Shaft bottom structure constructed by open caisson method

Abstract

The utility model relates to the technical field of open caisson construction, in particular to a shaft bottom structure for open caisson method construction, which comprises a frame rib, a supporting rib arranged in the frame rib, an inner reinforcing rib arranged on the inner side of the frame rib, an outer reinforcing rib arranged on the outer side of the frame rib, and connecting steel bars arranged at intervals in the circumferential direction. The opening side of the connecting steel bar is located on the inner side of the shaft, and the end of the connecting steel bar is provided with a connecting sleeve used for being connected with a bottom plate steel bar; when the pouring formwork is arranged, the end of the connecting sleeve is tightly attached to the pouring formwork. Through holes do not need to be formed in the pouring formwork, and formwork removal is simple and rapid; during manual earth cutting, the safety of constructors can be further guaranteed; the influence on transportation of the base soil by the connecting steel bars is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of caisson construction, in particular to a shaft bottom structure constructed by a caisson method. Background Art

[0002] The caisson method, also known as the caisson well drilling method, is a method in which a pre-fabricated section of an integral well wall is partially sunk into the soil by its own weight at the designed position of the well before excavation of the soil layer. Then, under its cover, the well is sunk while excavating and the well wall is built accordingly. After sinking to the designed elevation, the caisson floor is cast to seal the bottom.

[0003] The blade foot part is usually located at the lower end of the bottom shaft. When constructing the caisson, the shaft part with the blade foot must be constructed first, which is later referred to as the bottom shaft. When constructing the bottom shaft, it is necessary to reserve joint steel bars on the inside of the shaft according to the drawings to be combined with the later bottom sealing steel bars. According to the requirements and specifications of the drawings, the joint steel bars are generally about 1.5m; the reservation of joint steel bars has the following problems during construction: 1. The reserved joint steel bars usually require drilling holes in the template for the joint steel bars to pass through. The template is easily damaged when the template is removed, and the removal construction is more difficult; 2. When manual excavation is used in the early stage, it is not conducive to the safety of construction workers and slows down the construction progress of the entire project; 3. The subsequent transportation of the base soil is difficult, and the base soil is difficult to transport out due to the influence of the joint steel bars. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a shaft bottom structure for caisson construction that is convenient for subsequent bottom plate reinforcement connection and subsequent excavation.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A shaft bottom structure constructed by the caisson method includes frame bars, support bars are arranged in the frame bars, inner reinforcing bars are arranged on the inner side of the frame bars, and outer reinforcing bars are arranged on the outer side, the inner reinforcing bars and the outer reinforcing bars are both annular structural bars, and also includes connecting steel bars arranged at intervals in the annular direction, the connecting steel bars are U-shaped and are tied and fixed to the frame bars, one side of the connecting steel bar opening is located on the inner side of the shaft, and the end is provided with a connecting sleeve for connecting to the bottom plate steel bars; when setting a casting template, the end of the connecting sleeve is set close to the casting template.

[0007] Compared with the prior art, the utility model adopting the above technical solution has the following outstanding features:

[0008] After the concrete reaches the demolding strength and the casting formwork is removed, the end of the connecting sleeve is flush with the inner wall of the shaft, and the connecting port of the connecting sleeve is exposed, which is used to connect the bottom plate steel bars during the subsequent construction of the caisson bottom plate; no through holes are required on the casting formwork, and demolding is simple and quick; the safety of construction workers can be further guaranteed during manual excavation; and the transportation of the base soil is prevented from being affected by the joint steel bars.

[0009] As a preferred embodiment, a further technical solution of the utility model is:

[0010] A plugging piece is arranged in the connecting sleeve; during the subsequent caisson excavation operation, it plays a role in protecting the connecting sleeve and preventing the connecting sleeve from being contaminated by concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the bottom structure of a shaft constructed by the caisson method in the prior art;

[0012] Figure 2 It is a structural schematic diagram of the bottom shaft in the embodiment of the utility model;

[0013] Figure 3 It is a schematic diagram of the connection structure between the steel bar and the connecting sleeve in the embodiment of the utility model.

[0014] Explanation of the reference numerals in the accompanying drawings: 1. Frame reinforcement; 101. Inner longitudinal reinforcement; 102. Outer longitudinal reinforcement; 103. Blade foot reinforcement; 2. Support reinforcement; 3. Inner reinforcing ribs; 4. Outer reinforcing ribs; 5. Joint steel bars; 6. Connecting steel bars; 7. Connecting sleeve; 8. Well wall. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with specific embodiments, the purpose of which is only to provide a better understanding of the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0016] like Figure 1 , which is a shaft bottom structure constructed by the caisson method in the prior art, and a joint steel bar 5 is arranged on the frame reinforcement 1. The joint steel bar 5 is U-shaped, with one side of the opening located on the inner side of the shaft, and the end of the joint steel bar 5 extends to the inner side of the shaft. When setting the casting template, the casting template is provided with a through hole corresponding to the end of the joint steel bar 5. After the bottom shaft is cast, the demoulding strength is reached, and the demoulding is carried out. The open end of the joint steel bar 5 is located outside the shaft, and is combined with the shaft bottom plate steel bar when the shaft bottom plate steel bar is tied later. In the existing shaft bottom structure constructed by the caisson method, due to the external end of the joint steel bar 5, the casting template is easily damaged during demoulding, and the removal construction is more difficult. In the early stage of manual excavation, construction personnel may be pierced, and the soil at the base is difficult to transport out due to the influence of the joint steel bar 5.

[0017] Furthermore, if Figure 2 As shown, this embodiment discloses a shaft bottom structure different from the prior art caisson construction method, including a frame rib 1, the frame rib 1 includes an inner longitudinal rib 101 close to the inner wall of the shaft, an outer longitudinal rib 102 close to the outer wall of the shaft, and a blade foot rib 103 located at the blade foot of the bottom of the shaft, the upper end of the blade foot rib 103 is tied and fixed with the inner longitudinal rib 101 and the outer longitudinal rib 102; a support rib 2 is arranged between the inner and outer sides of the blade foot rib 103; an inner reinforcing rib 3 is arranged on the inner side of the blade foot rib 103, and an outer reinforcing rib 4 is arranged on the outer side, and the inner reinforcing rib 3 and the outer reinforcing rib 4 are both annular structural ribs; wherein the inner reinforcing rib 3, The outer reinforcing ribs 4 and the bracing ribs 2 both strengthen the blade foot ribs 103 to ensure the blade foot strength; they also include connecting steel bars 6 arranged at circumferential intervals, which are U-shaped and are tied and fixed to the blade foot ribs 103 in the frame ribs 1. The open side of the connecting steel bars 6 is located on the inner side of the shaft, and the end is provided with a connecting sleeve 7 for connecting to the bottom plate steel bars; when setting the casting formwork, the end of the connecting sleeve 7 is set close to the casting formwork; the casting formwork does not need to be provided with corresponding through holes, and demolding is simple and quick; after the concrete reaches the demolding strength and the casting formwork is removed, the end of the connecting sleeve 7 is flush with the inner wall of the shaft, and the connecting port of the connecting sleeve 7 is exposed.

[0018] Furthermore, after the casting formwork is removed, subsequent caisson construction is required. After the construction reaches the designed elevation, the caisson bottom plate construction can be carried out, so the base soil will be transported out. During the soil transportation operation, in order to avoid the connecting sleeve 7 being contaminated by concrete and affecting the subsequent connection of the caisson bottom plate steel bars, a sealing piece is also provided in the connecting sleeve 7; the sealing piece can be inserted after the casting formwork is disassembled, or it can be inserted before the casting formwork is installed; in this embodiment, the sealing piece is sealed with a cotton block and affixed with adhesive tape. Correspondingly, technical personnel in this field can also use wooden plugs or rubber plugs for sealing; when the steel bars of the caisson bottom plate are subsequently tied, it is only necessary to tear off the adhesive tape and take out the cotton block to connect the caisson bottom plate steel bars with the connecting steel bars 6.

[0019] Furthermore, the connecting sleeve 7 can adopt an internal thread connecting sleeve 7. When the bottom plate reinforcement is connected, a thread structure is provided at the end of the bottom plate reinforcement. The thread structure connection has a greater connection strength and is not easy to loosen.

[0020] Furthermore, the connecting sleeve 7 can adopt a connecting sleeve 7 with a smooth inner wall and no threads. When connecting the bottom plate steel bars, the end of the bottom plate steel bars is wrapped with raw tape. Compared with the above-mentioned threaded connection structure, the connecting sleeve 7 with a smooth inner wall is simpler to connect, and the provision of raw tape can enhance the airtightness of the interface.

[0021] The utility model avoids the external placement of the joint steel bars, and the safety of the construction workers can be further guaranteed during manual excavation; and the joint steel bars are prevented from affecting the transportation of the base soil.

[0022] The above description is only a preferred feasible embodiment of the present utility model, and does not limit the scope of rights of the present utility model. All equivalent changes made using the contents of the present utility model specification and its drawings are included in the scope of rights of the present utility model.

Claims

1. A shaft bottom structure constructed by caisson method, comprising frame ribs, support ribs are arranged in the frame ribs, inner reinforcing ribs are arranged inside the frame ribs, and outer reinforcing ribs are arranged outside the frame ribs, the inner reinforcing ribs and the outer reinforcing ribs are both annular structural ribs, characterized in that: It also includes connecting steel bars arranged at circumferential intervals. The connecting steel bars are U-shaped and are tied and fixed to the frame bars. The open side of the connecting steel bars is located on the inner side of the shaft, and the end is provided with a connecting sleeve for connecting to the bottom plate steel bars. When setting the casting formwork, the end of the connecting sleeve is set close to the casting formwork.

2. The bottom structure of the shaft constructed by the caisson method according to claim 1 is characterized in that: A blocking piece is arranged in the connecting sleeve.

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