A T-frame underpinning the original abutment pile foundation to reinforce the rigid frame bridge construction structure and method

Abstract

The present invention discloses a T-frame supporting the original abutment pile foundation to reinforce the rigid frame bridge construction structure and method, the structure includes a T-frame supporting mechanism arranged between the original abutment cap and the roadbed, the T-frame supporting mechanism includes a T-frame beam, an intermediate supporting component and a counterweight mechanism, the T-frame beam includes a No. 0 block, a No. 1 block and a No. 2 block; the method includes the following steps: 1. Construction of the T-frame beam; 2. Roughening and planting of the back wall of the original abutment cap; 3. Connection of the T-frame beam and the original abutment cap; 4. Drilling of the connection channel of the original abutment cap; 5. Installation of prestressed beams; 6. Concrete pouring of beam sections and tensioning of prestressed beams; 7. Reinforcement of the original abutment cap and two conversions of the entire force system. The present invention is not only suitable for bridge reinforcement projects affected by strong geological deformation and narrow working surfaces, but also ensures that the reinforced bridge has the same bearing capacity as the original bridge, and the construction method is novel, the construction period is short, and the economic benefits are high.

Description

Technical Field

[0001] The invention belongs to the technical field of rigid frame bridge reinforcement, and in particular relates to a construction structure and method for reinforcing a rigid frame bridge by replacing an original abutment pile foundation with a T-frame. Background Art

[0002] The original continuous rigid frame bridge is located in the flooded area of ​​Jinping Hydropower Station reservoir. Due to the water storage in the reservoir, the bank slope where the abutment on one side of the original bridge is located has undergone geological deformation, resulting in cracks in the mountain at the abutment. The original bridge needs to be reinforced to prevent the abutment instability caused by geological deformation from continuing to spread. Conventional reinforcement construction mainly involves setting a large-diameter deep pile foundation 2 meters outside the abutment pile foundation, setting a cap beam on the top of the pile foundation to support the original abutment to replace the original abutment pile foundation, and adding 2 prestressed simple beams with a span of 40 meters behind the back wall of the original abutment to span the range affected by the bank slope deformation. However, the pile foundation listed in this method has a large diameter and a deep depth, and is located in a strong deformation zone where the mountain is broken, which has great safety risks, and requires blocking traffic, restricting construction progress and other disadvantages. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a T-structure to replace the original abutment pile foundation to reinforce the rigid frame bridge construction structure in view of the deficiencies in the above-mentioned prior art. The structure has a reasonable design and is easy to operate. A variable-section T-structure beam is used to connect the original abutment cap to replace the existing original abutment pile foundation affected by the geological deformation and collapse of the bank slope. The structure is suitable for bridge reinforcement projects affected by strong geological deformation and narrow working surfaces, and ensures that the reinforced bridge has the same bearing capacity as the original bridge, with a short construction period and high economic benefits.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a T-frame supporting the original abutment pile foundation to strengthen the rigid frame bridge construction structure, characterized in that: it includes a T-frame supporting mechanism arranged between the original abutment cap and the roadbed, the T-frame supporting mechanism includes a T-frame beam, an intermediate supporting component supporting the T-frame beam, and a counterweight mechanism arranged at one end of the T-frame beam away from the original abutment cap, the T-frame beam includes a No. 0 block, a No. 1 block symmetrically arranged on both sides of the No. 0 block, and a No. 2 block symmetrically arranged on both sides of the No. 1 block, and a beam section concrete arranged on the top of the No. 0 block, the No. 1 block and the No. 2 block, and the counterweight mechanism is arranged at the top of the No. 0 block, the No. 1 block and the No. 2 block. The weight mechanism includes a solid counterweight section and a pile foundation arranged at the bottom of the solid counterweight section. A counterweight block is added to the end of block No. 2 close to the solid counterweight section. The bottom of the original abutment cap is provided with steel pipe piles, abutment foundations, columns and steel tube concrete in sequence from bottom to top. The steel tube concrete is hingedly connected to the bottom of the original abutment cap. The end of block No. 2 close to the original abutment cap is fixedly connected to the original abutment cap. The bottoms of blocks No. 2 and No. 1 are gradually tilted downward from the original abutment cap to block No. 0, 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.

[0005] The above-mentioned T-frame replaces the original abutment pile foundation to reinforce the rigid frame bridge construction structure, which is characterized by: the number of the intermediate support components is two, the two intermediate support components are symmetrically arranged about block No. 0, the intermediate support component includes a side pedestal fixedly connected to block No. 0 and a bored pile with the top end embedded in the side pedestal, the length of the side pedestal is equal to the length of block No. 0, the height of the side pedestal is less than the height of block No. 0, and the number of bored piles embedded in each side pedestal is two.

[0006] The above-mentioned T-frame replaces the original abutment pile foundation to reinforce the rigid frame bridge construction structure, which is characterized in that: the back wall of the original abutment cap is provided with a plurality of anchor holes, threaded steel bars are provided in the anchor holes, one end of the threaded steel bar extends into the anchor hole filled with anchor glue, and the other end of the threaded steel bar extends into block No. 2, the anchor hole is a blind hole, and the depth of the anchor hole is 10 to 12 times the diameter of the threaded steel bar, and one end of the threaded steel bar extends out of the original abutment cap and is fixedly connected to the steel mesh in block No. 2.

[0007] The above-mentioned T-frame replaces the original abutment pile foundation to reinforce the rigid frame bridge construction structure, which is characterized in that: the original abutment cap is provided with a first group of connecting holes located in the middle and lower part of the original abutment cap, a second group of connecting holes located on one side of the first group of connecting holes and a third group of connecting holes located on the other side of the first group of connecting holes, the horizontal spacing between two adjacent first connecting holes in the first group of connecting holes is 70cm~80cm, the horizontal spacing between two adjacent second connecting holes is 60cm~70cm, the horizontal spacing between two adjacent third connecting holes is the same as the horizontal spacing between two adjacent second connecting holes, and the spacing between two adjacent first connecting holes, two adjacent second connecting holes and two adjacent third connecting holes The vertical spacing of the first connecting hole, the second connecting hole and the third connecting hole are all 80cm~90cm, and the hole diameters of the first connecting hole, the second connecting hole and the third connecting hole are all 100mm~130mm, the horizontal spacing 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~180cm, the first connecting hole is lower than the center position of the original abutment cap along the height direction, and there is a gap between the second connecting hole and the third connecting hole and the top surface of the original abutment cap, connecting steel bars are passed through the first connecting hole, the second connecting hole and the third connecting hole, and locking nuts are both provided on 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 block No. 2.

[0008] The above-mentioned T-frame replaces the original abutment pile foundation to reinforce the rigid frame bridge construction structure, which is characterized in that: the tops of the blocks No. 0, No. 1 and No. 2 are penetrated with upper prestressed steel bundles, and the bottoms of the blocks No. 1 and No. 2 are penetrated with lower prestressed steel bundles, and the upper prestressed steel bundles and the lower prestressed steel bundles both include a corrugated pipe, a plurality of prestressed steel bars penetrated in the corrugated pipe, and a fixed steel pad penetrated at the fixed ends of the plurality of prestressed steel bars, a spiral reinforcement is sleeved between the fixed steel pad and the corrugated pipe, and the spiral reinforcement is located outside the plurality of prestressed steel bars, and the tensioning ends of the plurality of prestressed steel bars are sleeved with a tensioning steel pad and an anchor.

[0009] At the same time, the present invention also discloses a construction method for reinforcing a rigid frame bridge by replacing the original abutment pile foundation with a T-frame, which has simple steps, reasonable design, convenient implementation and good inspection and use effect. The method is characterized in that the method comprises the following steps:

[0010] Step 1: Construction of T-beam:

[0011] Step 101, excavating and leveling the roadbed near the abutment of the bridge to be repaired to form a T-beam construction area; wherein the cross section of the T-beam construction area is in an inverted trapezoidal shape;

[0012] Step 102: constructing a block No. 0 and a block No. 1 in the middle of the T-beam construction area; wherein, there are two blocks No. 1, and the two blocks No. 1 are symmetrically arranged at both ends of the block No. 0;

[0013] At the same time, percussion drills are used to drill holes on both sides of block 0 to form bored piles; wherein, the number of bored piles is four, the length centerline of the rectangle formed by the four bored piles coincides with the length centerline of block 0, the width centerline of the rectangle formed by the four bored piles coincides with the width centerline of block 0, and the distance between the bored piles and the outer side surface of block 0 is 2m to 2.5m;

[0014] Step 103, pre-embed reinforcing steel bars on both sides of block No. 0, and build cap templates on both sides of block No. 0 to cast in-situ concrete to form side caps; wherein the side caps are symmetrically arranged about block No. 0, and the length of the side caps is equal to the length of block No. 0, the height of the side caps is less than the height of block No. 0, and the tops of the four bored piles are all embedded in the side caps;

[0015] Step 2: Roughen the back wall of the original abutment cap and plant reinforcement:

[0016] Step 201, firstly use a breaker hammer to roughen the back wall of the original abutment cap, and then use a rock drill to re-chisel the back wall of the original abutment cap until the surface roughness of the back wall of the original abutment cap reaches the surface roughness level 2, thereby obtaining the roughened back wall;

[0017] Step 202, arranging reinforcement points on the roughened back wall; wherein the number of reinforcement points is multiple;

[0018] Step 203, drilling holes at each reinforcement point using a drilling machine, blowing out the rock powder in the drilled holes to form reinforcement holes, and filling the reinforcement holes with reinforcement glue;

[0019] Step 204, inserting a threaded steel bar into each of the anchor holes filled with the anchor glue; wherein one end of the threaded steel bar extends into the anchor hole filled with the anchor glue, and the other end of the threaded steel bar extends out of the anchor hole, the anchor hole is a blind hole, and the depth of the anchor hole is 10 to 12 times the diameter of the threaded steel bar;

[0020] Step 3: Connection between T-beam and original abutment cap:

[0021] Step 301, tying steel bars on one side of block No. 0 to form a steel mesh; wherein the threaded steel bars are welded to the steel mesh, and a plurality of corrugated pipes arranged along the length direction are sleeved at the bottom of the steel mesh, which are recorded as bottom corrugated pipes, and the bottom corrugated pipes are gradually tilted downward from the original abutment cap to the bottom of block No. 0;

[0022] Step 302: Set up a formwork outside the steel mesh and pour concrete to form block No. 2, until the concrete strength of block No. 2 reaches 90% of the concrete design strength; wherein, there are two blocks No. 2, and the two blocks No. 2 are arranged symmetrically with respect to block No. 0;

[0023] Step 303: support a counterweight template at one end of block No. 2 away from the original abutment cap and cast concrete in situ to form a counterweight;

[0024] Step 304: support a counterweight section template at the end of block 2 away from the original abutment cap and cast concrete in situ to form a solid counterweight section, and set a pile foundation at the bottom of the solid counterweight section;

[0025] Step 4: Drilling of the connection holes of the original abutment cap:

[0026] Step 401, arranging a plurality of hole sites on the side of the original abutment cap away from the back wall;

[0027] Step 402, use a geological drill to drill holes at each hole site and extend block No. 2 to form multiple connection holes; wherein the connection holes include a first group of connection holes located in the middle and lower part of the original abutment cap, a second group of connection holes located on one side of the first group of connection holes, and a third group of connection holes located on the other side of the first group of connection holes, the horizontal spacing between two adjacent first connection holes in the first group of connection holes is 70cm to 80cm, the horizontal spacing between two adjacent second connection holes is 60cm to 70cm, and the horizontal spacing between two adjacent third connection holes is equal to the horizontal spacing between two adjacent second connection holes. The vertical spacing between two adjacent first connection holes, two adjacent second connection holes and two adjacent third connection holes is 80cm-90cm, and the apertures of the first connection hole, the second connection hole and the third connection hole are 100mm-130mm, the horizontal spacing between the first group of connection holes and the second group of connection holes and between the first group of connection holes and the third group of connection holes are 180cm-180cm, the first connection hole is lower than the center position of the original abutment cap in the height direction, and there is a gap between the second connection hole and the third connection hole and the top surface of the original abutment cap;

[0028] Step 403, installing connecting steel bars in the first connecting hole, the second connecting hole and the third connecting hole; wherein, 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 provided with locking nuts;

[0029] Step 5: Installation of prestressed tendons:

[0030] Step 501, tying steel bars on the top surfaces of block No. 0, block No. 1 and block No. 2 to form a rectangular steel cage; wherein a plurality of corrugated pipes are provided in the rectangular steel cage along the width direction of the rectangular steel cage, and the corrugated pipes are arranged along the length direction of block No. 0, block No. 1 and block No. 2;

[0031] Step 502: A fixed steel plate is arranged at one end of the back wall of the corrugated pipe close to the original abutment cap, and a spiral rib is arranged between the fixed steel plate and the corrugated pipe.

[0032] and sequentially passing a plurality of prestressed steel bars through the fixed steel plate, the spiral bars and the corrugated pipe, and installing a tensioning steel plate and an anchor at the tensioning end where the plurality of prestressed steel bars sequentially pass through the corrugated pipe, thereby completing the installation of a prestressed bundle;

[0033] Step 503, according to the method described in step 502, prestressed steel strands are installed in each corrugated pipe and the bottom corrugated pipe in turn to obtain an upper prestressed steel strand and a lower prestressed steel strand;

[0034] Step 6: Concrete pouring of beam section and tensioning of prestressed tendons:

[0035] Step 601, set up a beam formwork outside the rectangular steel cage, and cast concrete in situ to form beam segment concrete until the concrete strength of the beam segment concrete reaches 90% of the concrete design strength;

[0036] Step 602, operating the tensioning steel pad and the anchor to tension the plurality of prestressed tendons;

[0037] Step 603: After the tensioning is completed, inject micro-expansion cement slurry into each of the bellows and the bottom bellows until the strength of the cement slurry in the bellows and the bottom bellows reaches 90% of the designed strength of the cement slurry;

[0038] Step 7: Reinforcement of the original abutment cap and two conversions of the entire force system:

[0039] Step 701, disconnect the original abutment cap and the original abutment pile foundation at the same time, remove the original abutment pile foundation, release the force on the pile foundation of the original abutment (6), and complete the first force system conversion;

[0040] Step 702, construct a pedestal foundation at the bottom of the original abutment cap, and construct columns on the pedestal foundation, set steel tube concrete at the top of the column and hingedly connect the beam section concrete with the original abutment cap to prevent the original bridge and the original abutment cap from deflecting, and complete the conversion of the second force system; wherein, the distance between the upper surface of the pedestal foundation and the bottom of block No. 0 is 250cm to 300cm.

[0041] The above method is characterized in that: in step 701, the original abutment cap and the two original abutment pile foundations are disconnected at the same time, and the specific process is as follows:

[0042] Step 7011, using a cutting machine to perform circumferential cutting at the connection between the original abutment cap and the top surfaces of the two original abutment pile foundations, until the original abutment cap is connected to the top surfaces of the two original abutment pile foundations;

[0043] Step 7012: Use a rock drill to drill away 150 mm to 200 mm of pile concrete at the top of the two original abutment pile foundations to expose the pile reinforcement;

[0044] Step 7013, using a gas welder to cut the pile body reinforcement, and then using a rock drill to peel off the remaining internal pile body concrete at 150 mm to 200 mm;

[0045] Step 7014, remove the remaining original abutment pile foundation.

[0046] The above method is characterized in that: in step 602, the prestressed tendons are tensioned, and the specific process is as follows:

[0047] Operate the tension steel pad and anchor, and apply 0~0.15Q ky Tension force, the first tension, and when 0.15Q is appliedky When the tension force is greater than 3min, the first tension is completed; apply 0.15Q ky ~Q ky Tension force, the second tension is carried out, and when Q is applied ky When the tension force is greater than 3min, the second tension is completed; among them, Q ky Design value for tension control stress.

[0048] Compared with the prior art, the present invention has the following advantages:

[0049] 1. Simple structure, reasonable design, easy installation and layout, and low investment cost.

[0050] 2. In the present invention, threaded steel bars are planted in the back wall of the roughened original abutment cap so that the threaded steel bars can be welded to the steel mesh in the end of the T-beam. At the same time, connecting steel bars are installed in the first connecting hole, the second connecting hole and the third connecting hole to further strengthen the connection between the original abutment cap and the T-beam.

[0051] 3. The solid counterweight section, counterweight block and prestressed beam are provided in the present invention in order to limit the shrinkage and creep of the beam section concrete on the top surface of the T-beam in the later stage, and in addition, after the original abutment cap and the two original abutment pile foundations are disconnected at the same time and the original abutment pile foundations are removed, steel pipe piles, abutment foundations, columns and steel tube concrete are provided to realize a hinged connection between the steel tube concrete and the beam section concrete, so as to replace the existing original abutment pile foundation affected by the geological deformation and bank collapse of the slope.

[0052] 4. The adopted T-frame construction method of replacing the original abutment pile foundation to reinforce the rigid frame bridge has simple steps, is easy to implement and simple to operate, ensuring that the T-frame replaces the original abutment pile foundation to reinforce the strength of the rigid frame bridge, so that the bearing capacity of the reinforced bridge is equivalent to that of the original bridge, and the construction method is novel, the construction period is short and the economic benefits are high.

[0053] 5. The adopted T-structure to replace the original abutment pile foundation to reinforce the rigid frame bridge construction method is easy to operate and has good use effect. First, the T-structure beam is constructed, and then the back wall of the original abutment cap is roughened and rebar is planted. After that, the T-structure beam is connected to the original abutment cap, and connecting holes are drilled in the original abutment cap and connecting steel bars are installed to realize the connection between the T-structure beam end and the original abutment cap; then the prestressed beam is installed, and cast-in-place concrete is formed at the top of the T-structure beam to form beam section concrete. When the beam section concrete meets the design requirements, the prestressed beam is tensioned and micro-expansive cement slurry is injected into the corrugated pipe; finally, the original abutment cap and the two original abutment pile foundations are disconnected at the same time to remove the original abutment pile foundation, and the original abutment cap is reinforced, so as to realize the T-structure to replace the original abutment pile foundation and reinforce the rigid frame bridge.

[0054] To sum up, the present invention is reasonably designed and easy to operate. It adopts a variable-section T-beam to connect the original abutment to replace the existing abutment pile foundation affected by the geological deformation and bank collapse of the slope. It is suitable for bridge reinforcement projects affected by strong geological deformation and narrow working surface, and ensures that the reinforced bridge has the same bearing capacity as the original bridge, and the construction method is novel, the construction period is short, and the economic benefit is high.

[0055] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a structural schematic diagram of the construction structure of the T-frame underpinning the original abutment pile foundation to reinforce the rigid frame bridge of the present invention.

[0057] Figure 2 It is a schematic diagram of the positions of the reinforcing bar holes, upper prestressed steel bundles, lower prestressed steel bundles, first connecting holes, second connecting holes and third connecting holes of the T-frame construction structure for reinforcing the rigid frame bridge by replacing the original abutment pile foundation of the present invention.

[0058] Figure 3 It is a schematic diagram of the positions of threaded steel bars, connecting steel bars and prestressed tendons in the construction structure of a rigid frame bridge reinforced by replacing the original abutment pile foundation with a T-frame according to the present invention.

[0059] Figure 4 The present invention is a flowchart of the method for reinforcing a rigid frame bridge by replacing the original abutment pile foundation with a T-frame.

[0060] Description of reference numerals:

[0061] 1—Block 0; 2—Block 1; 3—Bored piles;

[0062] 4—Block No. 2; 5—Side bearing abutment; 6—Original abutment cap;

[0063] 7—first connection hole; 8—second connection hole; 9—third connection hole;

[0064] 10—roadbed; 11—original bridge; 12—beam section concrete;

[0065] 13—solid counterweight section; 14—pile foundation; 15—counterweight block;

[0066] 16—cap foundation; 17—column; 18—concrete-filled steel tube;

[0067] 19—upper prestressed tendon; 20—lower prestressed tendon; 21—threaded steel bar;

[0068] 21-1—Rebar hole; 22—Connecting steel bar; 23—Locking nut;

[0069] 24—corrugated pipe; 25—fixed steel plate; 26—spiral rib;

[0070] 27—prestressed steel bar; 28—steel mesh; 29—bottom corrugated pipe;

[0071] 30—Steel pipe piles. DETAILED DESCRIPTION

[0072] like Figure 1 The structure shown is a T-frame structure for replacing the original abutment pile foundation to reinforce the rigid frame bridge construction structure, comprising a T-frame support mechanism arranged between the original abutment cap 6 and the roadbed 10, the T-frame support mechanism comprising a T-frame beam, an intermediate support component for supporting the T-frame beam, and a counterweight mechanism arranged at one end of the T-frame beam away from the original abutment cap 6, the T-frame beam comprising a No. 0 block 1, a No. 1 block 2 symmetrically arranged on both sides of the No. 0 block 1, and a No. 2 block 4 symmetrically arranged on both sides of the No. 1 block 2, and a beam section concrete 12 arranged on the tops of the No. 0 block 1, the No. 1 block 2 and the No. 2 block 4, the counterweight mechanism comprising a solid counterweight section 13 and a solid counterweight section 13 arranged at the bottom The pile foundation 14 of the part, the counterweight block 15 is added to the end of the block No. 2 4 near the solid counterweight section 13, the bottom of the original abutment cap 6 is sequentially provided with steel pipe piles 30, abutment foundation 16, columns 17 and steel tube concrete 18 from bottom to top, the steel tube concrete 18 is hingedly connected to the bottom of the original abutment cap 6, the end of the block No. 2 4 near the original abutment cap 6 is fixedly connected to the original abutment cap 6, the bottoms of the blocks No. 2 4 and No. 1 block 2 are gradually tilted downward from the original abutment cap 6 to the block No. 0 1, and the top of the beam section concrete 12, the top surface of the solid counterweight section 13 and the top of the original bridge 11 are flush.

[0073] In this embodiment, it should be noted that, during the actual construction process, the back wall of the original abutment cap 6 is roughened so that the surface roughness of the back wall of the original abutment cap 6 is surface roughness level 2.

[0074] In this embodiment, the number of the intermediate support components is two, and the two intermediate support components are symmetrically arranged about block No. 0 1. The intermediate support components include a side support platform 5 fixedly connected to block No. 0 1 and a bored pile 3 with the top end embedded in the side support platform 5. The length of the side support platform 5 is equal to the length of block No. 0 1, the height of the side support platform 5 is less than the height of block No. 0 1, and the number of bored piles 3 embedded in each side support platform 5 is two.

[0075] like Figure 2As shown, in this embodiment, the back wall of the original abutment cap 6 is provided with a plurality of anchor holes 21-1, and threaded steel bars 21 are provided in the anchor holes 21-1. One end of the threaded steel bars 21 extends into the anchor hole 21-1 filled with anchor glue, and the other end of the threaded steel bars 21 extends into block No. 2 4. The anchor hole 21-1 is a blind hole, and the depth of the threaded steel bars 21-1 is 10 to 12 times the diameter of the threaded steel bars 21. One end of the threaded steel bars 21 extends out of the original abutment cap 6 and is fixedly connected to the steel mesh 28 in block No. 2 4.

[0076] like Figure 2 As shown, in this embodiment, the original abutment cap 6 is provided with a first group of connection holes located in the middle and lower part of the original abutment cap 6, a second group of connection holes located on one side of the first group of connection holes, and a third group of connection holes located on the other side of the first group of connection holes. The horizontal spacing between two adjacent first connection holes 7 in the first group of connection holes is 70cm to 80cm, the horizontal spacing between two adjacent second connection holes 8 is 60cm to 70cm, the horizontal spacing between two adjacent third connection holes 9 is the same as the horizontal spacing between two adjacent second connection holes 8, and the vertical spacing between two adjacent first connection holes 7, two adjacent second connection holes 8 and two adjacent third connection holes 9 are all 80cm to 90cm. The hole diameters of the first connecting hole 7, the second connecting hole 8 and the third connecting hole 9 are all 100mm~130mm, the horizontal spacings 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~180cm, the first connecting hole 7 is lower than the center position of the original abutment cap 6 along the height direction, and there is a gap between the second connecting hole 8 and the third connecting hole 9 and the top surface of the original abutment cap 6, and connecting steel bars 22 are passed through the first connecting hole 7, the second connecting hole 8 and the third connecting hole 9, and locking nuts 23 are both provided on one end of the connecting steel bar 22 extending out of the original abutment cap 6 and the other end of the connecting steel bar 22 extending out of block No. 4.

[0077] like Figure 3 As shown, in this embodiment, the tops of the blocks 0 1, 1 2 and 2 4 are penetrated with upper prestressed steel bundles 19, the bottoms of the blocks 1 2 and 2 4 are penetrated with lower prestressed steel bundles 20, the upper prestressed steel bundles and the lower prestressed steel bundles both include a corrugated tube 24, a plurality of prestressed steel bars 27 penetrated in the corrugated tube 24 and a fixed steel pad 25 penetrated at the fixed ends of the plurality of prestressed steel bars 27, a spiral rib 26 is sleeved between the fixed steel pad 25 and the corrugated tube 24, the spiral rib 26 is located outside the plurality of prestressed steel bars 27, and the tensioning ends of the plurality of prestressed steel bars 27 are sleeved with tensioning steel pads and anchors.

[0078] In this embodiment, threaded steel bars are planted in the back wall of the roughened original abutment cap 6 so that the threaded steel bars can be welded to the steel mesh 28 in the end of the T-beam. At the same time, connecting steel bars are installed in the first connecting hole 7, the second connecting hole 8 and the third connecting hole 9 to further strengthen the connection between the original abutment cap and the T-beam.

[0079] like Figure 4 A construction method for reinforcing a rigid frame bridge by replacing an existing abutment pile foundation with a T-frame is shown, comprising the following steps:

[0080] Step 1: Construction of T-beam:

[0081] Step 101, excavating and leveling the roadbed near the abutment of the bridge to be repaired to form a T-beam construction area; wherein the cross section of the T-beam construction area is in an inverted trapezoidal shape;

[0082] Step 102: construct block 0 1 and block 1 2 in the middle of the T-beam construction area; wherein, there are two blocks 1 2, and the two blocks 1 2 are symmetrically arranged at both ends of block 0 1;

[0083] At the same time, an impact drill is used to drill holes on both sides of block 1 No. 0 to form bored piles 3; wherein, the number of bored piles 3 is four, the length center line of the rectangle surrounded by the four bored piles 3 coincides with the length center line of block 1 No. 0, the width center line of the rectangle surrounded by the four bored piles 3 coincides with the width center line of block 1 No. 0, and the distance between the bored piles 3 and the outer side surface of block 1 No. 0 is 2m to 2.5m;

[0084] Step 103, pre-embed reinforcing steel bars on both sides of block 0 1, and build cap templates on both sides of block 0 1 to cast concrete, so as to form side caps 5; wherein the side caps 5 are symmetrically arranged with respect to block 0 1, and the length of the side caps 5 is equal to the length of block 0 1, the height of the side caps 5 is less than the height of block 0 1, and the tops of the four bored piles 3 are all embedded in the side caps 5;

[0085] Step 2: Roughen the back wall of the original abutment cap and plant reinforcement:

[0086] Step 201, firstly use a breaker hammer to roughen the back wall of the original abutment cap 6, and then use a rock drill to chisel the back wall of the original abutment cap 6, until the surface roughness of the back wall of the original abutment cap 6 reaches the surface roughness level 2, thereby obtaining the roughened back wall;

[0087] Step 202, arranging reinforcement points on the roughened back wall; wherein the number of reinforcement points is multiple;

[0088] Step 203, drilling holes at each reinforcement point using a drilling machine, blowing out the rock powder in the drilled holes to form reinforcement holes 21-1, and filling the reinforcement holes 21-1 with reinforcement glue;

[0089] Step 204, inserting a threaded steel bar 21 into each of the anchor holes 21-1 filled with anchor glue; wherein one end of the threaded steel bar 21 extends into the anchor hole 21-1 filled with anchor glue, and the other end of the threaded steel bar 21 extends out of the anchor hole 21-1, the anchor hole 21-1 is a blind hole, and the depth of the anchor hole 21-1 is 10 to 12 times the diameter of the threaded steel bar 21;

[0090] Step 3: Connection between T-beam and original abutment cap:

[0091] Step 301, tying steel bars on one side of block 1 No. 0 to form a steel mesh 28; wherein the threaded steel bars 21 are welded to the steel mesh 28, and a plurality of corrugated pipes arranged along the length direction are sleeved at the bottom of the steel mesh 28, which are recorded as bottom corrugated pipes 29, and the bottom corrugated pipes 29 are arranged gradually downward from the original abutment cap 6 to the bottom of block 1 No. 0;

[0092] Step 302: Set up a formwork outside the steel mesh 28 and pour concrete to form block No. 2 4, until the concrete strength of block No. 2 4 reaches 90% of the concrete design strength; wherein, there are two blocks No. 2 4, and the two blocks No. 2 4 are symmetrically arranged about block No. 0 1;

[0093] Step 303, support a counterweight template at one end of block 2 4 away from the original abutment cap 6 and cast concrete in situ to form a counterweight 15;

[0094] Step 304: support a counterweight section template at one end of block 2 4 away from the original abutment cap 6 and cast concrete in situ to form a solid counterweight section 13, and set a pile foundation 14 at the bottom of the solid counterweight section 13;

[0095] Step 4: Drilling of the connection holes of the original abutment cap:

[0096] Step 401, arranging a plurality of hole sites on the side of the original abutment cap 6 away from the back wall;

[0097] Step 402, use a geological drill to drill holes at each hole site and extend block No. 2 4 to form a plurality of connection holes; wherein the connection holes include a first group of connection holes located in the lower middle part of the original abutment cap 6, a second group of connection holes located on one side of the first group of connection holes, and a third group of connection holes located on the other side of the first group of connection holes, the horizontal spacing between two adjacent first connection holes 7 in the first group of connection holes is 70cm to 80cm, the horizontal spacing between two adjacent second connection holes 8 is 60cm to 70cm, the horizontal spacing between two adjacent third connection holes 9 is the same as the horizontal spacing between two adjacent second connection holes 8, and the horizontal spacing between the two adjacent third connection holes 9 is the same as the horizontal spacing between the two adjacent second connection holes 8. The vertical spacing between two adjacent first connection holes 7, two adjacent second connection holes 8 and two adjacent third connection holes 9 is 80cm-90cm, and the apertures of the first connection holes 7, the second connection holes 8 and the third connection holes 9 are 100mm-130mm, the horizontal spacing between the first group of connection holes and the second group of connection holes and between the first group of connection holes and the third group of connection holes are 180cm-180cm, the first connection hole 7 is lower than the center position of the original abutment cap 6 in the height direction, and a gap is set between the second connection hole 8 and the third connection hole 9 and the top surface of the original abutment cap 6;

[0098] Step 403, installing the connecting steel bar 22 in the first connecting hole 7, the second connecting hole 8 and the third connecting hole 9; wherein, the end of the connecting steel bar 22 extending out of the original abutment 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;

[0099] Step 5: Installation of prestressed tendons:

[0100] Step 501, tying steel bars on the top surfaces of block 0 1, block 1 2 and block 2 4 to form a rectangular steel cage; wherein a plurality of corrugated tubes 24 are provided in the rectangular steel cage along the width direction of the rectangular steel cage, and the corrugated tubes 24 are arranged along the length direction of block 0 1, block 1 2 and block 2 4;

[0101] Step 502: A fixed steel plate 25 is provided at one end of the back wall of the corrugated pipe 24 close to the original abutment cap 6, and a spiral rib 26 is provided between the fixed steel plate 25 and the corrugated pipe 24.

[0102] A plurality of prestressed steel bars 27 are sequentially passed through the fixed steel plate 25, the spiral bars 26 and the corrugated pipe 24, and a tensioning steel plate and an anchor are installed at the tensioning end where the plurality of prestressed steel bars 27 sequentially pass through the corrugated pipe 24, thereby completing the installation of a prestressed bundle;

[0103] Step 503, according to the method described in step 502, prestressed steel strands are installed in each corrugated tube 24 and the bottom corrugated tube 29 in sequence to obtain an upper prestressed steel strand 19 and a lower prestressed steel strand 20;

[0104] Step 6: Concrete pouring of beam section and tensioning of prestressed tendons:

[0105] Step 601, set up a beam formwork outside the rectangular steel cage, and cast concrete in situ to form a beam segment concrete 12, until the concrete strength of the beam segment concrete 12 reaches 90% of the concrete design strength;

[0106] Step 602, operating the tensioning steel pad and the anchor to tension the plurality of prestressed tendons;

[0107] Step 603: After the tensioning is completed, micro-expansion cement slurry is injected into each of the bellows 24 and the bottom bellows 29 until the strength of the cement slurry in the bellows 24 and the bottom bellows 29 reaches 90% of the designed strength of the cement slurry;

[0108] Step 7: Reinforcement of the original abutment cap and two conversions of the entire force system:

[0109] Step 701, disconnect the original abutment cap 6 and the original abutment pile foundation at the same time, remove the original abutment pile foundation, release the force on the pile foundation of the original abutment (6), and complete the first force system conversion;

[0110] Step 702, construct a foundation 16 at the bottom of the original abutment cap 6, and construct a column 17 on the foundation 16, set a steel tube concrete 18 at the top of the column 17 and hingedly connect it with the beam section concrete 12 and the original abutment cap 6 to prevent the original bridge 11 and the original abutment cap 6 from deflecting, and complete the conversion of the second force system; wherein, the distance between the upper surface of the foundation 16 and the bottom of block 10 is 250cm to 300cm.

[0111] 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:

[0112] Step 7011, using a cutting machine to perform circumferential cutting at the connection between the original abutment cap 6 and the top surfaces of the two original abutment pile foundations, until the original abutment cap 6 is connected to the top surfaces of the two original abutment pile foundations;

[0113] Step 7012: Use a rock drill to drill away 150 mm to 200 mm of pile concrete at the top of the two original abutment pile foundations to expose the pile reinforcement;

[0114] Step 7013, using a gas welder to cut the pile body reinforcement, and then using a rock drill to peel off the remaining internal pile body concrete at 150 mm to 200 mm;

[0115] Step 7014, remove the remaining original abutment pile foundation.

[0116] In this embodiment, the prestressed tendons are tensioned in step 602, and the specific process is as follows:

[0117] Operate the tension steel pad and anchor, and apply 0~0.15Q ky Tension force, the first tension, and when 0.15Q is applied ky When the tension force is greater than 3min, the first tension is completed; apply 0.15Q ky ~Q ky Tension force, the second tension is carried out, and when Q is applied ky When the tension force is greater than 3min, the second tension is completed; among them, Q ky Design value for tension control stress.

[0118] In this embodiment, it is further preferred that the micro-expansive cement slurry is AEC micro-expansive cement slurry.

[0119] To sum up, the present invention is reasonably designed and easy to operate. It adopts a variable-section T-beam to connect the original abutment to replace the existing abutment pile foundation affected by the geological deformation and bank collapse of the slope. It is suitable for bridge reinforcement projects affected by strong geological deformation and narrow working surface, and ensures that the reinforced bridge has the same bearing capacity as the original bridge, and the construction method is novel, the construction period is short, and the economic benefit is high.

[0120] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A T-frame structure for reinforcing a rigid frame bridge by replacing the original abutment pile foundation, characterized in that: The invention comprises a T-shaped support mechanism arranged between an original abutment cap (6) and a roadbed (10), the T-shaped support mechanism comprising a T-shaped beam, an intermediate support component for supporting the T-shaped beam, and a counterweight mechanism arranged at one end of the T-shaped beam away from the original abutment cap (6), the T-shaped beam comprising a No. 0 block (1), a No. 1 block (2) symmetrically arranged on both sides of the No. 0 block (1), and a No. 2 block (4) symmetrically arranged on both sides of the No. 1 block (2), and a beam section concrete (12) arranged on the tops of the No. 0 block (1), the No. 1 block (2) and the No. 2 block (4), the counterweight mechanism comprising a solid counterweight section (13) and a pile foundation (14) arranged at the bottom of the solid counterweight section (13), the No. 2 block (4) being close to the No. 0 block (1). A counterweight block (15) is added to one end of the solid counterweight section (13); the bottom of the original abutment cap (6) is provided with steel pipe piles (30), abutment foundation (16), columns (17) and steel tube concrete (18) in sequence from bottom to top; the steel tube concrete (18) is hingedly connected to the bottom of the original abutment cap (6); one end of the No. 2 block (4) close to the original abutment cap (6) is fixedly connected to the original abutment cap (6); the bottoms of the No. 2 block (4) and the No. 1 block (2) are gradually tilted downward from the original abutment cap (6) to the No. 0 block (1); the top of the beam section concrete (12), the top surface of the solid counterweight section (13) and the top of the original bridge (11) are flush; The number of the intermediate support components is two, and the two intermediate support components are symmetrically arranged about the No. 0 block (1). The intermediate support components include a side support platform (5) fixedly connected to the No. 0 block (1) and a bored pile (3) with a top end embedded in the side support platform (5). The length of the side support platform (5) is equal to the length of the No. 0 block (1), the height of the side support platform (5) is less than the height of the No. 0 block (1), and the number of bored piles (3) embedded in each side support platform (5) is two; The back wall of the original abutment cap (6) is provided with a plurality of anchor holes (21-1), and threaded steel bars (21) are arranged in the anchor holes (21-1). One end of the threaded steel bar (21) extends into the anchor hole (21-1) filled with anchor glue, and the other end of the threaded steel bar (21) extends into block No. 2 (4). The anchor hole (21-1) is a blind hole, and the depth of the threaded steel bar (21-1) is 10 to 12 times the diameter of the threaded steel bar (21). One end of the threaded steel bar (21) extending out of the original abutment cap (6) is fixedly connected to the steel mesh (28) in block No. 2 (4).

2. A T-frame construction structure for replacing the original abutment pile foundation and reinforcing a rigid frame bridge according to claim 1, characterized in that: The original abutment cap (6) is provided with a first group of connection holes located in the middle and lower part of the original abutment cap (6), a second group of connection holes located on one side of the first group of connection holes, and a third group of connection holes located on the other side of the first group of connection holes. The horizontal spacing between two adjacent first connection holes (7) in the first group of connection holes is 70 cm to 80 cm, the horizontal spacing between two adjacent second connection holes (8) is 60 cm to 70 cm, the horizontal spacing between two adjacent third connection holes (9) is the same as the horizontal spacing between two adjacent second connection holes (8), the vertical spacing between two adjacent first connection holes (7), two adjacent second connection holes (8) and two adjacent third connection holes (9) is 80 cm to 90 cm, and the first connection holes (7), the second connection holes (8) and the third connection holes (9) are all 80 cm to 90 cm. The hole diameters of the connecting holes (8) and the third connecting holes (9) are both 100 mm to 130 mm, the horizontal spacings 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 both 180 cm to 180 cm, the first connecting hole (7) is lower than the center position of the original abutment cap (6) in the height direction, a gap is provided between the second connecting hole (8) and the third connecting hole (9) and the top surface of the original abutment cap (6), connecting steel bars (22) are passed through the first connecting hole (7), the second connecting hole (8) and the third connecting hole (9), and a locking nut (23) is provided on one end of the connecting steel bar (22) extending out of the original abutment cap (6) and the other end of the connecting steel bar (22) extending out of block No. 2 (4).

3. A T-frame construction structure for replacing the original abutment pile foundation and reinforcing a rigid frame bridge according to claim 1, characterized in that: An upper prestressed steel bundle (19) is passed through the top of the block No. 0 (1), the block No. 1 (2) and the block No. 2 (4), and a lower prestressed steel bundle (20) is passed through the bottom of the block No. 1 (2) and the block No. 2 (4). The upper prestressed steel bundle and the lower prestressed steel bundle both include a corrugated pipe (24), a plurality of prestressed steel bars (27) passed through the corrugated pipe (24), and a fixed steel pad (25) passed through the fixed ends of the plurality of prestressed steel bars (27). A spiral rib (26) is sleeved between the fixed steel pad (25) and the corrugated pipe (24). The spiral rib (26) is located outside the plurality of prestressed steel bars (27). The tensioning ends of the plurality of prestressed steel bars (27) are sleeved with a tensioning steel pad and an anchor.

4. A method for reinforcing a rigid frame bridge by replacing the original abutment pile foundation with a T-frame, characterized in that: The method comprises the following steps: Step 1: Construction of T-beam: Step 101, excavating and leveling the roadbed near the abutment of the bridge to be repaired to form a T-beam construction area; wherein the cross section of the T-beam construction area is in an inverted trapezoidal shape; Step 102: constructing block No. 0 (1) and block No. 1 (2) in the middle of the T-beam construction area; wherein the number of blocks No. 1 (2) is two, and the two blocks No. 1 (2) are symmetrically arranged at both ends of block No. 0 (1); At the same time, an impact drill is used to drill holes on both sides of block No. 0 (1) to form bored piles (3); wherein the number of bored piles (3) is four, the length center line of the rectangle surrounded by the four bored piles (3) coincides with the length center line of block No. 0 (1), the width center line of the rectangle surrounded by the four bored piles (3) coincides with the width center line of block No. 0 (1), and the distance between the bored piles (3) and the outer side surface of block No. 0 (1) is 2m to 2.5m; Step 103, pre-embed reinforcing steel bars on both sides of block No. 0 (1), and build a cap template on both sides of block No. 0 (1) and cast in situ concrete to form a side cap (5); wherein the side cap (5) is symmetrically arranged with respect to block No. 0 (1), and the length of the side cap (5) is equal to the length of block No. 0 (1), the height of the side cap (5) is less than the height of block No. 0 (1), and the top ends of the four bored piles (3) are all embedded in the side cap (5); Step 2: Roughen the back wall of the original abutment cap and plant reinforcement: Step 201, firstly use a breaker hammer to roughen the back wall of the original abutment cap (6), and then use a rock drill to re-chisel the back wall of the original abutment cap (6), until the surface roughness of the back wall of the original abutment cap (6) reaches the surface roughness level 2, thereby obtaining the roughened back wall; Step 202, arranging reinforcement points on the roughened back wall; wherein the number of reinforcement points is multiple; Step 203, drilling holes at each reinforcement planting point using a drilling machine, blowing out the rock powder in the drilled holes to form reinforcement planting holes (21-1), and filling the reinforcement planting holes (21-1) with reinforcement planting glue; Step 204, inserting a threaded steel bar (21) into each of the rebar embedding holes (21-1) filled with the rebar embedding glue; wherein one end of the threaded steel bar (21) extends into the rebar embedding hole (21-1) filled with the rebar embedding glue, and the other end of the threaded steel bar (21) extends out of the rebar embedding hole (21-1), the rebar embedding hole (21-1) is a blind hole, and the depth of the rebar embedding hole (21-1) is 10 to 12 times the diameter of the threaded steel bar (21); Step 3: Connection between T-beam and original abutment cap: Step 301, tying steel bars on one side of block No. 0 (1) to form a steel mesh (28); wherein the threaded steel bars (21) are welded to the steel mesh (28), and a plurality of corrugated pipes arranged along the length direction are sleeved at the bottom of the steel mesh (28), which are recorded as bottom corrugated pipes (29), and the bottom corrugated pipes (29) are arranged gradually downward from the original abutment cap (6) to the bottom of block No. 0 (1); Step 302, erecting a formwork outside the steel mesh (28) and pouring concrete to form block No. 2 (4), until the concrete strength of block No. 2 (4) reaches 90% of the concrete design strength; wherein the number of blocks No. 2 (4) is two, and the two blocks No. 2 (4) are symmetrically arranged with respect to block No. 0 (1); Step 303: support a counterweight template at one end of block No. 2 (4) away from the original abutment cap (6) and cast concrete in situ to form a counterweight (15); Step 304: support a counterweight section template at one end of block No. 2 (4) away from the original abutment cap (6) and cast concrete in situ to form a solid counterweight section (13), and set a pile foundation (14) at the bottom of the solid counterweight section (13); Step 4: Drilling of the connection holes of the original abutment cap: Step 401, arranging a plurality of hole sites on the side of the original abutment cap (6) away from the back wall; Step 402: Use a geological drill to drill holes at each hole location and extend block No. 2 (4) to form a plurality of connection holes; wherein the connection holes include a first group of connection holes located in the middle and lower part of the original abutment cap (6), a second group of connection holes located on one side of the first group of connection holes, and a third group of connection holes located on the other side of the first group of connection holes; the horizontal spacing between two adjacent first connection holes (7) in the first group of connection holes is 70 cm to 80 cm, the horizontal spacing between two adjacent second connection holes (8) is 60 cm to 70 cm, the horizontal spacing between two adjacent third connection holes (9) is the same as the horizontal spacing between two adjacent second connection holes (8), and the horizontal spacing between two adjacent first connection holes (7) is 60 cm to 70 cm. The vertical spacings between the connection holes (7), two adjacent second connection holes (8) and two adjacent third connection holes (9) are all 80 cm to 90 cm, and the diameters of the first connection holes (7), the second connection holes (8) and the third connection holes (9) are all 100 mm to 130 mm, and the horizontal spacings between the first group of connection holes and the second group of connection holes and between the first group of connection holes and the third group of connection holes are all 180 cm to 180 cm, the first connection hole (7) is lower than the center position of the original abutment cap (6) in the height direction, and a gap is provided between the second connection hole (8) and the third connection hole (9) and the top surface of the original abutment 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 abutment cap (6) and the other end of the connecting steel bar (22) extending out of the No. 2 block (4) are both sleeved with locking nuts (23); Step 5: Installation of prestressed tendons: Step 501: Tie steel bars on the top surfaces of block No. 0 (1), block No. 1 (2) and block No. 2 (4) to form a rectangular steel cage; wherein a plurality of corrugated pipes (24) are provided in the rectangular steel cage along the width direction of the rectangular steel cage, and the corrugated pipes (24) are arranged along the length direction of block No. 0 (1), block No. 1 (2) and block No. 2 (4); Step 502: a fixed steel plate (25) is arranged at one end of the corrugated pipe (24) close to the back wall of the original abutment cap (6), and a spiral rib (26) is arranged between the fixed steel plate (25) and the corrugated pipe (24). and sequentially passing a plurality of prestressed steel bars (27) through the fixed steel pad (25), the spiral bars (26) and the corrugated pipe (24), and installing a tensioning steel pad and an anchor at the tensioning end where the plurality of prestressed steel bars (27) sequentially pass through the corrugated pipe (24), thereby completing the installation of a prestressed bundle; Step 503, according to the method described in step 502, prestressed steel strands are sequentially installed in each corrugated pipe (24) and the bottom corrugated pipe (29) to obtain an upper prestressed steel strand (19) and a lower prestressed steel strand (20); Step 6: Concrete pouring of beam section and tensioning of prestressed tendons: Step 601, set up a beam formwork outside the rectangular steel cage, and cast concrete in situ to form beam segment concrete (12), until the concrete strength of the beam segment concrete (12) reaches 90% of the concrete design strength; Step 602, operating the tensioning steel pad and the anchor to tension the plurality of prestressed tendons; Step 603: After the tensioning is completed, micro-expansion cement slurry is injected into each of the bellows (24) and the bottom bellows (29) until the strength of the cement slurry in the bellows (24) and the bottom bellows (29) reaches 90% of the designed strength of the cement slurry; Step 7: Reinforcement of the original abutment cap and two conversions of the entire force system: Step 701, disconnect the original abutment cap (6) and the original abutment pile foundation at the same time, remove the original abutment pile foundation, release the force on the pile foundation of the original abutment, and complete the first force system conversion; Step 702, construct a cap foundation (16) at the bottom of the original abutment cap (6), and construct a column (17) on the cap foundation (16), and set a steel tube concrete (18) at the top of the column (17) to hinge the beam section concrete (12) and the original abutment cap (6) to prevent the original bridge (11) and the original abutment cap (6) from deflecting, thereby completing the conversion of the second force system; wherein, the distance between the upper surface of the cap foundation (16) and the bottom of block 0 (1) is 250cm to 300cm.

5. A method for reinforcing a rigid frame bridge by replacing the original abutment pile foundation with a T-frame as claimed in claim 4, characterized in that: In step 701, the original abutment cap (6) and the two original abutment pile foundations are disconnected at the same time. The specific process is as follows: Step 7011, using a cutting machine to perform circumferential cutting at the connection between the original abutment cap (6) and the top surfaces of the two original abutment pile foundations, until the original abutment cap (6) is connected to the top surfaces of the two original abutment pile foundations; Step 7012: Use a rock drill to drill away 150 mm to 200 mm of pile concrete at the top of the two original abutment pile foundations to expose the pile reinforcement; Step 7013, using a gas welder to cut the pile body reinforcement, and then using a rock drill to peel off the remaining internal pile body concrete at 150 mm to 200 mm; Step 7014, remove the remaining original abutment pile foundation.

6. A method for reinforcing a rigid frame bridge by replacing the original abutment pile foundation with a T-frame as claimed in claim 4, characterized in that: In step 602, the prestressed tendons are tensioned, and the specific process is as follows: Operate the tension steel pad and anchor, and apply 0~0.15Q ky Tension force, the first tension, and when 0.15Q is applied ky When the tension force is greater than 3min, the first tensioning is completed; Apply 0.15Q ky ~Q ky Tension force, the second tension is carried out, and when Q is applied ky When the tension force is greater than 3min, the second tension is completed; among them, Q ky Design value for tension control stress.

Images