Structure for preventing cracking of concrete outside steel pipe at arch foot of concrete filled steel tube arch bridge

Abstract

The invention discloses a structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking; the exposed arch rib section (D) is composed of a conventional exposed arch rib section (B), chord shear studs (15), bearing plates (16), inner chord stiffening rings (17), bearing plate stiffening ribs (18), annular sealing steel belts (19) and rubber waterstops (20); shear studs (15) are welded to the outer surfaces of the bearing plates (16), the upper chord of the embedded section (3) and the lower chord of the embedded section (4) at the lowermost ends of the upper chord (1) and the lower chord (2) of the arch rib in the exposed arch rib section (D); the invention overcomes the defect that the concrete outside the steel pipe of the arch rib cracks due to excessive lateral resistance between the outer wall of the steel pipe of the arch rib and the concrete in the prior art, and has the advantages of ensuring sufficient durability, safety and service life at the arch foot of this type of concrete-filled steel tube arch bridge.

Description

Technical Field

[0001] The present invention relates to the technical field of bridges, and more specifically to a structure for preventing the concrete outside the steel pipe of the arch rib at the arch foot of a concrete-filled steel tube arch bridge from cracking. Background Art

[0002] Concrete-filled steel tubes have the advantages of light weight, high strength, large bearing capacity, and convenient construction and installation, and are widely used in the three structural systems of arch bridges, such as Figure 1 、 Figure 2 and Figure 3 as shown.

[0003] To reliably connect the arch seat and the steel pipe of the arch rib, generally, the conventional embedded section of the arch rib steel pipe is buried in the concrete of the first-poured section of the arch seat, and then the chord joint steel pipe is used to connect the conventional embedded arch rib steel pipe and the exposed arch rib steel pipe, and then the concrete of the post-poured and sealed hinge section of the arch seat is used for consolidation, as Figure 4 shown. Since the steel pipe of the arch rib at the arch foot bears a large axial pressure, a frictional side resistance is generated between the outer wall of the steel pipe of the arch rib buried in the arch seat and the concrete, and this side resistance has a peeling effect on the concrete wrapped outside the steel pipe of the arch rib.

[0004] When the outside temperature suddenly drops, due to the inconsistent thermal expansion coefficients of steel and concrete, a peeling effect will also be generated between the concrete outside and the outer wall of the steel pipe of the arch rib. When the peeling effect is greater than the bonding force between the concrete and the steel pipe of the arch rib, it will cause the concrete outside the arch seat to crack.

[0005] Once the crack is too large, water and water vapor in nature will seep into the interior of the concrete along the crack, causing the internal steel bars and steel pipes to rust, reducing the structural bearing capacity, durability and service life. Deep cracks will even damage the integrity of the arch seat, change the stress mechanism of the arch seat concrete, and even cause the concrete to fall off and be damaged, affecting the structural safety.

[0006] To avoid the cracking of the concrete of the arch seat caused by excessive side resistance between the outer wall of the steel pipe of the arch rib and the concrete after the steel pipe of the arch rib is buried in the arch seat.

[0007] Therefore, there is an urgent need for a structure to solve the above problems. Summary of the Invention

[0008] The purpose of the present invention is to overcome the deficiencies of the above background art and propose a structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking.

[0009] The purpose of the present invention is implemented through the following technical solutions: A structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking, which includes a conventional embedded section of the arch rib, the concrete of the first-poured section of the arch seat, and the concrete of the post-poured and sealed hinge section of the arch seat;

[0010] The conventional arch rib embedded section is connected to the conventional exposed arch rib section (B) through the chord joint steel pipe.

[0011] The conventional arch rib embedded section is welded by the upper chord of the arch rib embedded section, the lower chord of the arch rib embedded section, radial webs, horizontal diagonal web members, cross braces, chord end stiffening bases, and base stiffening rib plates.

[0012] The upper chord of the embedded section and the lower chord of the embedded section are arranged parallel to each other and are both embedded in the concrete of the first - poured section of the arch seat.

[0013] Radial webs are vertically welded between the upper chord of the embedded section and the lower chord of the embedded section.

[0014] Horizontal diagonal web members are horizontally welded between the upper chord of the embedded section and the lower chord of the embedded section.

[0015] Chord end stiffening bases are vertically arranged at the ends of the upper chord of the embedded section and the lower chord of the embedded section.

[0016] Base stiffening rib plates are welded between the ends of the upper chord of the embedded section, the lower chord of the embedded section, and the chord end stiffening bases.

[0017] A hinge base is embedded in the conventional embedded section, and the hinge base is located on the bisector between the upper chord of the embedded section and the lower chord of the embedded section.

[0018] The conventional exposed arch rib section is composed of an arch rib upper chord, an arch rib lower chord, vertical web members, radial webs, hinge seat braces, hinge seat shafts, and cross braces.

[0019] Vertical web members are vertically welded between the upper chord of the arch rib section and the lower chord of the arch rib section.

[0020] Radial webs are perpendicularly welded between the upper chord of the arch rib section and the lower chord of the arch rib section.

[0021] A hinge seat shaft is arranged in the hinge base, and a hinge seat brace is welded between the lower chord of the arch rib and the hinge seat shaft.

[0022] It is characterized in that the arch rib embedded section is welded and composed of the conventional arch rib embedded section and chord shear studs.

[0023] The exposed arch rib section is composed of a conventional exposed arch rib section, chord shear studs, bearing plates, inner chord stiffening rings, bearing plate stiffening rib plates, annular sealing steel belts, and rubber water - stop strips.

[0024] Shear studs are welded to the outermost surfaces of the bearing plates, the upper chord of the embedded section, and the lower chord of the embedded section at the lowermost ends of the exposed arch rib section and the lower chord of the arch rib.

[0025] Both the upper chord and the lower chord of the arch rib penetrate through the bearing plate.

[0026] Stiffening rings are welded inside the chords of the upper chord and the lower chord of the arch rib at positions aligned with the bearing plate.

[0027] Stiffening ribs are welded between the upper chord of the arch rib and the bearing plate.

[0028] Stiffening ribs are welded between the lower chord of the arch rib and the bearing plate; circumferential sealing steel belts are welded around the bearing plate.

[0029] Rubber waterstops are pasted on the inner wall of the circumferential sealing steel belt between the circumferential sealing steel belt of the upper chord of the segmental arch rib and the lower chord of the arch rib.

[0030] In the above technical solution: One end of the embedded section of the arch rib is pre-embedded in the cast-in-place section of the arch seat; the embedded section of the arch rib is connected to the exposed arch rib section, and the other section is connected to the bearing plate to form an integral body.

[0031] In the above technical solution: Vertical suspenders are arranged between the lower chord of the arch rib and the main girder of the carriageway; vertical columns are arranged between the upper chord of the arch rib and the main girder of the carriageway.

[0032] In the above technical solution: Cross braces are horizontally welded between adjacent upper chords of the segmental arch rib.

[0033] In the above technical solution: A hinge base is embedded in the cast-in-place section of the arch seat.

[0034] The present invention has the following advantages: 1. The overall structural form of the present invention only welds shear studs, bearing plates, stiffening ribs of the bearing plate, circumferential sealing steel belts and pastes rubber waterstops on the existing structure upper chord.

[0035] 2. Especially under the condition that the arch foot size requirements of the lower-supported arch bridge and the half-through arch bridge are limited, the present invention can improve the compressive bearing capacity of the arch seat through the bearing plate without increasing the cross-sectional size of the arch seat. Description of the Drawings

[0036] Figure 1 It is the bridge type layout diagram of the lower-supported concrete-filled steel tube arch bridge in the prior art.

[0037] Figure 2 It is the bridge type layout diagram of the upper-supported concrete-filled steel tube arch bridge in the prior art.

[0038] Figure 3 It is the bridge type layout diagram of the half-through concrete-filled steel tube arch bridge in the prior art.

[0039] Figure 4 It is an elevation view of a conventional arch abutment.

[0040] Figure 5 It is an elevation view of the arch abutment recommended by the present invention.

[0041] Figure 6 It is an assembly drawing of embedded parts of a conventional arch abutment.

[0042] Figure 7 It is an assembly drawing of embedded parts of the arch abutment recommended by the present invention.

[0043] Figure 8 It is the concrete of the conventional arch abutment hinge-sealing section.

[0044] Figure 9 It is the concrete of the arch abutment hinge-sealing section recommended by the present invention

[0045] Figure 10 It is Figure 9 The schematic diagram of cross-section Ⅰ—Ⅰ in

[0046] Figure 11 It is Figure 9 The schematic diagram of cross-section Ⅱ—Ⅱ in

[0047] Figure 12 It is Figure 9 The schematic diagram of cross-section Ⅲ—Ⅲ in

[0048] Figure 13 It is Figure 12 The schematic diagram of cross-section Ⅳ—Ⅳ in

[0049] Figure 14 It is Figure 13 The detailed structure drawing of part E in

[0050] Figure 15 It is the schematic diagram of the bearing plate structure in the present invention.

[0051] Figure 16 It is the schematic diagram of the chord inner stiffening plate structure in the present invention.

[0052] Figure 17 It is a circumferentially closed steel strip.

[0053] Figure 18 It is a model diagram of a conventional arch abutment.

[0054] Figure 19 It is the mechanical principle diagram of a conventional arch abutment in the present invention.

[0055] Figure 20 It is the mechanical principle diagram of the arch abutment recommended by the present invention.

[0056] In the figure: upper chord member 1 of the arch rib, lower chord member 2 of the arch rib, upper chord member 3 of the embedded section of the arch rib, lower chord member 4 of the embedded section of the arch rib, vertical web member 5, radial web 6, hinge seat brace 7, hinge seat shaft 8, hinge shaft base 9, horizontal diagonal web member 10, cross bracing 11, stiffening base at the end of the chord member 12, base stiffening rib plate 13, chord member joint steel pipe 14, chord member shear stud 15, bearing plate 16, internal stiffening plate of the chord member 17, bearing plate stiffening rib plate 18, circumferential sealing steel strip 19, rubber water stop strip 20, cast-in-place concrete of the arch seat first section 21, cast-in-place concrete of the arch seat post-cast hinge sealing section 22, main beam of the carriageway 23, vertical suspender under the arch 24, vertical column on the arch 25, conventional embedded section A of the arch rib, conventional exposed arch rib section B, embedded section C of the arch rib, exposed arch rib section D. Detailed implementation mode

[0057] The implementation of the present invention will be described in detail below in conjunction with the accompanying drawings. However, they do not constitute a limitation to the present invention and are only for illustration purposes. At the same time, the advantages of the present invention will become clearer and easier to understand through the description.

[0058] Refer to Figures 1-20 As shown: a structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking, which includes a conventional embedded section A of the arch rib, a conventional exposed arch rib section B, a chord member joint steel pipe 14, cast-in-place concrete of the arch seat first section 21, and cast-in-place concrete of the arch seat post-cast hinge sealing section 22;

[0059] The conventional embedded section A of the arch rib is connected to the conventional exposed arch rib section B through the chord member joint steel pipe 14;

[0060] The conventional embedded section A of the arch rib is welded by an upper chord member 3 of the embedded section of the arch rib, a lower chord member 4 of the embedded section of the arch rib, a radial web 6, a horizontal diagonal web member 10, a cross bracing 11, a stiffening base at the end of the chord member 12, and a base stiffening rib plate 13;

[0061] The upper chord member 3 of the embedded section and the lower chord member 4 of the embedded section are arranged parallel to each other and are both embedded in the cast-in-place concrete of the arch seat first section 21;

[0062] A radial web 6 is perpendicularly welded between the upper chord member 3 of the embedded section and the lower chord member 4 of the embedded section;

[0063] A horizontal diagonal web member 10 is horizontally welded between the upper chord member 3 of the embedded section and the lower chord member 4 of the embedded section;

[0064] A stiffening base at the end of the chord member 12 is vertically arranged at the ends of the upper chord member 3 of the embedded section and the lower chord member 4 of the embedded section;

[0065] Base stiffening rib plates 13 are welded between the ends of the upper chord member 3 of the embedded section, the lower chord member 4 of the embedded section and the stiffening base at the end of the chord member 12;

[0066] The described conventional embedded section A is embedded with a hinge base 9, and the hinge base 9 is located on the bisector between the upper chord 3 and the lower chord 4 of the embedded section;

[0067] The described conventional exposed arch rib section B is composed of an arch rib upper chord 1, an arch rib lower chord 2, vertical web members 5, radial web plates 6, hinge seat braces 7, hinge seat shafts 8, and a cross bracing 11;

[0068] A vertical web member 5 is vertically welded between the arch rib upper chord 1 and the arch rib lower chord 2 of the section;

[0069] A radial web plate 6 is perpendicularly welded between the arch rib upper chord 1 and the arch rib lower chord 2 of the section;

[0070] A hinge seat shaft 8 is arranged inside the hinge base 9, and a hinge seat brace 7 is welded between the arch rib lower chord 2 and the hinge seat shaft 8;

[0071] The arch rib embedded section C is welded and composed of the described conventional arch rib embedded section A and chord shear studs 15;

[0072] The exposed arch rib section D is composed of the conventional exposed arch rib section B, chord shear studs 15, bearing plates 16, inner chord stiffening rings 17, bearing plate stiffening ribs 18, circumferential sealing steel belts 19, and rubber waterstops 20;

[0073] Shear studs 15 are welded to the outermost surfaces of the bearing plates 16, the upper chord 3 of the embedded section, and the lower chord 4 of the embedded section at the lowermost ends of the arch rib upper chord 1 and the arch rib lower chord 2 in the exposed arch rib section D;

[0074] Both the arch rib upper chord 1 and the arch rib lower chord 2 penetrate through the bearing plate 16;

[0075] Inner chord stiffening rings 17 are welded at positions inside the chords of the arch rib upper chord 1 and the arch rib lower chord 2 that are aligned with the bearing plate 16;

[0076] Bearing plate stiffening ribs 18 are welded between the arch rib upper chord 1 and the bearing plate 16;

[0077] Bearing plate stiffening ribs 18 are welded between the arch rib lower chord 2 and the bearing plate 16; The circumferential sealing steel belt 19 is welded around the bearing plate 16;

[0078] A rubber waterstop 20 is pasted on the inner wall of the circumferential sealing steel belt 19 between the circumferential sealing steel belt 19 of the arch rib upper chord 1 and the arch rib lower chord 2 of the section;

[0079] One end of the embedded section C of the arch rib is pre-embedded in the concrete 21 of the first-poured section of the arch seat; the embedded section C of the arch rib is connected to the exposed arch rib section D through the chord joint steel pipe 14; one end of the post-cast hinge-sealing section concrete 22 of the arch seat is connected to the concrete 21 of the first-poured section of the arch seat, and the other section is connected to the bearing plate 16 to form a whole.

[0080] An arch vertical hanger 24 is arranged between the lower chord 2 of the arch rib and the carriageway main beam 23; an arch upper vertical column 25 is arranged between the upper chord 1 of the arch rib and the carriageway main beam 23.

[0081] The adjacent upper chord 1 of the segment arch rib is horizontally welded with a cross bracing 11; a hinge base 9 is embedded in the concrete 21 of the first-poured section of the arch seat.

[0082] The present invention further includes the following specific working processes:

[0083] The first part

[0084] The main stress-bearing member of the arch bridge is the arch rib, which mainly bears axial force. The arch rib steel pipe must be embedded in the arch seat and safely transfer the axial force to the concrete arch seat and foundation.

[0085] In the past, the conventional method was to directly embed the upper chord 3 of the embedded section, the lower chord 4 of the embedded section, the radial web 6, the horizontal diagonal web 10, the cross bracing 11 and the chord end stiffening base 12, the base stiffening rib 13 into the concrete 21 of the first-poured section of the arch seat, as Figure 6 shown. The force transfer mainly depends on the frictional side resistance between the arch rib steel pipe wall and the concrete and the end resistance of the arch rib end stiffening base. The force transfer path is: the chord steel pipe wall → the arch rib end stiffening base.

[0086] The mechanical principle of the past conventional method is as Figure 19 shown. Under the action of axial force (N) and bending moment (M) on the arch rib, the anti-bending moment between the upper chord and the lower chord is (W), the upper chord bears axial force the lower chord bears axial force The end resistance and side resistance of the upper chord of the embedded section are R1 1 and R2 1 , the end resistance and side resistance of the lower chord of the embedded section are R1 2 and R2 2 , where the axial force N = R1 + R2, R1 = (R1 1 + R1 2 ), R2 = (R2 1 + R2 2 ).

[0087] Since the tip resistance is far from the interface, sufficient deformation is required to fully develop the tip resistance. To obtain a large tip resistance, excessive slip deformation will occur on the side walls of the arch rib. Once the concrete outside the arch rib steel pipe is not strongly constrained, circumferential cracks perpendicular to the axis of the steel pipe will occur, thereby reducing the structural bearing capacity, durability, and service life.

[0088] Part Two:

[0089] To prevent cracks from appearing in the concrete outside the arch rib steel pipe, the present invention proposes a new force transmission path to improve the force-bearing of the arch seat and avoid cracking of the concrete outside the arch rib steel pipe embedded at the arch foot.

[0090] The design to avoid cracking of the concrete outside the arch rib steel pipe embedded at the arch foot of a concrete-filled steel tube arch bridge mainly consists of three main components: a bearing plate on the interface between the arch seat and the arch rib, the arch rib steel pipe embedded in the arch seat, and the arch rib end stiffening base embedded in the arch seat.

[0091] The mechanical principle of the present invention is as Figure 20 shown. Under the action of axial force (N) and bending moment (M) on the arch rib, the anti-bending moment between the upper chord and the lower chord is (W), the upper chord bears the axial force the lower chord bears the axial force The tip resistance and side resistance of the upper chord of the embedded section are R1 1 and R2 1 , respectively. The tip resistance and side resistance of the lower chord of the embedded section are R1 2 and R2 2 , respectively. The pressure borne by the bearing plate is R3, where the axial force N = R1 + R2 + R3, R1 = (R1 1 + R1 2 ), R2 = (R2 1 + R2 2 ).

[0092] Part Three:

[0093] The force transmission path of the axial force of the arch rib steel pipe in the arch seat of the present invention is: bearing plate → chord steel pipe wall → chord wall shear studs → arch rib end stiffening base. Based on the traditional force transmission components (chord steel pipe wall → arch rib end stiffening base) in the arch seat of the present invention, two force transmission components, namely the bearing plate and the chord wall shear studs, are added.

[0094] The force-bearing of the two parts, namely the outer wall of the steel pipe in the traditional arch seat and the arch rib end stiffening base, is adjusted to the combined force-bearing of three parts: the bearing plate, the outer wall of the steel pipe, and the arch rib end stiffening base.

[0095] The bearing plate is composed of a bearing plate 16, a chord inner stiffening ring 17, a bearing plate stiffening rib plate 18, an annular sealing steel strip 19, and a rubber water stop strip 20. The arch rib steel pipe is composed of a buried upper chord 3, a buried lower chord 4, a radial web 6, a horizontal diagonal web 10, and a cross bracing 11. The arch rib end stiffening base is composed of 12 and 13, and the chord wall shear studs are component 15.

[0096] According to the principle of deformation coordination, after the bearing plate 16 shares part of the chord axial force, the force transmitted to the outer wall of the arch rib steel pipe and the arch rib end in the arch seat is reduced. At the same time, shear studs are added to the outer wall of the embedded arch rib chord to increase the contact area between the concrete and the outer wall of the steel pipe, further reducing the side resistance around the chord wall, thereby blocking the cracking of the arch seat caused by excessive side resistance around the chord wall.

[0097] The solution of the present invention utilizes the bearing plate to give play to the advantages of concrete in compression, reduces the axial force transmitted to the arch seat, thereby reducing the side resistance between the arch rib steel pipe wall and the concrete, blocking the direct cause of the cracking of the outer concrete, and ensuring that the concrete outside the steel pipe at the arch foot does not crack.

[0098] The assembly process of the present invention: Step 1: First, process the arch foot arch rib embedded section C according to the conventional method. The arch rib embedded section is composed of a buried upper chord 3, a buried lower chord 4, a radial web 6, a horizontal diagonal web 10, a cross bracing 11, a chord end stiffening base 12, a base stiffening rib plate 13, and a chord shear stud 15, which are welded together;

[0099] Step 2: Locate the arch rib embedded section C and the hinge shaft base 9, tie the arch seat steel bars, and pour the first-poured section concrete 21 of the arch seat, as Figure 7 shown;

[0100] Step 3: Install the exposed arch rib section D; place the hinge seat shaft 8 of the exposed arch rib section in the hinge shaft base and adjust the arch rib inclination angle.

[0101] Step 4: After adjusting the inclination angle of the exposed arch rib section, weld the chord joint steel pipes 14 between chord 1 and 3 and between chord 2 and 4;

[0102] Step 5: A rubber water stop strip 20 is pasted on the inner wall of the annular sealing steel strip 19 between the upper chord 1 and the arch rib lower chord 2;

[0103] Step 6: Tie the steel bars in the concrete for sealing the hinge, and pour the post-cast sealing hinge section concrete 22 of the arch seat, as Figure 9 the shaded part in.

[0104] Step 7: According to the type of bridge, in Figure 1 the shown bridge type, an arch vertical hanger 24 is arranged between the arch rib lower chord 2 and the carriageway main beam 23. In Figure 2And Figure 3 For the bridge type shown, vertical columns 25 above the arch are provided between the upper chord 1 of the arch rib and the carriageway main beam 23.

[0105] Parts not described in detail above are all prior arts.

Claims

1. Structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking, which includes a conventional arch rib embedded section A, a conventional exposed arch rib section B, a chord joint steel pipe (14), a cast-in-place section of the arch seat concrete (21), and a post-cast hinge-sealing section of the arch seat concrete (22); The conventional arch rib embedded section A is connected to the conventional exposed arch rib section B through the chord joint steel pipe (14); The said conventional arch rib embedded section A is welded by an upper chord of the arch rib embedded section (3), a lower chord of the arch rib embedded section (4), radial webs (6), horizontal diagonal web members (10), cross braces (11), a chord end stiffening base (12), and a base stiffening rib plate (13); The said upper chord of the embedded section (3) and the lower chord of the embedded section (4) are arranged parallel to each other and are both buried into the cast-in-place section of the arch seat concrete (21); A radial web (6) is vertically welded between the upper chord of the embedded section (3) and the lower chord of the embedded section (4); A horizontal diagonal web member (10) is horizontally welded between the upper chord of the embedded section (3) and the lower chord of the embedded section (4); Chord end stiffening bases (12) are vertically arranged at the ends of the upper chord of the embedded section (3) and the lower chord of the embedded section (4); Base stiffening rib plates (13) are welded between the ends of the upper chord of the embedded section (3), the lower chord of the embedded section (4) and the chord end stiffening bases (12); A hinge base (9) is buried in the said conventional arch rib embedded section A, and the said hinge base (9) is located on the bisector between the upper chord of the embedded section (3) and the lower chord of the embedded section (4); The said conventional exposed arch rib section B is composed of an arch rib upper chord (1), an arch rib lower chord (2), vertical web members (5), radial webs (6), hinge seat braces (7), a hinge seat shaft (8), and cross braces (11); Vertical web members (5) are vertically welded between the arch rib upper chord (1) and the arch rib lower chord (2), Radial webs (6) are perpendicularly welded between the arch rib upper chord (1) and the arch rib lower chord (2), A hinge seat shaft (8) is arranged in the said hinge base (9), and a hinge seat brace (7) is welded between the arch rib lower chord (2) and the hinge seat shaft (8); It is characterized in that: The arch rib embedded section C is welded and composed of the said conventional arch rib embedded section A and chord shear studs (15); One end of the said arch rib embedded section C is pre-buried in the cast-in-place section of the arch seat concrete (21); The said arch rib embedded section C is connected to the exposed arch rib section D through the chord joint steel pipe (14); The bearing plate structure is composed of a bearing plate (16), an inner chord stiffening ring (17), bearing plate stiffening rib plates (18), a circular sealing steel belt (19), and a rubber water stop strip (20). The arch rib steel pipe is composed of the upper chord of the buried section (3), the lower chord of the buried section (4), radial webs (6), horizontal diagonal web members (10), and cross braces (11). The arch rib end stiffening base is composed of a chord end stiffening base (12) and a base stiffening rib plate (13); The exposed arch rib segment D is composed of a conventional exposed arch rib segment B, chord shear studs (15), bearing plates (16), inner chord stiffening rings (17), bearing plate stiffening ribs (18), circumferential sealing steel belts (19), and rubber water stop strips (20). Shear studs (15) are welded to the outer surfaces of the bearing plates (16), upper chord embedded segments (3), and lower chord embedded segments (4) at the lowermost ends of the upper chord (1) and lower chord (2) of the arch rib in the exposed arch rib segment D. Both the upper chord (1) and lower chord (2) of the arch rib penetrate through the bearing plate (16). Inner chord stiffening rings (17) are welded at positions inside the chords of the upper chord (1) and lower chord (2) of the arch rib that are aligned with the bearing plate (16). Bearing plate stiffening ribs (18) are welded between the upper chord (1) of the arch rib and the bearing plate (16). Bearing plate stiffening ribs (18) are welded between the lower chord (2) of the arch rib and the bearing plate (16); circumferential sealing steel belts (19) are welded around the bearing plate (16). Rubber water stop strips (20) are pasted on the inner walls of the circumferential sealing steel belts (19) between the circumferential sealing steel belts (19) of the upper chord (1) and lower chord (2) of the arch rib. One end of the post-cast hinge-sealing section concrete (22) of the arch seat is connected to the pre-cast section concrete (21) of the arch seat, and the other end is connected to the bearing plate (16) to form an integral body. Vertical lower-arch suspenders (24) are provided between the lower chord (2) of the arch rib and the carriageway main girder (23); vertical upper-arch columns (25) are provided between the upper chord (1) of the arch rib and the carriageway main girder (23).

2. The structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking according to claim 1, characterized in that: Cross braces (11) are horizontally welded between adjacent upper chords (1) of the arch rib.

3. The structure for preventing the concrete outside the steel pipe at the arch foot of a concrete-filled steel tube arch bridge from cracking according to claim 1, characterized in that: Hinge base (9) is embedded in the pre-cast section concrete (21) of the arch seat.

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