A secondary floating cast-in-place immersed pipe with variable transverse span and a floating transportation method

Abstract

The present invention relates to a secondary floating cast submerged pipe with a variable transverse span and a floating use method. The submerged pipe includes a large end and a small end. The transverse width of the cross section of the large end of the submerged pipe is greater than the transverse width of the cross section of the small end of the submerged pipe. The transverse width of the cross section of the small end of the submerged pipe gradually decreases from the middle to the end along the longitudinal direction of the submerged pipe. The submerged pipe includes a top plate, a bottom plate and a wall. The top plate includes a first cast layer, and a layer to be cast is provided above the first cast layer. By reserving an uncast layer to be cast, the secondary floating cast submerged pipe with a variable transverse span is lighter than a complete submerged pipe structure, requires a shallower draft during floating, is easier to float, and improves the safety of floating. It can also reduce the excavation and deepening of the river below the floating line, save engineering investment, and form a complete top plate after the secondary floating cast of the layer to be cast, which can ensure the quality and safety of the submerged pipe used in the foundation pit.

Description

Technical Field

[0001] The present invention relates to the technical field of variable-section immersed tubes, in particular to a secondary floating cast immersed tube with a variable transverse span and a floating transportation method. Background Art

[0002] Currently, immersed tubes, both domestically and internationally, can be roughly divided into three structural types: early steel-shell immersed tubes (single-layer / double-layer), the widely used reinforced concrete weight-reducing immersed tubes, and the less commonly used steel-shell concrete immersed tubes. Currently, immersed tube tunnels in urban core areas may involve variable-section immersed tubes. This is because the number of lanes in an immersed tube is gradually reduced from multiple lanes, such as from 8 lanes to 6 lanes. The transportation of these variable-section immersed tube sections often requires the excavation of long-distance floating channels in urban rivers, which involves enormous dredging and rock drilling. This significantly extends the overall construction time of variable-section immersed tube tunnels. Furthermore, the increasing number of floating routes for variable-section immersed tubes results in longer floating cycles and requires more time for these operations. Moreover, the water depth of urban rivers is relatively shallow, which makes it difficult to meet the floating transportation needs. Currently, variable-section submerged tubes are usually floated during the tide, but the window period for floating during the tide is short, making it impossible to meet the floating depth for a long time; and urban rivers may involve important structures such as bridges and subways, making it impossible to significantly deepen the urban rivers, which makes the floating of variable-section submerged tubes difficult and the floating safety factor low.

[0003] In addition to the problem of floating draft, the longitudinal balance of variable-section immersed tube segments during floating is difficult to control, that is, the balance during floating is also a problem that needs to be solved urgently. Summary of the Invention

[0004] The purpose of the present invention is to provide a secondary floating cast submerged pipe with a variable lateral span and a floating method for use thereof, in view of the problems in the prior art of difficulty in floating the submerged pipe and low safety factor of floating when the water depth for floating the submerged pipe is difficult to meet.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A secondary floating cast immersed tube with a variable transverse span, the immersed tube comprising a large end and a small end, the transverse width of the cross section of the large end of the immersed tube being greater than the transverse width of the cross section of the small end of the immersed tube, the transverse width of the cross section of the small end of the immersed tube gradually decreasing from the middle to the end along the longitudinal direction of the immersed tube, the immersed tube comprising a top plate, a bottom plate and a wall, the top plate comprising a first cast layer, and a layer to be cast being located above the first cast layer.

[0007] By adopting the secondary floating cast submerged pipe with a variable transverse span as described in this solution, a portion of the top plate of the submerged pipe structure is cast to form a first cast layer, and a portion is reserved above the first cast layer as a layer to be cast that is not cast before floating. The cast first cast layer can cooperate with the bottom plate and wall to form a stable structure that can remain stable during floating, that is, the uncast layer to be cast will not affect the safety of floating. After the secondary floating cast submerged pipe with a variable transverse span is floated, if the secondary floating cast submerged pipe with a variable transverse span is first floated to a storage area next to the foundation pit, the layer to be cast of the secondary floating cast submerged pipe with a variable transverse span is subjected to secondary floating casting in the storage area to form a complete top plate structure, so that the submerged pipe structure is complete and will not affect the safety of use in the foundation pit. The first cast layer can be used as a casting bottom template for the layer to be cast, facilitating the secondary floating casting of the first cast layer on the water.

[0008] Moreover, because the top plate of the secondary floating cast submerged pipe with a changed transverse span has an uncast layer to be cast, the secondary floating cast submerged pipe with a changed transverse span is lighter than a complete submerged pipe structure, and the secondary floating cast submerged pipe with a changed transverse span requires a shallower draft during floating transportation, making the floating transportation of the secondary floating cast submerged pipe with a changed transverse span easier and improving the safety of floating transportation; and it can reduce the excavation and deepening of the river below the floating line, and can save engineering investment.

[0009] Preferably, part or all of the layer to be cast is located at the small end of the immersed tube, and the layer to be cast is symmetrical about the longitudinal center axis of the top plate.

[0010] The layers to be cast are symmetrical about the longitudinal center axis of the top plate, ensuring lateral balance on both sides of the submerged tube after launching. Furthermore, because the large end of the submerged tube has a larger lateral dimension, it displaces more water at the same draft. Therefore, after launching, the large end of the submerged tube will be higher than the small end. By placing part or all of the layers to be cast at the small end of the submerged tube, the weight of the small end can be reduced, thereby achieving longitudinal balance at both ends of the secondary floating cast submerged tube with a varying lateral span. Specifically, by placing part or all of the layers to be cast at the small end of the submerged tube, the draft of the submerged tube can be reduced while ensuring longitudinal balance at both ends, facilitating balance control during floating transport.

[0011] Preferably, the layer to be cast is located in the middle of the horizontal plane of the top plate, part of the layer to be cast is located at the large end of the immersed tube, and the distance between the layer to be cast and the large end face of the immersed tube is greater than the distance between the layer to be cast and the small end face of the immersed tube.

[0012] When the layer to be poured is located in the middle of the horizontal plane of the top plate and covers both the large and small ends of the immersed tube, the weight of the immersed tube can be greatly reduced, while ensuring the safety of floating the tube and the quality of the subsequent secondary floating pouring. The distance between the layer to be poured and the end surface of the large end of the immersed tube is greater than the distance between the layer to be poured and the end surface of the small end of the immersed tube, resulting in a larger area of ​​the layer to be poured at the small end, thereby achieving a balanced draft at both ends in the longitudinal direction, facilitating balance control during floating.

[0013] Preferably, the layer to be cast is surrounded by a second cast layer, and the ratio of the distance between the layer to be cast and the side edges of the top plate to the width of the top plate is greater than or equal to 10%; the ratio of the thickness of the first cast layer to the thickness of the top plate is greater than or equal to 30%; the ratio of the distance between the layer to be cast and the two end faces of the top plate to the length of the top plate is greater than or equal to 1 / 6.

[0014] The second cast layer ensures the structural strength of both ends and both sides of the top plate of the secondary floating cast submerged pipe with a changed lateral span, and ensures the safe floating transportation of the secondary floating cast submerged pipe with a changed lateral span. The ratio of the width of the second cast layer on both sides of the top plate to the width of the top plate is greater than or equal to 10%, which can ensure the connection strength between the top plate and the side wall. The ratio of the thickness of the first cast layer to the thickness of the top plate is greater than or equal to 30%, which can ensure the amount of concrete of the layer to be cast during the secondary floating casting and ensure the casting safety. The ratio of the distance between the layer to be cast and the two end surfaces of the top plate to the length of the top plate is greater than or equal to 1 / 6, which can ensure that there is enough safe installation space for the pipe top outfitting at both ends. And the second cast layer on all sides can be used as a side form for the later casting of the layer to be cast.

[0015] Preferably, a first weight-reducing component is provided in the reinforced concrete of the bottom plate and the wall, and the first weight-reducing component has a cavity that can be used for pouring concrete. Under the premise of ensuring floating safety, the first weight-reducing component is provided in the bottom plate and the wall, which can further reduce the deadweight of the secondary floating cast-in-place immersed pipe with a variable transverse span, so that the secondary floating cast-in-place immersed pipe with a variable transverse span requires a shallower draft during floating, making floating easier and improving the safety of floating.

[0016] and / or,

[0017] The second cast layers at both ends of the roof are equipped with second weight-reducing components, each containing a cavity for pouring concrete. The second weight-reducing components, installed within the second cast layers at both ends of the roof, further reduce the weight of the secondary floating cast submerged tubes with variable transverse spans. This allows for a shallower draft during floating, making floating easier and safer.

[0018] Preferably, when the first weight-reducing component is provided, the first weight-reducing component comprises a first embedded steel pipe transversely arranged in the bottom plate and a second embedded steel pipe vertically arranged in the wall, and the second embedded steel pipe is connected to the first embedded steel pipe;

[0019] When the second weight-reducing component is provided, the second weight-reducing component includes a third embedded steel pipe transversely arranged in the second cast layer, and the third embedded steel pipe has an upward communication port.

[0020] By adopting the above-mentioned first weight-reducing component, the connection between the bottom plate and the wall is good, and the wall and bottom plate can be greatly utilized to achieve weight reduction. When adopting the above-mentioned second weight-reducing component, the second cast layer can be used to set the third embedded steel pipe, which can further achieve weight reduction without affecting the secondary floating casting and submerged pipe floating without affecting the change in the lateral span, as well as the subsequent secondary floating casting. The third embedded steel pipe has an upward connecting port, which is always above the water surface during floating transportation, which can prevent water from entering the third embedded steel pipe; it is more convenient to pour concrete in the later stage, and can ensure the molding quality of the concrete poured into the third embedded steel pipe.

[0021] Preferably, the wall includes side walls and a middle wall, and the upper end of the second embedded steel pipe located on the side wall and whose longitudinal position corresponds to the layer to be poured is connected to a fourth embedded steel pipe, and the fourth embedded steel pipe is transversely arranged in the second cast layer on both sides of the top plate, and the fourth embedded steel pipe is connected to the layer to be poured.

[0022] The installation of fourth pre-buried steel pipes within the second cast layer on both sides of the roof further reduces the deadweight of the second floating cast submerged pipes with variable transverse spans by lightening the second cast layer, thereby enabling these pipes to be transported in shallower water depths. Furthermore, the fourth pre-buried steel pipes are connected to the corresponding second pre-buried steel pipes in the side walls and the corresponding first pre-buried steel pipes in the bottom slab, ensuring a stronger connection between the second cast layers on both sides of the bottom slab, side walls, and roof. This helps ensure the strength of the corners and overall strength of the second floating cast submerged pipes with variable transverse spans, and enhances safety during floating and secondary floating casting.

[0023] Preferably, the third embedded steel pipe is located in the transverse middle part of the top plate, and the corresponding ends of all the third embedded steel pipes are located on the same longitudinal line of the immersed tube, so that the lengths of the third embedded steel pipes at the large end and the small end of the immersed tube can be the same, thereby ensuring the draft balance at both ends in the longitudinal direction, which is convenient for balance control during floating transportation.

[0024] A method for floating a submerged tube comprises the following steps:

[0025] S1, manufacturing the secondary floating cast immersed tube with a variable transverse span;

[0026] S2, floating and transporting the secondary floating cast submerged tube with a changed transverse span to a storage area near the foundation trench;

[0027] S3, anchoring the secondary floating cast-in-place immersed tube with a changed transverse span in the storage area by dropping anchor;

[0028] S4. Pre-embed a waterstop in the layer to be cast of the secondary floating cast submerged pipe with a changed transverse span and prepare the joint surface. Then, concrete is poured into the layer to be cast of the secondary floating cast submerged pipe with a changed transverse span by pumping concrete to form a complete top plate.

[0029] The method for floating and using submerged tubes of the present invention reserves an uncast layer to be cast, so that the weight of the secondary floating cast submerged tube with a changed lateral span is lighter than that of a complete submerged tube structure, and the draft required for the secondary floating cast submerged tube with a changed lateral span when floating to the storage area near the foundation pit is shallower, making the floating of the secondary floating cast submerged tube with a changed lateral span easier and improving the safety of floating, and can reduce the excavation and deepening of the river below the floating line, which can save project investment, and pre-buried waterstop strips for the to-be-cast layer and well treated the joint surface, and then a complete top plate is formed after the secondary floating casting of the to-be-cast layer, which can avoid construction joints in the top plate, avoid the risk of water leakage between the concrete cast in the to-be-cast layer and the first cast layer, and can ensure the quality and safety of the submerged tubes used in the foundation pit.

[0030] Preferably, in step S1, when manufacturing the secondary floating cast submerged tube with a variable transverse span, the following conditions exist:

[0031] Case X: When the first weight-reducing component is provided, cooling water is injected into the cavity of the first weight-reducing component, and then the bottom plate and the wall are cast;

[0032] Case Y: When a second weight-reducing component is provided, cooling water is injected into the cavity of the second weight-reducing component, and then the top plate is cast;

[0033] and / or,

[0034] In step S4, both longitudinal ends of the immersed tube are poured simultaneously, and the speed of the secondary floating concrete pouring at the large end of the immersed tube is controlled to be greater than the speed of the secondary floating concrete pouring at the small end of the immersed tube, which can ensure the longitudinal balance of the immersed tube during pouring.

[0035] When manufacturing a secondary floating cast immersed tube with a changed transverse span in the early stage, cooling water is injected into the cavity of the first weight-reducing component or the second weight-reducing component to improve the heat dissipation effect of the concrete and reduce the probability of cracks on the concrete surface of the bottom plate and the side wall or the top plate; and the injected cooling water will not affect the quality of the secondary floating cast cavity in the later stage.

[0036] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0037] 1. The secondary floating cast sunken pipe with a variable transverse span of the present invention, by reserving an uncast layer to be cast, makes the secondary floating cast sunken pipe with a variable transverse span lighter than a complete sunken pipe structure, and makes the secondary floating cast sunken pipe with a variable transverse span require a shallower draft during floating transportation, making the floating of the secondary floating cast sunken pipe with a variable transverse span easier and improving the safety of floating transportation, and can reduce the excavation and deepening of the river below the floating line, which can save project investment, and form a complete top plate after the secondary floating casting of the layer to be cast, which can ensure the quality and safety of the sunken pipe used in the foundation pit.

[0038] 2. In the secondary floating cast submerged pipe with a variable transverse span described in the present invention, the layers to be cast are symmetrical about the longitudinal center axis of the top plate, which can ensure the transverse balance of the submerged pipe after it is launched into the water; part or all of the layers to be cast are located at the small end of the submerged pipe, which can reduce the water draft of the submerged pipe and ensure the balance of the longitudinal ends at the same time, which is convenient for balance control during floating transportation.

[0039] 3. The secondary floating cast submerged pipe with a changed transverse span described in the present invention is provided with a first weight-reducing component in the bottom plate and the wall, under the premise of ensuring the safety of floating transportation, which can further reduce the dead weight of the secondary floating cast submerged pipe with a changed transverse span, so that the secondary floating cast submerged pipe with a changed transverse span requires a shallower draft during floating transportation, and the floating transportation is easier and the floating safety is improved; a second weight-reducing component is provided in the second cast layer at both ends of the top plate, which can further reduce the dead weight of the secondary floating cast submerged pipe with a changed transverse span, so that the secondary floating cast submerged pipe with a changed transverse span requires a shallower draft during floating transportation, and the floating transportation is easier and the floating safety is improved.

[0040] 4. In the secondary floating cast-in-place immersed tube with a variable transverse span described in the present invention, the third pre-buried steel tube is located in the transverse middle of the top plate, and the corresponding ends of all the third pre-buried steel tubes are located on the same longitudinal line of the immersed tube. This can make the lengths of the third pre-buried steel tubes at the large and small ends of the immersed tube the same, thereby ensuring the draft balance at both ends in the longitudinal direction and facilitating balance control during floating transportation.

[0041] 5. The floating and using method of the submerged tube of the present invention makes the weight of the secondary floating cast submerged tube with a changed lateral span lighter than that of a complete submerged tube structure by reserving an uncast layer to be cast, and makes the secondary floating cast submerged tube with a changed lateral span require a shallower draft when floating to the storage area near the foundation pit, making the floating of the secondary floating cast submerged tube with a changed lateral span easier and improving the safety of floating, and can reduce the excavation and deepening of the river below the floating line, which can save engineering investment, and pre-buried waterstop strips for the to-be-cast layer and well treat the joint surface, and then form a complete top plate after the secondary floating casting of the to-be-cast layer, which can avoid construction joints in the top plate, avoid the risk of water leakage between the concrete cast in the to-be-cast layer and the first cast layer, and can ensure the quality and safety of the submerged tubes used in the foundation pit.

[0042] 6. The floating method of the present invention utilizes cooling water injected into the cavities of the first or second weight-reducing components during the initial fabrication of a secondary floating cast immersed tube with a variable transverse span to enhance heat dissipation from the concrete, reducing the likelihood of cracks forming on the concrete surfaces of the bottom slab, side walls, or roof. Furthermore, the injected cooling water does not affect the quality of the cavity during the subsequent secondary floating cast. During the secondary floating cast, both longitudinal ends of the immersed tube are cast simultaneously, with the concrete pouring speed at the larger end exceeding that at the smaller end, ensuring longitudinal balance during the cast. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic structural diagram of a secondary floating cast immersed tube with a variable transverse span according to the present invention;

[0044] Figure 2 yes Figure 1 Schematic diagram of the layout of the embedded steel pipe at AA in the middle;

[0045] Figure 3 yes Figure 1 Schematic diagram of the layout of the embedded steel pipe at the middle BB;

[0046] Figure 4 yes Figure 1 Schematic diagram of the layout of the embedded steel pipes at the center CC;

[0047] Figure 5 yes Figure 1 Schematic diagram of the layout of the embedded steel pipes at the middle DD;

[0048] Figure 6 yes Figure 5 A partial enlarged schematic diagram of the middle circle;

[0049] Figure 7 yes Figure 1 Schematic diagram of the layout of the embedded steel pipes at EE;

[0050] Figure 8 yes Figure 1 Schematic diagram of the layout of the embedded steel pipes at the middle FF;

[0051] Figure 9 It is method a pumping concrete;

[0052] Figure 10 It is method b to pump concrete.

[0053] Icons: 11-top plate; 12-bottom plate; 13-side wall; 14-middle wall; 111-first cast layer; 112-second cast layer; 113-layer to be cast; 21-first embedded steel pipe; 22-second embedded steel pipe; 23-third embedded steel pipe; 24-fourth embedded steel pipe; 25-connecting steel pipe; 26-pouring port; 27-exhaust port; 3-pump boat; 31-sky pump; 32-first pump pipe; 33-first anchor chain; 34-first anchor block; 35-second anchor chain; 36-second anchor block; 4-second pump pipe; 5-protective pier; 51-groove. DETAILED DESCRIPTION

[0054] The present invention will be described in detail below with reference to the accompanying drawings.

[0055] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0056] Example 1

[0057] This embodiment provides a secondary floating cast immersed tube with a variable transverse span, the immersed tube including a large end and a small end, the transverse width of the cross section of the large end of the immersed tube is greater than the transverse width of the cross section of the small end of the immersed tube, and the transverse width of the cross section of the small end of the immersed tube gradually decreases from the middle to the end along the longitudinal direction of the immersed tube, the immersed tube includes a top plate 11, a bottom plate 12 and a wall, the top plate 11 includes a first cast layer 111, and a layer to be cast 113 is provided above the first cast layer 111.

[0058] like Figure 1 As shown, the secondary floating cast immersed tube with a variable transverse span described in this scheme has a large end on the left end and a small end on the right end. The cross-sections of the left and right ends are both rectangular structures, each having a top, a bottom, side portions on both sides, and two middle portions in the middle, which correspond to the top plate 11, the bottom plate 12, the two side walls 13 and the two middle walls 14 of the immersed tube respectively.

[0059] The second floating casting of the submerged tube with a variable transverse span as described in this solution is used to cast a portion of the top plate 11 of the submerged tube structure to form a first cast layer 111, and a portion is reserved above the first cast layer 111 as a to-be-cast layer 113 which is not cast before floating. Figure 1 As shown, the poured first cast layer 111 can cooperate with the bottom plate 12 and the wall to form a stable structure, which can remain stable during floating transportation, that is, the uncast layer 113 to be cast will not affect the safety of floating transportation; after the secondary floating cast submerged pipe with a variable transverse span is floated, if the secondary floating cast submerged pipe with a variable transverse span is first floated to the storage area next to the foundation pit, the layer 113 to be cast of the secondary floating cast submerged pipe with a variable transverse span is cast in the storage area for a secondary floating state to form a complete top plate 11 structure, so that the submerged pipe structure is complete and will not affect the safety of use in the foundation pit. The first cast layer 111 can serve as the casting bottom template for the layer 113 to be cast, facilitating the secondary floating casting of the first cast layer 111 on the water.

[0060] In this embodiment, the layer to be poured 113 is symmetrical about the longitudinal center axis of the top plate 11, which can ensure that the two sides of the submerged tube are balanced after being launched into the water. Figure 1 The upper and lower sides of the submerged tube can be horizontal; and because the large end of the submerged tube has a larger transverse dimension, its displacement is greater under the same draft. Therefore, after the submerged tube is launched, its large end will be higher than the small end. By placing part or all of the layer to be cast 113 at the small end of the submerged tube, the weight of the small end can be reduced, thereby achieving longitudinal balance at both ends of the secondary floating cast submerged tube with a variable transverse span. In other words, by placing part or all of the layer to be cast 113 at the small end of the submerged tube, the draft of the submerged tube can be reduced while ensuring longitudinal balance at both ends, facilitating balance control during floating transportation.

[0061] like Figure 1 As shown, a better option is to place the layer to be poured 113 in the middle of the horizontal plane of the top plate 11, and cover both the large and small ends of the submerged tube, that is, part of the layer to be poured 113 is located at the small end of the submerged tube, and part of the layer to be poured 113 is located at the large end of the submerged tube; this can reduce the weight of the submerged tube to a greater extent and reduce the draft required for the submerged tube to float while ensuring the safety of the submerged tube floating and the quality safety after the secondary floating pouring in the later stage. Moreover, the distance between the layer to be poured 113 and the large end face of the submerged tube is greater than the distance between the layer to be poured 113 and the small end face of the submerged tube, so that the area of ​​the layer to be poured 113 at the small end is larger, that is, the weight reduction of the small end is greater than the weight reduction of the large end, thereby making the draft at both ends of the longitudinal direction balanced, that is, it can ensure Figure 1 The left and right ends of the boat are level when drafted, which facilitates balance control during floating transportation.

[0062] like Figure 1As shown, the layer to be poured 113 is surrounded by a second cast layer 112. The second cast layer 112 ensures the structural strength of the top plate 11 at both ends and both sides of the secondary floating cast submerged pipe with a variable transverse span, and ensures the safe floating transportation of the secondary floating cast submerged pipe with a variable transverse span. The ratio of the distance between the layer to be poured 113 and the side edges of the top plate 11 to the width of the top plate 11 is greater than or equal to 10%, which can ensure the connection strength between the top plate 11 and the side wall 13. The ratio of the thickness of the first cast layer 111 to the thickness of the top plate 11 is greater than or equal to 30%, which can ensure the amount of concrete for the layer to be poured 113 during the secondary floating cast and ensure casting safety. The ratio of the distance between the layer to be poured 113 and the two end faces of the top plate 11 to the length of the top plate 11 is greater than or equal to 1 / 6, which can ensure that there is sufficient safe installation space for the pipe top outfitting at both ends. The second cast layer 112 around the periphery can be used as a side form for the later casting of the layer to be cast 113.

[0063] The secondary floating cast submerged pipe with a changed transverse span described in this embodiment has a reserved uncast layer 113 to be cast, so that the secondary floating cast submerged pipe with a changed transverse span is lighter than a complete submerged pipe structure, and the secondary floating cast submerged pipe with a changed transverse span requires a shallower draft during floating transportation, making the floating of the secondary floating cast submerged pipe with a changed transverse span easier and improving the safety of floating transportation. It can also reduce the excavation and deepening of the river below the floating line, save engineering investment, and form a complete top plate 11 after the secondary floating casting of the layer 113 to be cast, which can ensure the quality and safety of the submerged pipes used in the foundation pit.

[0064] Example 2

[0065] This embodiment provides a secondary floating cast-in-place immersed pipe with a variable transverse span. Based on the first embodiment, a first weight-reducing component is provided within the reinforced concrete of the bottom plate 12 and the wall. The first weight-reducing component has a cavity that can be used for pouring concrete. While ensuring safe floating transportation, the first weight-reducing component is provided within the bottom plate 12 and the wall to further reduce the deadweight of the secondary floating cast-in-place immersed pipe with a variable transverse span. This allows the secondary floating cast-in-place immersed pipe with a variable transverse span to require a shallower draft during floating transportation, making floating transportation easier and safer.

[0066] and / or,

[0067] Second weight-reducing components are provided within the second cast layers 112 at both ends of the roof 11. These components have cavities for pouring concrete. This further reduces the weight of the secondary floating cast submerged pipes with variable transverse spans, allowing for shallower drafts during transport, making transport easier and safer.

[0068] Compared to the reinforced concrete structure of existing immersed tubes, the first and second weight-reducing components are lighter due to their inherent material and the presence of cavities. Replacing portions of the reinforced concrete structure of existing immersed tubes with the first and / or second weight-reducing components can make the tubes lighter and reduce their draft. Furthermore, the cavities of the first and second weight-reducing components aid buoyancy, further reducing the draft of the immersed tubes.

[0069] When the first weight-reducing component is provided, Figure 2 、 Figure 3 and Figure 7 As shown. The first weight-reducing component includes a first embedded steel pipe 21 horizontally arranged in the bottom plate 12 and a second embedded steel pipe 22 vertically arranged in the wall. The second embedded steel pipe 22 is connected to the first embedded steel pipe 21. By adopting the above-mentioned first weight-reducing component, the bottom plate 12 and the wall are well connected, and the wall and the bottom plate 12 can be greatly utilized to achieve weight reduction. The side wall 13 is provided with the second embedded steel pipe 22, and at least one of the middle walls 14 is provided with the second embedded steel pipe 22. The upper end of the second embedded steel pipe 22 located in the middle wall 14 extends upward from the top surface of the first cast layer 111 or the top surface of the top plate 11, as shown Figure 2 and Figure 7 As shown, Figure 2 The upper end of the second embedded steel pipe 22 of the middle wall 14 extends upward from the top surface of the first cast layer 111. Figure 7 The upper end of the second embedded steel pipe 22 of the middle wall 14 extends upward from the top surface of the top plate 11. Figure 1 and Figure 7 As shown, the second embedded steel pipe 22 located in the side wall 13 and corresponding to the second cast layer 112 at both ends of the top plate 11 vertically extends upward from the top surface of the top plate 11.

[0070] The second pre-buried steel pipe 22 extends vertically upward from the top surface of the first cast layer 111 or the top surface of the top plate 11. It can be used for pouring and exhaust, preventing water from entering the pre-buried steel pipe. It is also convenient for later concrete pouring and can ensure the molding quality of the concrete poured into the pre-buried steel pipe, ensure the casting quality of the first weight-reducing component, and improve the quality of the final immersed pipe. The top of the second pre-buried steel pipe 22 on both sides serves as a pouring port 26; the top of the second pre-buried steel pipe 22 located in the middle wall 14 serves as an exhaust port 27, which can ensure the casting quality and better control the balance during pouring, making the pouring safer.

[0071] like Figures 1-4 As shown, the upper end of the second embedded steel pipe 22 located in the side wall 13 and corresponding to the longitudinal position of the layer to be cast 113 is connected to a fourth embedded steel pipe 24. The fourth embedded steel pipe 24 is transversely arranged in the second cast layer 112 on both sides of the top plate 11. The fourth embedded steel pipe 24 is connected to the layer to be cast 113. The fourth embedded steel pipe 24 is connected to the pouring port 26 of the layer to be cast 113. After the concrete is poured into the layer to be cast 113, the pouring port 26 can be buried, which can ensure that the submerged pipe structure after the secondary floating casting is not easily damaged and is safer. The fourth embedded steel pipe 24 is arranged in the second cast layer 112 on both sides of the top plate 11. It can further reduce the deadweight of the secondary floating cast submerged pipe with a variable transverse span by reducing the second cast layer 112, so that the secondary floating cast submerged pipe with a variable transverse span requires a shallower draft during floating transportation. Moreover, the fourth embedded steel pipe 24 is connected with the corresponding second embedded steel pipe 22 in the side wall 13 and the corresponding first embedded steel pipe 21 in the bottom plate 12, which can ensure that the second cast layer 112 on both sides of the bottom plate 12, the side wall 13 and the top plate 11 are more strongly connected, which is beneficial to ensure the strength of the corners of the secondary floating cast submerged pipe with a changing lateral span and the overall strength, making floating transportation and secondary floating casting safer.

[0072] And as Figure 2 and Figure 3 As shown, the second embedded steel pipes 22 serving as the exhaust port 27 are staggered in the two middle walls 14 along the longitudinal direction of the immersed tube, which can ensure the strength of the middle wall 14 of the immersed tube while meeting the exhaust requirements and casting balance.

[0073] When the second weight-reducing component is provided, Figure 5 and Figure 6As shown, the second weight-reducing component includes a third pre-embedded steel pipe 23 disposed transversely within the second cast layer 112. The third pre-embedded steel pipe 23 has an upwardly directed connection port. Specifically, the third pre-embedded steel pipe 23 is connected via a vertically disposed connecting steel pipe 25. The top end of the connecting steel pipe 25 extends upward through the top surface of the roof 11 to form a connection port. The connection ports on either side serve as injection ports 26, while the connection port in the middle serves as an exhaust port 27. The exhaust ports 27 correspond to the top of the middle wall 14 and can be aligned vertically with the exhaust ports 27 of the first weight-reducing component, facilitating pre-embedding. The injection ports 26 of the second weight-reducing component are also aligned vertically with those of the first weight-reducing component, facilitating both pre-embedding and subsequent casting. When using this second weight-reducing component, the second cast layer 112 can be utilized to set the third pre-embedded steel pipe 23, further reducing weight without affecting the transverse span change during the secondary floating casting of the submerged pipe and subsequent secondary floating casting. The third embedded steel pipe 23 has an upward connecting port, which is always above the water surface during floating, thus preventing water from entering the third embedded steel pipe 23 ; and it is more convenient to pour concrete later, and the molding quality of the concrete poured into the third embedded steel pipe 23 can be guaranteed.

[0074] like Figure 1 and Figure 5 As shown, the third pre-embedded steel tube 23 is located in the transverse middle of the top plate 11, and the corresponding ends of all the third pre-embedded steel tubes 23 are located on the same longitudinal line of the immersed tube. That is, when the ends of all the third pre-embedded steel tubes 23 are located within the boundaries of the right end of the immersed tube, the length of the third pre-embedded steel tubes 23 at the large and small ends of the immersed tube can be made the same, or the length of the third pre-embedded steel tube 23 at the large end of the immersed tube can be made shorter than that at the small end of the immersed tube. This ensures that the weight reduction at the small end of the immersed tube due to the third pre-embedded steel tube 23 is less than that at the large end of the immersed tube. This ensures that the longitudinal draft at both ends is balanced, facilitating balance control during floating. Of course, this also requires that the longitudinal density of the first weight-reducing component provided at the small end of the immersed tube is greater than that at the large end of the immersed tube, thereby ensuring that the weight reduction of the first weight-reducing component provided at the small end of the immersed tube is greater than that of the first weight-reducing component provided at the large end of the immersed tube.

[0075] like Figure 5-Figure 7 As shown, a protective pier 5 is provided on the outer surface of the immersed tube. This pier 5 serves as a collision protection structure for the immersed tube. In this embodiment, the protective pier 5 has a groove 51. At least a portion of the protective pier 5 is positioned corresponding to the communication port, and the communication port is located within the groove 51 of the corresponding protective pier 5. Specifically, at least a portion of the protective pier 5 is adjusted based on the position of the communication port so that the communication port is located within the groove 51 of the corresponding protective pier 5. This allows the protective pier 5 to not only protect the immersed tube from collision but also protect the communication port, ensuring smooth subsequent pouring.

[0076] When making a secondary floating cast-in-place immersed pipe with a variable transverse span, the bottom plate 12 and the wall are cast together, and the top plate 11 is tied after the bottom plate 12 and the wall formwork are installed. The immersed pipe is first tied with the bottom plate 12 and the wall reinforcement and the first embedded steel pipe 21 and the second embedded steel pipe 22 are buried inside. Then the large cavity of the formwork is entered, and the top plate 11 reinforcement is tied and the third embedded steel pipe 23 is embedded. In order to set the middle upward connecting port, such as Figure 8 As shown, the left-right direction corresponds to the longitudinal direction of the immersed tube. In the sections corresponding to the second cast layers 112 at the longitudinal ends, the first and second weight-reducing components need to be staggered along the longitudinal direction of the immersed tube. Given the limited thickness of the top plate 11 and the space available for the protective layer and reinforcement, staggered placement helps ensure the structural strength of the top plate 11, improving its load-bearing properties and facilitating quality and safety control.

[0077] Example 3

[0078] This embodiment provides a method for floating a submerged tube, comprising the following steps:

[0079] S1, manufacturing the secondary floating cast immersed tube with a variable transverse span;

[0080] S2, floating and transporting the secondary floating cast submerged tube with a changed transverse span to a storage area near the foundation trench;

[0081] S3, anchoring the secondary floating cast-in-place immersed tube with a changed transverse span in the storage area by dropping anchor;

[0082] S4. Pre-embed a waterstop in the layer 113 to be cast of the secondary floating cast submerged pipe with a changed transverse span and prepare the joint surface. Then, concrete is poured into the layer 113 to be cast of the secondary floating cast submerged pipe with a changed transverse span by pumping concrete to form a complete top plate 11.

[0083] By adopting the method for floating and using the submerged tube described in this embodiment, by reserving the uncast layer 113 to be cast, the weight of the secondary floating cast submerged tube with a changed lateral span is lighter than that of the complete submerged tube structure, and the secondary floating cast submerged tube with a changed lateral span requires a shallower draft when floating to the storage area near the foundation pit, making the floating of the secondary floating cast submerged tube with a changed lateral span easier and improving the safety of floating, and can reduce the excavation and deepening of the river below the floating line, which can save project investment, and pre-embed the water stop strip for the casting layer 113 and do a good job of joint surface treatment, and then form a complete top plate 11 after the secondary floating casting of the casting layer 113, which can avoid the occurrence of construction joints in the top plate 11, avoid the risk of water leakage between the concrete cast in the casting layer 113 and the first cast layer 111, and can ensure the quality and safety of the submerged tubes used in the foundation pit.

[0084] In step S4, the concrete pumping can be completed by adopting method a or method b;

[0085] Method a: A pump ship 3 is used to pump concrete. The pump ship 3 is anchored on the side of the secondary floating cast submerged pipe with a changed transverse span. The pump ship 3 is provided with a sky pump 31. The sky pump 31 has a first pump pipe 32. The first pump pipe 32 is used to pump concrete. Figure 9 As shown, the pumpboat 3 is anchored to a first anchor block 34 via a first anchor chain 33, located within the underwater rock face. The second floating cast submerged pipe, with its variable transverse span, is anchored to a second anchor block 36 via a second anchor chain 35, also located within the underwater rock face. This ensures the stability of the pumpboat 3 during casting and the balance of the second floating cast submerged pipe. The pumpboat 3 can also move longitudinally along the submerged pipe, anchoring at the corresponding longitudinal position of the next submerged pipe and performing the second floating cast of the submerged pipe at that corresponding longitudinal position.

[0086] Method b: Lay the second pump pipe 4 from the shore to the layer to be poured 113. Figure 10 As shown, the second pump pipe 4 can be arranged on the water surface by providing a buoyancy-aiding structure, thereby reducing the impact and damage of water on the second pump pipe 4.

[0087] In step S4, both longitudinal ends of the immersed tube are poured simultaneously, and the speed of the secondary floating concrete pouring at the large end of the immersed tube is controlled to be greater than the speed of the secondary floating concrete pouring at the small end of the immersed tube, which can ensure the longitudinal balance of the immersed tube during pouring.

[0088] When the secondary floating cast submerged pipe with a changing transverse span is the structure in Example 2, it is necessary to first use method a and method b to cast the concrete of the first embedded steel pipe 21, the second embedded steel pipe 22, the third embedded steel pipe 23, etc., and then use the strength after forming to cast the concrete of the layer to be cast 113 to form a complete top plate 11 to ensure casting safety.

[0089] In step S1, when manufacturing the secondary floating cast submerged tube with a variable transverse span as described in Example 2, the following conditions exist:

[0090] Case X: When the first weight-reducing component is provided, cooling water is injected into the cavity of the first weight-reducing component, and then the bottom plate 12 and the wall are cast;

[0091] Case Y: When a second weight-reducing component is provided, cooling water is injected into the cavity of the second weight-reducing component, and then the top plate 11 is cast; when a secondary floating cast immersed tube with a changed lateral span is produced in the early stage, cooling water is injected into the cavity of the first weight-reducing component or the second weight-reducing component to improve the heat dissipation effect of the concrete, thereby reducing the probability of cracks on the concrete surface of the bottom plate 12 and the side wall 13 or the top plate 11; and the injected cooling water will not affect the quality of the secondary floating cast cavity in the later stage.

[0092] 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 and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A secondary floating cast immersed tube with variable transverse span, characterized in that: The immersed tube comprises a large end and a small end, the transverse width of the cross section of the large end of the immersed tube is greater than the transverse width of the cross section of the small end of the immersed tube, and the transverse width of the cross section of the small end of the immersed tube gradually decreases from the middle to the end along the longitudinal direction of the immersed tube; the immersed tube comprises a top plate (11), a bottom plate (12) and a wall, the top plate (11) comprises a first cast layer (111), and a layer to be cast (113) is provided above the first cast layer (111); the layer to be cast (113) is located in the middle of the horizontal plane of the top plate (11), part of the layer to be cast (113) is located at the large end of the immersed tube, part of the layer to be cast (113) is located at the small end of the immersed tube, and the layer to be cast (113) is adjacent to the immersed tube. The distance between the large end faces is greater than the distance between the layer to be cast (113) and the small end face of the immersed tube, and the layer to be cast (113) is symmetrical about the longitudinal center axis of the top plate (11); the layer to be cast (113) is surrounded by a second cast layer (112), and the ratio of the distance between the layer to be cast (113) and the side edges of the top plate (11) to the width of the top plate (11) is greater than or equal to 10%; the ratio of the thickness of the first cast layer (111) to the thickness of the top plate (11) is greater than or equal to 30%; the ratio of the distance between the layer to be cast (113) and the two end faces of the top plate (11) to the length of the top plate (11) is greater than or equal to 1 / 6; The reinforced concrete of the bottom plate (12) and the wall has a first weight-reducing component, the first weight-reducing component has a cavity, and the cavity can be used for pouring concrete; and / or the second poured layer (112) located at both ends of the top plate (11) is provided with a second weight-reducing component, the second weight-reducing component has a cavity, and the cavity can be used for pouring concrete.

2. The secondary floating casting immersed tube with variable transverse span according to claim 1, characterized in that: When the first weight-reducing component is provided, the first weight-reducing component comprises a first embedded steel pipe (21) transversely arranged in the bottom plate (12) and a second embedded steel pipe (22) vertically arranged in the wall, the second embedded steel pipe (22) being connected to the first embedded steel pipe (21); When the second weight-reducing component is provided, the second weight-reducing component comprises a third embedded steel pipe (23) transversely arranged in the second cast layer (112), and the third embedded steel pipe (23) has an upward communication port.

3. The secondary floating casting immersed tube with variable transverse span according to claim 2, characterized in that: The wall body comprises a side wall (13) and a middle wall (14); the upper end of the second embedded steel pipe (22) located on the side wall (13) and corresponding in longitudinal direction to the layer to be cast (113) is connected to a fourth embedded steel pipe (24); the fourth embedded steel pipe (24) is transversely arranged in the second cast layer (112) on both sides of the top plate (11); and the fourth embedded steel pipe (24) is connected to the layer to be cast (113).

4. The secondary floating casting immersed tube with variable transverse span according to claim 3, characterized in that: The third embedded steel pipe (23) is located in the transverse middle of the top plate (11), and the corresponding ends of all the third embedded steel pipes (23) are located on the same longitudinal line of the immersed pipe.

5. A method for floating a submerged tube, characterized in that: The following steps are involved: S1. Manufacturing a secondary floating cast immersed tube with a variable transverse span as described in any one of claims 1 to 4; S2, floating and transporting the secondary floating cast submerged tube with a changed transverse span to a storage area near the foundation trench; S3, anchoring the secondary floating cast-in-place immersed tube with a changed transverse span in the storage area by dropping anchor; S4, pre-embed a water stop in the layer to be cast (113) of the secondary floating cast submerged pipe with a changed transverse span and prepare the joint surface, and then cast concrete in the layer to be cast (113) by pumping concrete to form a complete top plate (11); in step S4, the longitudinal ends of the submerged pipe are cast simultaneously, and the speed of the secondary floating cast concrete at the large end of the submerged pipe is controlled to be greater than the speed of the secondary floating cast concrete at the small end of the submerged pipe.

6. The method for floating a submerged tube according to claim 5, characterized in that: In step S1, the following conditions exist: Case X: When a first weight-reducing component is provided, cooling water is injected into the cavity of the first weight-reducing component, and then the bottom plate (12) and the wall are cast; Case Y: When a second weight-reducing component is provided, cooling water is injected into the cavity of the second weight-reducing component, and then the top plate (11) is cast.

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