Novel separated steel casing

Abstract

The utility model discloses a novel separating type steel casing which comprises an upper layer steel casing and a lower layer steel casing which are sequentially arranged in an abutting mode in the vertical direction, a plurality of auxiliary steel bars are laid between the lower layer steel casing and the upper layer steel casing, and the two ends of the auxiliary steel bars are connected with the bottom of the lower layer steel casing respectively. And the top of the upper-layer steel casing is welded. According to the utility model, the structure of the existing steel casing is improved, the two-section type structure is adopted, and the two sections are connected into a whole by using the auxiliary steel bars, so that one section can be detached for recycling by cutting off the auxiliary steel bars in the project construction process, and further, the one-time investment of the steel casing is reduced, and the use cost of the steel casing is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of bridge bored pile construction, in particular to a novel separated steel casing. Background Art

[0002] With the rapid development of high-speed railway construction in recent years, the railway construction environment is no longer limited to land construction, and involves more and more underwater bored pile construction in rivers, lakes, waterways, etc. In general, underwater bored piles have a large pile diameter and a long pile length, and need to be constructed with the help of temporary trestles and water platforms. Before construction, steel casings need to be buried. According to the specification, the casing needs to be buried at least 0.5m higher than the construction platform, which leads to the length of a single steel casing being too long.

[0003] The construction process of traditional underwater bored piles is the same as that of bored piles on the road. At present, the construction technology is relatively complete, but there is no better way to deal with the steel casing. Removing the casing too early may affect the quality of the pile head. Removing the casing too long may cause the casing to be unable to be removed smoothly. Increasing the pulling force may also affect the quality of the pile head, and there is also a certain risk to the stability of the working platform.

[0004] At present, most domestic projects adopt the method of leaving the steel casing in place after the concrete pouring is completed, and then removing it together or after the foundation pit is excavated. The underwater foundation pit needs to be excavated after the foundation pit protection measures are completed, which leads to excessive one-time amortization cost of the steel casing, and a large amount of steel casing needs to be invested in the early stage. The rental period of the casing is long, which increases the project cost. Utility Model Content

[0005] The utility model provides a novel separated steel casing to solve the above technical problems.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] A new type of separated steel casing comprises an upper steel casing and a lower steel casing which are arranged closely in sequence along the vertical direction. A plurality of auxiliary steel bars are laid between the lower steel casing and the upper steel casing. The two ends of the plurality of auxiliary steel bars are respectively welded to the bottom of the lower steel casing and the top of the upper steel casing. During the project construction process, one section of the auxiliary steel bars can be removed and recycled by cutting off the auxiliary steel bars, thereby reducing the amount of steel casing invested at one time and reducing the use cost of the steel casing.

[0008] Preferably, it also includes a protective sleeve that is sleeved at the connection between the lower steel casing and the upper steel casing. The setting of the protective sleeve, on the one hand, limits the lower steel casing and the upper steel casing to facilitate the setting of auxiliary steel bars, and on the other hand, reduces the shear force on the auxiliary steel bars. Specifically, the protective sleeve is connected to the upper steel casing as a whole, and the protective sleeve is connected to the upper steel casing to form an assembly part, and the lower steel casing can be detachably inserted into the assembly part, so that the protective sleeve can be pulled out together with the upper steel casing.

[0009] Preferably, the protective sleeve is detachably connected to the upper steel casing to enable the protective sleeve to be removed.

[0010] Compared with the prior art, the utility model has the following beneficial effects:

[0011] 1. The utility model improves the structure of the existing steel casing, adopts a two-section structure, and uses auxiliary steel bars to connect them into a whole. During the project construction process, one section can be removed and recycled by cutting off the auxiliary steel bars, thereby reducing the amount of steel casing invested at one time and reducing the cost of using the steel casing.

[0012] 2. When in use, only the upper steel casing is cut off, and the lower steel casing is still retained. During the entire construction process, the pile head concrete will not be disturbed, ensuring that the construction quality of the underwater bored piles is not affected.

[0013] 3. The protective sleeve sets up to limit the lower steel casing and the upper steel casing on the one hand, facilitating the setting of auxiliary steel bars, and on the other hand, reduces the shear force on the auxiliary steel bars. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0015] Figure symbols: 1. Upper steel casing, 2. Lower steel casing, 3. Auxiliary steel bars, 4. Protective cover. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments and drawings. The schematic implementation manner of the utility model and its description are only used to explain the utility model and are not intended to limit the utility model.

[0017] Example 1

[0018] like Figure 1A new type of separate steel casing shown is suitable for underwater bored pile construction, including an upper steel casing 1 and a lower steel casing 2 arranged closely in sequence along the vertical direction, a plurality of auxiliary steel bars 3 are laid between the lower steel casing 2 and the upper steel casing 1, and the two ends of the plurality of auxiliary steel bars 3 are respectively welded to the bottom of the lower steel casing 2 and the top of the upper steel casing 1. During the project construction process, the upper steel casing 1 can be removed and recycled by cutting off the auxiliary steel bars 3, thereby reducing the amount of the upper steel casing 1 invested at one time and reducing the cost of use.

[0019] During the specific implementation process, the technical personnel select the lower steel casing 2 of corresponding length in advance based on the relevant data such as the pile top elevation and the over-pouring concrete height. The upper steel casing 1, the lower steel casing 2 and the auxiliary steel bars 3 are transported to the construction site by flatbed trucks and then assembly can begin. First, the upper steel casing 1 and the lower steel casing 2 are arranged closely in the vertical direction, and then the two ends of the auxiliary steel bars 3 are respectively welded to the ends of the upper steel casing 1 and the lower steel casing 2 that are away from each other to form a separated steel casing, wherein the auxiliary steel bars 3 are generally selected with a strength not less than HRB400 A16 steel bars, and the weld length is controlled at 10d. Then the separated steel casing is hoisted into the underwater drilling hole. Finally, after the pile foundation concrete is poured, the auxiliary steel bars 3 on the top of the upper steel casing 1 are manually cut off, and the upper steel casing 1 can be hoisted and separated from the lower steel casing 2. At this time, the upper steel casing 1 can be recycled, thereby reducing the amount of steel casing invested at one time and reducing the use cost of the steel casing. The lower steel casing 2 is still retained, and the pile head concrete will not be disturbed during the entire construction process, ensuring that the construction quality of the underwater bored pile is not affected.

[0020] Example 2

[0021] On the basis of Example 1, the above also includes a protective sleeve 4 sleeved at the connection between the lower steel casing 2 and the upper steel casing 1. The setting of the protective sleeve 4, on the one hand, limits the lower steel casing 2 and the upper steel casing 1, and facilitates the setting of the auxiliary steel bars 3. On the other hand, when the connected upper steel casing 1 and the lower steel casing 2 are lowered into the water for drilling, the shear force on the auxiliary steel bars 3 is reduced. Specifically, the protective sleeve 4 is connected to the upper steel casing 1 as a whole, and the protective sleeve 4 is connected to the upper steel casing 1 to form an assembly part, and the lower steel casing 2 is detachably inserted into the assembly part. In specific implementation, when the auxiliary steel bars 3 are cut off and the upper steel casing 1 is lifted from the underwater drilling, the protective sleeve 4 is also lifted out and recycled together with the upper steel casing 1. Preferably, the protective sleeve 4 is detachably connected to the upper steel casing 1.

[0022] Of course, the present invention may have many other implementation modes. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and deformations based on the present invention, but these corresponding changes and deformations should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. A new type of separated steel casing, characterized in that: The invention comprises an upper steel casing (1) and a lower steel casing (2) which are arranged closely in sequence along the vertical direction, a plurality of auxiliary steel bars (3) are laid between the lower steel casing (2) and the upper steel casing (1), and the two ends of the plurality of auxiliary steel bars (3) are respectively welded to the bottom of the lower steel casing (2) and the top of the upper steel casing (1).

2. The novel separated steel casing according to claim 1 is characterized in that: It also includes a protective sleeve (4) sleeved on the connection between the lower steel casing (2) and the upper steel casing (1); The protective sleeve (4) is connected to the upper steel casing (1) to form a whole, and after the protective sleeve (4) is connected to the upper steel casing (1), an assembly portion is formed, and the lower steel casing (2) can be detachably inserted into the assembly portion.

3. The new type of separated steel casing according to claim 2 is characterized in that: The protective sleeve (4) is detachably connected to the upper steel casing (1).

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