Supporting structure of underwater pipe jacking working well and construction method

Abstract

The invention relates to a supporting structure of an underwater pipe jacking working well and a construction method. The supporting structure comprises a U-shaped backrest supporting structure arranged on the rear side of the pipe jacking working pit, soil retaining supporting structures arranged on the two sides of the pipe jacking working pit, a cofferdam arranged on the periphery of the pipe jacking working pit and a filling core arranged between the pipe jacking working pit and the cofferdam, and the cofferdam and the filling core are connected with a water area shoreline. The pipe jacking working pit, the U-shaped backrest supporting structure and the soil retaining supporting structure are symmetrically distributed on the two sides of the center line of the pipe jacking, the width of the filling core on the rear side of the U-shaped backrest supporting structure is two times of the depth of the pipe jacking working pit, and the width of the filling cores on the two sides of the pipe jacking working pit is 2 m. The supporting structure of the underwater pipe-jacking working well is adopted, the waterproof effect, safety and stability of the supporting structure of the underwater pipe-jacking working well are guaranteed, the problem that a conventional supporting structure of a land pipe-jacking working well cannot meet the requirements for water retaining and pipe-jacking construction jacking force in water is effectively solved, and the safety of pipe-jacking construction on urban roads and municipal facilities is guaranteed; and the construction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit support for a jacking pipe working shaft, and in particular to a support structure and a construction method for an underwater jacking pipe working shaft. Background Art

[0002] In the field of urban infrastructure construction and underground engineering, pipe jacking construction is a commonly used trenchless construction technology, especially when laying pipelines through special areas such as existing roads, pipelines and waters. The pipe jacking working shaft is a necessary structural facility in pipe jacking construction. When the pipe jacking leads directly to the water, the conventional practice is to place the pipe jacking working shaft on land and set up a cofferdam in the water area to receive it. Since there is a wide area of ​​original soil behind the land working shaft and there is no influence of surface water, the working shaft support structure only needs to consider the retaining effect. However, most of the urban land is existing roads and municipal facilities, there are many underground pipelines, and the ground traffic is busy. There are situations where the pipe jacking working shaft cannot be placed. The pipe jacking working shaft needs to be placed in the water, and the conventional land pipe jacking working shaft support structure cannot meet the water retaining and pipe jacking construction jacking force functions in the water, and construction cannot be carried out in the water. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a support structure and construction method for an underwater pipe jacking working well in view of the deficiencies of the above-mentioned prior art, which can meet the functional requirements of the underwater pipe jacking working well, is convenient for construction, and solves the problem that some urban land cannot accommodate pipe jacking working wells.

[0004] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a support structure for an underwater jacking pipe working pit, characterized in that it includes a U-shaped backrest support structure arranged on the rear side of the jacking pipe working pit, a retaining support structure arranged on both sides of the jacking pipe working pit, a cofferdam arranged around the jacking pipe working pit and a core filling arranged between the jacking pipe working pit and the cofferdam, the cofferdam and the core filling are connected to the shoreline of the water area, the jacking pipe working pit, the U-shaped backrest support structure, and the retaining support structure are symmetrically distributed on both sides of the jacking pipe center line, the core filling width on the rear side of the U-shaped backrest support structure is twice the depth of the jacking pipe working pit, and the core filling width on both sides of the jacking pipe working pit is 2m.

[0005] The beneficial effects of the present invention are as follows: the present invention ensures the waterproof effect and safety and stability of the underwater jacking work well support structure through the combination of the U-shaped backrest support structure, the retaining support structure, the cofferdam and the core filling, effectively solves the problem that the conventional land jacking work well support structure cannot meet the water retaining and jacking force of jacking construction in water and cannot be constructed in water, ensures the safe operation of the existing urban roads and municipal facilities during jacking construction, and improves the construction efficiency of jacking projects.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows: Furthermore, the U-shaped backrest support structure is bored cast-in-place piles arranged in a U shape with equal spacing. The tops of the bored cast-in-place piles are connected with reinforced concrete crown beams. A mesh sprayed concrete surface is set in front of the bored cast-in-place piles. Two bored cast-in-place piles are arranged on both sides of the U shape.

[0007] The beneficial effect of the above further scheme is: by adopting U-shaped bored cast-in-place piles arranged at equal intervals to form a U-shaped backrest support structure, and connecting the tops of the bored cast-in-place piles with reinforced concrete crown beams, and arranging a hanging mesh sprayed concrete surface in front of the bored cast-in-place piles, on the one hand, a reliable backrest supporting force can be provided for the jacking pipe during the jacking construction, and on the other hand, the safety and stability of the jacking working pit itself can be guaranteed when the jacking pipe is not under construction.

[0008] Furthermore, the retaining support structure adopts hot-rolled U-shaped steel sheet piles and is connected with bored cast-in-place piles. Steel purlins and internal supports are arranged on the tops of the hot-rolled U-shaped steel sheet piles. The steel purlins are composed of a single H-shaped steel or a double I-shaped steel, and the internal supports are circular steel pipes.

[0009] The beneficial effect of the above further scheme is: by using hot-rolled U-shaped steel sheet piles as the retaining support structure and connecting them with bored cast-in-place piles, steel purlins and internal supports are arranged on the top of the hot-rolled U-shaped steel sheet piles, so as to ensure the stability of the core filling slopes on both sides of the jacking working pit.

[0010] Furthermore, the cofferdam is a trapezoidal clay cofferdam with a 2m wide platform on the top and a gentler slope on the water side than on the back side.

[0011] The beneficial effect of the above further scheme is that by setting up a trapezoidal clay cofferdam as a water barrier, a water-free construction space can be provided for the construction of the support structure of the jacking working shaft, and a water-isolating effect can be played during the jacking construction process.

[0012] Furthermore, the core filling is formed by layered rolling of clay soil, the thickness of each layer is not more than 0.3m, and the compaction coefficient is not less than 0.90.

[0013] The beneficial effect of the above further scheme is that by adopting layered rolling and filling of clay soil, the compaction quality of the core can be effectively guaranteed, the stability of the site during pile foundation construction and the resistance of the passive zone of the U-shaped backrest support structure during pipe jacking construction can be ensured to meet the requirements.

[0014] Furthermore, the jacking work pit should meet the requirements of the working size of the jacking machine. A reinforced concrete jacking pipe backrest is set in front of the bored piles. The reinforced concrete jacking pipe backrest is tightly attached to the mesh sprayed concrete face. A 10 cm thick plain concrete cushion layer is set at the bottom of the jacking work pit.

[0015] The beneficial effects of the above further scheme are: by arranging a reinforced concrete jacking pipe backrest in front of the bored piles in the jacking working pit, the flatness of the working surface of the jacking machine cylinder can be ensured, and the jacking force can be evenly transmitted to the bored piles at the rear; by arranging a 10 cm thick plain concrete cushion layer at the bottom of the jacking working pit, the jacking work site can be ensured to be dry and flat, facilitating construction.

[0016] Furthermore, the U-shaped backrest support structure, retaining support structure, cofferdam and core filling top are located at the same elevation and are not less than 0.5m above the water surface outside the cofferdam.

[0017] The beneficial effect of the above further scheme is: by setting the U-shaped backrest support structure, retaining support structure, cofferdam and core filling top at the same elevation and at least 0.5m higher than the water surface outside the cofferdam, it can be ensured that the water outside the cofferdam cannot flood the jacking pipe working shaft support structure, thereby ensuring the safety of construction in the pit.

[0018] The present invention also provides a construction method for a support structure of an underwater pipe jacking working well, comprising the following steps: constructing the cofferdam and pumping out the water in the cofferdam; Fill the core in the cofferdam in layers to the top elevation of the platform; Constructing the bored cast-in-place piles of the U-shaped backrest support structure and the hot-rolled U-shaped steel sheet piles of the retaining support structure on the core filling platform; After the pile inspection is passed, the reinforced concrete crown beam of the U-shaped backrest support structure and the steel purlin and inner support of the retaining support structure are constructed; After the jacking working pit is formed by layered excavation, a mesh sprayed concrete face and a 10 cm thick plain concrete cushion layer are constructed before the bored piles, and a reinforced concrete jacking backrest is constructed after the designed strength is reached; After the reinforced concrete jacking pipe backrest reaches the designed strength, the construction is completed and the jacking pipe construction conditions are met. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a schematic plan view of a support structure for an underwater pipe jacking working shaft according to an embodiment of the present invention.

[0020] Figure 2 The present invention is a longitudinal section schematic diagram of a support structure for an underwater pipe jacking working shaft according to an embodiment of the present invention.

[0021] Figure 3 The present invention is a schematic cross-sectional view of a support structure for an underwater pipe jacking working shaft according to an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the construction of a cofferdam and the removal of water from the cofferdam according to an embodiment of the present invention.

[0023] Figure 5 It is a construction schematic diagram of filling the core in the cofferdam and constructing bored cast-in-place piles and hot-rolled U-shaped steel sheet piles according to an embodiment of the present invention.

[0024] Figure 6 It is a construction schematic diagram of the construction of the crown beam, steel surrounding purlin and inner support of the embodiment of the present invention, and the layered excavation forms the jacking working pit, the construction of the hanging mesh sprayed concrete surface, the cushion layer and the jacking backrest.

[0025] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. U-shaped backrest support structure, 2. retaining support structure, 3. cofferdam, 4. core filling, 5. jacking working pit, 6. jacking pipe, 7. water surface outside the cofferdam; 11. bored cast-in-place piles, 12. reinforced concrete crown beam, 13. mesh sprayed concrete facing, 21. hot-rolled U-shaped steel sheet piles, 22. steel purlins, 23. internal support, 31. side slope facing the water, 32. platform, 33. side slope away from the water, 51. reinforced concrete jacking pipe backrest, 52. plain concrete cushion. DETAILED DESCRIPTION

[0026] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] like Figures 1 to 3 As shown, a support structure for an underwater jacking working pit comprises a U-shaped backrest support structure 1 arranged at the rear side of a jacking working pit 5, a retaining support structure 2 arranged at both sides of the jacking working pit 5, a cofferdam 3 arranged around the jacking working pit 5 and a core filling 4 arranged between the jacking working pit 5 and the cofferdam 3, wherein the cofferdam 3 and the core filling 4 are connected to the shoreline of the water area, the jacking working pit 5, the U-shaped backrest support structure 1 and the retaining support structure 2 are symmetrically distributed on both sides of the center line of the jacking pipe 6, the width of the core filling 4 at the rear side of the U-shaped backrest support structure 1 is twice the depth of the jacking working pit 5, and the width of the core filling 4 on both sides of the jacking working pit 5 is 2m.

[0028] The present invention ensures the waterproof effect and safety and stability of the underwater jacking work well support structure through the combination of the U-shaped backrest support structure 1, the retaining support structure 2, the cofferdam 3 and the core filling 4, and effectively solves the problem that the conventional land jacking work well support structure cannot meet the water retaining and jacking force of the jacking construction in the water and cannot be constructed in the water, thereby ensuring the safe operation of the existing urban roads and municipal facilities during the jacking construction 6 and improving the construction efficiency of the jacking project.

[0029] In one or more embodiments of the present invention, the U-shaped backrest support structure 1 is a U-shaped bored cast-in-place pile 11 arranged at equal intervals, the top of the bored cast-in-place pile 11 is connected by a reinforced concrete crown beam 12, a mesh sprayed concrete surface 13 is arranged in front of the bored cast-in-place pile 11, and the number of bored cast-in-place piles 11 arranged on both sides of the U-shape is 2. The U-shaped backrest support structure is formed by adopting the bored cast-in-place piles 11 arranged at equal intervals in a U-shape, and the top of the bored cast-in-place pile 11 is connected by a reinforced concrete crown beam 12, and a mesh sprayed concrete surface 13 is arranged in front of the bored cast-in-place pile 11. In this way, on the one hand, a reliable rear backrest jacking force can be provided for the jacking pipe 6 during construction, and on the other hand, the safety and stability of the jacking pipe working pit 5 itself can be ensured when the jacking pipe 6 is not under construction.

[0030] In one or more embodiments of the present invention, the retaining support structure 2 adopts hot-rolled U-shaped steel sheet piles 21 and is connected to bored cast-in-place piles 11. Steel purlins 22 and internal supports 23 are arranged on the top of the hot-rolled U-shaped steel sheet piles 21. The steel purlins 22 are composed of a single H-shaped steel or a double I-shaped steel. The internal support 23 is a circular steel pipe. By adopting hot-rolled U-shaped steel sheet piles 21 as the retaining support structure 2 and connecting it to bored cast-in-place piles 11, steel purlins 22 and internal supports 23 are arranged on the top of the hot-rolled U-shaped steel sheet piles 21. In this way, the stability of the core filling slopes on both sides of the jacking working pit 5 can be ensured.

[0031] In one or more embodiments of the present invention, the cofferdam 3 is a trapezoidal clay cofferdam with a 2m wide platform 32 on the top. The slope of the water-facing side slope 32 is gentler than the slope of the water-receiving side slope 33. By setting the trapezoidal clay cofferdam as a water barrier, a water-free construction space can be provided for the construction of the support structure of the jacking working shaft, and a water-isolating effect can be played during the jacking construction process.

[0032] In one or more embodiments of the present invention, the core fill 4 is formed by layered rolling and filling of clay, the thickness of each layer is not more than 0.3m, and the compaction coefficient is not less than 0.90. By adopting layered rolling and filling of clay, the compaction quality of the core fill can be effectively guaranteed, ensuring the stability of the site during pile foundation construction and the resistance of the passive zone of the U-shaped backrest support structure during jacking pipe construction to meet the requirements.

[0033] In one or more embodiments of the present invention, the jacking work pit 5 should meet the requirements of the working size of the jacking machine. A reinforced concrete jacking pipe backrest 51 is set in front of the bored pile 11 of the jacking work pit 5. The reinforced concrete jacking pipe backrest 51 is closely attached to the mesh sprayed concrete protective surface 13. A 10 cm thick plain concrete cushion layer 52 is set at the bottom of the jacking work pit 5. By setting the reinforced concrete jacking pipe backrest 51 in front of the bored pile 11 of the jacking work pit 5, the flatness of the working surface of the jacking machine cylinder can be ensured, and the jacking force can be evenly transmitted to the bored pile 11 at the rear. By setting a 10 cm thick plain concrete cushion layer 52 at the bottom of the jacking work pit 5, the dryness and flatness of the jacking work construction site can be ensured, which is convenient for construction.

[0034] In one or more embodiments of the present invention, the U-shaped backrest support structure 1, the retaining support structure 2, the cofferdam 3 and the top of the core filling 4 are located at the same elevation and are not less than 0.5m above the water surface 7 outside the cofferdam.

[0035] like Figures 4 to 6 As shown, the present invention also provides a construction method for a support structure of an underwater pipe jacking working well, comprising the following steps: Constructing the cofferdam 3 and pumping out the water in the cofferdam 3; Fill the core 4 in the cofferdam 3 in layers to the top elevation of the platform; Constructing the bored cast-in-place piles 11 of the U-shaped backrest support structure 1 and the hot-rolled U-shaped steel sheet piles 21 of the retaining support structure 2 on the core filling platform; After the pile inspection is passed, the reinforced concrete crown beam 12 of the U-shaped backrest support structure 1 and the steel surrounding purlin 22 and the inner support 23 of the retaining support structure 2 are constructed; After the jacking working pit 5 is formed by layered excavation, a mesh sprayed concrete protective surface 13 and a 10 cm thick plain concrete cushion layer 52 at the bottom of the pit are constructed in front of the bored pile 11, and a reinforced concrete jacking backrest 51 is constructed after reaching the designed strength; After the reinforced concrete jacking pipe backrest 51 reaches the designed strength, the construction is completed and the jacking pipe 6 construction conditions are met.

[0036] The support structure and construction method of an underwater jacking pipe working well of the present invention ensure the waterproof effect and safety and stability of the support structure of the underwater jacking pipe working well, effectively solve the problem that the support structure of a conventional terrestrial jacking pipe working well cannot meet the functions of water retaining and jacking force for jacking construction in water, and cannot be constructed in water, ensure the safe operation of existing urban roads and municipal facilities during jacking construction, and improve the construction efficiency of jacking projects.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A support structure for an underwater pipe jacking working well, characterized in that: The invention comprises a U-shaped backrest support structure (1) arranged at the rear side of a jacking working pit (5), a retaining support structure (2) arranged at both sides of the jacking working pit (5), a cofferdam (3) arranged around the jacking working pit (5), and a core filling (4) arranged between the jacking working pit (5) and the cofferdam (3), wherein the cofferdam (3) and the core filling (4) are connected to the shoreline of the water area, the jacking working pit (5), the U-shaped backrest support structure (1), and the retaining support structure (2) are symmetrically distributed on both sides of the center line of the jacking pipe (6), the width of the core filling (4) at the rear side of the U-shaped backrest support structure (1) is twice the depth of the jacking working pit (5), and the width of the core filling (4) on both sides of the jacking working pit (5) is 2m.

2. The support structure of the underwater jacking working well according to claim 1 is characterized in that: The U-shaped backrest support structure (1) is a bored cast-in-place pile (11) arranged at equal intervals in a U shape. The tops of the bored cast-in-place piles (11) are connected by reinforced concrete crown beams (12). A mesh sprayed concrete protective surface (13) is arranged in front of the bored cast-in-place piles (11). Two bored cast-in-place piles (11) are arranged on both sides of the U shape.

3. The support structure of the underwater jacking working well according to claim 1 is characterized in that: The retaining support structure (2) adopts hot-rolled U-shaped steel sheet piles (21) and is connected to bored cast-in-place piles (11). A steel purlin (22) and an inner support (23) are arranged on the top of the hot-rolled U-shaped steel sheet piles (21). The steel purlin (22) is composed of a single H-shaped steel or a double I-shaped steel. The inner support (23) is a circular steel pipe.

4. The support structure of the underwater jacking working well according to claim 1 is characterized in that: The cofferdam (3) is a trapezoidal clay cofferdam, with a 2m wide platform (32) arranged on the top, and the slope of the waterside slope (31) is gentler than the slope of the waterside slope (33).

5. The support structure of the underwater jacking working well according to claim 1 is characterized in that: The core filling (4) is formed by layered rolling and filling of clay soil, the thickness of each layer is not more than 0.3m, and the compaction coefficient is not less than 0.

90.

6. The support structure of the underwater jacking working well according to claim 1 is characterized in that: The pipe jacking working pit (5) should meet the requirements of the working size of the pipe jacking machine. A reinforced concrete pipe jacking backrest (51) is arranged in front of the bored pile (11) of the pipe jacking working pit (5). The reinforced concrete pipe jacking backrest (51) is in close contact with the mesh sprayed concrete protective surface (13). A 10 cm thick plain concrete cushion layer (52) is arranged at the bottom of the pipe jacking working pit (5).

7. The supporting structure of the underwater jacking working well according to claim 1 is characterized in that: The tops of the U-shaped backrest support structure (1), the retaining support structure (2), the cofferdam (3) and the core filling (4) are located at the same elevation and are not less than 0.5 m above the water surface (7) outside the cofferdam.

8. A construction method for a support structure of an underwater pipe jacking working well, characterized in that: The steps include: constructing the cofferdam (3) and pumping out the water in the cofferdam (3); Fill the core (4) in the cofferdam (3) in layers to the top elevation of the platform; constructing the bored cast-in-place piles (11) of the U-shaped backrest support structure (1) and the hot-rolled U-shaped steel sheet piles (21) of the retaining support structure (2) on the core filling platform; After the piles are inspected and found to be qualified, the reinforced concrete crown beam (12) of the U-shaped backrest support structure (1) and the steel surrounding purlin (22) and inner support (23) of the retaining support structure (2) are constructed; After the jacking working pit (5) is formed by layered excavation, a mesh sprayed concrete protection surface (13) in front of the bored piles (11) and a 10 cm thick plain concrete cushion layer (52) at the bottom of the pit are constructed, and after reaching the designed strength, a reinforced concrete jacking backrest (51) is constructed; After the reinforced concrete jacking pipe backrest (51) reaches the designed strength, the construction is completed and the jacking pipe (6) construction conditions are met.

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