CN116815615A - Structure and construction method of high-filling bridge head anti-void assembled pre-stressed butt strap - Google Patents

Abstract

The invention discloses a structure and a construction method of an anti-void assembled pre-stressed access board of a high-fill bridge head, which are suitable for judging and processing the void of the bridge head access board of a high-fill roadbed. The invention can rapidly judge the position and the area of the void, and can timely and repeatedly perform grouting treatment on the void part of the access board according to the size of the void area, thereby effectively avoiding the problem of bridge head skip caused by the rupture of the access board due to the large-area void under the access board.

Description

Structure and construction method of high-fill soil bridge head prefabricated prestressed slab to prevent voiding

Technical field

The invention relates to the technical fields of bridge structures and construction, and in particular to a high-fill soil bridge head anti-fallout assembled prestressed slab structure and a construction method.

Background technique

High-fill soil roadbed bridge head jumping has always been a difficult problem in highway construction. Because the high-fill soil roadbed has a heavy weight and a large amount of natural settlement, the fill soil under the bridge head deck on the back of the abutment can easily settle and become voided, causing the deck to break and form Bridge jumping. Since the void is larger on the side closer to the bridge than on the subgrade side in the vertical direction under the slab, and larger in the middle of the road than on the side of the road, the resulting void boundary line is difficult to accurately calculate theoretically. The traditional geological radar detection technology for slab voiding has a certain degree of locality and one-sidedness because the slab is a hidden project. It cannot accurately determine the location and area of the void, let alone the height of the void. A bridge head of the present invention The hollow-proof assembled prestressed slab structure can accurately determine the position, area and height of hollows based on the monitoring value, which can be used as a basis for grouting treatment.

The present invention adopts high-grade prestressed concrete slab design, which is thinner than ordinary reinforced concrete slabs, saving the amount of steel bars and concrete; the prestressed slabs work seamlessly, increasing the durability of the slab; the stiffness of the slab increases, reducing the It reduces the impact of the passing car load and the resulting deformation of the decking, and reduces the pressure from the bottom of the slab on the underlying layer, thus slowing down the settlement speed of the fill behind the platform.

Post-construction settlement continues to occur during the subgrade settlement period, and it is difficult to completely eliminate the voiding problem of the slab with one grouting operation. The present invention is provided with multiple grouting holes, and can perform grouting treatment multiple times on the voiding points that continue to occur during the settlement period. The traditional treatment method requires drilling and grouting on the deck. First, it affects traffic during the construction period. Second, drilling requires destroying the asphalt concrete surface layer on the deck. After the damage, the asphalt surface layer needs to be milled and re-paved. Third, the construction period It is long, expensive and has potential safety hazards. The grouting steel pipe of the present invention is led from the reserved grouting holes to both sides of the bridgehead roadbed. During grouting, grouting construction is performed on both sides of the bridgehead roadbed without damaging the asphalt surface layer and without affecting vehicle traffic. After grouting, the pipeline is filled with slurry. After solidification, the pipeline cannot be reused. Therefore, multiple grouting single valve devices are installed to ensure that multiple grouting operations can be performed. When grouting, the pressure is from bottom to top. The setting of the wedge-shaped cork can prevent the slurry from entering unused grouting steel pipes, thus ensuring that multiple groutings can be carried out, solving the problem of the slab being empty during the subgrade settlement period, and preventing the bridge head from jumping. produce.

Contents of the invention

The technical problems to be solved by this invention are: ordinary reinforced concrete slabs with high fill soil subgrade at the bridge head have low stiffness and large vibration, and the exact position and area of the void cannot be judged, and multiple grouting cannot be performed.

In order to solve the above technical problems, the present invention provides a structure of a high-fill soil bridge head anti-fallout assembled prestressed slab, which is used for the judgment and processing of the hollowing-out of the bridge head slab on the high-fill soil roadbed. It is characterized in that: The structure consists of the following three parts:

Prefabricated prestressed lap panels, which are configured to be bolted to the corbels;

One or more sets of monitoring devices are installed near the boundary line of the slab at different stages, and are composed of a steel stress meter installed on the upper part and a pressure sensor installed on the lower part;

The grouting one-way valve device includes a grouting steel pipe, a reserved hole for grouting in the lap plate, a wedge-shaped cork and a sealing rubber gasket, wherein the sealing rubber gasket is arranged at the bottom of the lap plate.

According to another specific embodiment of the present invention, the assembled prestressed strap further includes:

Precast panel group A (2), precast panel group B (3) and prestressed wet joints (4) are arranged along the length of the roadbed. Precast panel group A (2) and precast panel group B (3) are composed of multiple It consists of two horizontally arranged concrete plates. The adjacent horizontal concrete plates are connected by tie rods (5). One end of the prefabricated plate group A (2) is fixed to the corbels (1) of the abutment through anchor bolts. The prefabricated plate group A The other end of (2) is connected to the prefabricated panel group B (3) through a prestressed wet joint (4).

According to yet another specific embodiment of the present invention, the prestressed wet joint (4) further includes:

Precast patterned steel strands (20) in prefabricated panel group A (2), steel strands (8), connectors (9), plastic pipes (10), and sealing sleeves in prefabricated panel group B (3) (11), corrugated pipe (12), wet joint concrete (21).

According to yet another specific embodiment of the present invention, the monitoring device further includes:

It consists of several strain gauges (13) tied to the bottom longitudinal structural steel bars and a pressure sensor (14) embedded in the vertical position of the bottom of the deck plate corresponding to the strain gauge (13).

According to yet another specific embodiment of the present invention, the grouting one-way valve device further includes: a reserved hole (15) for grouting in the slab, a wedge-shaped cork (17), and a sealing rubber gasket.

According to another specific embodiment of the present invention, the thickness of the prefabricated panel group A (2) is 25cm ~ 40cm, the width is adjusted according to the width of the lane, the length is 7m ~ 8m, and the concrete grade is 40Mpa ~ 50Mpa; steel strand The diameter is 15.20mm and the strength is 1860Mpa; the anchorage is BJM15-3 series.

According to another specific embodiment of the present invention, the steel strand reinforcement of the prefabricated panel group A (2) is designed so that a certain length of void can exist, and the target value is a void length of 4m to 5m.

According to another specific embodiment of the present invention, the thickness of the prefabricated panel group B (3) is 25cm~40cm, the width is adjusted according to the width of the lane, the length is determined according to the height of the back filling, and the concrete label is 40Mpa~50Mpa; The steel strand diameter is 15.20mm and the strength is 1860Mpa; the anchorage is BJM15-2 series.

According to another aspect of the present invention, a construction method of a high-fill soil bridge head anti-fallout assembled prestressed slab structure is provided, which includes the following steps:

1) Prefabrication: Prefabricated prefabricated panel group A (2) and prefabricated panel group B (3). Prefabricated panel group A (2) reserves patterned steel strands (20) and installs them longitudinally at the bottom of prefabricated panel group A (2). Strain gauges (13) are pre-embedded in the structural steel bars (16), pressure sensor installation slots are reserved at corresponding positions at the bottom of the plate, and prefabricated plate group A (2) is reserved with holes (15) reserved for grouting;

2) Tension grouting: After the concrete strength of prefabricated panel group A (2) reaches 100%, the steel strand (23) is tensioned and grouted;

3) Chiseling: chisel the wet joint (4) side of precast panel group A (2) and precast panel group B (3);

4) Pressure sensor installation: Remove the prefabricated panel group A (2) and reserve the installation slot template, install the pressure sensor (14) in the installation slot, and adjust the bottom pressure-bearing surface of the pressure sensor (14) and the prefabricated panel group A (2) After the bottom of the board is flush, use structural glue to fix the pressure sensor;

5) Installation of one-way valve: Clean the reserved hole (15) for grouting on the prefabricated board, insert the wedge-shaped cork (17) from the bottom into the reserved hole (15) for grouting on the lap board, and finally seal it with The rubber pad (18) sticks the wedge-shaped cork (17) at the bottom of the lap board to seal it tightly;

6) Pressure sensor cushion construction: At the position of the pressure sensor (14) corresponding to the slab cushion, pre-cut a 50cm×50cm×2cm square groove on the lower bearing layer (6), spread fine sand and compact it. The top surface is flush with the surrounding cushion;

7) Installation of prefabricated panels: Lay two layers of linoleum felt on the corbels (1) of the bridge abutment, use a crane to install the prefabricated panel group A (2), and connect one end of the prefabricated panel group A (2) with the corbels (1). Fix the anchor bolts, and then hoist the prefabricated panel group B (3) to the predetermined position for installation;

8) Steel strand connection: Use the connector (9) to connect the precast patterned steel strands (20) of prefabricated panel group A (2) and the steel strands (8) of prefabricated panel group B (3). , the plastic pipe (10) is sleeved on the outside of the connector (9), the end of the plastic pipe (10) close to the side of the prefabricated panel group A (2) is sealed, and the end of the plastic pipe (10) close to the side of the prefabricated panel group B (3) is connected to The bellows (12) of the prefabricated panel group B (3) are connected in a sealed manner, and the space required for the tensile movement of the steel strand connector (9) is left at both ends of the plastic pipe (10);

9) Wet joint construction: The longitudinal prestressed wet joint (4) and the transverse ordinary concrete connection joint (24) connected by the tie rod (5) are poured from one side of the bridge at one time, and sprinkled with water to cover and cure for 7 days;

10) Tensioning of precast panel group B (3): When the strength of the prestressed wet joint (4) reaches 100%, tension the steel strands of precast panel group B (3), and grout and seal the anchors after the tensioning is completed;

11) Expansion joint treatment: fill the expansion joint between the front wall (22) and the precast panel group A (2) with polyurethane asphalt;

12) Installation of grouting pipe: Use the grouting steel pipe (19) to connect with the reserved hole (15) for grouting of the lap plate reserved on the precast panel group A (2) and lead it to the bridge head on the outside of the lap plate.

The beneficial effects of the present invention are:

1) The monitoring device set up in the present invention can accurately detect and judge the position, area and height of the void, thereby accurately calculating the void volume, performing grouting treatment in a timely manner, preventing the breakage of the decking, and preventing the bridgehead from jumping;

2) The present invention uses prestressed concrete slabs, which are thinner than ordinary reinforced concrete slabs, saving the amount of steel bars and concrete; the prestressed slabs work seamlessly, increasing the durability of the slabs; the stiffness of the slabs increases, reducing the The impact of the passing car load and the resulting deformation of the decking reduce the pressure from the bottom of the slab on the underlying layer, thereby slowing down the settlement rate of the fill behind the platform.

3) The present invention is provided with multiple reserved holes for grouting in the deck. The setting of the one-way valve ensures that the use of a reserved hole for grouting in a certain deck will not affect the later use of the reserved holes for grouting in other decks. The grouting can be carried out multiple times according to the different times when the void occurs, which solves the problem of multiple grouting for the slab to be voided.

Description of the drawings

Figure 1 is a schematic cross-sectional structural diagram of the present invention;

Figure 2 is a schematic plan view of the present invention;

Figure 3 is an enlarged schematic diagram of the prestressed wet joint of the present invention;

Figure 4 is a schematic cross-sectional view of prefabricated panel groups A and B near the wet joint ends of the present invention;

Figure 5 is a schematic diagram of the reserved grouting hole structure of the present invention;

Figure 6 is a schematic diagram of the longitudinal section along the road at the bridge head;

Figure 7 is a schematic cross-section along the road at the bridge head;

Figure 8 is a schematic diagram of the demarcation line at the bridge head.

In the picture: 1. Corbel; 2. Precast panel group A; 3. Precast panel group B; 4. Prestressed wet joint; 5. Tie rod; 6. Lower bearing layer; 7. Pavement structure; 8. B plate steel Stranded wire; 9. Connector; 10. Plastic pipe; 11. Sealing sleeve; 12. Corrugated pipe; 13. Strain gauge; 14. Pressure sensor; 15. Reserved holes for grouting in the slab; 16. Longitudinal structural steel bars; 17 , wedge-shaped cork; 18. Sealing rubber gasket; 19. Grouting steel pipe; 20. Pre-embedded patterned steel strand; 21. Wet joint concrete; 22. Front wall; 23. A-plate steel strand; 24. Ordinary concrete Joining seams.

Implementation

First of all, it is necessary to explain the rules about the voiding of the roadbed under the slab:

1. As shown in Figure 6, a schematic diagram of the longitudinal section of the bridge head along the road is given. It can be seen that the void depth on the bridge head side along the longitudinal direction of the road is greater than the subgrade side.

2. As shown in Figure 7, a schematic diagram of the transverse section along the road at the bridge head is given. It can be seen that the void depth in the road along the transverse direction of the roadbed is greater than at the road shoulder.

3. As shown in Figure 8, a schematic diagram of the void dividing line at the bridge head is given. It can be seen that with the different periods of highway operation, the void dividing lines of the slab and roadbed are different. The position and shape of the void line are related to the slab. It is related to structural design, vehicle load, roadbed foundation, backfill treatment method, etc.

Therefore, in view of the above-mentioned relevant rules in the actual construction process and the defects in the prior art described in the present invention, the present invention provides a high-fill soil bridge head anti-fallout assembled prestressed slab as shown in Figure 1-2 The structure is used to judge and handle the voiding of bridgehead slabs on high-fill soil subgrades. It is characterized in that the structure includes the following three parts:

Prefabricated prestressed lap panels, which are configured to be bolted to the corbels;

One or more sets of monitoring devices are arranged at different positions of the decking, and are composed of a steel stress meter arranged on the upper part and a pressure sensor arranged on the lower part;

The grouting one-way valve device includes a grouting steel pipe, a reserved hole for grouting in the lap plate, a wedge-shaped cork and a sealing rubber gasket, wherein the sealing rubber gasket is arranged at the bottom of the lap plate.

Preferably, the detection device is arranged near or at the proximal end of the emptying boundary line of the strapping plate at different stages.

It should be noted that prefabricated and prestressed technologies have been commonly used on bridges, but prestressed technology has not yet been applied to slabs. The prestressed decking has the following advantages:

1. The thickness of the slab is smaller than that of ordinary reinforced concrete slabs, and the amount of steel bars and concrete used in the slab is less than that of ordinary reinforced concrete.

2. After the tie plate is prestressed, the rigidity of the tie plate becomes larger and the deformation becomes smaller, which reduces the amplitude of the plate during driving and delays the time of emptying under the tie plate.

3. Prestressed slabs work seamlessly, extending the life of the slabs.

In addition, preferably, the sensor layout on the strap has the following rules:

1. There are a certain number of monitoring points on the decking, and steel strain gauges and pressure sensors are arranged above and below each monitoring point.

2. The monitoring points are arranged near the demarcation lines of the slabs of different periods in equidistant rows on the plane of the slab.

3. By bringing the values of the steel strain gauges and pressure sensors at each monitoring point during no-load and load conditions into the stress equation of the slab escapement, the voidage area and voidage height can be obtained. The traditional radar monitoring technology for voiding has certain limitations and one-sidedness because the slab is a concealed project. It cannot accurately determine the location and area of the void, and it cannot judge the void height of the slab and cannot calculate the required amount of grouting. of slurry volume.

As shown in Figure 1-2, the monitoring device consists of several strain gauges (13) tied to the longitudinal structural steel bars at the bottom and pressure sensors (14) embedded at the vertical positions corresponding to the strain gauges (13) at the bottom of the slab. .

As shown in Figure 2, the structure of the prefabricated prestressed lap panel includes precast panel group A (2), precast panel group B (3) and prestressed wet joints (4) arranged along the length direction of the roadbed. The precast panel group Both A (2) and precast panel group B (3) are composed of multiple horizontally arranged concrete panels. Adjacent transverse concrete panels are connected by tie rods (5). One end of precast panel group A (2) is connected to the bridge abutment. The corbels (1) are fixed by anchor bolts, and the other end of the prefabricated panel group A (2) is connected to the prefabricated panel group B (3) through a prestressed wet joint (4).

As shown in Figure 2-3, the thickness of prefabricated panel group A (2) is 25cm ~ 40cm, the width is adjusted according to the width of the lane, the length is 7m ~ 8m, the concrete grade is 40Mpa ~ 50Mpa; the diameter of the steel strand is 15.20mm, and the strength is 1860Mpa ;The anchorage adopts BJM15-3 series. The steel strand reinforcement of prefabricated panel group A (2) is designed to allow for a certain length of void, and the target value is a void length of 4m to 5m.

As shown in Figure 2-3, the thickness of prefabricated panel group B (3) is 25cm ~ 40cm, the width is adjusted according to the width of the lane, the length is determined according to the height of the backfill, the concrete label is 40Mpa ~ 50Mpa; the diameter of the steel strand is 15.20mm , strength 1860Mpa; anchorage adopts BJM15-2 series.

As shown in Figure 4, the prestressed wet joint (4) includes: pre-embedded patterned steel strands (20) in prefabricated panel group A (2), and steel strands (8) in prefabricated panel group B (3). ), connector (9), plastic pipe (10), sealing sleeve (11), bellows (12), wet joint concrete (21).

As shown in Figure 5, the grouting one-way valve device consists of a reserved hole for grouting (15), a wedge-shaped cork (17), and a sealing rubber gasket (18).

Among them, it should be noted that if the strap is hollowed out to a certain area, the strap will be damaged if the load stress is greater than the design stress. Therefore, the hollow part needs to be grouted in time when the load stress on the strap reaches the critical value of the design stress. Handle to avoid deck board damage.

Due to different conditions such as geology, load, and post-stage treatment methods, as the road is used for a long time, hollowing may continue to occur, requiring multiple grouting treatments.

The traditional treatment method requires drilling and grouting on the deck. First, the construction affects traffic. Second, drilling requires destroying the asphalt concrete surface layer on the deck. After the damage, the asphalt surface layer needs to be milled and re-paved. Third, the construction period It is long, expensive and has potential safety hazards.

Therefore, the grouting one-way valve device of the present invention is preferably composed of a separate grouting steel pipe, a reserved hole for grouting in the lap plate, a wedge-shaped cork, and a sealing rubber gasket. The grouting steel pipes are led from the reserved holes for grouting to both sides of the roadbed at the bridge head. During grouting, grouting construction is carried out on both sides of the roadbed without damaging the asphalt surface layer and without affecting vehicle traffic. After grouting, the pipeline is filled with slurry. After solidification, the pipeline cannot be reused, so multiple grouting single valve devices are installed. When grouting, the pressure is from bottom to top, and the wedge-shaped cork is installed to prevent grout from entering unused grouting steel pipes, thereby ensuring that multiple grouting can be carried out.

In addition, the present invention also provides a construction method of a high-fill soil bridge head anti-fallout assembled prestressed slab structure, which includes the following steps:

1) Prefabrication: Prefabricated prefabricated panel group A (2) and prefabricated panel group B (3). Prefabricated panel group A (2) reserves patterned steel strands (20) and installs them longitudinally at the bottom of prefabricated panel group A (2). Strain gauges (13) are pre-embedded in the structural steel bars (16), pressure sensor installation slots are reserved at corresponding positions at the bottom of the plate, and prefabricated plate group A (2) is reserved with holes (15) reserved for grouting;

2) Tension grouting: After the concrete strength of prefabricated panel group A (2) reaches 100%, the steel strand (23) is tensioned and grouted;

3) Chiseling: chisel the wet joint (4) side of precast panel group A (2) and precast panel group B (3);

4) Pressure sensor installation: Remove the prefabricated panel group A (2) and reserve the installation slot template, install the pressure sensor (14) in the installation slot, and adjust the bottom pressure-bearing surface of the pressure sensor (14) and the prefabricated panel group A (2) After the bottom of the board is flush, use structural glue to fix the pressure sensor;

5) Installation of one-way valve: Clean the reserved hole (15) for grouting on the prefabricated board, insert the wedge-shaped cork (17) from the bottom into the reserved hole (15) for grouting on the lap board, and finally seal it with The rubber pad (18) sticks the wedge-shaped cork (17) at the bottom of the lap board to seal it tightly;

6) Pressure sensor cushion construction: At the position of the pressure sensor (14) corresponding to the slab cushion, pre-cut a 50cm×50cm×2cm square groove on the lower bearing layer (6), spread fine sand and compact it. The top surface is flush with the surrounding cushion;

7) Installation of prefabricated panels: Lay two layers of linoleum felt on the corbels (1) of the bridge abutment, use a crane to install the prefabricated panel group A (2), and connect one end of the prefabricated panel group A (2) with the corbels (1). Fix the anchor bolts, and then hoist the prefabricated panel group B (3) to the predetermined position for installation;

8) Steel strand connection: Use the connector (9) to connect the precast patterned steel strands (20) of prefabricated panel group A (2) and the steel strands (8) of prefabricated panel group B (3). , the plastic pipe (10) is sleeved on the outside of the connector (9), the end of the plastic pipe (10) close to the side of the prefabricated panel group A (2) is sealed, and the end of the plastic pipe (10) close to the side of the prefabricated panel group B (3) is connected to The bellows (12) of the prefabricated panel group B (3) are connected in a sealed manner, and the space required for the tensile movement of the steel strand connector (9) is left at both ends of the plastic pipe (10);

9) Wet joint construction: The longitudinal prestressed wet joint (4) and the transverse ordinary concrete connection joint (24) connected by the tie rod (5) are poured from one side of the bridge at one time, and sprinkled with water to cover and cure for 7 days;

10) Tensioning of precast panel group B (3): When the strength of the prestressed wet joint (4) reaches 100%, tension the steel strands of precast panel group B (3), and grout and seal the anchors after the tensioning is completed;

11) Expansion joint treatment: fill the expansion joint between the front wall (22) and the precast panel group A (2) with polyurethane asphalt;

12) Installation of grouting pipe: Use the grouting steel pipe (19) to connect with the reserved hole (15) for grouting of the lap plate reserved on the precast panel group A (2) and lead it to the bridge head on the outside of the lap plate.

Although example embodiments and their advantages have been described in detail, it should be understood that various changes, substitutions and modifications can be made to these embodiments without departing from the spirit of the invention and the scope of protection as defined by the appended claims. For other examples, one of ordinary skill in the art will readily appreciate that the order of process steps may be varied while remaining within the scope of the present invention.

In addition, the application scope of the present invention is not limited to the process, mechanism, manufacture, material composition, means, methods and steps of the specific embodiments described in the specification. From the disclosure of the present invention, those of ordinary skill in the art will easily understand that there are processes, mechanisms, manufacturing, material compositions, means, methods or steps that currently exist or will be developed in the future, which perform the same functions as the present invention. Corresponding embodiments are described that function substantially the same or achieve substantially the same results, and may be applied in accordance with the present invention. Therefore, the appended claims of the present invention are intended to include these processes, mechanisms, manufactures, material compositions, means, methods or steps within the scope of protection thereof.

Claims (9)

1. The utility model provides a structure of high fill bridge head anticreep assembled prestressing force butt strap for the judgement and the processing that the bridge head butt strap of high fill roadbed is emptyd, its characterized in that, the structure includes following three part:

the assembly type prestress butt strap is arranged to be bolted on the bracket;

the one or more groups of monitoring devices are arranged at different positions of the access board and consist of a reinforcing steel bar stress meter arranged at the upper part and a pressure sensor arranged at the lower part;

the grouting one-way valve device comprises a grouting steel pipe, a butt strap grouting preformed hole, a wedge-shaped cork stopper and a sealing rubber pad, wherein the sealing rubber pad is arranged at the bottom of the butt strap.

2. The structure of the high fill bridgehead anti-void fabricated prestressed access panel of claim 1, further comprising:

precast slab group A (2), precast slab group B (3) and prestressing force wet joint (4) that set up along road bed length direction, precast slab group A (2) and precast slab group B (3) are constituteed by a plurality of horizontal concrete slab pieces of arranging, are connected through pull rod (5) between the adjacent horizontal concrete slab piece, and one end of precast slab group A (2) is fixed through the crab-bolt with bracket (1) of abutment, and the other end of precast slab group A (2) is connected with precast slab group B (3) through prestressing force wet joint (4).

3. The structure of the high fill bridgehead void prevention fabricated prestressed butt strap of claim 2, wherein said prestressed wet joint (4) further comprises:

the steel strand wires (20) of pre-buried binding in prefabricated plate group A (2), steel strand wires (8), connector (9), plastic tubing (10), seal cover (11), bellows (12), wet joint concrete (21) in prefabricated plate group B (3).

4. The structure of the prefabricated prestressed bridge deck for preventing the bridge head from coming out of the high-filling soil according to claim 1 or 2, wherein said monitoring device further comprises:

the strain gauge comprises a plurality of strain gauges (13) bound on the steel bars of the bottom longitudinal structure and pressure sensors (14) pre-buried at the bottom of the access board and vertically corresponding to the positions of the strain gauges (13).

5. The structure of the high-filling bridge head anti-void assembled pre-stressed butt strap according to claim 1 or 2, wherein,

the grouting one-way valve device further comprises: the butt strap grouting preformed hole (15), the wedge-shaped cork (17) and the sealing rubber pad.

6. The structure of the high-filling bridge head anti-void assembled pre-stressed butt strap according to claim 2 or 3, wherein,

the plate thickness of the precast slab set A (2) is 25 cm-40 cm, the width is adjusted according to the width of the lane, the length is 7 m-8 m, and the concrete mark is 40 Mpa-50 Mpa; the diameter of the steel strand is 15.20mm, and the strength is 1860Mpa; the anchor adopts BJM15-3 series.

7. The structure of the high-filling bridge head anti-void assembled pre-stressed butt strap according to claim 2 or 3, wherein,

the precast slab group A (2) steel strand reinforcing bars are designed according to the existence of a certain length of void, and the target value is 4-5 m of the void length.

8. The structure of the high-filling bridge head anti-void assembled pre-stressed butt strap according to claim 2 or 3, wherein,

the plate thickness of the precast slab group B (3) is 25 cm-40 cm, the width is adjusted according to the width of the lane, the length is determined according to the height of the land filling at the back of the platform, and the concrete mark is 40 Mpa-50 Mpa; the diameter of the steel strand is 15.20mm, and the strength is 1860Mpa; the anchor adopts BJM15-2 series.

9. A construction method of the structure of the high fill bridgehead anti-void assembled pre-stressed strap according to claim 2 or 3, comprising the steps of:

1) Prefabricating: prefabricated plate group A (2) and prefabricated plate group B (3), prefabricated plate group A (2) reserves the steel strand wires of binding flowers (20), and pre-buried strainometer (13) on vertical constructional steel bar (16) in prefabricated plate group A (2) bottom, reserve the pressure sensor mounting groove in the corresponding position of the board bottom, reserve strap grouting preformed hole (15) on prefabricated plate group A (2);

2) Stretching and grouting: after the concrete strength of the precast slab set A (2) reaches 100%, tensioning and grouting the steel strands (23);

3) Roughening: roughening wet joints (4) of the precast slab set A (2) and the precast slab set B (3);

4) And (3) mounting a pressure sensor: removing a prefabricated plate group A (2) to reserve a mounting groove template, mounting a pressure sensor (14) in a mounting groove, adjusting the bearing surface at the bottom of the pressure sensor (14) to be flush with the bottom of the prefabricated plate group A (2), and fixing the pressure sensor by using structural adhesive;

5) And (3) mounting a one-way valve: cleaning a reserved access plate grouting preformed hole (15) on the precast slab, plugging a wedge-shaped cork stopper (17) into the access plate grouting preformed hole (15) from the bottom, and finally firmly sealing the wedge-shaped cork stopper (17) at the bottom of the access plate by using a sealing rubber pad (18);

6) And (3) construction of a pressure sensor cushion layer: a square groove with the length of 50cm multiplied by 2cm is chiseled in advance on the lower bearing layer (6) at the position of the pressure sensor (14) corresponding to the lapping pad layer, fine sand is paved and compacted, and the top surface of the fine sand is leveled with the surrounding pad layer;

7) And (3) installing prefabricated plates: paving two layers of felt on a bracket (1) of a bridge abutment, installing a precast slab set A (2) by adopting a crane, fixing one end of the precast slab set A (2) and the bracket (1) by adopting an anchor bolt, and then hoisting a precast slab set B (3) to a preset position for installation;

8) And (3) steel strand connection: the method comprises the steps that a connector (9) is adopted to connect a pre-buried tie steel strand (20) of a precast slab set A (2) with a steel strand (8) of a precast slab set B (3), a plastic pipe (10) is sleeved outside the connector (9), the end part, close to one side of the precast slab set A (2), of the plastic pipe (10) is sealed, the end part, close to one side of the precast slab set B (3), is connected with a corrugated pipe (12) of the precast slab set B (3) in a sealing mode, and space required by stretching and moving of the steel strand connector (9) is reserved at two ends of the plastic pipe (10);

9) Wet joint construction: one side of the bridge is poured with a longitudinal prestress wet joint (4) and a common concrete connecting joint (24) which is transversely connected by a pull rod (5), and water is sprayed to cover and preserve for 7 days;

10 Stretching the prefabricated plate group B (3): when the strength of the prestressed wet joint (4) reaches 100%, tensioning the steel strands of the precast slab group B (3), and grouting and sealing the anchor after tensioning is finished;

11 Expansion joint treatment: filling polyurethane asphalt at the expansion joint between the front wall (22) and the precast slab set A (2);

12 Grouting pipe installation: and a grouting steel pipe (19) is connected with a reserved access plate grouting preformed hole (15) reserved on the precast plate group A (2) and led to the bridge head at the outer side of the access plate.