

[0013] S3, construct retaining walls on the left and right sides of the foundation pit, construct the first high-pressure rotary jet grouting piles at the bottom of the foundation pit, and construct the second high-pressure rotary jet grouting piles on the left and right sides of the bridge pier between the original road and the river;

[0014] S4, laying at least one circular culvert in the foundation pit, and after laying the circular culvert, backfilling with 3-8% lime soil to the bottom of the road structure;

[0015] S5, laying the road structure body on the bottom of the pavement structure.

[0016] Optionally, before laying the road structure body on the bottom of the pavement structure, it also includes: excavating a first installation groove for burying the weak current pipeline on the left side of the bottom of the pavement structure and excavating a second installation groove for burying the power pipeline on the right side of the bottom of the pavement structure; after the first installation groove and the second installation groove are completed, laying the weak current pipeline in the first installation groove and laying the power pipeline in the second installation groove.

[0017] Optionally, laying the road structure body on the bottom of the pavement structure includes: laying a 10-15% lime soil cushion layer on the bottom of the road structure, then laying a 30-40 cm thick C30 concrete cushion layer on the lime soil cushion layer, and finally laying a 10-15 cm thick asphalt layer on the C30 concrete cushion layer.

[0018] Optionally, the lime soil cushion layer is 12% lime soil, and the C30 concrete cushion layer is 36 cm.

[0019] Optionally, after laying the road structure body on the bottom of the pavement structure, the method further includes: building anti-collision guardrails at the bridge piers between the original road and the river.

[0020] As described above, the road structure and construction method for passing under a bridge of the present invention have at least the following beneficial effects: through the first high-pressure rotary jet pile, steel sheet pile support retaining wall, high-pressure rotary jet pile gravity retaining wall, and the setting of lime soil adjusted back in the foundation pit, the stability of the roadbed of the newly built road is ensured, and the newly built road is ensured not to sink or deform under the repeated action of vehicle loads; and circular culverts are provided at the bottom of the original road and the river to ensure that the river water can be drained to avoid the river water flooding the newly built road during the flood season, causing traffic jams and the like; in addition, second high-pressure rotary jet piles are provided on the left and rear sides of the bridge piers respectively to ensure that the newly built road will not cause the bearing capacity of the bridge piers to decrease. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Shown is a structural schematic diagram of a road structure passing under a bridge according to the present invention.

[0022] Figure 2 Shown is a flow chart of a construction method of a road structure passing under a bridge according to the present invention.

[0023] Component number description:

[0024] 100. Original road, 200. River, 300. Bridge pier, 1. Foundation pit, 2. Support retaining wall, 3. First high-pressure rotary jet pile, 4. Second high-pressure rotary jet pile, 5. Circular culvert, 6. Anti-collision guardrail. DETAILED DESCRIPTION

[0025] The following describes the implementation of the present invention through specific embodiments. People skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0026] Please refer to all the following drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no substantive technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0027] The following embodiments are for illustration only and can be combined with each other, and are not limited to the contents presented in the following single embodiments.

[0028] See also Figure 1 The present invention provides a road structure that passes under a bridge. It is suitable for engineering scenarios where there is a bridge between a river 200 and an original road 100 below an existing bridge, and it is necessary to cross the river 200 to widen the road. The structure includes: foundation pits 1 are respectively provided on the original road 100 and the river 200, and support retaining walls are respectively provided on the left and right sides of the foundation pit 1. The support retaining walls include steel sheet pile support retaining walls and high-pressure rotary jet pile gravity retaining walls. The steel sheet pile support retaining wall is a continuous wall-type retaining structure formed by orderly connecting hot-rolled steel sections (such as U-shaped and Z-shaped) with locking or clamping mouths. The core of the structure is to form a continuous wall by vertically inserting steel sheet piles into the foundation, and to use the stiffness and depth of the steel sheet piles to resist soil pressure and water pressure. The steel sheet pile support retaining wall is located 5 meters outside the original bridge, and its rapid construction characteristics are used to form an outer retaining barrier. The high-pressure rotary jet pile gravity retaining wall is a cement-soil continuous wall structure formed by high-pressure jet grouting technology. Its core principle is to use high-pressure cement slurry to cut the soil and mix and solidify it to form a gravity support system with soil and water retaining functions. The high-pressure rotary jet pile gravity retaining wall is set within 5 meters of the original bridge, and forms a rigid connection with the foundation of the pier 300 through the cement-soil wall to control the deformation of the deep soil. A plurality of first high-pressure rotary jet piles 3 are provided at the bottom of the foundation pit 1. Multiple rows of first high-pressure rotary jet piles 3 are arranged in a grid at the bottom of the foundation pit 1. The pile diameter can be 500-1200mm, and the pile spacing can be 1-2.0m to form a composite foundation bearing layer. A plurality of second high-pressure rotary jet piles 4 are respectively provided on the left and right sides of the pier 300 between the original road 100 and the river 200 to enhance the bearing capacity of the pier 300.

[0029] At least one circular culvert 5 is installed in each foundation pit 1 to drain river water, ensuring that river water can be discharged through the circular culvert 5 during flood season. After the circular culvert 5 is laid, 3-8% lime soil is backfilled to the bottom of the road structure, and the road structure itself is laid on the bottom of the road structure.

[0030] In this embodiment, the first high-pressure jet grouting piles 3, the steel sheet pile retaining wall 2, the high-pressure jet grouting pile gravity retaining wall, and the return of lime soil in the foundation pit 1 ensure the stability of the newly constructed roadbed and prevent it from sinking and deforming under the repeated effects of vehicle loads. Circular culverts 5 are also installed at the bottom of the existing road 100 and the river 200 to ensure that river water can be drained, preventing the river from flooding the newly constructed road during flood season and causing traffic jams.

[0031] In order to prevent the bridge pier 300 from being hit in the event of a traffic accident, in this embodiment, anti-collision guardrails 6 are provided on both sides of the bridge pier 300 between the original road 100 and the river 200.

[0032] The road structure consists of a 10-15% lime soil cushion layer set on the bottom of the road structure, a 30-40cm thick C30 concrete cushion layer laid on the lime soil cushion layer, and a 10-15cm thick asphalt layer laid on the C30 concrete cushion layer, thereby forming a flexible-rigid composite base layer + asphalt surface layer structural system to ensure the long-term use of the road.

[0033] The front and rear sides of the foundation pit 1 are respectively provided with circular pipe culvert 5 fixing seats, which can be made of C25 concrete to fix the circular pipe culvert 5 to prevent the circular pipe of the circular pipe culvert 5 from being displaced under the impact of water flow.

[0034] like Figure 2 As shown, on the other hand, the present invention also provides a construction method of a road structure passing under a bridge, comprising the above-mentioned road structure passing under a bridge, and further comprising the following steps:

[0035] S1: River 200 is intercepted and backfilled to the bottom of the pavement structure. The original road 100 is excavated to the bottom of the pavement structure. The river 200 can be backfilled with loess and compacted layer by layer to ensure stability after backfilling.

[0036] S2, excavating a foundation pit 1 on the existing road 100 and river 200. The depth of the foundation pit 1 can be adjusted according to different usage scenarios. For example, when the flow of the river 200 is large, the depth of the foundation pit 1 can be increased to ensure that a large diameter circular pipe can be laid.

[0037] S3: Construct retaining walls 2 on the left and right sides of the foundation pit 1, construct first high-pressure jet grouting piles 3 at the bottom of the foundation pit 1, and construct second high-pressure jet grouting piles 4 on the left and right sides of the bridge piers 300 between the original road 100 and the river 200. This ensures that the foundation pit 1 does not collapse, improves the road's capacity, and ensures that the newly built road does not reduce the bearing capacity of the original bridge piers 300.

[0038] S4. Lay at least one circular culvert 5 in foundation pit 1. After laying the circular culvert 5, backfill the foundation pit with 3-8% lime soil to the bottom of the road structure. The number of circular culverts 5 can be adjusted based on the width of the road and the flow rate of the river. For example, if the flow rate of the river is large and the road width is sufficient, multiple circular culverts 5 can be installed.

[0039] S5, laying the road structure body on the bottom of the pavement structure.

[0040] Before laying the road structure body (S5) on the bottom of the pavement structure, the following steps are also included: excavating a first installation groove on the left side of the bottom of the pavement structure to bury the weak current pipeline and excavating a second installation groove on the right side of the bottom of the pavement structure to bury the power pipeline; laying a 10 cm thick gravel cushion layer on the bottom of the first installation groove and the second installation groove; and smoothing the gravel cushion layer with 7-10 cm thick C15 concrete to improve the bearing capacity of the first installation groove and the second installation groove. After the first installation groove and the second installation groove are completed, the weak current pipeline is laid in the first installation groove and the power pipeline is laid in the second installation groove.

[0041] Laying the road structure on the pavement base includes laying a 10-15% lime soil cushion layer, followed by a 30-40cm thick C30 concrete cushion layer, and finally a 10-15cm thick asphalt layer on the C30 concrete cushion layer. Specifically, the lime soil cushion layer can be 12% lime soil, and the C30 concrete cushion layer can be 36cm thick, ensuring that the road structure meets the required bearing capacity.

[0042] After the road structure body is laid on the bottom of the pavement structure, the following steps are also included: constructing a crash barrier 6 at the bridge pier 300 between the original road 100 and the river 200 to prevent the bridge pier 300 from being damaged when an alternating accident occurs.

[0043] After the road structure body is paved, crosswalks, guardrails, etc. may also be installed, which is not limited in this embodiment.

[0044] In summary, the present invention effectively overcomes various shortcomings of the prior art and has high industrial utilization value.

[0045] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A road structure passing under a bridge, characterized in that: include: Foundation pits are set up on the original road and river respectively, with retaining walls set up on the left and right sides of the foundation pits respectively, and a plurality of first high-pressure rotary grouting piles are set up at the bottom of the foundation pits; a plurality of second high-pressure rotary grouting piles are set up on the left and right sides of the bridge pier between the original road and the river respectively; The retaining wall includes a steel sheet pile retaining wall and a high-pressure rotary grouting pile gravity retaining wall. The steel sheet pile retaining wall is located 5 meters outside the original bridge, and the high-pressure rotary grouting pile gravity retaining wall is set within 5 meters of the original bridge. At least one circular culvert is set in each foundation pit for diverting river water, and 3-8% lime soil is used to backfill to the bottom of the road structure; A road structure body is laid on the bottom of the road structure.

2. The road structure under a bridge according to claim 1, characterized in that: Anti-collision guardrails are installed on both sides of the bridge piers between the original road and the river.

3. The road structure under a bridge according to claim 1, characterized in that: The road structure body comprises a 10-15% lime soil cushion layer arranged on the bottom of the road structure, a 30-40cm thick C30 concrete cushion layer laid on the lime soil cushion layer, and a 10-15cm thick asphalt layer laid on the C30 concrete cushion layer.

4. The road structure under a bridge according to claim 1, characterized in that: Circular culvert fixing seats are respectively provided on the front and rear sides of the foundation pit.

5. The road structure under a bridge according to claim 4, characterized in that: The circular pipe culvert fixing seat is made of C25 concrete.

6. A construction method for a road structure passing under a bridge, characterized by: The method comprises the road structure under a bridge according to any one of claims 1 to 5, further comprising the following steps: S1, intercepting the river, backfilling the river to the bottom height of the pavement structure, and excavating the original road to the bottom height of the pavement structure; S2, excavation of foundation pit on the original road and river; S3, construct retaining walls on the left and right sides of the foundation pit, construct the first high-pressure rotary jet grouting piles at the bottom of the foundation pit, and construct the second high-pressure rotary jet grouting piles on the left and right sides of the bridge pier between the original road and the river; S4, laying at least one circular culvert in the foundation pit, and after laying the circular culvert, backfilling with 3-8% lime soil to the bottom of the road structure; S5, laying the road structure body on the bottom of the pavement structure.

7. The construction method of a road structure passing under a bridge according to claim 6, characterized in that: Before laying the road structure body on the bottom of the pavement structure, the method further comprises: A first installation groove for burying weak-current pipelines is excavated on the left side of the bottom of the pavement structure, and a second installation groove for burying power pipelines is excavated on the right side of the bottom of the pavement structure. After the first installation groove and the second installation groove are completed, the weak-current pipeline is laid in the first installation groove and the power pipeline is laid in the second installation groove.

8. The method for constructing a road structure under a bridge according to claim 6, characterized in that: The method of laying the road structure body on the bottom of the pavement structure includes: A 10-15% lime soil cushion layer is laid on the bottom of the road structure, and then a 30-40cm thick C30 concrete cushion layer is laid on the lime soil cushion layer, and finally a 10-15cm thick asphalt layer is laid on the C30 concrete cushion layer.

9. The construction method of a road structure passing under a bridge according to claim 8, characterized in that: The lime soil cushion layer is 12% lime soil, and the C30 concrete cushion layer is 36 cm.

10. The construction method of a road structure passing under a bridge according to claim 6, characterized in that: After laying the road structure body on the bottom of the pavement structure, the method further comprises: Build anti-collision guardrails at the bridge piers between the original road and the river.

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