River-crossing continuous beam bridge dismantling construction method based on temporary supporting system

Abstract

The invention discloses a river-crossing continuous beam bridge dismantling construction method based on a temporary supporting system. The river-crossing continuous beam bridge dismantling construction method comprises the steps that S1, a main pier zero block is temporarily consolidated; s2, a temporary supporting system is erected below the side span box girder; s3, the side span box girder sections are dismantled, and the temporary supporting systems in the areas corresponding to the side span box girder sections are synchronously dismantled; s4, the main pier zero block is dismantled; s5, the main pier column, the side pier column, the bearing platform and the pile foundation are dismantled; the main pier zero block is temporarily solidified, a temporary supporting system is erected below the side span box girder, a powerful foundation is provided for safe and efficient dismantling of the girder bridge, the overall stability in the main bridge upper structure dismantling process is ensured, and the safety risk is reduced; in addition, the river-crossing continuous beam bridge dismantling construction method based on the temporary supporting system can reduce the influence of navigation channels to the maximum extent, and the beam bridge dismantling efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of river-crossing continuous beam bridge demolition construction, and particularly relates to a river-crossing continuous beam bridge demolition construction method based on a temporary support system. BACKGROUND

[0002] In order to improve the flood drainage capacity of inland waterways and adapt to the standards of corresponding waterway upgrading and reconstruction, most existing overpass bridges in the waterways need to be demolished and reconstructed. The traditional bridge demolition method is to blast in place and salvage and clean the debris in water, which has a long closure time and affects the existing traffic of roads and bridges. Meanwhile, if there is any omission in the debris cleaning, passing ships are prone to collision risks, which seriously affects the safety of waterway navigation. SUMMARY

[0003] The present application aims to solve the problems in the prior art that the beam bridge demolition construction has a large impact on the navigable waterway, the beam bridge demolition efficiency is low, and the safety risk is large, and provides a river-crossing continuous beam bridge demolition construction method based on a temporary support system.

[0004] The present application solves the above technical problems by the following technical scheme:

[0005] A river-crossing continuous beam bridge demolition construction method based on a temporary support system, comprising the following steps:

[0006] S1. Temporary consolidation of the No. 0 block of the main pier;

[0007] S2. Temporary support system is erected under the side span box girder;

[0008] S3. Demolish the side span box girder segment, and simultaneously remove the temporary support system in the corresponding area of the side span box girder segment;

[0009] S4. Demolish the No. 0 block of the main pier;

[0010] S5. Demolish the main pier column, side pier column, pile cap and pile foundation.

[0011] In the present application, the temporary consolidation of the No. 0 block of the main pier and the erection of the temporary support system under the side span box girder provide a strong foundation for safe and efficient demolition of the beam bridge, ensure the overall stability during the demolition process of the superstructure of the main bridge, and reduce the safety risk. In addition, the river-crossing continuous beam bridge demolition construction method based on the temporary support system can minimize the impact on the navigable waterway, and has high beam bridge demolition efficiency.

[0012] Preferably, the main pier column and the pile cap are sequentially arranged below the No. 0 block of the main pier, the pile cap is used to support the main pier column, and the main pier column is used to support the No. 0 block of the main pier. In step S1, the following step is further included:

[0013] S1.1. Pour grouting material around the support to fill and compact;

[0014] S1.2. Steel corbels are arranged on both sides of the support at the top of the main pier column to resist overturning.

[0015] In the scheme, the four sides of the support are filled with grouting material to ensure the strength and stability of the main pier as a whole, thereby providing a stable foundation for the removal of the beam bridge and the No. 0 block of the main pier.

[0016] Preferably, the temporary support system comprises a first temporary support system and a second temporary support system;

[0017] In step S2, the following steps are further included:

[0018] S2.1. The first temporary support system is arranged in water;

[0019] S2.2. The second temporary support system is arranged on land on the shore.

[0020] In the scheme, the above arrangement meets the needs of water and land use, and has the characteristics of high safety, detachability and reusability, and significant economic benefits.

[0021] Preferably, the first temporary support system comprises a temporary support pier, a first steel support, a first cushion block, a distribution beam, and a Bailey frame;

[0022] In step S2.1, the following steps are further included:

[0023] S2.1.1. The temporary support pier is arranged in water, and the pile foundation has a soil penetration depth of not less than 13.5m;

[0024] S2.1.2. The temporary support pier and the top surface of the pile cap are both provided with a distribution beam;

[0025] S2.1.3. A plurality of rows of Bailey frames are arranged above the distribution beam;

[0026] S2.1.4. A plurality of distribution beams are further arranged on the top of the plurality of rows of Bailey frames;

[0027] S2.1.5. A first steel support is arranged above each distribution beam;

[0028] S2.1.6. A first cushion block is used to press against the side span box girder at the top of each steel support.

[0029] In the scheme, the temporary support is arranged in water, and the pile foundation has a depth of not less than 13.5 m in soil, so that the temporary support is stably fixed in water; the arrangement of the distribution beam, the Bailey frame, the first steel support and the cushion block is for stably supporting the upper part of the beam bridge by the first temporary support system, so that the beam bridge segments can be safely removed; the arrangement of the cushion block ensures that the support is compact, so that the box girder on both sides of the main pier is prevented from rotating or moving greatly after the middle span closure segment of the box girder is disconnected.

[0030] Preferably, the first steel support comprises first section steel and first channel steel.

[0031] In step S2.1.5.1, the first section steel is arranged transversely at the web position of the side span box girder and longitudinally according to the cutting line position of the side span box girder.

[0032] S2.1.5.1. The first section steel is arranged transversely at the web position of the side span box girder and longitudinally according to the cutting line position of the side span box girder.

[0033] S2.1.5.2. The first section steel is connected by the first channel steel as a transverse connecting rod.

[0034] In the scheme, the arrangement and connection of the first section steel and the first channel steel stably support the upper part of the beam bridge by the first steel support; the first section steel is connected by the first channel steel as a transverse connecting rod to ensure the stability of the support system as a whole.

[0035] Preferably, the second temporary support system comprises a cast-in-situ reinforced concrete strip foundation, second steel supports and second cushion blocks.

[0036] In step S2.2.1, the cast-in-situ reinforced concrete strip foundation is arranged on the land on the bank.

[0037] S2.2.1. The cast-in-situ reinforced concrete strip foundation is arranged on the land on the bank.

[0038] S2.2.2. A plurality of second steel supports are arranged on the cast-in-situ reinforced concrete strip foundation.

[0039] S2.2.3. The top of each second steel support is tightly pressed against the side span box girder by a second cushion block.

[0040] In the scheme, the arrangement of the cast-in-situ reinforced concrete strip foundation, the second steel supports and the second cushion blocks stably supports the side span box girder of the beam bridge close to the land by the second temporary support system; the arrangement of the second cushion block ensures that the support is compact, so that the box girder on both sides of the main pier is prevented from rotating or moving greatly after the middle span closure segment of the box girder is disconnected.

[0041] Preferably, the second steel support comprises second section steel and second channel steel.

[0042] In step S2.2.1, the cast-in-situ reinforced concrete strip foundation is arranged on the land on the bank.

[0043] S2.2.1.1. The cast-in-place reinforced concrete strip foundation is made of concrete with a strength of not less than 30 N / mm2, a thickness of not less than 45 cm, and a width of not less than 2.7 m;

[0044] S2.2.1.2. The second type steel is arranged transversely at the web position of the side span box girder and longitudinally according to the cutting line position of the side span box girder;

[0045] S2.2.1.3. The second type steel is arranged transversely at the web position of the side span box girder and longitudinally according to the cutting line position of the side span box girder;

[0046] In the scheme, the above arrangement further stably supports the side span box girder of the beam bridge close to the land by the second temporary support system.

[0047] Preferably, step S3 further comprises the following steps:

[0048] S3.1. Breaking the pavement layer, removing the fender wall and the flange plate, and cutting and removing the midspan closure section;

[0049] S3.2. Cutting and removing the side span box girder section, and the cutting position needs to be shifted by 0.5 m at the original connection position of the side span box girder section;

[0050] S3.2. Simultaneously removing the side span box girder section and the midspan box girder section, and the removal speed of the side span box girder section is slower than that of the midspan box girder section;

[0051] S3.3. After the side span box girder section is removed, the temporary support structure under the corresponding area is simultaneously removed by using a crawler crane;

[0052] Preferably, step S3.2 further comprises the following steps:

[0053] S3.2.1. The side span box girder section is sequentially lifted by a crawler crane to a height of more than 1.5 m above the original beam bridge deck, and after confirming that the site is correct, the side span box girder section is moved to the land on the shore. At the same time of removing the side span box girder section, the midspan box girder section is cut and removed by using a floating crane, and then is hoisted and transported to the land on the shore for crushing.

[0054] In the scheme, the pavement layer is broken, the fender wall and the flange plate are removed, and the midspan closure section is cut and removed, so as to facilitate the removal of the side span box girder section and the midspan box girder section. The removal sequence of the side span is symmetrically performed from the side span to the direction of the main pier, and the removal sequence of the midspan is symmetrically performed from the midspan closure section to the direction of the two side main piers. The removal speed of the side span box girder section is slower than that of the midspan box girder section, so that two box girder sections of the side span are reserved as counterweights to ensure the overall stability of the main bridge box girder during the removal process.

[0055] In addition, the box girder segments of each side span are hoisted by crawler cranes, the box girder segments of each mid span are hoisted by floating cranes to a height of 1.5 m above the original bridge deck, and then the box girder segments of each side span and mid span are moved to the land on the shore after confirming that the site is correct, so that the hoisting of the box girders to be removed is stable, the box girders will not sink into the water, the existing bridge structure will not be collided, the impact on the navigation channel is prevented, and safety is improved.

[0056] Preferably, step S4 further comprises the following steps:

[0057] S4.1. cutting the No. 0 block of the main pier into 5 segments along the direction of the bridge, and dividing the third segment into 4 parts along the cross section;

[0058] S4.2. symmetrically removing the parts of the No. 0 block of the main pier along the direction of the bridge;

[0059] S4.3. hoisting the parts of the No. 0 block of the main pier by a floating crane to a height of 1.5 m above the original bridge deck, and then moving the parts of the No. 0 block of the main pier to the land on the shore after confirming that the site is correct.

[0060] In the present scheme, the No. 0 block of the main pier is cut into 5 segments, divided into 4 parts along the cross section of the third segment, and symmetrically removed along the direction of the bridge, so that the removal is efficient, the imbalance of the two sides during the removal of the No. 0 block of the main pier is avoided, the hoisting load is relatively reduced, safety and economy are improved.

[0061] In addition, the parts of the No. 0 block of the main pier are moved to the land on the shore by a 150-ton floating crane, which is safe, efficient, and has less impact on the normal navigation of the navigation channel.

[0062] Preferably, step S6 further comprises the following steps:

[0063] S5.1. the cutting and removal of the main pier column is performed by hoisting with a floating crane;

[0064] S5.2. the cutting and removal of the side pier column is performed by hoisting with a crawler crane;

[0065] S5.3. a Larsen steel sheet pile is erected for dredging on the side of the pile foundation close to the land on the shore, a steel enclosing purlin is arranged on the top of the Larsen steel sheet pile, at least 2 anchor piles are erected on the shore, and a steel reinforcing bar is connected with the steel enclosing purlin to enhance the rigidity of the steel enclosing purlin;

[0066] S5.4. the pile cap and pile foundation are cut into blocks by underwater rope sawing by divers, and then hoisted to the land on the shore by a floating crane for crushing treatment.

[0067] In the scheme, the setting of the Larson steel plate, the steel encloses the purlin and the anchor pile makes the pile foundation has high demolition efficiency and high safety; in addition, the pile cap and the pile foundation are cut into blocks by the diver under water, and then are all hoisted to the land on the shore by the floating crane for crushing treatment, which can further improve the demolition efficiency and reduce the influence on the navigation channel.

[0068] The positive progress effect of the application is that the temporary consolidation of the main pier zero block and the erection of the temporary support system under the side span box girder provide a strong foundation for safe and efficient demolition of the beam bridge, ensure the overall stability in the process of the main bridge superstructure demolition and reduce the safety risk; in addition, the river-crossing continuous beam bridge demolition construction method based on the temporary support system can minimize the influence on the navigation channel, and the beam bridge has high demolition efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0069] Figure 1 It is the front view of the beam bridge of an embodiment of the application.

[0070] Figure 2 It is the front view of the temporary support system of an embodiment of the application.

[0071] Figure 3 It is the cross-sectional view of the temporary support system of an embodiment of the application.

[0072] Figure 4 It is another cross-sectional view of the temporary support system of an embodiment of the application.

[0073] Figure 5 It is another cross-sectional view of the temporary support system of an embodiment of the application.

[0074] Figure 6 It is the plan view of the temporary support system of an embodiment of the application.

[0075] Figure 7 It is the cross-sectional view of the second temporary support system of an embodiment of the application.

[0076] Figure 8 It is the front view of the main pier of an embodiment of the application.

[0077] Figure 9 It is the cross-sectional view of the main pier of an embodiment of the application.

[0078] Figure 10 It is the cutting position diagram of the side span box girder of an embodiment of the application.

[0079] Figure 11 It is the structure schematic diagram of the crawler crane hoisting of an embodiment of the application.

[0080] Figure 12 It is the cutting block diagram of the main pier zero block of an embodiment of the application.

[0081] Figure 13 Cutting (third segment) block diagram of the main pier zero block of an embodiment of the present application.

[0082] Figure 14 Cutting block plan view of the pile cap of an embodiment of the present application.

[0083] Figure 15 Structural diagram of the pile foundation of the pile cap of an embodiment of the present application.

[0084] Figure 16 Schematic diagram of the pile foundation extraction process of an embodiment of the present application.

[0085] Figure 17 Construction method for the removal of a river-crossing continuous girder bridge based on a temporary support system of an embodiment of the present application.

[0086] Explanation of reference numerals:

[0087] Girder bridge 100

[0088] Main pier zero block 1

[0089] Side span box girder segment 2

[0090] Anti-collision wall 21

[0091] Flange plate 22

[0092] Middle span box girder segment 3

[0093] Main pier column 4

[0094] Side pier column 5 Pile cap 6

[0095] Pile foundation 7

[0096] First temporary support system 8

[0097] Temporary support pier 81

[0098] First steel support 82

[0099] First cushion block 83

[0100] Bailey truss 84

[0101] Larsen steel sheet pile 85

[0102] Steel corbel anti-overturning device 86

[0103] Distribution beam 87

[0104] Support 88

[0105] Second temporary support system 9

[0106] Cast-in-place reinforced concrete strip foundation 91

[0107] Second steel support 92

[0108] Second cushion block 93

[0109] Crawler crane 10 DETAILED DESCRIPTION

[0110] The application will be further described by way of examples without thereby limiting the application to the examples.

[0111] As Figures 1-17 shown, in the embodiment, a temporary support system-based continuous girder bridge 100 across river demolition construction method is provided, which comprises the steps of: S1. temporary consolidation of the main pier zero block 1; S2. erection of a temporary support system under the side span box girder; S3. removal of the side span box girder segment 2, and synchronous removal of the temporary support system in the corresponding area of the side span box girder segment; S4. removal of the main pier zero block 1; S5. removal of the main pier column 4, the side pier column 5, the pile cap 6 and the pile foundation 7.

[0112] In the embodiment, the temporary consolidation of the main pier zero block 1 and the erection of the temporary support system under the side span box girder provide a strong foundation for safe and efficient demolition of the girder bridge 100, ensure the overall stability during the removal of the superstructure of the main bridge, and reduce the safety risk; in addition, the temporary support system-based continuous girder bridge 100 across river demolition construction method can minimize the impact on the navigation channel, and the girder bridge 100 has high demolition efficiency.

[0113] It should be noted that in the removal process of S3, the midspan box girder segment is also removed.

[0114] As Figure 2 shown, the main pier column 4 and the pile cap 6 are sequentially arranged below the main pier zero block 1, the pile cap 6 is used to support the main pier column 4, and the main pier column 4 is used to support the main pier zero block 1, and the step S1 further comprises the steps of:

[0115] S1.1. pouring grouting material around the support 88 to fill and compact;

[0116] S1.2. arranging a steel corbel anti-overturning device 86 on both sides of the support 88 at the top of the main pier column 4.

[0117] In the embodiment, by pouring grouting material around the support 88 to fill and compact and arranging a steel corbel anti-overturning device 86 on both sides of the support 88 at the top of the main pier column 4, the overall strength and stability of the main pier are ensured to provide a stable foundation for the removal of the main pier zero block 1 and other structures in the girder bridge 100.

[0118] It should be noted that the main pier top of the main pier zero block 1 is temporarily consolidated, as Figures 8-9The space between the top of the main pier and the main bridge box girder (around the support 88, about 24 cm high) is filled with high-strength grouting material before cutting and removing. Before pouring the high-strength grouting material, the pier top surface concrete around the support 88 is chiseled and then cleaned with a high-pressure water gun. To ensure the overall stability of the main pier zero block 1 during the removal process, temporary anti-overturning steel brackets are set up on both sides of the support 88 at the bottom of the main pier top box girder. The steel brackets are made of Q235b steel and are connected and fixed between the box girder and the pier body using M30 chemical bolt dowel.

[0119] As shown in Figure 2 The temporary support system includes a first temporary support system 8 and a second temporary support system 9. In step S2, it also includes steps S2.1. The first temporary support system 8 is set in water; S2.2. The second temporary support system 9 is set on the land on the shore.

[0120] In this embodiment, the above arrangement meets the water and land requirements, has the characteristics of high safety, can be dismantled and reused, and has significant economic benefits.

[0121] It should be noted that the first temporary support system 8 is a full steel pipe support system on the land area, and the second temporary support system 9 is a temporary pier system in the water area, which is arranged in two spans and three piers. The lower structure of the side pier and the middle pier near the shore side uses a channel steel pile foundation, and the pile foundation has a soil penetration depth of not less than 13.5m. The side pier near the main pier directly uses the old bridge main pier pile cap 6 foundation to build the temporary pier system in the water area.

[0122] As shown in Figure 2 The first temporary support system 8 includes a temporary pier 81, a first steel support 82, a first pad 83, a distribution beam 87, and a Bailey frame 84.

[0123] In step S2.1, it also includes steps S2.1.1. The temporary pier 81 is set in water, and the pile foundation has a soil penetration depth of not less than 13.5m; S2.1.2. The top of the temporary pier 81 and the top surface of the pile cap 6 are both provided with a distribution beam 87; S2.1.3. A plurality of rows of Bailey frames 84 are arranged above the distribution beam 87; S2.1.4. A plurality of distribution beams 87 are arranged on the top of the plurality of rows of Bailey frames 84; S2.1.5. A first steel support 82 is arranged above each distribution beam 87; S2.1.6. The first pad 83 is used to top the first steel support 82 between the top of each steel support and the side span box girder.

[0124] In the embodiment, the temporary support pier 81 is arranged in water, and the pile foundation has a depth of not less than 13.5 m, so that the temporary support pier 81 is stably fixed in water; the distribution beam 87, the Bailey frame 84, the first steel support 82 and the cushion block are arranged to enable the first temporary support system 8 to stably support the upper part of the beam bridge 100, so as to stably and safely remove the box girder segments of the side span of the beam bridge 100; wherein the arrangement of the first cushion block 83 ensures that the support is compact, so as to prevent the box girders on both sides of the main pier from rotating or moving greatly after the midspan closure segment of the box girder is disconnected.

[0125] It should be noted that the temporary support pier 81 includes side piers and middle piers close to the bank, and the lower structures of the side piers and the middle piers adopt the structure of the channel steel pile foundation 7 plus the double-layer double-spliced I-shaped steel distribution beam 87, and the channel steel pile foundation 7 has a depth of not less than 13.5 m; in addition, the first cushion block 83 adopts a wedge-shaped steel cushion block, and preferably, the first steel support 82 includes first section steels and first channel steels.

[0126] As shown in FIG. 2, the first type steel is arranged in the position of the web of the side span box girder in a transverse direction and is arranged according to the cutting line position of the side span box girder in a longitudinal direction. Figure 2 As shown in FIG. 2, the first type steel is arranged in the position of the web of the side span box girder in a transverse direction and is arranged according to the cutting line position of the side span box girder in a longitudinal direction.

[0127] In the embodiment, the arrangement mode and the connection mode of the first type steel and the first channel steel enable the first steel support 82 to stably support the upper part of the beam bridge 100; wherein the first channel steel is used as a transverse connecting rod between the first type steels.

[0128] It should be noted that the first type steel adopts a φ609×16 mm type steel, and the first channel steel adopts a 16a channel steel (the “16” represents that the nominal height of the channel steel is 160 mm, and the “a” represents the model number); in addition, the bottom of the box girder close to the main pier has a large inclination angle, the corresponding bottom of the box girder at the corresponding position of the arrangement of the first steel support 82 is planted with a steel bar and welded with a steel plate, and then fine stone micro-expansion concrete is poured to flatten the compression surface, so as to ensure that the support is compact, the stress is stable, and the safety of the temporary support system is improved.

[0129] In addition, the upper part of the temporary support pier 81 adopts a single-layer reinforced Bailey frame 84 (height 1.5 m), 6 rows of Bailey frames 84 are arranged at the top of each φ609 temporary type steel support, and a double-spliced 70# I-shaped steel distribution beam 87 is further arranged at the top of the Bailey frame 84.

[0130] The top surface of the old bridge pile cap 6 is provided with a structure of 3 φ609 type steel columns plus a double-spliced 70# I-shaped steel distribution beam 87.

[0131] As shown in FIG. 2, the first type steel is arranged in the position of the web of the side span box girder in a transverse direction and is arranged according to the cutting line position of the side span box girder in a longitudinal direction. Figure 2As shown, the second temporary support system 9 includes a cast-in-situ reinforced concrete strip foundation 91, second steel supports 92 and second pads 93; in step S2.2, further including steps: S2.2.1. The cast-in-situ reinforced concrete strip foundation 91 is arranged on the land on the bank; S2.2.2. A plurality of second steel supports 92 are arranged on the cast-in-situ reinforced concrete strip foundation 91; S2.2.3. The top of each second steel support 92 is tightly pressed against the side span box girder by a second pad 93.

[0132] In the present embodiment, the above-mentioned arrangement of the cast-in-situ reinforced concrete strip foundation 91, the second steel supports 92 and the second pads 93 enables the second temporary support system 9 to stably support the side span box girder of the beam bridge 100 close to the land; wherein the arrangement of the second pads 93 ensures that the support can be compact.

[0133] It should be noted that the steel bars in the cast-in-situ reinforced concrete strip foundation 91 are made of HRB400, with a diameter of 14mm and a two-way reinforcement of 200mm, and a steel bar protection layer thickness of 40mm; in addition, in addition to the cast-in-situ reinforced concrete strip foundation 91, other components are fabricated components, which are convenient and fast to assemble and disassemble, and the components can be reused, with significant economic benefits.

[0134] In addition, it should be noted that the first steel is φ609×16mm steel, and the first channel steel is 16a channel steel (“16” represents the nominal height of the channel steel is 160mm, and “a” represents the model); in addition, the first pad 83 is a wedge-shaped steel pad.

[0135] As shown in Figure 2 the second steel supports 92 include second steel and second channel steel; in step S2.2.1, further including steps: S2.2.1.1. The cast-in-situ reinforced concrete strip foundation 91 is made of concrete with a strength not less than 30N / mm², a thickness not less than 45cm and a width not less than 2.7m; S2.2.1.2. The second steel is arranged transversely at the web position of the side span box girder and longitudinally according to the cutting line position of the side span box girder; S2.2.1.3. The second steel is connected by the second channel steel as a transverse connecting rod.

[0136] In the present embodiment, the above-mentioned arrangement further enables the second temporary support system 9 to stably support the side span box girder of the beam bridge 100 close to the land.

[0137] It should be noted that the second steel is φ609×16mm steel, and the second channel steel is 16a channel steel (“16” represents the nominal height of the channel steel is 160mm, and “a” represents the model).

[0138] As shown in Figure 3 in step S3, further including steps: S3.1. Breaking the pavement layer, removing the fender wall 21 and the flange plate 22, and cutting and removing the midspan closure section;

[0139] S3.2. Cutting and removing the side span box girder segments 2, the cutting position should be 0.5m away from the original connection of the side span box girder segments 2;

[0140] S3.3. After the side span box girder segments are removed, the temporary support structure under the corresponding area is removed synchronously by using the crawler crane.

[0141] Preferably, in step S3.2, the step of S3.2.1. is further included: using the crawler crane to hoist each side span box girder segment 2 to a height of 1.5m above the original bridge deck 1 of the original bridge 100, and then moving each side span box girder segment 2 to the land on the shore after confirming that the site is correct; while the side span box girder segments are removed, the middle span box girder segments are cut and removed by using the floating crane, and then hoisted and transported to the land on the shore for crushing.

[0142] In the embodiment, the pavement layer is first broken, the fender wall 21 and the flange plate 22 are removed, and the middle span closure segment is cut and removed, so as to facilitate the removal of the side span box girder segments 2 and the middle span box girder segments 3; the removal sequence of the side span box girder segments 2 is symmetrically performed from the side span to the direction of the main pier, the removal sequence of the middle span is symmetrically performed from the middle span closure segment to the direction of the two main piers, and the removal speed of the side span box girder segments 2 is slower than that of the middle span box girder segments 3, so that two box girder segments are reserved as counterweights in the side span, and the overall stability of the main bridge box girder in the removal process is ensured.

[0143] In addition, each side span box girder segment 2 and middle span box girder segment 3 is hoisted to a height of 1.5m above the original bridge deck 1 of the original bridge 100 by using the crawler crane 10 and the floating crane respectively, and then moved to the land on the shore after confirming that the site is correct, which makes the removed box girders not sink into the water, not collide with the existing bridge structure, prevents affecting the navigation channel, and is relatively safe.

[0144] In the removal process of S3.2, the side span box girder segments 2 and the middle span box girder segments 3 are removed synchronously, and the removal speed of the side span box girder segments 2 is slower than that of the middle span box girder segments 3.

[0145] It should be noted that the steps of the embodiment are as follows: pre-step: breaking the pavement layer (not shown in the figure); removing the fender wall 21 and the flange plate 22; and cutting and removing the middle span closure segment.

[0146] Cutting step: the cutting position of the box girder should be 0.5m away from the original connection of the box girder segments, avoiding the segment connection; for example, Figure 2, the red line is the original segment connection line position, and the blue line is the cutting line; if a transverse bridge deck is wide, it can be cut multiple times along the transverse bridge; specifically: the existing box girder is cut and segmented according to the new box girder segment, and since the interface of the old bridge box girder segment is segmented pouring has longitudinal prestressed anchor cable, in order to prevent the anchor from being damaged during the process of cutting and removing the concrete, thereby causing the prestress of the other box girder segments behind to fail, the box girder removal cutting section is shifted by 0.5m on both sides of the original box girder segment interface, and paint is used to mark the cutting line on the beam body, as shown in Figure 2 and Figure 10 , the blue line is the cutting line.

[0147] Removal direction: symmetrically removed from the side span to the main pier direction; in order to ensure the overall stability of the continuous girder bridge 100, the side span box girder segment 2 and the midspan box girder segment 3 are removed synchronously, during the process, according to the operation arrangement, when the operation involving the synchronous removal of the midspan box girder segment 3 is involved, the full-section intermittent temporary navigation is implemented; when the gap traffic control is implemented, the maritime department is assisted to guide the passing ships to enter the temporary berthing area. After the traffic control is lifted, the stranded ships are dredged under the guidance of the maritime department. In order to reasonably alleviate the influence of single navigation closure on passing ships, the specific time of single navigation closure is preferably after 8am, the single navigation closure time is <=8h (the daily navigation closure time is proposed according to the maritime department), and the construction process is optimized to shorten the single navigation closure time as much as possible. For only the side span box girder segment 2 removal operation, there is no influence on the navigation channel, and the navigation is normal.

[0148] Hoisting steps: one 250-ton crawler crane 10 is used to hoist, which is stopped in the side span, the beam car is stopped on the main bridge outside the construction road, after the box girder segment cutting is completed, the crawler crane 10 slowly lifts the box girder segment to the bottom which is 1.5m higher than the original bridge deck by using the special lifting frame, and confirms that the site is correct. The crawler crane 10 rotates the rod and places the box girder segment on the beam car, then loosens the hook, and then prepares for the next box girder segment cutting and removal. After the box girder segment is removed, the temporary support structure under the corresponding segment can be removed. In order to ensure the overall stability during the removal of the main span superstructure, the progress of the side span box girder cutting and removal is always slower than that of the two midspan segments.

[0149] As shown in Figures 15-17 , in step S4, it further includes steps: S4.1. cutting the main pier zero block 1 (as shown in Figures 12-13 ) into 5 segments along the direction of the girder bridge 100, and further dividing the third segment (pier top solid block 0-3#, see Figures 12-13 ) into 4 parts along the cross section; S4.2. symmetrically removing each part of the main pier zero block 1 along the direction of the girder bridge 100; S4.3. lifting each part of the main pier zero block 1 to more than 1.5m above the original girder bridge 100 bridge deck by using a floating crane, and confirming that the site is correct before moving each part of the main pier zero block 1 to the shore land.

[0150] In the embodiment, the main pier No. 1 block is cut into five segments, as shown in Figure 12 ; the cross section of the third segment is further divided into four parts, as shown in Figure 13 ; and the parts of the main pier No. 1 block are symmetrically removed along the direction of the beam bridge 100. The removal method is efficient, and does not cause imbalance of the two sides during the removal of the main pier No. 1 block, reduces the lifting load, is relatively safe and economical.

[0151] In addition, the parts of the main pier No. 1 block are moved to the land on the shore by using a 150-ton floating crane, which is relatively safe, efficient, and has less impact on the normal navigation of the navigation channel.

[0152] It should be noted that when the main pier No. 1 block is removed, a 150-ton floating crane is used. When the main pier No. 1 block is cut and removed, the removal is symmetrically performed in the bridge direction, and is alternately performed in sequence, as shown in Figures 12-13 ; when lifting, the floating crane slowly lifts the box girder segment to a height of more than 1.5 m above the original bridge deck, and then moves the box girder segment to the land on the shore after confirming that the site is correct, and then loosens the lifting hook. Then, the next concrete structure cutting and lifting is prepared, or the floating crane is parked on the shore, which does not affect the normal navigation of the navigation channel, as shown in Figure 10 , and the red line is the block line.

[0153] As shown in Figure 11 , in step S6, the steps further include: S5.1. The cutting and removal of the main pier column 4 is performed by using a floating crane for lifting; S5.2. The cutting and removal of the side pier column 5 is performed by using a crawler crane 10 for lifting; S5.3. A Larsen steel sheet pile 85 is erected on the side of the pile foundation 7 close to the land on the shore for dredging, a steel enclosing purlin is arranged on the top of the Larsen steel sheet pile 85, at least two anchor piles are arranged on the shore, and a steel reinforcing bar is connected with the steel enclosing purlin to enhance the rigidity of the steel enclosing purlin; and S5.4. The pile foundation 7 and the pile cap 6 are cut and divided into blocks by using a diver for underwater rope saw cutting, and then are lifted to the land on the shore by using a floating crane for crushing treatment.

[0154] In the embodiment, the arrangement of the Larsen steel sheet pile, the steel enclosing purlin and the anchor pile makes the removal of the pile foundation 7 efficient and safe; in addition, the pile cap 6 and the pile foundation 7 are cut and divided into blocks by using a diver for underwater rope saw cutting, and then are lifted to the land on the shore by using a floating crane for crushing treatment, which can further improve the removal efficiency and reduce the impact on the navigation channel.

[0155] It should be noted that after the superstructure removal task is completed, the lower structure removal construction of the pier column, the pile cap 6 and the pile foundation 7 can be performed, and the removal range is 2 m below the planned riverbed.

[0156] The main pier column 4 is cut by using a static cutting device, the main pier column 4 is cut and removed by using a 150t floating crane for hoisting, the side pier column 5 is cut and removed by using a 250t crawler crane 10 for hoisting, and the specific cutting blocks of the pier column are distributed according to the hoisting capacity of the hoisting device, for example, the main pier column 4 is divided into five segments, and the side pier column 5 is divided into three segments.

[0157] The main pier pile cap 6 is cut and divided into blocks by a diver using a rope saw underwater, and the cutting and dividing into blocks are as shown in Figure 14 (blue line is the cutting line position), and a 150t floating crane is used for single machine hoisting removal. The pile cap 6 is removed in the order of "central separation zone to the side of the bridge". Before each cutting block is cut off from the lower pile foundation 7, a steel wire rope is passed through the hoisting hole, and a floating crane is used to hold and bear the force. After cutting is completed, the cut concrete blocks are hoisted and moved to the shore by the floating crane, and are crushed on site.

[0158] In order to facilitate the cutting of the pile cap 6 and the bottom pile foundation 7 by the diver, dredging is performed around the main pier pile cap 6 and the bottom before cutting. Long-arm excavators are mainly used for dredging, and a few long-arm excavators that cannot dredge to the position are dredged by using a shovel dredger, and long-arm excavators, mud pumps and related equipment are arranged on the shore to unload the sludge and mud. The sludge and mud are dried by a mud drying device and then transported out.

[0159] As shown in Figures 14-17 , in order to facilitate the cutting of the pile foundation 7 at the bottom of the pile cap 6 by the diver, dredging is required to 1.5m below the ground surface of the pile cap 6, the bottom elevation of the pile cap 6 is -2.80m, and the bottom of the pile cap 6 needs to be dredged to the elevation of -4.30m. According to the requirements, the old bridge water pile foundation 7 is cut off to 0.5m below the present mud surface or 2.0m below the planned river bottom (i.e. -5.26m elevation), and the lower elevation value is taken, the pile foundation 7 needs to be cut to -5.26m, so the pile foundation 7 needs to be dredged to the elevation of -5.76m. The pile cap 6 removal dredging elevation and the pile foundation 7 removal elevation are close, so the pile cap 6 and the pile foundation 7 are considered to be removed together, so the dredging needs to be to the elevation of -5.76m.

[0160] According to the actual situation on site, the main pier dredging depth is large, and a Larsen steel sheet pile 85 (type IV, cross-sectional size is 400x170x15.5mm, pile length is 18m, and pile bottom elevation is -16.30m) foundation pit support is set on the side of the river channel shore. During dredging construction, the dredging is first performed to the top surface elevation of the pile cap 6 (i.e. -0.300m, as shown in Figure 15), the slope coefficient of the mud surface on the bank is 1:3; then the Larsen steel sheet pile 85 is set; finally, the bottom surface of the pile cap 6 and the surrounding area are dredged to the elevation -5.76 m, and the slope coefficient of the mud surface near the channel side is 1:2. A steel bracing purlin is arranged on the top of the steel sheet pile, two anchor piles (type IV Larsen steel sheet pile 85, pile length 12 m) are arranged on the bank, and the steel bracing purlin is pulled with a φ25 steel bar to strengthen the rigidity of the bracing purlin. The monitoring of the steel sheet pile support is strengthened during the construction process to ensure the safety of the construction.

[0161] Cutting and pile pulling: a φ2000x14mm large-diameter steel casing is set, and the length of the steel casing is 10 m. The steel casing is sunk by a 250t crawler crane 10 on the bank lifting an ICE hydraulic hammer. After the steel casing is set in place, the soil outside the pile in the casing is flushed into mud slurry by a high-pressure water jet device. After the mud slurry in the steel casing is pumped out by a mud pump, personnel enter the steel casing to cut the pipe pile at the corresponding position, such as Figure 16 . The pile section after cutting is lifted out by a 250t crawler crane 10. After the pile section 7 is lifted out, the steel casing is pulled out by an ICE hydraulic hammer.

[0162] Cutting and pulling of the side pier pile cap 6 and the pile foundation 7: if the old bridge pier conflicts with the new bridge pile cap 6, the pile cap 6 and the pile foundation 7 are removed; if there is no conflict, no treatment is needed.

[0163] The conflict side pier pile cap 6 is removed by impact pick + air pick breaking, and excavated by the excavator to the designated location. Before the pile cap 6 is removed, the steel sheet pile is set around the pile cap 6 to ensure the safety of the pile cap 6 foundation pit. The conflict side pier pile foundation 7 needs to be pulled out. The treatment is similar to that of the main pier pile foundation 7. A large-diameter steel casing is set, the depth of the steel casing is greater than the pile penetration depth, then the soil in the casing is flushed into mud slurry by a high-pressure water jet device, the mud slurry around the pile is pumped out, the side friction of the pile is greatly reduced, the pile foundation 7 is pulled out by a lifting device, the cavity is filled with mud slurry mixed with 10% cement after the pile foundation 7 is pulled out, and then the steel casing is pulled out.

[0164] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship of the device or element in the normal use, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element must have a specific orientation at any time, be constructed and operated in a specific orientation, therefore it cannot be understood as a limitation on the present application in this respect.

[0165] Although the specific embodiments of the present application have been described above, it is understood by those skilled in the art that the present application is only illustrated by way of example, and the scope of protection of the present application is defined by the appended claims. Those skilled in the art can make various changes or modifications to the embodiments without departing from the principles and essence of the present application, and such changes and modifications fall within the scope of protection of the present application.

Claims

1. A method for dismantling a continuous beam bridge across a river based on a temporary support system, characterized in that, It includes the following steps: S1. Temporary consolidation of the zero block of the main pier; S2. A temporary support system is erected under the side span box girder; S3. Dismantle the side span box girder segments and simultaneously remove the temporary support system in the corresponding areas of the side span box girder segments; S4. Demolish block number zero of the main pier; S5. Demolish the main pier columns, side pier columns, pile caps and pile foundations.

2. The method for dismantling a continuous beam bridge across a river based on a temporary support system as described in claim 1, characterized in that, The main pier column and the pier cap are sequentially arranged below the zero block of the main pier. The pier cap is used to support the main pier column, and the main pier column is used to support the zero block of the main pier. Step S1 also includes the following step: S1.

1. Grouting material is poured around the support at the top of the main pier column to fill it densely; S1.

2. Steel bracket anti-overturning devices are installed on both sides of the support at the top of the main pier column.

3. The method for dismantling a continuous beam bridge across a river based on a temporary support system as described in claim 1, characterized in that, The temporary support system includes a first temporary support system and a second temporary support system; Step S2 further includes the following step: S2.

1. The first temporary support system is installed in water; S2.

2. The second temporary support system is set up on land on shore.

4. The method for dismantling a continuous beam bridge across a river based on a temporary support system as described in claim 3, characterized in that, The first temporary support system includes temporary piers, a first steel support, a first pad block, a distribution beam, and a Bailey bridge; Step S2.1 further includes the following step: S2.1.

1. The temporary support is set in water, and its pile foundation is inserted into the soil at a depth of not less than 13.5m; S2.1.

2. The distribution beam is provided on the top of the temporary support and the top surface of the pier. S2.1.

3. Multiple rows of Bailey bridges are provided above the distribution beam; S2.1.

4. Multiple distribution beams are then installed on top of the multiple rows of Bailey bridges; S2.1.

5. The first steel support is provided above each of the aforementioned distribution beams; S2.1.

6. The top of each of the steel supports is secured to the side span box girder using the first pad block.

5. The method for dismantling a continuous beam bridge across a river based on a temporary support system as described in claim 4, characterized in that, The first steel support includes a first section steel and a first channel steel; Step S2.1.5 further includes the following step: S2.1.5.

1. The first type of steel is arranged laterally at the web position of the side span box girder, and longitudinally arranged according to the cutting line position of the side span box girder; S2.1.5.

2. The first channel steel is used as a transverse connecting member between the first steel sections.

6. The method for demolishing a continuous beam bridge across a river based on a temporary support system as described in claim 3, characterized in that, The second temporary support system includes a cast-in-place reinforced concrete strip foundation, a second steel support, and a second pad block; Step S2.2 further includes the following step: S2.2.

1. The cast-in-place reinforced concrete strip foundation is set on the land on the shore; S2.2.

2. Multiple second steel supports are installed on the cast-in-place reinforced concrete strip foundation; S2.2.

3. The top of each second steel support is secured to the side span box girder using the second pad block.

7. The method for demolishing a continuous beam bridge across a river based on a temporary support system as described in claim 6, characterized in that, The second steel support includes a second type of steel and a second channel steel; Step S2.2.1 further includes the following step: S2.2.1.

1. The cast-in-place reinforced concrete strip foundation shall be made of concrete with a strength of not less than 30 N / mm², a thickness of not less than 45 cm, and a width of not less than 2.7 m; S2.2.1.

2. The second type of steel is arranged laterally at the web position of the side span box girder, and longitudinally arranged according to the cutting line position of the side span box girder; S2.2.1.

3. The second channel steel is used as a transverse connecting member between the second type of steel.

8. The method for demolishing a continuous beam bridge across a river based on a temporary support system as described in claim 1, characterized in that, Step S3 further includes the following step: S3.

1. Remove the pavement layer, demolish the crash barrier and flange plates, and cut and demolish the mid-span closure section; S3.

2. Cut and remove the side span box girder segment. The cutting position must be shifted 0.5m from the original connection point of the side span box girder segment. S3.3 After the side span box girder segment is removed, the temporary support system below the corresponding area of ​​the side span box girder segment is simultaneously dismantled using a crawler crane; Preferably, step S3.2 further includes the step of: S3.2.

1. Using crawler cranes, each of the side span box girder segments is sequentially hoisted to a height of 1.5m above the original bridge deck. After confirming that the site is correct, each of the side span box girder segments is moved to the land on the shore. While the side span box girder segments are being dismantled, the middle span box girder segments are lifted by floating cranes and cut and dismantled, and then transported to the land on the shore for crushing.

9. The method for demolishing a continuous beam bridge across a river based on a temporary support system as described in claim 1, characterized in that, Step S4 further includes the following step: S4.

1. Along the direction of the beam bridge, cut the main pier block 0 into 5 segments, and then divide it into 4 parts along the cross section of the third segment; S4.

2. Along the direction of the beam bridge, symmetrically dismantle each part of the zero block of the main pier; S4.

3. Using a floating crane, lift each part of the main pier's zero block to a height of more than 1.5m above the original beam bridge deck. After confirming that there are no problems on site, move each part of the main pier's zero block to the land on the shore.

10. The method for demolishing a continuous beam bridge across a river based on a temporary support system as described in claim 9, characterized in that, Step S6 further includes the following step: S5.

1. The cutting and dismantling of the main pier column shall be carried out by a floating crane; S5.

2. The cutting and dismantling of the side pier columns shall be carried out by crawler crane; S5.

3. Larssen sheet piles are installed on the side of the pile foundation closest to the land shore for dredging. A steel waler is installed on the top of the Larssen sheet piles. At least two anchor piles are installed on the shore shore and reinforced with steel bars to strengthen the rigidity of the steel waler. S5.

4. The foundation and the pile foundation are cut into sections by divers using underwater wire saws, and then both are lifted to the shore by floating cranes for crushing.

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