CN110924318A

CN110924318A - Construction structure and method for T-frame underpinning original abutment pile foundation reinforcing rigid frame bridge

Info

Publication number: CN110924318A
Application number: CN201911351108.4A
Authority: CN
Inventors: 多冉伟; 杨宏刚; 窦晗; 王礼平; 吴礼华; 胡利军
Original assignee: China Railway First Engineering Group Co Ltd; Third Engineering Branch of China Railway First Engineering Group Co Ltd
Current assignee: China Railway First Engineering Group Co Ltd; Third Engineering Branch of China Railway First Engineering Group Co Ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-03-27

Abstract

The invention discloses a T-frame underpinning original abutment pile foundation reinforced rigid frame bridge construction structure and a method, wherein the structure comprises a T-frame underpinning mechanism arranged between an original abutment cap and a roadbed, the T-frame underpinning mechanism comprises a T-frame beam, a middle supporting part and a counterweight mechanism, and the T-frame beam comprises a No. 0 block, a No. 1 block and a No. 2 block; the method comprises the following steps: firstly, constructing a T-shaped structural beam; secondly, roughening and planting ribs on the back wall of the original bridge platform cap; thirdly, connecting the T-shaped beam with the original bridge abutment cap; drilling a connecting pore passage of the original bridge platform cap; fifthly, mounting the prestressed tendons; sixthly, pouring concrete of the beam section and tensioning the prestressed beam; seventhly, reinforcing the original bridge abutment cap and performing two times of conversion on the whole stress system. The invention is not only suitable for bridge reinforcing engineering influenced by strong geological deformation and narrow operation surface, but also ensures that the bearing capacity of the reinforced bridge is equivalent to that of the original bridge, and the construction method is novel, short in construction period and high in economic benefit.

Description

Construction structure and method for T-frame underpinning original abutment pile foundation reinforcing rigid frame bridge

Technical Field

The invention belongs to the technical field of rigid frame bridge reinforcement, and particularly relates to a T-frame underpinning original abutment pile foundation reinforced rigid frame bridge construction structure and method.

Background

The original continuous rigid frame bridge is located in a submerged area of a silk screen hydropower station reservoir area, and due to the fact that reservoir water storage of the reservoir area causes geological deformation of a bank slope where a bridge abutment on one side of an original bridge is located, a mountain body at the bridge abutment is cracked, and the original bridge needs to be reinforced to prevent bridge abutment instability caused by the geological deformation from continuing to spread. The conventional reinforcement construction is mainly characterized in that a large-diameter deep pile foundation is arranged at the position 2 meters outside an abutment pile foundation, a cover beam for supporting an original abutment is arranged at the top of the pile foundation to replace the original abutment pile foundation, and a prestressed simple and straight beam with the length of 2-span-40 meters is additionally arranged behind a back wall of the original abutment to span the range influenced by the deformation of a bank slope. However, the pile foundation listed by the method has the defects of large diameter, deep depth, high safety risk, traffic blockage, construction progress restriction and the like because the pile foundation is located in a strong deformation area with broken mountain bodies.

Disclosure of Invention

The invention aims to solve the technical problems in the prior art, and provides a T-structure underpinning original abutment pile foundation reinforced rigid frame bridge construction structure which is reasonable in design and convenient and fast to operate.

In order to solve the technical problems, the invention adopts the technical scheme that: the utility model provides a T constructs original abutment pile foundation of underpinning and consolidates rigid frame bridge construction structures, its characterized in that: the T-shaped support mechanism is arranged between an original bridge abutment cap and a roadbed, and comprises a T-shaped support beam, a middle support part for supporting the T-shaped support beam, and a counterweight mechanism arranged at one end, far away from the original bridge abutment cap, of the T-shaped support beam, wherein the T-shaped support beam comprises a No. 0 block, a No. 1 block symmetrically arranged at two sides of the No. 0 block, a No. 2 block symmetrically arranged at two sides of the No. 1 block, and beam section concrete arranged at the tops of the No. 0 block, the No. 1 block and the No. 2 block, the counterweight mechanism comprises a solid counterweight section and a pile foundation arranged at the bottom of the solid counterweight section, a counterweight block is additionally arranged at one end, close to the solid counterweight section, of the No. 2 block, a steel pipe pile, a bearing platform foundation, a stand column and steel pipe concrete are sequentially arranged at the bottom of the original bridge abutment cap from bottom to top, the steel pipe concrete is hinged and connected with the bottom of the original bridge abutment cap, one end, close to the original bridge abutment cap, of, the bottom of the No. 2 block and the bottom of the No. 1 block are gradually arranged from the original bridge platform cap to the No. 0 block in a downward inclined mode, and the top of the beam section concrete, the top surface of the solid counterweight section and the top of the original bridge are flush.

Foretell a T constructs original abutment pile foundation of underpinning and consolidates rigid frame bridge construction structures, its characterized in that: the number of the middle supporting parts is two, the middle supporting parts are symmetrically arranged about the No. 0 block, each middle supporting part comprises a side bearing platform fixedly connected with the No. 0 block and a drilled pile with the top end embedded in the side bearing platform, the length of the side bearing platform is equal to that of the No. 0 block, the height of the side bearing platform is smaller than that of the No. 0 block, and the number of the drilled piles embedded in each side bearing platform is two.

Foretell a T constructs original abutment pile foundation of underpinning and consolidates rigid frame bridge construction structures, its characterized in that: the back wall of former abutment cap is provided with a plurality of bar planting holes, the downthehole twisted steel that is provided with of bar planting, the one end of twisted steel stretches into the bar planting that fills the bar planting and glue downthehole, the other end of twisted steel stretches into No. 2 pieces, the bar planting hole is the blind hole, just the degree of depth in bar planting hole is 10 times ~ 12 times of twisted steel diameter, the twisted steel stretches out the reinforcing bar net fixed connection in the one end of former abutment cap and No. 2 pieces.

Foretell a T constructs original abutment pile foundation of underpinning and consolidates rigid frame bridge construction structures, its characterized in that: the original bridge abutment cap is provided with a first group of connecting holes positioned at the middle lower part of the original bridge abutment cap, a second group of connecting holes positioned at one side of the first group of connecting holes and a third group of connecting holes positioned at the other side of the first group of connecting holes, the horizontal distance between two adjacent first connecting holes in the first group of connecting holes is 70-80 cm, the horizontal distance between two adjacent second connecting holes is 60-70 cm, the horizontal distance between two adjacent third connecting holes is the same as the horizontal distance between two adjacent second connecting holes, the vertical distance between two adjacent first connecting holes, two adjacent second connecting holes and two adjacent third connecting holes is 80-90 cm, the aperture of each first connecting hole, each second connecting hole and each third connecting hole is 100-130 mm, and the horizontal distance between each first group of connecting holes and the second group of connecting holes and between each first group of connecting holes and each third group of connecting holes is 180-180 cm, the first connecting hole is lower than the central position of the original bridge abutment cap along the height direction, a gap is arranged between the second connecting hole and the top surface of the original bridge abutment cap, connecting steel bars are arranged in the first connecting hole, the second connecting hole and the third connecting hole in a penetrating mode, and one end, extending out of the original bridge abutment cap, of each connecting steel bar and the other end, extending out of the corresponding No. 2 block, of each connecting steel bar are all sleeved with a locking nut.

Foretell a T constructs original abutment pile foundation of underpinning and consolidates rigid frame bridge construction structures, its characterized in that: no. 0 piece, No. 1 piece and No. 2 piece the top is worn to be equipped with prestressing tendons, prestressing tendons is worn to be equipped with down in the bottom of No. 1 piece and No. 2 piece, go up prestressing tendons and prestressing tendons all include bellows, many the prestressing tendons of wearing to establish in the bellows and wear to establish the fixed steel backing plate at many prestressing tendons stiff ends down, the cover is equipped with the spiral muscle between fixed steel backing plate and the bellows, the spiral muscle is located outside many prestressing tendons, and the stretch-draw pot head of many prestressing tendons is equipped with stretch-draw steel backing plate and ground tackle.

Meanwhile, the invention also discloses a T-frame underpinning original abutment pile foundation reinforced rigid frame bridge construction method which is simple in method steps, reasonable in design, convenient to implement and good in inspection and use effects, and is characterized by comprising the following steps:

step one, construction of a T-shaped structural beam:

step 101, excavating and leveling a roadbed close to a bridge abutment of a bridge to be repaired to form a T-shaped beam construction area; the cross section of the construction area of the T-shaped beam is in an inverted trapezoid shape;

102, constructing at the middle position of a T-shaped beam construction area to form a No. 0 block and a No. 1 block; the number of the No. 1 blocks is two, and the two No. 1 blocks are symmetrically arranged at two ends of the No. 0 block;

simultaneously, drilling holes on two sides of the No. 0 block by adopting a percussion drill to form drilled piles; the number of the drilled piles is four, the length center line of a rectangle formed by the four drilled piles is overlapped with the length center line of the No. 0 block, the width center line of the rectangle formed by the four drilled piles is overlapped with the width center line of the No. 0 block, and the distance between the drilled piles and the outer side face of the No. 0 block is 2-2.5 m;

103, embedding reinforcing steel bars on two sides of the No. 0 block, and building bearing platform templates on two sides of the No. 0 block to cast concrete in situ to form a side bearing platform; the side bearing platforms are symmetrically distributed about the No. 0 block, the length of each side bearing platform is equal to that of the No. 0 block, the height of each side bearing platform is smaller than that of the No. 0 block, and the top ends of the four drilling piles are embedded in the side bearing platforms;

step two, roughening and planting ribs on the back wall of the original bridge platform cap:

step 201, firstly, roughening the back wall of the original bridge abutment cap by using a breaking hammer, and then, performing additional chiseling on the back wall of the original bridge abutment cap by using a rock drill until the surface roughness of the back wall of the original bridge abutment cap is level 2, so as to obtain the roughened back wall;

202, arranging bar planting points on the roughened back wall; wherein, the number of the bar planting points is a plurality;

step 203, drilling holes at each bar planting point by using a drilling machine, blowing away rock powder in the drilled holes to form bar planting holes, and filling bar planting glue in the bar planting holes;

step 204, inserting a threaded steel bar into each bar planting hole filled with bar planting glue; one end of the deformed steel bar extends into a bar planting hole filled with bar planting glue, the other end of the deformed steel bar extends out of the bar planting hole, the bar planting hole is a blind hole, and the depth of the bar planting hole is 10-12 times of the diameter of the deformed steel bar;

step three, connecting the T-shaped structure beam with the original bridge platform cap:

step 301, binding steel bars on one side of the No. 0 block to form a steel bar mesh; the bottom corrugated pipe is arranged from the original bridge platform cap to the bottom of the No. 0 block in a gradually downward inclined mode;

step 302, erecting a template outside the reinforcing mesh and pouring concrete to form a No. 2 block until the concrete strength of the No. 2 block reaches 90% of the designed concrete strength; the number of the No. 2 blocks is two, and the two No. 2 blocks are symmetrically distributed relative to the No. 0 block;

303, erecting a counterweight block template at one end of the No. 2 block, which is far away from the original bridge platform cap, and casting concrete in situ to form a counterweight block;

304, erecting a counterweight section template at one end of the No. 2 block, which is far away from the original bridge platform cap, and casting concrete in situ to form a solid counterweight section, and arranging a pile foundation at the bottom of the solid counterweight section;

drilling a connecting hole channel of the original bridge platform cap:

401, distributing a plurality of hole sites on the side surface of the original bridge platform cap far away from the back wall;

step 402, drilling holes at each hole site by using a geological drill and extending No. 2 blocks to form a plurality of connecting holes; wherein the connecting holes comprise a first group of connecting holes positioned at the middle lower part of the original bridge platform cap, a second group of connecting holes positioned at one side of the first group of connecting holes and a third group of connecting holes positioned at the other side of the first group of connecting holes, the horizontal distance between two adjacent first connecting holes in the first group of connecting holes is 70-80 cm, the horizontal distance between two adjacent second connecting holes is 60-70 cm, the horizontal distance between two adjacent third connecting holes is the same as the horizontal distance between two adjacent second connecting holes, the vertical distance between two adjacent first connecting holes, two adjacent second connecting holes and two adjacent third connecting holes is 80-90 cm, the apertures of the first connecting holes, the second connecting holes and the third connecting holes are 100-130 mm, the horizontal distances between the first group of connecting holes and the second group of connecting holes and between the first group of connecting holes and the third group of connecting holes are 180-180 cm, the first connecting hole is lower than the center of the original bridge platform cap along the height direction, and gaps are formed between the second connecting hole and the top surface of the original bridge platform cap and between the third connecting hole and the top surface of the original bridge platform cap;

step 403, installing connecting steel bars in the first connecting hole, the second connecting hole and the third connecting hole; one end of the connecting steel bar extending out of the original abutment cap and the other end of the connecting steel bar extending out of the No. 2 block are both sleeved with locking nuts;

step five, mounting the prestressed tendons:

step 501, binding steel bars on the top surfaces of the No. 0 block, the No. 1 block and the No. 2 block to form a rectangular steel bar cage; a plurality of corrugated pipes penetrate through the rectangular reinforcement cage along the width direction of the rectangular reinforcement cage, and the corrugated pipes are arranged along the length directions of the No. 0 block, the No. 1 block and the No. 2 block;

502, arranging a fixed steel base plate at one end of the corrugated pipe close to the back wall of the original bridge platform cap, and arranging spiral ribs between the fixed steel base plate and the corrugated pipe

Sequentially penetrating a plurality of prestressed reinforcements through the fixed steel backing plate, the spiral reinforcements and the corrugated pipe, and sequentially penetrating a plurality of prestressed reinforcements through the tensioning end of the corrugated pipe to install a tensioning steel backing plate and an anchorage device so as to finish the installation of a prestressed beam;

step 503, sequentially installing prestressed steel bundles in each corrugated pipe and the bottom corrugated pipe according to the method in the step 502 to obtain an upper prestressed steel bundle and a lower prestressed steel bundle;

step six, beam section concrete pouring and prestressed beam tensioning:

step 601, erecting a beam body template outside the rectangular reinforcement cage, and casting concrete in situ to form beam section concrete until the concrete strength of the beam section concrete reaches 90% of the designed concrete strength;

step 602, operating a tensioning steel base plate and an anchorage device to tension a plurality of prestressed tendons;

step 603, after tensioning is finished, injecting micro-expansion cement slurry into each corrugated pipe and the bottom corrugated pipe until the strength of the cement slurry in the corrugated pipes and the bottom corrugated pipe reaches 90% of the designed strength of the cement slurry;

step seven, reinforcing the original bridge platform cap and converting the whole stress system for two times:

step 701, simultaneously disconnecting the original abutment cap and the original abutment pile foundation, removing the original abutment pile foundation, relieving the pile foundation stress of the original abutment (6), and completing the first stress system conversion;

step 702, constructing a bearing platform foundation at the bottom of the original bridge platform cap, constructing an upright column on the bearing platform foundation, arranging concrete-filled steel tubes at the top end of the upright column to be hinged with the beam section concrete and the original bridge platform cap, preventing the original bridge and the original bridge platform cap from warping downwards, and completing the conversion of a second stress system; wherein, the distance between the upper surface of the bearing platform base and the bottom of the No. 0 block is 250 cm-300 cm.

The above method is characterized in that: in step 701, the original abutment cap and the two original abutment pile foundations are disconnected simultaneously, and the specific process is as follows:

7011, performing annular cutting at the connecting part of the original bridge abutment cap and the top surfaces of the two original bridge abutment pile foundations by using a cutting machine until the original bridge abutment cap is connected with the top surfaces of the two original bridge abutment pile foundations;

7012, chiseling 150-200 mm pile body concrete at the top ends of two original bridge platform pile foundations by using a rock drill to expose pile body reinforcing steel bars;

7013, cutting the pile body reinforcing steel bars by using an air welder, and stripping the residual internal pile body concrete at the position of 150-200 mm by using a rock drill;

and 7014, removing the residual original bridge abutment pile foundation.

The above method is characterized in that: in step 602, tensioning the prestressed tendons, specifically, the process is as follows:

operating and stretching the steel backing plate and the anchorage device, and applying 0-0.15Q_kyTensioning force, performing first tensioning, and applying 0.15Q_kyFinishing the first tensioning when the tensioning force is more than 3 min; applying 0.15Q_ky～Q_kyTensioning for the second time while applying Q_kyFinishing the second tensioning when the tensioning force is more than 3 min; wherein Q is_kyThe stress design values are controlled for tensioning.

Compared with the prior art, the invention has the following advantages:

1. simple structure, reasonable in design and simple and convenient, the input cost is lower in the installation.

2. According to the invention, the threaded reinforcing steel bars are planted in the back wall of the original bridge platform cap after roughening so as to weld the threaded reinforcing steel bars and the reinforcing mesh in the end of the T-shaped structural beam, and meanwhile, the connecting reinforcing steel bars are arranged in the first connecting hole, the second connecting hole and the third connecting hole so as to further reinforce the connection between the original bridge platform cap and the T-shaped structural beam.

3. The invention is provided with a solid counterweight section, a counterweight block and a prestressed beam, which aims to limit the downward penetration of the concrete of the beam section caused by the shrinkage and creep of the concrete of the beam section on the top surface of a later T-shaped structural beam.

4. The construction method for reinforcing the rigid frame bridge by replacing the original abutment pile foundation through the T-shaped structure has the advantages of simple steps, convenience in implementation and simplicity and convenience in operation, ensures the strength of the rigid frame bridge by replacing the original abutment pile foundation through the T-shaped structure, enables the bearing capacity of the reinforced bridge to be equivalent to that of the original bridge, and is novel, short in construction period and high in economic benefit.

5. The construction method for replacing the original abutment pile foundation reinforced rigid frame bridge by the T-frame is simple and convenient to operate and good in using effect, firstly, construction of a T-frame beam is carried out, secondly, back wall roughening and rib planting are carried out on an original abutment cap, then the T-frame beam is connected with the original abutment cap, a connecting pore channel is drilled in the original abutment cap, connecting reinforcing steel bars are installed, and the end of the T-frame beam is connected with the original abutment cap; secondly, mounting a prestressed tendon, pouring concrete on the top end of the T-shaped beam in situ to form beam section concrete, stretching the prestressed tendon when the beam section concrete meets the design requirement, and injecting micro-expansion cement slurry into the corrugated pipe; and finally, simultaneously disconnecting the original bridge abutment cap and the two original bridge abutment pile foundations to remove the original bridge abutment pile foundations and reinforce the original bridge abutment cap, so that the original bridge abutment pile foundations are underpinned by the T-frame to reinforce the rigid frame bridge.

In conclusion, the method is reasonable in design and convenient and fast to operate, the T-shaped structural beam with the variable cross section is adopted to connect the original bridge abutment so as to replace the existing bridge abutment pile foundation affected by geological deformation and bank collapse of the bank slope, the method is suitable for bridge reinforcing engineering affected by strong geological deformation and narrow operation surface, the bearing capacity of the reinforced bridge is equivalent to that of the original bridge, the construction method is novel, the construction period is short, and the economic benefit is high.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural diagram of a construction structure for underpinning an original abutment pile foundation reinforced rigid frame bridge by using a T-frame.

Fig. 2 is a schematic position diagram of a steel bar planting hole, an upper prestressed steel beam, a lower prestressed steel beam, a first connecting hole, a second connecting hole and a third connecting hole of a T-frame underpinning original abutment pile foundation reinforcing rigid frame bridge construction structure.

Fig. 3 is a schematic position diagram of a T-frame underpinning original abutment pile foundation reinforcing rigid frame bridge construction structure twisted steel, connecting steel and prestressed tendons.

Fig. 4 is a flow chart of a method for underpinning an original abutment pile foundation reinforced rigid frame bridge construction method by using a T-frame.

Description of reference numerals:

blocks No. 1-0; block No. 2-1; 3, drilling a pile;

block No. 4-2; 5, a side bearing platform; 6-original bridge abutment cap;

7-a first connection hole; 8-second connection hole; 9-third connection hole;

10-roadbed; 11-original bridge; 12-beam section concrete;

13-solid counterweight segment; 14-pile foundation; 15-a balancing weight;

16-a cushion cap foundation; 17-upright column; 18-steel tube concrete;

19-upper prestressed tendons; 20-prestressed steel bundles; 21-twisted steel bars;

21-1-planting tendon holes; 22-connecting reinforcing steel bars; 23-a locking nut;

24-a bellows; 25, fixing a steel backing plate; 26-spiral ribs;

27-prestressed reinforcement; 28-reinforcing mesh; 29-bottom bellows;

and 30, steel pipe pile.

Detailed Description

As shown in figure 1, the T-shaped structure underpins the original bridge abutment pile foundation reinforcing rigid frame bridge construction structure, which comprises a T-shaped structure supporting mechanism arranged between an original bridge abutment cap 6 and a roadbed 10, wherein the T-shaped structure supporting mechanism comprises a T-shaped structure beam, a middle supporting part for supporting the T-shaped structure beam, and a counterweight mechanism arranged at one end of the T-shaped structure beam far away from the original bridge abutment cap 6, the T-shaped structure beam comprises a No. 0 block 1, a No. 1 block 2 symmetrically arranged at two sides of the No. 0 block 1, a No. 2 block 4 symmetrically arranged at two sides of the No. 1 block 2, and a beam section concrete 12 arranged at the tops of the No. 0 block 1, the No. 1 block 2 block and the No. 2 block 4, the counterweight mechanism comprises a solid counterweight section 13 and a pile foundation 14 arranged at the bottom of the solid counterweight section 13, a counterweight 15 is additionally arranged at one end, close to the solid counterweight section 13, of the No. 2 block 4, a steel pipe 30, Cushion cap basis 16, stand 17 and steel pipe concrete 18, steel pipe concrete 18 is connected with the bottom of former bridge platform cap 6 is articulated, 2 number piece 4 is close to the one end and the former bridge platform cap 6 fixed connection of former bridge platform cap 6, 2 number piece 4 and 1 number piece 2 bottom is laid by former bridge platform cap 6 to 0 number piece 1 downward sloping gradually, roof beam section concrete 12's top, solid counter weight section 13's top surface and former bridge 11's top flush mutually.

In this embodiment, it should be noted that, in an actual construction process, the back wall of the original abutment cap 6 is subjected to roughening treatment so that the surface roughness of the back wall of the original abutment cap 6 is level 2.

In this embodiment, the number of the middle support parts is two, two the middle support parts are symmetrically arranged about No. 0 block 1, the middle support part comprises a side bearing platform 5 fixedly connected with No. 0 block 1 and drilled piles 3 with the top ends embedded in the side bearing platform 5, the length of the side bearing platform 5 is equal to that of No. 0 block 1, the height of the side bearing platform 5 is smaller than that of No. 0 block 1, and the number of the drilled piles 3 embedded in each side bearing platform 5 is two.

As shown in fig. 2, in this embodiment, the back wall of the original abutment cap 6 is provided with a plurality of rebar planting holes 21-1, the rebar 21 is disposed in the rebar planting hole 21-1, one end of the rebar 21 extends into the rebar planting hole 21-1 filled with rebar planting glue, the other end of the rebar 21 extends into the No. 2 block 4, the rebar planting holes 21-1 are blind holes, the depth of the rebar planting holes 21-1 is 10 to 12 times of the diameter of the rebar 21, and one end of the rebar 21 extending out of the original abutment cap 6 is fixedly connected to the rebar mesh 28 in the No. 2 block 4.

As shown in fig. 2, in this embodiment, a first group of connection holes located at the middle lower portion of an original bridge platform cap 6, a second group of connection holes located at one side of the first group of connection holes, and a third group of connection holes located at the other side of the first group of connection holes are disposed on the original bridge platform cap 6, a horizontal distance between two adjacent first connection holes 7 in the first group of connection holes is 70cm to 80cm, a horizontal distance between two adjacent second connection holes 8 is 60cm to 70cm, a horizontal distance between two adjacent third connection holes 9 is the same as a horizontal distance between two adjacent second connection holes 8, vertical distances between two adjacent first connection holes 7, two adjacent second connection holes 8, and two adjacent third connection holes 9 are both 80cm to 90cm, and apertures of the first connection holes 7, the second connection holes 8, and the third connection holes 9 are all 100mm to 130mm, first group's connecting hole with between the second group's connecting hole and first group's connecting hole with horizontal interval between the third group's connecting hole is 180cm ~ 180cm, first connecting hole 7 is less than former bridge platform cap 6 and puts along the central point of direction of height, be provided with the clearance between second connecting hole 8 and third connecting hole 9 and the former bridge platform cap 6 top surface, wear to establish connecting reinforcement 22 in first connecting hole 7, second connecting hole 8 and the third connecting hole 9, connecting reinforcement 22 stretches out the one end of former bridge platform cap 6 and connecting reinforcement 22 and stretches out the other end of No. 2 piece 4 and all overlap and establish lock nut 23.

As shown in fig. 3, in this embodiment, prestressing steel bundle 19 is worn to be equipped with at No. 0 piece 1, No. 1 piece 2 and No. 2 piece 4's top, prestressing steel bundle 20 is worn to be equipped with down in No. 1 piece 2 and No. 2 piece 4's bottom, go up prestressing steel bundle and prestressing steel bundle down and all include bellows 24, many wear to establish prestressing steel 27 in bellows 24 and wear to establish the fixed steel backing plate 25 at many prestressing steel 27 stiff ends, the cover is equipped with spiral muscle 26 between fixed steel backing plate 25 and the bellows 24, spiral muscle 26 is located outside many prestressing steel 27, and the stretch-draw pot head of many prestressing steel 27 is equipped with stretch-draw steel backing plate and ground tackle.

In this embodiment, the threaded steel bars are embedded in the back wall of the original bridge cap 6 after the chiseling, so that the threaded steel bars are welded to the steel bar mesh 28 at the end of the T-beam, and meanwhile, the connecting steel bars are installed in the first connecting hole 7, the second connecting hole 8 and the third connecting hole 9, so as to further reinforce the connection between the original bridge cap and the T-beam.

As shown in fig. 4, the construction method for underpinning the original abutment pile foundation reinforcing rigid frame bridge by the T-frame includes the following steps:

step one, construction of a T-shaped structural beam:

102, constructing at the middle position of a T-shaped beam construction area to form a No. 0 block 1 and a No. 1 block 2; the number of the No. 1 blocks 2 is two, and the two No. 1 blocks 2 are symmetrically arranged at two ends of the No. 0 block 1;

meanwhile, percussion drilling is adopted on two sides of the No. 0 block 1 to form a drilled pile 3; the number of the drilled piles 3 is four, the length center line of a rectangle surrounded by the four drilled piles 3 is superposed with the length center line of the No. 0 block 1, the width center line of the rectangle surrounded by the four drilled piles 3 is superposed with the width center line of the No. 0 block 1, and the distance between the drilled piles 3 and the outer side surface of the No. 0 block 1 is 2-2.5 m;

103, embedding reinforcing steel bars on two sides of the No. 0 block 1, and building bearing platform templates on two sides of the No. 0 block 1 to cast concrete in situ to form a side bearing platform 5; the side bearing platforms 5 are symmetrically arranged relative to the No. 0 block 1, the length of each side bearing platform 5 is equal to that of the No. 0 block 1, the height of each side bearing platform 5 is smaller than that of the No. 0 block 1, and the top ends of the four drilled piles 3 are embedded in the side bearing platforms 5;

step 201, firstly, roughening the back wall of the original bridge platform cap 6 by using a breaking hammer, and then, performing additional chiseling on the back wall of the original bridge platform cap 6 by using a rock drill until the surface roughness of the back wall of the original bridge platform cap 6 is 2-level surface roughness, so as to obtain the roughened back wall;

step 203, drilling holes at each bar planting point by using a drilling machine, blowing away rock powder in the drilled holes to form bar planting holes 21-1, and filling bar planting glue in the bar planting holes 21-1;

204, inserting the twisted steel 21 into each bar embedding hole 21-1 filled with the bar embedding glue; one end of the deformed steel bar 21 extends into a bar embedding hole 21-1 filled with bar embedding glue, the other end of the deformed steel bar 21 extends out of the bar embedding hole 21-1, the bar embedding hole 21-1 is a blind hole, and the depth of the bar embedding hole 21-1 is 10-12 times of the diameter of the deformed steel bar 21;

step 301, binding steel bars on one side of the No. 0 block 1 to form a steel bar mesh 28; wherein, the thread steel bar 21 is welded with the steel bar net 28, the bottom of the steel bar net 28 is sleeved with a plurality of corrugated pipes which are arranged along the length direction and are marked as bottom corrugated pipes 29, and the bottom corrugated pipes 29 are gradually arranged from the original bridge platform cap 6 to the bottom of the No. 0 block 1 in a downward inclined way;

step 302, erecting a template outside the reinforcing mesh 28 and pouring concrete to form a No. 2 block 4 until the concrete strength of the No. 2 block 4 reaches 90% of the designed concrete strength; the number of the No. 2 blocks 4 is two, and the two No. 2 blocks 4 are symmetrically distributed around the No. 0 block 1;

step 303, erecting a counterweight block template at one end of the No. 2 block 4 far away from the original bridge platform cap 6 and casting concrete in situ to form a counterweight block 15;

304, erecting a counterweight section template at one end of the No. 2 block 4, which is far away from the original bridge platform cap 6, and casting concrete in situ to form a solid counterweight section 13, and arranging a pile foundation 14 at the bottom of the solid counterweight section 13;

drilling a connecting hole channel of the original bridge platform cap:

401, distributing a plurality of hole sites on the side surface of the original bridge platform cap 6 far away from the back wall;

step 402, drilling holes at each hole site by using a geological drill and extending a No. 2 block 4 to form a plurality of connecting holes; the connecting holes comprise a first group of connecting holes positioned at the middle lower part of the original bridge platform cap 6, a second group of connecting holes positioned at one side of the first group of connecting holes and a third group of connecting holes positioned at the other side of the first group of connecting holes, the horizontal distance between two adjacent first connecting holes 7 in the first group of connecting holes is 70-80 cm, the horizontal distance between two adjacent second connecting holes 8 is 60-70 cm, the horizontal distance between two adjacent third connecting holes 9 is the same as the horizontal distance between two adjacent second connecting holes 8, the vertical distance between two adjacent first connecting holes 7, two adjacent second connecting holes 8 and two adjacent third connecting holes 9 is 80-90 cm, the apertures of the first connecting holes 7, the second connecting holes 8 and the third connecting holes 9 are all 100-130 mm, and the horizontal distances between the first group of connecting holes and the second group of connecting holes and between the first group of connecting holes and the third group of connecting holes are all 180cm About 180cm, the first connecting hole 7 is lower than the center position of the original bridge platform cap 6 along the height direction, and gaps are formed between the second connecting hole 8 and the top surface of the original bridge platform cap 6 and between the third connecting hole 9 and the top surface of the original bridge platform cap 6;

step 403, installing connecting steel bars 22 in the first connecting hole 7, the second connecting hole 8 and the third connecting hole 9; wherein, one end of the connecting steel bar 22 extending out of the original bridge platform cap 6 and the other end of the connecting steel bar 22 extending out of the No. 2 block 4 are both sleeved with a locking nut 23;

step five, mounting the prestressed tendons:

step 501, binding steel bars on the top surfaces of a No. 0 block 1, a No. 1 block 2 and a No. 2 block 4 to form a rectangular steel bar cage; a plurality of corrugated pipes 24 penetrate through the rectangular reinforcement cage along the width direction of the rectangular reinforcement cage, and the corrugated pipes 24 are arranged along the length direction of the No. 0 block 1, the No. 1 block 2 and the No. 2 block 4;

502, arranging a fixed steel backing plate 25 at one end of the corrugated pipe 24 close to the back wall of the original bridge platform cap 6, and arranging a spiral rib 26 between the fixed steel backing plate 25 and the corrugated pipe 24

Sequentially penetrating a plurality of prestressed reinforcements 27 through the fixed steel backing plate 25, the spiral reinforcements 26 and the corrugated pipe 24, and installing a tension steel backing plate and an anchorage at the tension end of the corrugated pipe 24 through which the plurality of prestressed reinforcements 27 sequentially penetrate to complete the installation of a prestressed beam;

step 503, sequentially installing prestressed steel bundles in each corrugated pipe 24 and the bottom corrugated pipe 29 according to the method in the step 502 to obtain an upper prestressed steel bundle 19 and a lower prestressed steel bundle 20;

step six, beam section concrete pouring and prestressed beam tensioning:

step 601, erecting a beam body template outside the rectangular reinforcement cage, and casting concrete in situ to form beam section concrete 12 until the concrete strength of the beam section concrete 12 reaches 90% of the designed concrete strength;

step 603, after tensioning is completed, injecting micro-expansion cement slurry into each corrugated pipe 24 and the bottom corrugated pipe 29 until the strength of the cement slurry in the corrugated pipes 24 and the bottom corrugated pipe 29 reaches 90% of the designed strength of the cement slurry;

step 701, simultaneously disconnecting the original abutment cap 6 and the original abutment pile foundation, removing the original abutment pile foundation, relieving the pile foundation stress of the original abutment (6), and completing the first stress system conversion;

step 702, constructing a bearing platform foundation 16 at the bottom of the original bridge platform cap 6, constructing an upright post 17 on the bearing platform foundation 16, arranging a steel pipe concrete 18 at the top end of the upright post 17 to be hinged with the beam section concrete 12 and the original bridge platform cap 6, preventing the original bridge 11 and the original bridge platform cap 6 from being warped downwards, and completing the conversion of a second stress system; wherein, the distance between the upper surface of the bearing platform foundation 16 and the bottom of the No. 0 block 1 is 250 cm-300 cm.

In this embodiment, in step 701, the original abutment cap 6 and the two original abutment pile foundations are disconnected at the same time, and the specific process is as follows:

7011, performing annular cutting at the connecting part of the original abutment cap 6 and the top surfaces of the two original abutment pile foundations by using a cutting machine until the original abutment cap 6 is connected with the top surfaces of the two original abutment pile foundations;

and 7014, removing the residual original bridge abutment pile foundation.

In this embodiment, the prestressed tendons are tensioned in step 602, and the specific process is as follows:

In this embodiment, it is further preferable that the micro-expansive cement slurry is AEC micro-expansive cement slurry.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. The utility model provides a T constructs original abutment pile foundation of underpinning and consolidates rigid frame bridge construction structures, its characterized in that: construct including the T that sets up between former abutment cap (6) and road bed (10) and hold in the palm the mechanism, T constructs the support mechanism and includes T constructs the roof beam, constructs the middle support part that the roof beam supported, sets up the counter weight mechanism who keeps away from former abutment cap (6) one end at T and constructs the roof beam, T constructs the roof beam and includes No. 0 piece (1), the symmetry sets up No. 1 piece (2) in No. 0 piece (1) both sides and symmetry sets up No. 2 piece (4) in No. 1 piece (2) both sides to and set up at No. 0 piece (1), No. 1 piece (2) and No. 2 roof beam section concrete (12) at No. 0 piece (1), No. 2 piece (4) and No. 2 piece (4) top, counter weight mechanism includes solid counter weight section (13) and pile foundation (14) that set up in solid counter weight section (13) bottom, No. 2 piece (4) are close to the one end of solid counter weight section (13) and are equipped with balancing weight (15), the bottom of former abutment cap (6) is sup, Cushion cap basis (16), stand (17) and steel pipe concrete (18), steel pipe concrete (18) are connected with the bottom of former bridge platform cap (6) is articulated, 2 number piece (4) are close to the one end and former bridge platform cap (6) fixed connection of former bridge platform cap (6), the bottom of 2 number piece (4) and 1 number piece (2) is laid by former bridge platform cap (6) to 0 number piece (1) downward sloping gradually, the top of roof beam section concrete (12), the top surface of solid counter weight section (13) and the top of former bridge (11) flush mutually.

2. The T structure underpins original abutment pile foundation reinforcement rigid frame bridge construction structure according to claim 1, characterized in that: the quantity of middle support part is two, two the middle support part is laid about No. 0 piece (1) symmetry, the middle support part includes side cushion cap (5) and the drilled pile (3) of top inlaying in side cushion cap (5) with No. 0 piece (1) fixed connection, the length of side cushion cap (5) equals the length of No. 0 piece (1), and the height of side cushion cap (5) is less than the height of No. 0 piece (1), and the quantity of the drilled pile (3) of inlaying in every side cushion cap (5) is two.

3. The T structure underpins original abutment pile foundation reinforcement rigid frame bridge construction structure according to claim 1, characterized in that: the back wall of former bridge platform cap (6) is provided with a plurality of bar planting holes (21-1), be provided with in the bar planting hole (21-1) rebar (21), the one end of rebar (21) stretches into in filling bar planting hole (21-1) of bar planting glue, the other end of rebar (21) stretches into in No. 2 piece (4), bar planting hole (21-1) is the blind hole, just the degree of depth of bar planting hole (21-1) is 10 ~ 12 times of rebar (21) diameter, rebar (21) stretch out the one end of former bridge platform cap (6) and reinforcing bar net (28) fixed connection in No. 2 piece (4).

4. The T structure underpins original abutment pile foundation reinforcement rigid frame bridge construction structure according to claim 1, characterized in that: the original bridge platform cap (6) is provided with a first group of connecting holes positioned at the middle lower part of the original bridge platform cap (6), a second group of connecting holes positioned at one side of the first group of connecting holes and a third group of connecting holes positioned at the other side of the first group of connecting holes, the horizontal distance between two adjacent first connecting holes (7) in the first group of connecting holes is 70-80 cm, the horizontal distance between two adjacent second connecting holes (8) is 60-70 cm, the horizontal distance between two adjacent third connecting holes (9) is the same as the horizontal distance between two adjacent second connecting holes (8), the vertical distance between two adjacent first connecting holes (7), two adjacent second connecting holes (8) and two adjacent third connecting holes (9) is 80-90 cm, and the aperture of each first connecting hole (7), second connecting hole (8) and third connecting hole (9) is 100-130 mm, first group's connecting hole with between the second group's connecting hole and first group's connecting hole with horizontal interval between the third group's connecting hole is 180cm ~ 180cm, first connecting hole (7) are less than former bridge platform cap (6) and put along the central point of direction of height, be provided with the clearance between second connecting hole (8) and third connecting hole (9) and former bridge platform cap (6) top surface, wear to establish connecting reinforcement (22) in first connecting hole (7), second connecting hole (8) and third connecting hole (9), the one end that connecting reinforcement (22) stretched out former bridge platform cap (6) and the other end that connecting reinforcement (22) stretched out No. 2 piece (4) all overlap and establish lock nut (23).

5. The T structure underpins original abutment pile foundation reinforcement rigid frame bridge construction structure according to claim 1, characterized in that: no. 0 the top of No. 0 piece (1), No. 1 piece (2) and No. 2 piece (4) is worn to be equipped with prestressing tendons (19), prestressing tendons (20) are worn to be equipped with down in the bottom of No. 1 piece (2) and No. 2 piece (4), it all includes bellows (24), many prestressing tendons (27) of wearing to establish in bellows (24) and wears to establish fixed steel backing plate (25) at many prestressing tendons (27) stiff end to go up prestressing tendons and prestressing tendons down, the cover is equipped with spiral muscle (26) between fixed steel backing plate (25) and bellows (24), spiral muscle (26) are located outside many prestressing tendons (27), and the stretch-draw pot head of many prestressing tendons (27) is equipped with stretch-draw steel backing plate and ground tackle.

6. A construction method for a T-frame underpinning original abutment pile foundation reinforced rigid frame bridge is characterized by comprising the following steps:

step one, construction of a T-shaped structural beam:

102, constructing at the middle position of a T-shaped beam construction area to form a No. 0 block (1) and a No. 1 block (2); the number of the No. 1 blocks (2) is two, and the two No. 1 blocks (2) are symmetrically arranged at two ends of the No. 0 block (1);

meanwhile, percussion drilling is adopted on two sides of the No. 0 block (1) to form a drilled pile (3); the number of the drilled piles (3) is four, the length center line of a rectangle surrounded by the four drilled piles (3) is superposed with the length center line of the No. 0 block (1), the width center line of the rectangle surrounded by the four drilled piles (3) is superposed with the width center line of the No. 0 block (1), and the distance between the drilled piles (3) and the outer side face of the No. 0 block (1) is 2-2.5 m;

103, embedding reinforcing steel bars on two sides of the No. 0 block (1), and building bearing platform templates on two sides of the No. 0 block (1) to cast concrete in situ to form a side bearing platform (5); the side bearing platforms (5) are symmetrically arranged relative to the No. 0 block (1), the length of each side bearing platform (5) is equal to that of the No. 0 block (1), the height of each side bearing platform (5) is smaller than that of the No. 0 block (1), and the top ends of the four drilling piles (3) are embedded in the side bearing platforms (5);

step 201, firstly, chiseling a back wall of an original bridge platform cap (6) by using a breaking hammer, and then, performing additional chiseling on the back wall of the original bridge platform cap (6) by using a rock drill until the surface roughness of the back wall of the original bridge platform cap (6) is level 2, so as to obtain the chiseled back wall;

step 203, drilling holes at each bar planting point by using a drilling machine, blowing away rock powder in the drilled holes to form bar planting holes (21-1), and filling bar planting glue in the bar planting holes (21-1);

204, inserting a twisted steel bar (21) into each bar embedding hole (21-1) filled with bar embedding glue; one end of the deformed steel bar (21) extends into a bar planting hole (21-1) filled with bar planting glue, the other end of the deformed steel bar (21) extends out of the bar planting hole (21-1), the bar planting hole (21-1) is a blind hole, and the depth of the bar planting hole (21-1) is 10-12 times of the diameter of the deformed steel bar (21);

step 301, binding steel bars on one side of the No. 0 block (1) to form a steel bar mesh (28); wherein the threaded steel bars (21) are welded with the steel bar mesh (28), the bottom of the steel bar mesh (28) is sleeved with a plurality of corrugated pipes distributed along the length direction and marked as bottom corrugated pipes (29), and the bottom corrugated pipes (29) are gradually distributed from the original bridge platform cap (6) to the bottom of the No. 0 block (1) in a downward inclined mode;

step 302, erecting a template outside the reinforcing mesh (28) and pouring concrete to form a No. 2 block (4) until the concrete strength of the No. 2 block (4) reaches 90% of the designed concrete strength; the number of the No. 2 blocks (4) is two, and the two No. 2 blocks (4) are symmetrically distributed relative to the No. 0 block (1);

step 303, erecting a balancing weight template at one end of the No. 2 block (4) far away from the original bridge platform cap (6) and casting concrete in situ to form a balancing weight (15);

304, erecting a counterweight section template at one end of the No. 2 block (4) far away from the original bridge platform cap (6) and casting concrete in situ to form a solid counterweight section (13), and arranging a pile foundation (14) at the bottom of the solid counterweight section (13);

drilling a connecting hole channel of the original bridge platform cap:

401, distributing a plurality of hole sites on the side surface of the original bridge platform cap (6) far away from the back wall;

step 402, drilling holes at each hole site by using a geological drill and extending a No. 2 block (4) to form a plurality of connecting holes; wherein the connecting holes comprise a first group of connecting holes positioned at the middle lower part of the original bridge platform cap (6), a second group of connecting holes positioned at one side of the first group of connecting holes and a third group of connecting holes positioned at the other side of the first group of connecting holes, the horizontal distance between two adjacent first connecting holes (7) in the first group of connecting holes is 70-80 cm, the horizontal distance between two adjacent second connecting holes (8) is 60-70 cm, the horizontal distance between two adjacent third connecting holes (9) is the same as the horizontal distance between two adjacent second connecting holes (8), the vertical distances between two adjacent first connecting holes (7), two adjacent second connecting holes (8) and two adjacent third connecting holes (9) are 80-90 cm, and the apertures of the first connecting holes (7), the second connecting holes (8) and the third connecting holes (9) are all 100-130 mm, the horizontal distance between the first group of connecting holes and the second group of connecting holes and the horizontal distance between the first group of connecting holes and the third group of connecting holes are both 180 cm-180 cm, the first connecting holes (7) are lower than the center position of the original bridge platform cap (6) along the height direction, and gaps are arranged between the second connecting holes (8) and the top surfaces of the third connecting holes (9) and the original bridge platform cap (6);

step 403, installing connecting steel bars (22) in the first connecting hole (7), the second connecting hole (8) and the third connecting hole (9); one end of the connecting steel bar (22) extending out of the original bridge platform cap (6) and the other end of the connecting steel bar (22) extending out of the No. 2 block (4) are both sleeved with a locking nut (23);

step five, mounting the prestressed tendons:

step 501, binding steel bars on the top surfaces of the No. 0 block (1), the No. 1 block (2) and the No. 2 block (4) to form a rectangular steel bar cage; the rectangular reinforcement cage is internally provided with a plurality of corrugated pipes (24) in a penetrating manner along the width direction of the rectangular reinforcement cage, and the corrugated pipes (24) are arranged along the length directions of the No. 0 block (1), the No. 1 block (2) and the No. 2 block (4);

502, arranging a fixed steel backing plate (25) at one end of the corrugated pipe (24) close to the back wall of the original bridge platform cap (6), and arranging a spiral rib (26) between the fixed steel backing plate (25) and the corrugated pipe (24)

Sequentially penetrating a plurality of prestressed reinforcements (27) through the fixed steel backing plate (25), the spiral reinforcements (26) and the corrugated pipe (24), and sequentially penetrating the plurality of prestressed reinforcements (27) through the tensioning end of the corrugated pipe (24) to install a tensioning steel backing plate and an anchorage device so as to finish the installation of a prestressed beam;

step 503, according to the method in step 502, sequentially installing prestressed steel bundles in each corrugated pipe (24) and the bottom corrugated pipe (29) to obtain an upper prestressed steel bundle (19) and a lower prestressed steel bundle (20);

step six, beam section concrete pouring and prestressed beam tensioning:

601, erecting a beam body template outside the rectangular reinforcement cage, and casting concrete in situ to form beam section concrete (12) until the concrete strength of the beam section concrete (12) reaches 90% of the designed concrete strength;

step 603, after tensioning is finished, injecting micro-expansion cement slurry into each corrugated pipe (24) and the bottom corrugated pipe (29) until the strength of the cement slurry in the corrugated pipes (24) and the bottom corrugated pipe (29) reaches 90% of the designed strength of the cement slurry;

step 701, simultaneously disconnecting the original abutment cap (6) and the original abutment pile foundation, removing the original abutment pile foundation, relieving the pile foundation stress of the original abutment (6), and completing the first stress system conversion;

step 702, constructing a bearing platform foundation (16) at the bottom of the original bridge platform cap (6), constructing an upright post (17) on the bearing platform foundation (16), arranging a steel pipe concrete (18) at the top end of the upright post (17), and connecting the steel pipe concrete (18) with the beam section concrete (12) in a hinged manner with the original bridge platform cap (6) to prevent the original bridge (11) and the original bridge platform cap (6) from being warped downwards and complete the conversion of a second stress system; wherein, the distance between the upper surface of the bearing platform foundation (16) and the bottom of the No. 0 block (1) is 250 cm-300 cm.

7. The construction method for the T-frame underpinning of the original abutment pile foundation reinforced rigid frame bridge according to the claim 6 is characterized in that: in step 701, the original abutment cap (6) and two original abutment pile foundations are disconnected simultaneously, and the specific process is as follows:

7011, performing annular cutting at the connecting position of the original bridge platform cap (6) and the top surfaces of the two original bridge platform pile foundations by using a cutting machine until the original bridge platform cap (6) is connected with the top surfaces of the two original bridge platform pile foundations;

and 7014, removing the residual original bridge abutment pile foundation.

8. The construction method for the T-frame underpinning of the original abutment pile foundation reinforced rigid frame bridge according to the claim 6 is characterized in that: in step 602, tensioning the prestressed tendons, specifically, the process is as follows: