Anti-floating anchor rod construction method

Abstract

The application provides an anti-floating anchor rod construction method. The anti-floating anchor rod prestress is applied and the anchoring end of the anti-floating anchor rod is arranged to be implemented after the completion of the construction of the to-be-constructed raft foundation and the removal of the underground structure formwork, so that the key line is not occupied (that is, compared with the existing construction method, the anchor rod pile body maintenance and prestress application are transferred from the key line to the non-key line), thereby effectively accelerating the construction speed and being suitable for projects with a tight construction period or projects in which the raft foundation needs to be quickly formed.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a method for constructing anti-buoyancy anchor bolts. Background Technology

[0002] To save costs, construction projects often use anti-buoyancy anchors instead of conventional pull-out piles for underground structures. Anti-buoyancy anchors are a type of anti-buoyancy measure for underground structures in construction projects, and their implementation is economical. However, their use also has drawbacks; improper construction can easily lead to water leakage in the raft foundation. Therefore, designers typically place the anchoring ends of the anti-buoyancy anchors in the foundation pad, and conceal the prestressed anchor body, reinforcing bars, and high-strength nuts (for locking the prestress) within the raft foundation concrete to reduce the risk of leakage. The conventional construction process for anti-buoyancy anchors is as follows: anchor drilling → lowering the reinforcing bars → grouting the holes and pouring the foundation pad → curing → applying prestress to the anchors → pouring the raft foundation concrete → underground structure construction.

[0003] The anti-buoyancy anchor bolts constructed using the above method can significantly reduce the risk of leakage in raft foundations. However, they have a long construction period and are not suitable for projects with tight schedules or where rapid construction of the raft foundation is required.

[0004] Therefore, how to reduce the risk of leakage in raft foundations while shortening the construction period of anti-buoyancy anchors is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing anti-buoyancy anchors, which can reduce the risk of leakage in raft foundations while shortening the construction period of anti-buoyancy anchors.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for constructing anti-buoyancy anchor bolts, the method comprising:

[0007] S1: Drill anti-buoyancy anchor holes according to the design documents to form anti-buoyancy anchor holes;

[0008] S2: The threaded steel bar with PE pipe sheath is hoisted into the anti-buoyancy anchor bolt hole and lowered to the design elevation. The top of the PE pipe extends into the underground raft foundation for the first predetermined length.

[0009] S3: A steel sleeve is fixedly attached to the outer sleeve of the fine-rolled threaded steel bar. The bottom end of the steel sleeve extends into the pad layer by a second predetermined length, and the top end of the steel sleeve is flush with the raft foundation surface.

[0010] S4: Grouting is carried out on the anti-buoyancy anchor holes located below the bottom elevation of the cushion layer;

[0011] S5: Pour the foundation concrete to form the foundation layer;

[0012] S6: waterproof layer construction is carried out on the cushion layer, and water-swelling sealing strip two is arranged at the junction of the steel casing and the cushion layer;

[0013] S7: raft foundation reinforcement is bound, and raft foundation concrete is poured to form the raft foundation;

[0014] S8: underground structure construction is carried out, and prestress is applied to the finished rolled threaded steel after the underground structure is demolded;

[0015] S9: the finished rolled threaded steel after prestress is applied is cut, so that the top elevation of the cut finished rolled threaded steel is at least 50 mm lower than the building floor surface;

[0016] S10: the building floor is poured.

[0017] Optionally, in the anti-floating anchor rod construction method, before the finished rolled threaded steel with the PE pipe outside is lowered to the design elevation through the anti-floating anchor rod hole in step S2, the method further comprises the following steps:

[0018] Corrosion-resistant grease is filled between the PE pipe and the finished rolled threaded steel;

[0019] The sealing strip is used to seal the combined end part of the PE pipe and the finished rolled threaded steel.

[0020] Optionally, in the anti-floating anchor rod construction method, step S3 further comprises the following steps:

[0021] Water-swelling sealing strip one is filled in the gap between the bottom of the steel casing and the finished rolled threaded steel;

[0022] The water-stop ring piece is welded on the outer wall of the steel casing located at the middle position of the raft foundation.

[0023] Optionally, in the anti-floating anchor rod construction method, the process of applying prestress to the finished rolled threaded steel in step S8 comprises the following steps:

[0024] The steel casing is grouted;

[0025] The finished rolled threaded steel is sleeved with the rod body steel reinforcement and the matching steel pad before the initial setting of the grouting material two, and prestress tension is carried out, and the high-strength nut of the rod body steel reinforcement is fixed after tension to the design value, so as to complete the prestress tension of the finished rolled threaded steel.

[0026] Optionally, in the anti-floating anchor rod construction method, the process of cutting the finished rolled threaded steel after prestress is applied in step S9 comprises:

[0027] The finished rolled threaded steel with the high-strength nut of the outer leakage rod body steel reinforcement is cut.

[0028] Optionally, in the anti-floating anchor rod construction method, the process of waterproof layer construction on the cushion layer in step S6 comprises:

[0029] Laying a flexible waterproofing membrane on the cushion to form a waterproof layer.

[0030] Optionally, in the anti-floating anchor rod construction method, the first predetermined length is 200 mm.

[0031] Optionally, in the anti-floating anchor rod construction method, the second predetermined length is 200 mm.

[0032] In the anti-floating anchor rod construction method provided by the present application, the anti-floating anchor rod construction method comprises: S1: drilling an anti-floating anchor rod according to a design document to form an anti-floating anchor rod hole; S2: hoisting a precision rolled threaded steel with a PE pipe into the anti-floating anchor rod hole and lowering it to a design elevation, with the top end of the PE pipe extending into the first predetermined length of the underground raft foundation; S3: sleeving a steel casing pipe on the precision rolled threaded steel, with the bottom end of the steel casing pipe extending into the second predetermined length below the cushion and the top end of the steel casing pipe being flush with the raft foundation surface; S4: performing grouting construction on the anti-floating anchor rod hole below the bottom elevation of the cushion; S5: pouring the cushion concrete to form the cushion; S6: performing waterproof layer construction on the cushion and arranging a water-swelling waterstop at the junction of the steel casing pipe and the cushion; S7: binding the raft foundation reinforcement and pouring the raft foundation concrete to form the raft foundation; S8: performing underground structure construction, and after the underground structure is removed, applying prestress to the precision rolled threaded steel; S9: cutting the precision rolled threaded steel after prestress is applied, so that the top elevation of the cut precision rolled threaded steel is at least 50 mm lower than the building floor surface; and S10: pouring the building floor. By arranging the anti-floating anchor rod prestress application and the anchoring end of the anti-floating anchor rod to be implemented after the raft foundation construction is completed and the underground structure is removed, the key line is not occupied (i.e., compared with the existing construction method, the anchor rod pile maintenance and prestress application are transferred from the key line to the non-key line), thereby effectively accelerating the construction speed and being suitable for projects with a tight construction period or requiring rapid formation of the raft foundation. BRIEF DESCRIPTION OF DRAWINGS

[0033] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which like reference characters refer to the like parts throughout the figures, and in which:

[0034] Figure 1 is a flowchart of the anti-floating anchor rod construction method in an embodiment of the present application;

[0035] Figure 2 is an elevation view after construction based on the anti-floating anchor rod construction method in an embodiment of the present application.

[0036] In the drawings:

[0037] 1 - finished rolling threaded steel; 2 - PE pipe; 3 - sealing rubber strip; 4 - steel sleeve; 5 - water-swelling sealing strip 1; 10 - water-swelling sealing strip 2; 6 - sealing ring; 7 - grouting material 1; 12 - grouting material 2; 8 - cushion layer; 9 - waterproof layer; 11 - raft foundation; 13 - steel reinforcement of the rod body matched with steel pad; 14 - high-strength nut matched with the steel reinforcement of the rod body; 15 - building floor. DETAILED DESCRIPTION

[0038] The anti-floating anchor rod construction method proposed by the present application will be further described in detail below in combination with the drawings and specific embodiments. The advantages and features of the present application will be more apparent according to the following description and claims. It should be noted that the drawings are all very simplified and use non-precise proportions, only for the purpose of facilitating and clarifying the purpose of assisting in the description of the embodiments of the present application.

[0039] The present application will now be further described in detail in combination with the drawings. These drawings are all simplified schematic diagrams, only to schematically illustrate the basic structure of the present application, and therefore only show the structures related to the present application.

[0040] In the description of the application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0041] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0042] In the application, unless otherwise specifically specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0043] The inventor has found through long-term research that the reason why the construction period of the conventional anti-floating anchor is long is that the maintenance and prestress application of the anti-floating anchor pile body are located on the key line, which seriously affects the construction period.

[0044] The anti-floating anchor construction method of the present application solves the above problems by the principle that the raft foundation is constructed first, and the prestress application and the concealed anchoring end of the anti-floating anchor are implemented after the raft foundation construction is completed and the underground structure formwork system is removed, that is, the steps of the maintenance and prestress application of the anti-floating anchor pile body are transferred from the original key line to the non-key line, thereby effectively speeding up the construction speed, so that the anti-floating anchor construction method can be suitable for projects with tight construction period or raft foundation that needs to be quickly formed.

[0045] Please refer to Figure 1 and Figure 2 , the anti-floating anchor construction method comprises:

[0046] S1: According to the design file, the anti-floating anchor hole is formed by drilling the anti-floating anchor hole. The drilling diameter and depth of the anti-floating anchor hole need to be constructed according to the design file requirements.

[0047] S2: The finish rolled threaded steel 1 sleeved with the PE pipe 2 is hoisted into the anti-floating anchor hole and is lowered to the design elevation, and the top end of the PE pipe 2 extends into the first predetermined length of the underground raft foundation 11. In this embodiment, the first predetermined length is preferably 200mm.

[0048] Specifically, before the finish rolled threaded steel 1 sleeved with the PE pipe 2 is lowered to the design elevation through the anti-floating anchor hole, it further comprises:

[0049] Corrosion-resistant grease is filled between the PE pipe 2 and the finish rolled threaded steel 1; the corrosion-resistant grease has good corrosion resistance and can isolate air, moisture and other corrosion factors, so that the corrosion problem between the metal and the plastic material caused by direct contact between the PE pipe 2 and the finish rolled threaded steel 1 can be prevented, thereby prolonging the service life of the components.

[0050] The sealing strip 3 is used to seal the combined end of the PE pipe 2 and the finish rolled threaded steel 1. The sealing strip has good elasticity and sealing performance, can tightly fit on the connecting surface, prevent external moisture, dust and other impurities from entering the connecting part, thereby keeping the connecting part clean and dry, and effectively maintaining the sealing property between the combined end of the PE pipe 2 and the finish rolled threaded steel 1.

[0051] S3: The finish rolled threaded steel 1 is sleeved with a steel sleeve 4, the bottom end of the steel sleeve 4 extends into the second predetermined length below the cushion layer 8, and the top end of the steel sleeve 4 is flush with the surface of the steel raft foundation 11. In this embodiment, the second predetermined length is preferably 200mm.

[0052] In other words, the length of the steel casing = the thickness of the raft foundation + the thickness of the cushion layer 8 + the second predetermined length.

[0053] Preferably, in order to improve the stability of the anti-floating anchor structure, the step S3 further comprises the following water stopping step:

[0054] A water-swelling water-stopping strip 5 is filled in the gap between the bottom of the steel casing 4 and the finished threaded steel 1. The water-swelling water-stopping strip is a new type of waterproof sealing material, which swells after absorbing water, fills the gap between the two, and thus achieves the effect of water stopping.

[0055] A water-stopping ring 6 is welded on the outer wall of the steel casing 4 located at the middle position of the raft foundation 11.

[0056] S4: Grouting construction is performed on the anti-floating anchor hole below the bottom elevation of the cushion layer 8; after grouting construction, the anti-floating anchor hole below the bottom elevation of the cushion layer 8 is filled with grouting material 7.

[0057] S5: Pouring of the cushion layer concrete to form the cushion layer 8.

[0058] S6: Water-proof layer 9 construction is performed on the cushion layer 8, and water-swelling water-stopping strip 10 is arranged at the junction of the steel casing 4 and the cushion layer 8. Specifically, the water-proof layer is formed by laying flexible waterproof coiled material on the cushion layer 8.

[0059] S7: Binding of the raft foundation reinforcement, pouring of the raft foundation concrete to form the raft foundation 11.

[0060] S8: Underground structure construction is performed, and after the underground structure is removed, prestress is applied to the finished threaded steel 1.

[0061] The process of applying prestress to the finished threaded steel 1 includes the following steps:

[0062] Grouting construction is performed on the steel casing 4;

[0063] Before the initial setting of the grouting material 12, the finished threaded steel 1 is sleeved into the rod steel supporting steel pad 13, and then prestress tensioning is performed, the tensioning is performed to the design value, and then the rod steel supporting high-strength nut 14 is used for fixation (i.e. prestress locking) to complete the prestress tensioning of the finished threaded steel 1.

[0064] S9: cutting the finished rolled thread steel 1 after prestress is applied, so that the top elevation of the cut finished rolled thread steel 1 is at least 50mm lower than the building floor surface. Specifically, the finished rolled thread steel 1 of the outer leakage rod body steel bar matched with the high-strength nut 14 is cut, and the length of the cut is taken as the standard that the top elevation of the cut finished rolled thread steel 1 is at least 50mm lower than the building floor surface, so as to facilitate the subsequent pouring of the building floor 15 to realize the concealment of the rod body steel bar matched with the high-strength nut 14 and the outer leakage finished rolled thread steel 1 (i.e. the anchoring end of the anti-floating anchor rod).

[0065] S10: pouring the building floor.

[0066] The anti-floating anchor rod construction method can ensure that the underground structure of the implementation project is sequentially performed according to the process of cushioning layer → raft foundation → underground structure construction, and the raft foundation is constructed first, and the prestress of the anti-floating anchor rod is applied and the anchoring end of the anti-floating anchor rod is concealed after the construction of the raft foundation is completed and the underground structure formwork system is removed. The whole process does not occupy the key line, and can effectively speed up the construction speed, and is suitable for projects with short construction period or raft foundation that needs to be quickly formed.

[0067] It should be noted that, for the above-mentioned method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the action sequence described, because according to the present application, certain steps can be performed in other order or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily necessary for the present application.

[0068] The above description is only a description of the preferred embodiments of the present application, and does not limit the scope of the present application in any way. Any modification or modification of the above-mentioned disclosure by those skilled in the art falls within the protection scope of the claims.

Claims

1. A method of construction of an anti-float anchor, characterized in that, The method comprises the following steps: S1: drilling an anti-floating anchor hole according to a design file; S2: lowering a deformed steel bar (1) with a PE pipe (2) sleeved thereon into the anti-floating anchor hole to a design elevation, with the top end of the PE pipe (2) extending into a raft foundation (11) by a first predetermined length; S3: sleeving a steel casing (4) on the deformed steel bar (1), with the bottom end of the steel casing (4) extending below a cushion layer (8) by a second predetermined length, and the top end of the steel casing (4) being flush with the raft foundation (11); S4: performing grouting construction on the anti-floating anchor hole below the bottom elevation of the cushion layer (8); S5: pouring cushion layer concrete to form the cushion layer (8); S6: performing waterproof layer (9) construction on the cushion layer (8), and arranging water-swelling sealing strips (10) at the joint between the steel casing (4) and the cushion layer (8); S7: binding raft foundation steel bars and pouring raft foundation concrete to form the raft foundation (11); S8: performing underground structure construction, and applying prestress to the deformed steel bar (1) after the underground structure is removed; the process of applying prestress to the deformed steel bar (1) comprises the following steps: performing grouting construction on the steel casing (4); sleeving the deformed steel bar (1) on a rod steel bar matching steel pad (13) before the initial setting of grouting material (12), and then performing prestress tensioning, and fixing the deformed steel bar (1) by using a rod steel bar matching high-strength nut (14) after the deformed steel bar (1) is tensioned to a design value, so as to complete the prestress tensioning of the deformed steel bar (1); S9: cutting the deformed steel bar (1) after prestress is applied, so that the top elevation of the cut deformed steel bar (1) is at least 50 mm lower than a building floor surface; S10: pouring a building floor (15).

2. The anti-floating anchor construction method according to claim 1, wherein Before the deformed steel bar (1) with the PE pipe (2) sleeved thereon is lowered through the anti-floating anchor hole to the design elevation in step S2, the method further comprises the following steps: filling corrosion-resistant grease between the PE pipe (2) and the deformed steel bar (1); sealing the joint between the PE pipe (2) and the deformed steel bar (1) by using a sealing rubber strip (3).

3. The anti-floating anchor construction method according to claim 1, wherein In step S3, the method further comprises the following steps: filling water-swelling sealing strips (5) in the gap between the bottom of the steel casing (4) and the deformed steel bar (1); welding water-stopping ring pieces (6) on the outer wall of the steel casing (4) at a middle position of the raft foundation (11).

4. The anti-floating anchor construction method according to claim 1, wherein In step S9, the process of cutting the deformed steel bar (1) after prestress is applied comprises the following step: cutting the deformed steel bar (1) with the rod steel bar matching high-strength nut (14) exposed.

5. The anti-floating anchor rod construction method according to any one of claims 1 to 4, characterized in that, In step S6, the process of performing waterproof layer construction on the cushion layer (8) comprises the following step: laying flexible waterproof coiled material on the cushion layer (8) to form the waterproof layer.

6. The anti-floating anchor rod construction method according to any one of claims 1 to 4, characterized in that, The first predetermined length is 200 mm.

7. The anti-floating anchor construction method according to any one of claims 1 to 4, wherein The second predetermined length is 200 mm.

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