A construction method for widening and strengthening a bridge by using a front-mounted lightweight composite column platform

Abstract

The present invention discloses a construction method for a front-mounted light-weight composite column-type platform to widen and reinforce a bridge. The method comprises the following steps: filling and compacting the widened side of an existing bridge to form a widened roadbed slope; constructing steel sheet piles on the widened side of an existing bridge to form a protective structure; excavating the surface of the widened roadbed slope to form a construction platform; constructing a cap beam pile foundation and a platform front pile foundation on the construction platform; constructing a tie beam between the two platform front pile foundations, constructing a diagonal bracing beam between the platform front pile foundation and the cap beam pile foundation, and arranging the diagonal bracing beam in a downward direction toward the platform front pile foundation; constructing a cap beam on the top of the cap beam pile foundation; backfilling the construction platform, constructing a slab, and erecting a bridge deck. The present invention improves the anti-deformation stability of the bridge and the seismic performance of the abutment by arranging a cap beam, a cap beam pile foundation, a platform front pile foundation, and a diagonal bracing beam. The use of reusable steel sheet piles saves protective engineering and reduces engineering costs.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge engineering construction, in particular to a construction method for widening and reinforcing a bridge by splicing a front-mounted light-weight combined column platform. Background Art

[0002] With the development of urbanization in my country, the demand for the transportation industry continues to grow. Existing highway bridges are unable to meet the functional use of the existing traffic flow, and the original highway bridges need to be widened and expanded. In order to reduce the impact of the expansion project on the traffic around the construction section, while the existing bridges are widened and constructed normally, it is also necessary to ensure the traffic of the original highway. The existing highway bridge widening plan requires the installation of anti-slip piles along the edge of the existing abutment. Under the protection of the anti-slip piles, the existing roadbed and abutment slopes on the outside are excavated and filled with soil, and then the widened structure of the abutment is constructed from the ground, and then the abutment is backfilled behind the abutment to construct the roadbed. Although this plan can keep the old bridge traffic smooth, it requires a large investment, the anti-slip piles are temporary structures and need to be abolished, the investment efficiency is low, and the abutments of the existing widened bridges have weak seismic performance.

[0003] In view of this, it is necessary to propose a construction method for widening and reinforcing bridges with a front-mounted lightweight composite column platform to solve the above-mentioned defects. Summary of the Invention

[0004] The main purpose of the present invention is to provide a construction method for widening and reinforcing a bridge using a front-mounted lightweight composite column abutment, aiming to address the problem of weak seismic performance of abutments in existing bridge widening construction methods. To achieve the above-mentioned purpose, the present invention provides a construction method for widening and reinforcing a bridge using a front-mounted lightweight composite column abutment, the method comprising the following steps:

[0005] S1, filling and compacting the widened side of the existing roadbed slope at the longitudinal end of the existing bridge according to target construction requirements, thereby forming a widened roadbed slope at the longitudinal end of the existing bridge;

[0006] S2, constructing steel sheet piles on the transversely widened side of the existing bridge abutment, so that the steel sheet piles are vertically inserted into the widened roadbed slope to form a retaining structure;

[0007] S3, excavating the surface of the widened roadbed slope to form a construction platform for constructing the widened and reinforced bridge on the lateral outside of the steel sheet piles;

[0008] S4, constructing a cap beam pile foundation and a platform front pile foundation on the construction platform according to the target construction plan, and making the platform front pile foundation be in front of the cap beam pile foundation;

[0009] S5, constructing the inter-pile structure, constructing a tie beam between two adjacent platform front pile foundations, constructing a diagonal bracing beam between the platform front pile foundation and the cap beam pile foundation, and arranging the diagonal bracing beam in a downwardly inclined direction toward the platform front pile foundation;

[0010] S6, constructing the structure on the pile, constructing the cap beam on top of the cap beam pile foundation;

[0011] S7, backfilling the construction platform, constructing a slab on the upper part of the cap beam, and erecting a bridge deck on the top of the cap beam, wherein the bridge deck is above the slab.

[0012] Preferably, the method further includes step S8: judging whether the existing bridge needs to be demolished according to the condition of the abutments of the existing bridge, and if demolition is required, proceeding to step S81; if demolition is not required, proceeding to step S82;

[0013] S81: Suspend the opening of the existing bridge to traffic, open the widened and reinforced bridge to traffic, and renovate the existing bridge;

[0014] S82, remove the steel sheet piles, complete the construction of the widened and reinforced bridge, and the widened and reinforced bridge is opened to traffic.

[0015] Preferably, the step S81 specifically includes:

[0016] S811: Suspend the opening of the existing bridge to traffic, widen and reinforce the bridge and open it to traffic, excavate the existing roadbed and abutment structure in the area of ​​the old abutment cap beam of the existing bridge, and form a construction platform for the old abutment of the existing bridge;

[0017] S812: construct the old abutment cap beam pile foundation and the old abutment front pile foundation, and make the old abutment cap beam pile foundation in front of the old abutment front pile foundation;

[0018] S813, constructing the inter-pile structure, constructing the old abutment tie beam between the two old abutment front pile foundations, constructing the old abutment diagonal support beam between the old abutment front pile foundation and the old abutment cap beam pile foundation, and arranging the old abutment diagonal support beam in a downwardly inclined direction toward the old abutment front pile foundation;

[0019] S814, constructing the structure on the piles, constructing the old abutment cap beam on top of the pile foundation of the old abutment cap beam;

[0020] S815, backfill the old abutment construction platform, construct the old abutment slab on the upper part of the old abutment cap beam, erect the old abutment deck on the top of the old abutment cap beam, the old abutment deck is above the old abutment slab, remove the steel sheet piles, and the renovated existing bridge is open to traffic.

[0021] Preferably, in step S1, the target construction requirements are specifically: the elevation of the fill adopts the bottom elevation of the cap beam, and the compaction degree of the fill adopts the compaction degree of the existing roadbed slope.

[0022] Preferably, the step S4 further comprises: constructing the cap beam pile foundation and the platform front pile foundation by using a bored cast-in-place pile method.

[0023] Preferably, the steel sheet piles are Larsen steel sheet piles, and the ratio of the bottom buried depth of the Larsen steel sheet piles to the cantilever length above the bottom is greater than 1.

[0024] Preferably, the cap beam pile foundation and the platform front pile foundation are made of concrete with a label of C30, the diagonal bracing beam and the tie beam are made of concrete with a label of C30, and the cap beam is made of concrete with a label of C35.

[0025] Preferably, the cap beam includes a cap beam body, a platform back retaining wall and an ear wall. The platform back retaining wall and the ear wall are both arranged to protrude from the top surface of the cap beam body. The ear wall is arranged in a surface direction perpendicular to the platform back retaining wall. The platform back retaining wall is arranged on the side of the cap beam body away from the platform front pile foundation. The first side of the ear wall is connected to the side wall of the platform back retaining wall, and the second side of the ear wall extends outward in the longitudinal direction.

[0026] Compared with the prior art, the construction method of the front-mounted lightweight combined column platform for widening and reinforcing a bridge provided by the present invention has the following beneficial effects:

[0027] The present invention provides a construction method for widening and reinforcing a bridge with a front-mounted lightweight composite column-type platform. By arranging a cap beam, a cap beam pile foundation, a platform front pile foundation and a diagonal bracing beam to form a combined spatial force structure, the application range of the structure is improved. The arranged diagonal bracing beam serves as the main force transmission component to control the deformation displacement of the cap beam and the cap beam pile foundation, thereby improving the deformation stability of the bridge and the seismic resistance of the abutment. By adopting reusable steel sheet piles as the enclosing structure, the protective project is saved, the project cost is greatly reduced, the construction cost is reduced, and the application range is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0029] Figure 1 Schematic diagram of a construction method for widening and reinforcing a bridge in one embodiment of the present invention;

[0030] Figure 2 A front view of a widened and reinforced bridge in which one side of an existing bridge is widened and reinforced in accordance with an embodiment of the present invention;

[0031] Figure 3 A top view of a widened and reinforced bridge in which one side of an existing bridge is widened and reinforced in accordance with an embodiment of the present invention;

[0032] Figure 4 This is a front view of a widened and reinforced bridge in which both sides of an existing bridge are widened and reinforced in one embodiment of the present invention;

[0033] Figure 5 A side view of a widened and reinforced bridge in which both sides of an existing bridge are widened and reinforced in accordance with an embodiment of the present invention;

[0034] Figure 6 A top view of a widened and reinforced bridge in which both sides of an existing bridge are widened and reinforced in accordance with an embodiment of the present invention;

[0035] Description of Figure Numbers:

[0036] Widening and reinforcement of bridge 100; widening of roadbed slope 110; abutment tapered slope 111; widening of roadbed 112, steel sheet piles 120; cap beam pile foundation 130; abutment front pile foundation 140; tie beam 150; diagonal bracing beam 160; cap beam 170; cap beam body 171; abutment back retaining wall 172; ear wall 173; existing bridge 200; existing roadbed slope 210; existing roadbed 211; old abutment cap beam pile foundation 220; old abutment front pile foundation 230; old abutment tie beam 240; old abutment diagonal bracing beam 250; old abutment cap beam 260.

[0037] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0038] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0041] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0042] Please refer to the attached Figures 1 to 6 The present invention provides a construction method for widening and reinforcing a bridge by using a front-mounted lightweight combined column platform, the method comprising the steps of:

[0043] S1, filling and compacting the widened side of the existing roadbed slope 210 at the longitudinal end of the existing bridge 200 according to target construction requirements, thereby forming a widened roadbed slope 110 at the longitudinal end of the existing bridge 200;

[0044] S2, constructing steel sheet piles 120 on the transversely widened side of the abutment of the existing bridge 200, so that the steel sheet piles 120 are vertically inserted into the widened roadbed slope 110 to form a retaining structure;

[0045] S3, excavating the surface of the widened roadbed slope 110 to form a construction platform for constructing the widened and reinforced bridge 100 on the lateral outside of the steel sheet piles 120;

[0046] S4, constructing the cap beam pile foundation 130 and the platform front pile foundation 140 on the construction platform according to the target construction plan, and making the platform front pile foundation 140 in front of the cap beam pile foundation 130;

[0047] S5, constructing the inter-pile structure, constructing a tie beam 150 between two adjacent front-stage pile foundations 140, constructing a diagonal bracing beam 160 between the front-stage pile foundation 140 and the cap beam pile foundation 130, and arranging the diagonal bracing beam 160 in a downwardly inclined direction toward the front-stage pile foundation 140;

[0048] S6, constructing the pile structure, constructing the cap beam 170 on top of the cap beam pile foundation 130;

[0049] S7, backfilling the construction platform, constructing a slab on the upper part of the cap beam 170, and erecting a bridge deck on the top of the cap beam 170, wherein the bridge deck is located above the slab.

[0050] Specifically, backfill construction is first performed on the widening side of the existing roadbed slope 210 at the longitudinal end of the existing bridge 200, and the fill is compacted. The longitudinal direction refers to the passage direction of the bridge, and the longitudinal end refers to the two ends of the bridge along the passage direction. The target construction requirements are the fill elevation and fill compaction degree, which can be selected according to actual needs to form a widened roadbed slope 110. The widened roadbed slope 110 includes two parts: the part of the existing roadbed slope that is modified and the newly formed widened roadbed slope. The widened roadbed slope 110 is formed on the transverse widening side of the existing bridge 200. The steel sheet piles 120 are constructed on the side to form a retaining structure. The horizontal direction refers to the direction perpendicular to the passage direction of the bridge. The horizontal widening side refers to the two ends of the bridge along the passage direction. The steel sheet piles 120 are reusable. The widened roadbed slope 110 in the area of ​​the cap beam 170 of the widened bridge is excavated to form a construction platform. The cap beam pile foundation 130 and the platform front pile foundation 140 are constructed on the construction platform without setting platform columns. The cap beam 170 is constructed on the top of the cap beam pile foundation 130. The cap beam pile foundation 130 is directly connected to the cap beam 170, which saves materials.

[0051] It should be noted that the front pile foundation 140 is at the front side of the cap beam pile foundation 130. The front side refers to the front direction along the abutment cone slope 111. Generally, the front side of the abutment cone slope 111 is an open area with unrestricted space. The rear side of the abutment cone slope 111 is the roadbed driving lane surface, that is, the widened roadbed or the existing roadbed. The diagonal bracing beam 160 is arranged between the front pile foundation 140 and the cap beam pile foundation 130 corresponding to the front pile foundation 140. The diagonal bracing beam 160 is the main force transmission component, which can control the deformation displacement of the cap beam 170 and the cap beam pile foundation 130, thereby strengthening the integrity of the superstructure and improving the seismic performance of the abutment. In addition, a tie beam 150 is connected between the two front pile foundations 140. The tie beam 150 serves as a pull rod. The beam used, the tie beam 150 connects the two platform front pile foundations 140 into a whole load-bearing structure, improves the load-bearing structure of the platform front pile foundation 140, and strengthens the overall stiffness of the platform front pile foundation 140. A scaffolding is constructed on the upper part of the cap beam 170. The scaffolding can be set on the top of the cap beam 170, or on other structures on the top of the cap beam 170. For example, a platform back retaining wall is set on the top of the cap beam 170, and the scaffolding can be set on the platform back retaining wall. The bridge deck serves as the final road surface for traffic, so the bridge deck is above the scaffolding. The scaffolding is set between the upper part of the cap beam 170 and the widened roadbed to prevent the settlement of the bridge connection part and alleviate the bridge head jumping phenomenon. The bridge deck is erected on the top of the cap beam 170, the construction is completed, and the widened bridge is open to traffic.

[0052] It is worth noting that when the reinforcement structure is used as a quality improvement and reinforcement renovation project for an existing column-type abutment, the reinforcement structure is set at the front end of the abutment cone slope 111. Therefore, the reinforcement structure can be constructed directly under the abutment of the old bridge without interrupting the traffic on the old bridge, thereby reinforcing the old bridge.

[0053] The construction method for reinforcing the old bridge pier is as follows: set up construction steel sheet piles 120 on the old bridge pier cone slope 111; under the protection of the steel sheet piles 120, excavate the platform of the pile foundation 140 in front of the pier; jump excavate the construction of the pile foundation 140 in front of the pier; construct the upper structure and tie beam 150 of the pile foundation 140 in front of the pier; pull out the steel sheet piles 120 in front of the pier, and construct steel sheet piles 120 on both sides of the corresponding diagonal bracing beam 160; excavate and construct the platform of the diagonal bracing beam 160; construct the diagonal bracing beam 160, and the connection between the diagonal bracing beam 160 and the cap beam pile foundation 130 is connected by embedded steel bars; complete the backfill of the cone slope platform and pull out the steel sheet piles 120.

[0054] The construction method for reinforcing old bridge abutments is applicable to the reconstruction, reinforcement and new bridge construction projects of old bridge abutments, which increases the application scope of column abutments and has significant economic benefits.

[0055] The present invention improves the scope of application of the structure by arranging a cap beam 170, a cap beam pile foundation 130, a platform front pile foundation 140 and a diagonal bracing beam 160 to form a combined spatial force-bearing structure, and increases the scope of application of the columnar abutment from less than 5m of fill to no more than 8m of fill. The arranged diagonal bracing beam 160 serves as the main force transmission component to control the deformation displacement of the cap beam 170 and the cap beam pile foundation 130, thereby improving the anti-deformation stability of the bridge and the seismic resistance of the abutment. By adopting reusable steel sheet piles 120 as the enclosing structure, the protective project is saved, the project cost is greatly reduced, and the construction cost is reduced. By keeping the old road open and widening and reinforcing the bridge 100 to keep it open, they are used alternately without affecting the normal traffic in the old bridge section during the road widening construction, and have a wide scope of application.

[0056] As a preferred embodiment of the present invention, the method further includes step S8: determining whether the existing bridge 200 needs to be demolished based on the condition of the abutments of the existing bridge 200, and if demolition is required, proceeding to step S81; if demolition is not required, proceeding to step S82;

[0057] S81: suspend the opening of 200 existing bridges to traffic, widen and reinforce 100 bridges for traffic, and renovate 200 existing bridges;

[0058] S82, remove 120 steel sheet piles, complete the construction of 100 widened and reinforced bridges, and open the widened and reinforced bridges 100 to traffic.

[0059] In detail, when the construction of the widened and reinforced bridge 100 is completed, it is determined whether the existing bridge 200 needs to be demolished based on the condition of the abutments of the existing bridge 200. If the abutments are in good condition and can continue to be used, the steel sheet piles 120 are removed, and the construction of the widened and reinforced bridge 100 is completed, and the widened and reinforced bridge 100 is opened to traffic; if the abutments are in poor condition and need to be rebuilt, the opening of the existing bridge 200 to traffic is suspended, the widened and reinforced bridge 100 is opened to traffic, and the existing bridge 200 is renovated.

[0060] As a preferred embodiment of the present invention, step S81 specifically includes:

[0061] S811: Suspend the opening of existing Bridge 200 to traffic, widen and reinforce Bridge 100 for traffic opening, excavate the existing roadbed and abutment structure in the area of ​​the old abutment cap beam 260 of existing Bridge 200, and form a construction platform for the old abutment of existing Bridge 200;

[0062] S812, constructing the old abutment cap beam pile foundation 220 and the old abutment front pile foundation 230, and making the old abutment cap beam pile foundation 220 in front of the old abutment front pile foundation 230;

[0063] S813, constructing the inter-pile structure, constructing the old abutment tie beam 240 between the two old abutment front pile foundations 230, constructing the old abutment diagonal bracing beam 250 between the old abutment front pile foundation 230 and the old abutment cap beam pile foundation 220, and arranging the old abutment diagonal bracing beam 250 in a downwardly inclined direction toward the old abutment front pile foundation 230;

[0064] S814, constructing the structure on the piles, constructing the old abutment cap beam 260 on top of the old abutment cap beam pile foundation 220;

[0065] S815, backfill the old abutment construction platform, construct the old abutment slab on the upper part of the old abutment cap beam 260, erect the old abutment deck on the top of the old abutment cap beam 260, the old abutment deck is located above the old abutment slab, remove the steel sheet piles 120, and the renovated existing bridge 200 is open to traffic.

[0066] It should be understood that after the existing bridge 200 is closed to traffic, the abutment structure of the existing bridge 200 is excavated first to form an old abutment construction platform. The steps of reconstructing the existing bridge 200 are similar to the steps of constructing the widened and reinforced bridge 100. The cap beam pile foundation 130 and the abutment front pile foundation 140 are constructed on the construction platform. The construction method can adopt the bored cast-in-place pile method without setting abutment columns. The old abutment cap beam pile foundation 220 and the old abutment front pile foundation 230 can use C30 concrete. The old abutment cap beam 220 is constructed on the top of the old abutment cap beam pile foundation 220. 60. The old abutment cap beam pile foundation 220 is directly connected to the old abutment cap beam 260. The old abutment cap beam 260 adopts C35 concrete. The old abutment tie beam 240 is constructed between the two old abutment front pile foundations 230. The old abutment diagonal bracing beam 250 is constructed between the old abutment front pile foundation 230 and the old abutment cap beam pile foundation 220. C30 concrete can be used for the old abutment tie beam 240 and the old abutment diagonal bracing beam 250. The old abutment construction platform is backfilled, the slab and bridge deck are constructed, and the steel sheet piles 120 are removed to open the existing bridge 200 after renovation.

[0067] By adopting reusable steel sheet piles 120 as the retaining structure, the protection project is saved, the construction cost of the existing bridge 200 is greatly reduced, and the seismic and deformation resistance of the abutment is improved; by arranging the old abutment cap beam 260, the old abutment cap beam pile foundation 220, the old abutment front pile foundation 230 and the old abutment diagonal bracing beam 250 to form a combined spatial force structure, the structural applicability is improved, the deformation resistance of the bridge is improved, and the seismic performance of the abutment is improved.

[0068] Furthermore, in step S1 , the target construction requirements are specifically as follows: the elevation of the fill adopts the elevation of the bottom surface of the cap beam 170 , and the compaction degree of the fill adopts the compaction degree of the existing roadbed slope 210 .

[0069] It should be noted that in step S1 , the target construction requirements are specifically set to: the elevation of the fill adopts the bottom elevation of the cap beam 170 , and the compaction degree of the fill adopts the compaction degree of the existing roadbed slope 210 .

[0070] As a preferred embodiment of the present invention, step S4 further includes: constructing the cap beam pile foundation 130 and the platform front pile foundation 140 using a bored cast-in-place pile method. It should be noted that in this embodiment, the bored cast-in-place pile method is used to construct the cap beam pile foundation 130 and the platform front pile foundation 140. This method is mechanized, simple to construct, fast, with low noise and vibration, mature technology, and a safe and reliable construction process.

[0071] As a preferred embodiment of the present invention, the steel sheet pile 120 is a Larsen steel sheet pile 120 , and the ratio of the bottom buried depth length of the Larsen steel sheet pile 120 to the cantilever length of the upper bottom surface is greater than 1.

[0072] It should be understood that the type of steel sheet pile 120 can be selected according to actual needs. In this embodiment, the steel sheet pile 120 adopts Larsen steel sheet pile 120. Larsen steel sheet pile 120 has a fast construction speed, low construction cost, high strength and environmental protection, can be reused, provides the necessary safety and has strong timeliness. At the same time, the length of the cantilever can also be freely adjusted according to the actual situation on site. In this embodiment, the ratio of the bottom buried depth of the Larsen steel sheet pile 120 to the cantilever length above the bottom surface is set to be greater than 1, and the structure is stable.

[0073] Furthermore, the cap beam pile foundation 130 and the front platform pile foundation 140 use concrete labeled C30, the diagonal bracing beam 160 and the tie beam 150 use concrete labeled C30, and the cap beam 170 uses concrete labeled C35.

[0074] It should be noted that the cap beam pile foundation 130 and the front platform pile foundation 140 in this embodiment use C30 concrete, which is easy to use, low in price and has good durability; the cap beam 170 uses concrete labeled C35, which has high compressive strength and strong bearing capacity, and can well withstand the load of the superstructure.

[0075] As a preferred embodiment of the present invention, the cap beam 170 includes a cap beam body 171, a platform back retaining wall 172 and an ear wall 173. The platform back retaining wall 172 and the ear wall 173 are both protruding from the top surface of the cap beam body 171. The ear wall 173 is arranged in a surface direction perpendicular to the platform back retaining wall 172. The platform back retaining wall 172 is arranged on the side of the cap beam body 171 away from the platform front pile foundation 140. The first side of the ear wall 173 is connected to the side wall of the platform back retaining wall 172, and the second side of the ear wall 173 extends outward in the longitudinal direction.

[0076] It should be understood that, in this embodiment, the cap beam 170 includes a cap beam body 171, a back platform retaining wall 172 and an ear wall 173. The back platform retaining wall 172 is arranged on the side of the cap beam body 171 away from the front platform pile foundation 140, and is used to retain soil to keep the fill behind the abutment stable. The ear wall 173 is arranged on the side of the back platform retaining wall 172. This side refers to the side of the back platform retaining wall 162 away from the front platform pile foundation 140. The surface direction of the back platform retaining wall 162 refers to the direction perpendicular to the direction of travel of the widened bridge 100, that is, the ear wall is arranged longitudinally. One or two ear walls can be set. It can play a safety role on the side of the front platform pile foundation 140 beam, and can also play the role of supporting the bridge head slab, restraining the back platform soil, and preventing the soil from sinking and deforming, resulting in the bridge head jumping phenomenon.

[0077] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform, characterized in that: The method comprises the steps of: S1, filling and compacting the widened side of the existing roadbed slope at the longitudinal end of the existing bridge according to target construction requirements, thereby forming a widened roadbed slope at the longitudinal end of the existing bridge; S2, constructing steel sheet piles on the transversely widened side of the existing bridge abutment, so that the steel sheet piles are vertically inserted into the widened roadbed slope to form a retaining structure; S3, excavating the surface of the widened roadbed slope to form a construction platform for constructing the widened and reinforced bridge on the lateral outside of the steel sheet piles; S4, constructing a cap beam pile foundation and a platform front pile foundation on the construction platform according to the target construction plan, and making the platform front pile foundation be in front of the cap beam pile foundation; S5, constructing the inter-pile structure, constructing a tie beam between two adjacent platform front pile foundations, constructing a diagonal bracing beam between the platform front pile foundation and the cap beam pile foundation, and arranging the diagonal bracing beam in a downwardly inclined direction toward the platform front pile foundation; S6, constructing the structure on the pile, constructing the cap beam on top of the cap beam pile foundation; S7, backfilling the construction platform, constructing a slab on the upper part of the cap beam, and erecting a bridge deck on the top of the cap beam, wherein the bridge deck is above the slab.

2. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 1 is characterized in that: The method further includes step S8: determining whether the existing bridge needs to be demolished based on the condition of the abutments of the existing bridge, and if demolition is required, proceeding to step S81; if demolition is not required, proceeding to step S82; S81: Suspend the opening of the existing bridge to traffic, open the widened and reinforced bridge to traffic, and renovate the existing bridge; S82, remove the steel sheet piles, complete the construction of the widened and reinforced bridge, and the widened and reinforced bridge is opened to traffic.

3. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 2 is characterized in that: The step S81 specifically includes: S811: Suspend the opening of the existing bridge to traffic, widen and reinforce the bridge and open it to traffic, excavate the existing roadbed and abutment structure in the area of ​​the old abutment cap beam of the existing bridge, and form a construction platform for the old abutment of the existing bridge; S812: construct the old abutment cap beam pile foundation and the old abutment front pile foundation, and make the old abutment cap beam pile foundation in front of the old abutment front pile foundation; S813, constructing the inter-pile structure, constructing the old abutment tie beam between the two old abutment front pile foundations, constructing the old abutment diagonal support beam between the old abutment front pile foundation and the old abutment cap beam pile foundation, and arranging the old abutment diagonal support beam in a downwardly inclined direction toward the old abutment front pile foundation; S814, constructing the structure on the piles, constructing the old abutment cap beam on top of the pile foundation of the old abutment cap beam; S815, backfill the old abutment construction platform, construct the old abutment slab on the upper part of the old abutment cap beam, erect the old abutment deck on the top of the old abutment cap beam, the old abutment deck is above the old abutment slab, remove the steel sheet piles, and the renovated existing bridge is open to traffic.

4. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 1 is characterized in that: In step S1, the target construction requirements are specifically: the elevation of the fill adopts the bottom elevation of the cap beam, and the compaction degree of the fill adopts the compaction degree of the existing roadbed slope.

5. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 1 is characterized in that: The step S4 further includes: constructing the cap beam pile foundation and the platform front pile foundation by using a bored cast-in-place pile method.

6. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 1 is characterized in that: The steel sheet piles are Larsen steel sheet piles, and the ratio of the bottom surface buried depth of the Larsen steel sheet piles to the cantilever length of the upper bottom surface is greater than 1.

7. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 1 is characterized in that: The cap beam pile foundation and the platform front pile foundation are made of concrete with a label of C30, the diagonal bracing beam and the tie beam are made of concrete with a label of C30, and the cap beam is made of concrete with a label of C35.

8. The construction method for widening and reinforcing a bridge by using a front-mounted lightweight composite column platform according to claim 1 is characterized in that: The cap beam includes a cap beam body, a platform back retaining wall and an ear wall. The platform back retaining wall and the ear wall are both protruding from the top surface of the cap beam body. The ear wall is arranged in a surface direction perpendicular to the platform back retaining wall. The platform back retaining wall is arranged on the side of the cap beam body away from the platform front pile foundation. The first side of the ear wall is connected to the side wall of the platform back retaining wall, and the second side of the ear wall extends outward in the longitudinal direction.

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