UHPC bridge suitable for rural highway and construction method of UHPC bridge

Abstract

The invention discloses a UHPC bridge suitable for rural highways and a construction method thereof.The UHPC bridge comprises a main beam, a bridge deck slab and a pavement layer, and the main beam comprises two UHPC anti-collision guardrails located on the two sides of the bridge deck slab; prestressed steel beams, tensile steel bars, pre-buried sections of bridge deck transverse steel bars and a plurality of longitudinal structural bars are arranged in the UHPC anti-collision guardrail, the tensile steel bars are arranged on the collision face of the UHPC anti-collision guardrail, and the lower ends of the tensile steel bars are bound and fixed to the pre-buried sections of the bridge deck transverse steel bars. The tensile steel bars are further fixedly connected with the longitudinal constructional bars; the bridge deck slab transverse reinforcing steel bars are annular stirrups, and the bridge deck slab transverse reinforcing steel bars and the bridge deck slab longitudinal reinforcing steel bars in the bridge deck slab are welded and fixed. On the basis of meeting the flood control and navigation requirements of the river channel, the height of the bridge structure can be reduced, and the length of a bridgehead wiring road is reduced.

Description

Technical Field

[0001] The present invention specifically relates to a UHPC bridge suitable for rural roads and a construction method thereof. Background Art

[0002] The elevation of the roads on both sides of the rural river is low. If a bridge is built on the river, Figure 1 In the conventional prefabricated hollow slab bridge structure shown in the figure, the bridge uses prefabricated hollow slab a as the main load-bearing component. After comprehensively considering the flood control level of the river channel and the clear height for navigation, the elevation of the newly built bridge is often higher than the roads on both sides, affecting the travel of residents on both sides of the original road. Because the elevation of the newly built bridge is higher than the roads on both sides, a long fill connection road needs to be set up at the bridge head. Based on the above situation, it is particularly important to reduce the structural height of the bridge. Summary of the invention

[0003] One of the purposes of the present invention is to provide a UHPC bridge suitable for rural roads. On the basis of meeting the requirements of river flood control and navigation, the height of the bridge structure can be reduced, the length of the bridgehead connecting road can be reduced, and the impact on the travel of residents in the houses on both sides of the original road can be reduced.

[0004] The above-mentioned object of the present invention can be achieved through the following technical solutions.

[0005] A UHPC bridge suitable for rural roads, the UHPC bridge comprising a main beam, a bridge deck and a pavement layer, the bridge deck being connected to the main beam as a whole, the pavement layer being arranged above the bridge deck, the main beam comprising two UHPC crash barriers located on both sides of the bridge deck, the interior of the UHPC crash barriers being provided with prestressed steel bundles, tensioned steel bars, embedded sections of bridge deck transverse steel bars and a plurality of longitudinal structural bars, wherein the prestressed steel bundles are arranged at the top and bottom of the UHPC crash barriers, the tensioned steel bars are arranged at the collision surface of the UHPC crash barriers and the lower ends of the tensioned steel bars are tied and fixed to the embedded sections of the bridge deck transverse steel bars, the tensioned steel bars are also fixedly connected to the longitudinal structural bars; the bridge deck transverse steel bars are annular stirrups, and the bridge deck transverse steel bars are welded and fixed to the bridge deck longitudinal steel bars in the bridge deck.

[0006] The two anti-collision guardrails of the present invention are connected to the cast-in-place bridge deck. The anti-collision guardrails also serve as the main structure of the bridge. Compared with conventional beams, the strength of the UHPC anti-collision guardrails can be fully utilized. The anti-collision guardrail uses UHPC high-performance concrete, and the height of the compression zone is about 40% of the same cross-sectional structure using conventional C50 concrete. Therefore, the amount of prestressed steel bundles set inside the anti-collision guardrail can be more, and the amount of prestressed steel bundles can be increased by up to 2.5 times. By using the structure of the present invention, the height of the main beam can be reduced by increasing the amount of prestressed steel bundles and reducing the weight of the main beam, thereby reducing the difficulty of transportation and hoisting of the main beam.

[0007] The present invention also has the following preferred design:

[0008] The longitudinal structural ribs of the present invention are arranged close to the surface of the UHPC crash barrier.

[0009] The bridge deck of the present invention can be made of ordinary concrete slab.

[0010] The transverse reinforcement of the bridge deck of the present invention is a square stirrup.

[0011] The prestressed steel bundle at the bottom of the UHPC crash barrier of the present invention is the main force-bearing steel bundle. In the 1 / 4 to 3 / 4 section of the bridge span, the prestressed steel bundle at the bottom of the UHPC crash barrier is arranged inside the annular stirrups formed by the transverse steel bars of the bridge deck. When approaching the end of the bridge, the prestressed steel bundle bends upward and is anchored at the end of the bridge; the prestressed steel bundle at the top of the UHPC crash barrier is used to prevent tensile stress from occurring at the top of the UHPC crash barrier. It is arranged in a straight line inside the tensile steel bars of the UHPC crash barrier and is anchored at the end of the bridge.

[0012] A construction method for a UHPC bridge suitable for a rural road comprises the following steps:

[0013] Step S1: prefabricate the UHPC anti-collision guardrail of the bridge in a factory and connect two UHPC anti-collision guardrails with the transverse steel bars of the bridge deck to form a main beam, and the metal corrugated pipe of the prestressed steel bundle in the UHPC anti-collision guardrail is embedded before the UHPC anti-collision guardrail is cast;

[0014] Step S2: tensioning the prestressed steel strands in the main beam to put the entire cross section of the main beam structure in a compressed state, grouting, anchor sealing, and completing the prefabrication of the main beam body;

[0015] Step S3: transporting the prefabricated main beam to the site and hoisting it into place as required;

[0016] Step S4: using the main beam as a support to set up a formwork support, and using the formwork support as a transverse fixing support for the main beam;

[0017] Step S5: using the formwork support to set up the bottom formwork of the bridge deck, and welding and connecting the longitudinal reinforcement of the bridge deck and the transverse reinforcement of the bridge deck;

[0018] Step S6: Casting the bridge deck, and removing the formwork support after the bridge deck strength reaches the required level;

[0019] Step S7: construct the pavement layer of the bridge deck and other auxiliary structures.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention uses two anti-collision guardrails connected to the cast-in-place bridge deck. The anti-collision guardrail also serves as the main structure of the bridge. The anti-collision guardrail uses UHPC high-performance concrete. Compared with conventional beams, the strength of the UHPC anti-collision guardrail can be fully utilized. The height of the compression zone is about 40% of the same cross-sectional structure using conventional C50 concrete. Therefore, the amount of prestressed steel bundles set inside the anti-collision guardrail can be more, and the amount of prestressed steel bundles can be increased by up to 2.5 times. By increasing the amount of prestressed steel bundles, the height of the main beam below the bridge deck can be reduced while ensuring that the bending performance of the main beam meets the requirements, thereby reducing the height difference between the bridge deck and the roads on both sides and reducing the length of the connecting road.

[0022] 2. By adopting the structure of the present invention, less material is needed for the main beam, the weight of the main beam is smaller, and the difficulty of transportation and hoisting is lower.

[0023] 3. The anti-collision guardrail of the present invention only needs to arrange tensile steel bars on the collision surface. Compared with conventional anti-collision guardrails, the amount of steel bars used can be greatly reduced, and the workload of steel bar tying can also be reduced.

[0024] 4. The anti-collision guardrail of the present invention adopts UHPC high-strength concrete, and the crack resistance of the surface is greatly enhanced, which can effectively reduce the scratch damage on the surface of the anti-collision guardrail during daily use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of a bridge using conventional prefabricated hollow slabs as main beams in the prior art;

[0026] Figure 2 It is a cross-sectional view of a UHPC bridge suitable for rural roads according to the present invention;

[0027] Figure 3 It is a structural schematic diagram of a UHPC bridge suitable for rural roads according to the present invention;

[0028] Figure 4 yes Figure 3 A-A cross-sectional view;

[0029] Figure 5It is a prestressed steel strand arrangement diagram of a UHPC bridge suitable for rural roads in the present invention;

[0030] Figure 6 yes Figure 5 B-B cross-sectional view;

[0031] Figure 7 It is a reinforcement arrangement diagram of a UHPC bridge suitable for rural roads in the present invention;

[0032] Figure 8 yes Figure 7 Reinforcement layout diagram inside the UHPC crash barrier;

[0033] Fig. 9 It is a steel bar arrangement diagram in the anti-collision guardrail in the prior art;

[0034] Fig.10 : is a comparison diagram of the bending bearing capacity of the UHPC bridge of the present invention and the conventional prefabricated hollow slab bridge in the embodiment;

[0035] Fig.11 It is a schematic diagram of the structure of the formwork support of the bridge deck.

[0036] Explanation of the reference numerals: 1. UHPC anti-collision guardrail; 2. Prestressed steel strands; 3. Bridge deck; 4. Pavement layer; 5. Tensile steel bars; 6. Transverse steel bars of the bridge deck; 7. Longitudinal structural bars; 8. Longitudinal steel bars of the bridge deck; 9. Formwork support. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and embodiments so that those skilled in the art can better understand and implement the technical solution of the present invention.

[0038] A UHPC bridge suitable for rural roads, such as Figures 2 to 8 As shown, the UHPC bridge includes a main beam, a bridge deck 3 and a pavement layer 4, the bridge deck 3 is connected to the main beam as a whole, the pavement layer 4 is arranged above the bridge deck 3, the main beam includes two UHPC crash barriers 1 located on both sides of the bridge deck 3, and the interior of the UHPC crash barrier 1 is provided with a prestressed steel bundle 2, a tensile steel bar 5, an embedded section of the bridge deck transverse steel bar 6, and a plurality of longitudinal structural bars 7, wherein the prestressed steel bundle 2 is arranged at the top and bottom of the UHPC crash barrier 1, the tensile steel bar 5 is arranged on the collision surface of the UHPC crash barrier 1, and the lower end of the tensile steel bar 5 is tied and fixed to the embedded section of the bridge deck transverse steel bar 6, and the tensile steel bar 5 is also fixedly connected to the longitudinal structural bar 7; the bridge deck transverse steel bar 6 is annular stirrup, and the bridge deck transverse steel bar 6 is welded and fixed to the bridge deck longitudinal steel bar 8 in the bridge deck 3. The bridge deck 3 is cast on site between the two UHPC crash barriers 1, and forms a whole with the bridge deck transverse steel bar 6 and the bridge deck longitudinal steel bar 8.

[0039] In one embodiment, the longitudinal structural ribs 7 are arranged close to the surface of the UHPC crash barrier 1 .

[0040] In one embodiment, the bridge deck 3 may be made of ordinary concrete slabs, which can reduce material costs.

[0041] In one embodiment, the bridge deck transverse reinforcement 6 is a square stirrup.

[0042] In one embodiment, the prestressed steel bundle 2 at the bottom of the UHPC crash barrier 1 is the main force-bearing steel bundle. In the 1 / 4 to 3 / 4 section of the bridge span, the prestressed steel bundle 2 at the bottom of the UHPC crash barrier 1 is arranged inside the annular stirrups formed by the transverse steel bars 6 of the bridge deck. When approaching the end of the bridge, the prestressed steel bundle 2 bends upward and is anchored at the end of the bridge; the prestressed steel bundle 2 at the top of the UHPC crash barrier 1 is used to prevent tensile stress from occurring at the top of the UHPC crash barrier 1. It is arranged in a straight line inside the tensile steel bars 5 of the UHPC crash barrier 1 and is anchored at the end of the bridge.

[0043] The above-mentioned construction method of UHPC bridges suitable for rural roads includes the following steps:

[0044] Step S1: prefabricate the UHPC anti-collision guardrail 1 of the bridge in a factory and connect two UHPC anti-collision guardrails 1 with the transverse steel bars 6 of the bridge deck to form a main beam, and the metal corrugated pipe of the prestressed steel bundle 2 in the UHPC anti-collision guardrail 1 is embedded before the UHPC anti-collision guardrail 1 is cast;

[0045] Step S2: tensioning the prestressed steel strands 2 in the main beam to put the entire cross section of the main beam structure in a compressed state, grouting and anchor sealing to complete the prefabrication of the main beam body;

[0046] Step S3: transporting the prefabricated main beam to the site and hoisting it into place as required;

[0047] Step S4: Fig.11 As shown, the main beam is used as a support to set up a formwork support 9, and the formwork support 9 is used as a transverse fixing support of the main beam;

[0048] Step S5: using the formwork support 9 to set up the bottom formwork of the bridge deck, and welding and connecting the longitudinal reinforcement 8 of the bridge deck and the transverse reinforcement 6 of the bridge deck;

[0049] Step S6: Cast the bridge deck 3, and remove the formwork support 9 after the strength of the bridge deck 3 reaches the required level;

[0050] Step S7: construct the pavement layer 4 of the bridge deck and other auxiliary structures.

[0051] Take a bridge with a net width of 4.5m and a span of 16m as an example. Figure 1 As shown in FIG. 1 , conventional prefabricated hollow slab beams are used, and the height of the structure below the bridge deck is: 0.08m (bridge deck pavement) + 0.15m (integrated layer) + 0.85m (prefabricated hollow slab) = 1.08m, while the UHPC bridge suitable for rural roads in the present invention is used, such as Figure 2 As shown, the height of the structure below the bridge deck is only: 0.08m (bridge deck pavement, i.e., pavement layer 4) + 0.3m (bridge deck 3) = 0.38m. Compared with conventional prefabricated hollow slab beams, the beam height is reduced by 0.7m, a reduction of about 70%. If converted to 3% based on the longitudinal slope of the connecting road, the length of the connecting road on each side of the bridge can be reduced by about 23m, and a total of 46m on both sides.

[0052] At the same time, according to the calculation, Fig.10 As shown in FIG. 1 , the bending resistance of the cross-section of the main beam of the bridge of the present invention is about 2.7 times that of the conventional prefabricated hollow slab. Therefore, the bridge of the present invention only needs to use two UHPC anti-collision guardrails 1 as the main load-bearing components of the main beam, and Figure 1 The bridge using conventional prefabricated hollow slabs shown in the figure needs to use 4 prefabricated hollow slabs as the main load-bearing components. In addition, since UHPC high-performance concrete is used in the anti-collision guardrail and main beam, only tensile reinforcement 5 is required to be arranged on the collision surface. Fig. 9 Compared with conventional anti-collision guardrails, it can greatly reduce the amount of steel bars used, reduce the workload of steel bar binding, and effectively reduce the scratch damage on the surface of the anti-collision guardrail during daily use.

[0053] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A UHPC bridge suitable for rural roads, the UHPC bridge comprising a main beam, a bridge deck and a pavement layer, the bridge deck and the main beam are connected as one, the pavement layer is arranged above the bridge deck, and is characterized in that: The main beam includes two UHPC crash guardrails located on both sides of the bridge deck, and the interior of the UHPC crash guardrails is provided with prestressed steel bundles, tensioned steel bars, embedded sections of bridge deck transverse steel bars and multiple longitudinal structural bars, wherein the prestressed steel bundles are arranged at the top and bottom of the UHPC crash guardrails, the tensioned steel bars are arranged on the collision surface of the UHPC crash guardrails and the lower ends of the tensioned steel bars are tied and fixed to the embedded sections of the bridge deck transverse steel bars, and the tensioned steel bars are also fixedly connected to the longitudinal structural bars; the bridge deck transverse steel bars are annular stirrups, and the bridge deck transverse steel bars are welded and fixed to the bridge deck longitudinal steel bars in the bridge deck.

2. The UHPC bridge suitable for rural roads according to claim 1 is characterized in that: The longitudinal structural ribs are arranged close to the surface of the UHPC crash barrier.

3. The UHPC bridge suitable for rural roads according to claim 1 is characterized in that: The bridge deck is an ordinary concrete slab.

4. The UHPC bridge suitable for rural roads according to claim 3 is characterized by: The transverse reinforcement of the bridge deck is square stirrups.

5. The UHPC bridge suitable for rural roads according to claim 1 is characterized in that: The prestressed steel bundle at the bottom of the UHPC crash barrier is the main load-bearing steel bundle. In the 1 / 4 to 3 / 4 section of the bridge span, the prestressed steel bundle at the bottom of the UHPC crash barrier is arranged inside the annular stirrups formed by the transverse steel bars of the bridge deck. When approaching the end of the bridge, the prestressed steel bundle bends upward and is anchored at the end of the bridge; the prestressed steel bundle at the top of the UHPC crash barrier is used to prevent tensile stress from occurring at the top of the UHPC crash barrier. It is arranged in a straight line inside the tensile steel bars of the UHPC crash barrier and anchored at the end of the bridge.

6. A construction method for a UHPC bridge suitable for rural roads according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step S1: prefabricate the UHPC anti-collision guardrail of the bridge in a factory and connect two UHPC anti-collision guardrails with the transverse steel bars of the bridge deck to form a main beam, and the metal corrugated pipe of the prestressed steel bundle in the UHPC anti-collision guardrail is embedded before the UHPC anti-collision guardrail is cast; Step S2: tensioning the prestressed steel strands in the main beam to put the entire cross section of the main beam structure in a compressed state, grouting, anchor sealing, and completing the prefabrication of the main beam body; Step S3: transporting the prefabricated main beam to the site and hoisting it into place as required; Step S4: using the main beam as a support to set up a formwork support, and using the formwork support as a transverse fixing support for the main beam; Step S5: using the formwork support to set up the bottom formwork of the bridge deck, and welding and connecting the longitudinal reinforcement of the bridge deck and the transverse reinforcement of the bridge deck; Step S6: Casting the bridge deck, and removing the formwork support after the bridge deck strength reaches the required level; Step S7: construct the pavement layer of the bridge deck and other auxiliary structures.

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