Pile foundation casing and cast-in-place pile construction method

Abstract

The application discloses a pile foundation casing and a construction method of a cast-in-place pile, and comprises a first casing wall and a second casing wall used for surrounding the pile foundation casing, a slot is formed in the first casing wall, the slot penetrates through the first casing wall along the axial direction of the first casing wall, the second casing wall is embedded in the slot and can slide along the slot, and a positioning structure for fixing a concrete guide pipe is arranged on the top end of the second casing wall, so that the height position of the second casing wall and the concrete guide pipe is unchanged when the first casing wall is lifted in the pile foundation construction, the concrete shrinkage can be timely supplemented, the operation is convenient, the construction difficulty is small, the time and labor cost can be saved, and the construction efficiency is obviously improved.

Description

Technical Field

[0001] This invention relates to the field of pile foundation construction technology, and in particular, to a pile foundation casing. Furthermore, this invention also relates to a construction method for cast-in-place piles using the aforementioned pile foundation casing. Background Technology

[0002] Pile foundations are an ancient type of foundation. The number and arrangement of piles in a pile foundation should be determined according to the superstructure and load conditions. Column pile foundations can use a single pile or a group of piles arranged in a polygon. Wall pile foundations are often arranged in rows. When the building load is large and the floor area is small, they should be arranged in a full-area pile foundation. Building pile foundations are usually low-cap pile foundations. Pile foundations are widely used in high-rise buildings.

[0003] In the process of pile foundation construction, pile casings are usually used. For example... Figure 1 As shown, when using existing pile casings, to prevent the casings from being unable to be pulled out after construction and to avoid pile defects caused by excessive single-stage casing pull-out, it is necessary to intermittently raise the pile casings upwards, coordinating with a crane to hoist concrete to the top of the casing for concrete pouring. However, as the pile casings are continuously raised, the height of the concrete hoisted to the top of the casing also increases accordingly. On the one hand, the construction process requires one crane to lift the casing and another crane to hoist concrete from the top opening of the casing for pouring, which is difficult to align, cumbersome to operate, inefficient, and energy-intensive. On the other hand, for piles with large axial lengths, the height of the top opening of the casing is much higher than the ground, making it difficult to hoist concrete to the top opening. As a result, when pouring the upper pile body, the casing must be pulled out, and then the concrete volume of the pile body must be supplemented. This operation method makes it impossible to guarantee the quality of the concrete pouring of the upper pile body, and the worse the soil quality, the greater the quality defects of the pile body. Summary of the Invention

[0004] This invention provides a construction method for pile foundation casing and cast-in-place piles to solve the technical problems of existing pile foundation casings, where the hoisting height of concrete needs to be raised synchronously with the lifting of the pile foundation casing, resulting in high construction difficulty, cumbersome operation, low efficiency, high equipment energy consumption, and difficulty in ensuring the quality of the pile body.

[0005] According to one aspect of the present invention, a pile foundation casing is provided, comprising a first casing wall and a second casing wall for forming the pile foundation casing. The first casing wall has a slot that extends through the first casing wall along its axial direction. The second casing wall is embedded in the slot and can slide along the slot. A positioning structure for fixing a concrete guide pipe is provided on the top end of the second casing wall, so that when the first casing wall is raised during pile foundation construction, the height and position of the second casing wall and the concrete guide pipe remain unchanged.

[0006] Further, the positioning structure is a through hole opened on the second casing wall for inserting the concrete guide pipe, or a clamp arranged on the top surface of the second casing wall.

[0007] Further, a limiting block for preventing the second casing wall from sliding out of the slot is arranged on the bottom end of the first casing wall, and a lug corresponding to the limiting block is arranged on the second casing wall.

[0008] Further, the lug is completely matched with the outer side surface of the first casing wall.

[0009] Further, a locking mechanism for limiting the position of the second casing wall is arranged on the top end of the first casing wall, and the locking mechanism comprises a pin shaft arranged on the first casing wall and a buckle for hooking the second casing wall hinged to the pin shaft.

[0010] Further, a connecting plate is arranged at the top end of the slot, the pin shaft is arranged on the connecting plate, and the buckle is matched with the positioning structure.

[0011] Further, the buckle is matched with the lug.

[0012] Further, the slot of the first casing wall and the second casing wall are slidingly matched through a sliding groove and a sliding bar.

[0013] Further, an elastic sealing layer is arranged between the sliding groove and the sliding bar.

[0014] According to another aspect of the present application, a construction method of a cast-in-place pile is also provided, which adopts the pile casing described above, and comprises the following steps:

[0015] S1, hoisting,

[0016] The second casing wall is fixedly connected with the first casing wall through the locking mechanism to prevent the second casing wall from sliding during hoisting, and the pile casing is hoisted to the pile foundation position by a crane;

[0017] S2, burying,

[0018] The pile casing is buried, the top surface of the pile casing is 30-50 cm higher than the ground surface to ensure that the positioning structure is higher than the ground surface, and the locking mechanism is opened;

[0019] S3, equipment in place,

[0020] The concrete guide pipe is connected to the pumping machine, the positioning structure is extended into the pile bottom position inside the pile casing, and the concrete is prepared for pouring;

[0021] S4, pouring,

[0022] Start the pumping machine, the concrete conduit pumps the concrete into the pile foundation casing, with the concrete, use the crane to lift the first casing wall, until the lug on the second casing wall is clamped on the limiting block at the bottom end of the first casing wall, the concrete can be directly poured to the pile top over-pouring position at one time;

[0023] S5, clearing the field,

[0024] After the cast-in-place pile pouring is completed, the concrete conduit is disassembled from the positioning structure on the second casing wall, and the second casing wall is pulled out by the crane.

[0025] The present application has the following beneficial effects:

[0026] The pile foundation casing of the present application is a spliced structure, the second casing wall is embedded in the slot on the first casing wall, so that the first casing wall and the second casing wall can slide relative to each other along the axial direction, the concrete conduit is positioned from the positioning structure on the second casing wall and extends into the pile foundation casing, during the construction process, the height of the second casing wall can remain unchanged when the first casing wall is pulled up, so that the height of the concrete conduit also remains unchanged, the process of pulling up the first casing wall does not affect the concrete pouring, the concrete pouring can be uninterrupted, the concrete shrinkage can be timely supplemented, the operation is convenient, the construction difficulty is small, the time and labor cost can be saved, and the construction efficiency is significantly improved; since the concrete conduit does not need to be lifted, the concrete can be directly poured to the pile top over-pouring position at one time, and the longer the axial direction of the pile body, the more obvious the advantage of using the pile foundation casing of the present application for construction.

[0027] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present application, the schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 is a structure schematic diagram of using the existing pile foundation casing for construction;

[0030] Figure 2 is a structure schematic diagram of the top end of the pile foundation casing of the preferred embodiment of the present application;

[0031] Figure 3 is a top view of the pile foundation casing of the preferred embodiment of the present application;

[0032] Figure 4 is a structure schematic diagram of the second casing wall of the preferred embodiment of the present application;

[0033] Figure 5 isFigure 4 a sectional view along the direction of A-A;

[0034] Figure 6 a structural schematic view of the bottom end of the pile casing according to the preferred embodiment of the present application;

[0035] Figure 7 Figure 6 a sectional view along the direction of B-B;

[0036] Figure 8 a structural schematic view of the elastic sealing layer according to the preferred embodiment of the present application;

[0037] Figure 9 a structural schematic view of the sliding groove according to the preferred embodiment of the present application;

[0038] Figure 10 a structural schematic view of the clamping groove according to the preferred embodiment of the present application;

[0039] Figure 11 a structural schematic view of the pile casing according to the preferred embodiment of the present application in use.

[0040] Legend:

[0041] 1, first casing wall; 11, slot; 12, limiting block; 13, locking mechanism; 131, pin shaft; 132, buckle; 14, connecting plate; 2, second casing wall; 21, through hole; 22, lug; 3, concrete guide pipe; 4, sliding groove; 41, clamping groove; 5, sliding bar; 51, clamping bar; 6, elastic sealing layer. DETAILED DESCRIPTION

[0042] The embodiments of the present application will be described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways as defined and covered by the following.

[0043] Please refer to Figures 2 to 11 , the pile casing according to the embodiment, comprising a first casing wall 1 and a second casing wall 2 for enclosing the pile casing, the first casing wall 1 is provided with a slot 11, the slot 11 penetrates the first casing wall 1 along the axial direction of the first casing wall 1, the second casing wall 2 is embedded in the slot 11 and can slide along the slot 11, the top end of the second casing wall 2 is provided with a positioning structure for fixing the concrete guide pipe 3, so that the height position of the second casing wall 2 and the concrete guide pipe 3 remains unchanged when the first casing wall 1 is lifted during pile construction.

[0044] ​The pile foundation casing of the embodiment is a spliced structure. The second casing wall 2 is embedded in the slot 11 on the first casing wall 1, so that the first casing wall 1 and the second casing wall 2 can slide relative to each other in the axial direction. The concrete guide pipe 3 is positioned by the positioning structure on the second casing wall 2 and extends into the pile foundation casing. During construction, the height of the second casing wall 2 remains unchanged when the first casing wall 1 is lifted, so that the height of the concrete guide pipe 3 also remains unchanged. The process of lifting the first casing wall 1 does not affect concrete pouring, and concrete pouring can be uninterrupted, concrete shrinkage can be supplemented in time, and the operation is convenient, the construction difficulty is small, time and labor costs can be saved, and the construction efficiency is significantly improved. Since the concrete guide pipe 3 does not need to be lifted, the concrete can be directly poured to the pile top over-pouring position at one time, and the longer the pile shaft in the axial direction, the more obvious the advantage of using the pile foundation casing of the embodiment for construction. Optionally, the pile foundation casing is cylindrical, the first casing wall 1 is a superior arc segment, and the second casing wall 2 is an inferior arc segment, which is suitable for circular pile foundation construction. Optionally, the corresponding chord length of the second casing wall 2 is 22-25 cm. The longer the arc length of the second casing wall 2, the more directly related the second casing wall 2 to the quality of the pile body concrete. For example, the diameter of the pile foundation casing is 1000 mm, the diameter of the concrete guide pipe 3 is 20 cm, the first casing wall 1 and the second casing wall 2 are both semicircles, and after the first casing wall 1 is lifted, concrete shrinkage can be supplemented, but when the second casing wall 2 is lifted, a large amount of concrete shrinkage is still caused and cannot be supplemented. The smaller the arc length of the second casing wall 2 (for example, the corresponding chord length is 25 cm), the less the concrete shrinkage caused by the lifting of the second casing wall 2, and the concrete over-pouring can completely make up for the loss of quality. However, the corresponding chord length of the second casing wall 2 cannot be less than the diameter of the concrete guide pipe 3 (20 cm). As the diameter of the pile foundation casing increases, the arc length of the second casing wall 2 changes little or not at all, which can meet the requirement that there is at least 1 cm of margin on both sides of the positioning structure. Optionally, the pile foundation casing is a square cylinder, the first casing wall 1 is connected by three side walls and has a “door” type structure in cross section, and the second casing wall 2 and the first casing wall 1 form a square cylinder in the shape of a “mouth” character, which is suitable for square pile foundation construction. Optionally, the wall thickness of the pile foundation casing is 10-15 mm. A wall thickness less than 10 mm is not conducive to the processing of the sliding groove 4 and the sliding bar 5. Although a larger wall thickness is more conducive to the processing of the sliding groove 4 and the sliding bar 5, the cost of the pile foundation casing is higher and the weight is larger, and the energy consumption of hoisting is also increased accordingly. Therefore, a wall thickness greater than 15 mm is not cost-effective.

[0045] As shown in Figure 2 , Figure 4 , Figure 5 and Figure 6 , in the embodiment, the positioning structure is a through hole 21 formed on the second casing wall 2 for inserting the concrete guide pipe 3. The concrete guide pipe 3 is inserted into the bottom end of the pile foundation casing from the through hole 21, as shown in Figure 11As shown, the self-bending can prevent the concrete conduit 3 from slipping off, has simple structure and good positioning effect; in addition, the through hole 21 can also be used as a fixing hole for lifting the second casing wall 2, without adding additional lifting connection structure, and the processing cost is low. Alternatively, the positioning structure can also be a clamp arranged on the top surface of the second casing wall 2, the clamp is matched with the outer diameter of the concrete conduit 3, and the fixing effect is better.

[0046] As shown in Figure 6 and Figure 7 In this embodiment, the bottom end of the first casing wall 1 is provided with a limiting block 12 for preventing the second casing wall 2 from slipping off from the slot 11, and the second casing wall 2 is provided with a lug 22 corresponding to the limiting block 12. The limiting block 12 is arranged on the outer side of the bottom end of the first casing wall 1, and two limiting blocks 12 are arranged on the two sides of the slot 11. During construction, the first casing wall 1 is lifted until the lug 22 on the second casing wall 2 abuts against the limiting block 12, which can prevent the second casing wall 2 from slipping off in the axial direction, and for the pile casing with a short axial length, the second casing wall 2 can be lifted by continuing to lift the first casing wall 1, without the need for additional lifting device, thereby saving construction cost.

[0047] As shown in Figure 4 and Figure 6 In this embodiment, the lug 22 is completely attached to the outer side of the first casing wall 1, the slide bar 5 is arranged inside and outside the lug 22, and the connection between the first casing wall 1 and the second casing wall 2 is supported, which can align the first casing wall 1 and the second casing wall 2, and prevent the connection between the first casing wall 1 and the second casing wall 2 from deforming in the radial direction.

[0048] As shown in Figure 5 In this embodiment, the top end of the first casing wall 1 is provided with a locking mechanism 13 for limiting the position of the second casing wall 2, the locking mechanism 13 includes a pin shaft 131 arranged on the first casing wall 1 and a buckle 132 hinged with the pin shaft 131 for hooking the second casing wall 2, which can prevent the second casing wall 2 from slipping during lifting. Alternatively, the distance between the axis of the pin shaft 131 and the top surface of the first casing wall 1 is less than or equal to 20 cm, so that the through hole 21 is higher than the ground, ensuring concrete overfilling and preventing sundries and water from entering the pile casing through the through hole 21.

[0049] As shown in Figure 4 and Figure 5As shown, in the embodiment, the top end of the slot 11 is provided with a connecting plate 14, a pin shaft 131 is arranged on the connecting plate 14, and the buckle 132 is matched with the through hole 21 or the clamping hoop. In use, the second casing wall 2 can be fixed by hooking the through hole 21 with the buckle 132. The structure is simple, the operation is convenient, and the processing cost is low. Alternatively, the locking mechanism 13 can also be arranged on the outer side of the top end of the first casing wall 1, the buckle 132 is matched with the lug 22, and the second casing wall 2 can be fixed by hooking the lug 22 with the buckle 132.

[0050] As shown in Figure 8 and Figure 9 , in the embodiment, the slot 11 of the first casing wall 1 is slidably connected with the second casing wall 2 through the sliding groove 4 and the sliding bar 5. The two opposite end faces of the slot 11 are provided with the sliding bar 5, and the second casing wall 2 is provided with the sliding groove 4 matched with the sliding bar 5. The first casing wall 1 and the second casing wall 2 can be slidably connected by embedding the sliding bar 5 in the sliding groove 4. The structure is simple, the processing cost is low. Alternatively, the sliding bar 5 and the sliding groove 4 are parallel to each other along the circumferential direction, so that the sliding bar 5 and the sliding groove 4 can be pulled out in the circumferential direction, so that the diameter of the whole pile casing can be slightly expanded to facilitate the pile casing to be pulled out. Alternatively, the end of the sliding bar 5 is provided with a clamping bar 51 to prevent it from falling out, and the sliding groove 4 is provided with a clamping groove 41 matched with the clamping bar 51 to prevent the second casing wall 2 from sliding off in the circumferential direction. Alternatively, as shown in Figure 10 , the clamping groove 41 is a dovetail groove, and the clamping bar 51 is matched with the clamping groove 41 to prevent the second casing wall 2 from sliding off in the circumferential direction. It can be understood that the sliding groove 4 can also be arranged on the two opposite end faces of the slot 11, and the sliding bar 5 can be arranged on the second casing wall 2 to achieve the sliding connection. Alternatively, the limiting block 12 is arranged at the bottom end of the clamping groove 41, and the clamping bar 51 is arranged at the top end of the second casing wall 2 as the lug 22. When the first casing wall 1 is lifted upward, the clamping bar 51 slides in the clamping groove 41. When the first casing wall 1 is lifted to the highest position, the clamping bar 51 abuts against the limiting block 12. Such a structure can prevent the second casing wall 2 from sliding off in the circumferential direction and also prevent the second casing wall 2 from sliding off in the axial direction.

[0051] As shown in Figure 8 , Figure 9 and Figure 10 , in the embodiment, the sliding groove 4 and the sliding bar 5 are provided with an elastic sealing layer 6, which is fixedly connected to the sliding groove 4 or the sliding bar 5 to prevent the elastic sealing layer 6 from falling off during the sliding of the second casing wall 2. When the first casing wall 1 and the second casing wall 2 are embedded, the elastic sealing layer 6 is in a compressed state, achieving the water stopping effect. Alternatively, the elastic sealing layer 6 is made of elastic isoprene rubber, which has good elasticity and wear resistance, can achieve the sealing effect, and has a long service life.

[0052] A construction method of a cast-in-place pile, which adopts the pile foundation casing, comprises the following steps:

[0053] S1, hoisting,

[0054] The second casing wall 2 is fixedly connected with the first casing wall 1 by the buckle 132 of the locking mechanism 13, so as to prevent the second casing wall 2 from sliding in the hoisting process and causing damage to personnel and equipment.

[0055] S2, burying,

[0056] The pile foundation casing is buried, the top surface of the pile foundation casing is 30-50 cm higher than the ground, the through hole 21 is higher than the ground, so that the concrete conduit 3 can be inserted into the pile foundation casing and the concrete over-pouring is ensured; if the top surface of the pile foundation casing is greater than 50 cm from the ground, the construction is not convenient; if the top surface of the pile foundation casing is less than 30 cm from the ground, the concrete over-pouring cannot be ensured and sundries are easy to fall into the pile foundation casing, and the locking mechanism 13 is opened.

[0057] S3, equipment positioning,

[0058] One end of the concrete conduit 3 is connected with a pumping machine, and the other end is inserted into the pile bottom position inside the pile foundation casing through the through hole 21, and the concrete is prepared to be poured;

[0059] S4, pouring,

[0060] The pumping machine is started, the concrete conduit 3 pumps the concrete into the pile foundation casing, and at the same time, the first casing wall 1 is lifted by the crane until the lug 22 on the second casing wall 2 is clamped on the limiting block 12 at the bottom end of the first casing wall 1, and the concrete can be directly poured to the pile top over-pouring position at one time;

[0061] S5, clearing the site,

[0062] After the cast-in-place pile pouring is completed, the concrete conduit 3 is disassembled from the through hole 21 on the second casing wall 2, the second casing wall 2 is pulled out by the crane, and the next pile construction is prepared.

[0063] The construction method of the cast-in-place pile provided by the application has the advantages that the concrete conduit 3 is inserted into the pile foundation casing through the through hole 21 on the second casing wall 2, the second casing wall 2 can slide relative to the first casing wall 1, the height of the second casing wall 2 remains unchanged when the first casing wall 1 is lifted, the height of the concrete conduit 3 also remains unchanged, the process of lifting the first casing wall 1 does not affect the concrete pouring, the concrete pouring can be uninterrupted, the concrete shrinkage can be timely supplemented, the operation is convenient, the construction difficulty is small, the time and labor cost can be saved, and the construction efficiency is significantly improved; since the concrete conduit 3 does not need to be lifted, the concrete can be directly poured to the pile top over-pouring position at one time, and the longer the axial direction of the pile body is, the more obvious the construction advantage of the application is.

[0064] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pile foundation casing, characterized in that, Includes a first casing wall (1) and a second casing wall (2) for forming the casing of the pile foundation. A slot (11) is provided on the first protective casing wall (1), and the slot (11) penetrates the first protective casing wall (1) along the axial direction. The second protective sleeve wall (2) is embedded in the slot (11) and can slide along the slot (11). The top of the second casing wall (2) is provided with a positioning structure for fixing the concrete guide pipe (3), so that when the first casing wall (1) is lifted during pile foundation construction, the height and position of the second casing wall (2) and the concrete guide pipe (3) remain unchanged. The groove (11) of the first protective wall (1) and the second protective wall (2) are slidably engaged by a sliding groove (4) and a sliding strip (5), and an elastic sealing layer (6) is provided between the sliding groove (4) and the sliding strip (5).

2. The pile foundation casing according to claim 1, characterized in that, The positioning structure is a through hole (21) opened on the second casing wall (2) for inserting the concrete guide pipe (3), or The clamps are installed on the top surface of the second protective casing (2).

3. The pile foundation casing according to claim 2, characterized in that, The bottom end of the first protective sleeve wall (1) is provided with a limiting block (12) to prevent the second protective sleeve wall (2) from slipping out of the slot (11), and the second protective sleeve wall (2) is provided with a lug (22) corresponding to the limiting block (12).

4. The pile foundation casing according to claim 3, characterized in that, The lug (22) fits against the outer side of the first protective sleeve wall (1).

5. The pile foundation casing according to claim 3, characterized in that, The top end of the first protective wall (1) is provided with a locking mechanism (13) for limiting the position of the second protective wall (2). The locking mechanism (13) includes a pin (131) disposed on the first protective wall (1) and a buckle (132) hinged to the pin (131) for hooking the second protective wall (2).

6. The pile foundation casing according to claim 5, characterized in that, A connecting plate (14) is provided at the top of the slot (11), the pin (131) is provided on the connecting plate (14), and the buckle (132) is adapted to the positioning structure.

7. The pile foundation casing according to claim 5, characterized in that, The buckle (132) is adapted to the lug (22).

8. A construction method for cast-in-place piles, characterized in that, The use of a pile foundation casing as described in any one of claims 1 to 7 includes the following steps: S1. Lifting, The second casing wall is fixedly connected to the first casing wall by a locking mechanism to prevent the second casing wall from sliding during hoisting. The pile foundation casing is then hoisted to the pile foundation location by a crane. S2, buried. The pile foundation casing is buried, with the top surface of the pile foundation casing 30-50cm above the ground to ensure that the positioning structure is above the ground and the locking mechanism is opened. S3. Equipment in place. The concrete duct is connected to the pump and extends into the bottom of the pile inside the pile casing via a positioning structure, ready for concrete pouring. S4, Pouring. Start the pumping machine, and the concrete duct pumps the concrete into the pile foundation casing. As the concrete is pumped in, use a crane to lift the first casing wall until the lug on the second casing wall is caught on the limiting block at the bottom of the first casing wall. The concrete is poured directly to the over-pour position at the top of the pile in one go. S5, Clear the area. After the cast-in-place pile is poured, the concrete guide pipe is removed from the positioning structure on the second casing wall, and the second casing wall is pulled out by a crane.

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