A variable-section steel frame bag pile structure and construction method

Abstract

The present invention relates to the field of building construction, and in particular to a variable-section steel frame bag pile structure, comprising a steel cage, a grouting pipe inserted into the steel cage, and a bag sleeved outside the steel cage, wherein the steel cage is provided with an auxiliary supporting structure, thereby solving the technical problem that the existing bag pile structure is unstable during construction, resulting in the shaking of the bag during cement slurry pouring and thus causing the instability of the bag pile structure.

Description

Technical Field

[0001] The invention relates to the field of building construction, and in particular to a variable-section steel bar skeleton bag pile structure and a construction method. Background Art

[0002] In engineering construction, bag piles are usually used in combination with steel cages. The bag piles can stop the flow of sand and water, and the bag piles can also maximize the structural effect of the steel cage.

[0003] Bag piles are made by first using a drilling machine to vertically drill a cylindrical hole at the pile position, generally with a hole diameter of 300mm, then placing a bag equipped with a grouting pipe into the cylindrical hole, and then injecting cement slurry into the bag. The grouting pressure can reach 2Mpa. When the strength of the cement slurry reaches a certain level, the entire pile forms a column. The piles can be clamped together well under the strong expansion force during grouting; however, the existing construction method is to place the bag as a whole into the cylindrical hole, and then pour cement slurry. In this process, since the cylindrical hole is a slender structure, the bag pile is placed in the long cylindrical hole, and then the cement slurry is poured. Since the cement slurry is in liquid form and the liquid is fluid, and the bag is also made of flexible material, it will cause deformation during the pouring process, making it difficult to ensure the vertical stability of the bag pile.

[0004] The invention patent with Chinese patent application number 202010864934.5 discloses a variable-section steel frame bag pile structure and construction method. The variable-section steel frame bag pile structure of the invention utilizes a combination of geotextile bags and steel frames, which has the effects of water stopping and water isolation; at the same time, the bag pile also has the functions of reinforcing the soil, improving the bearing capacity of the soil, and reducing the settlement of the foundation. In addition, the invention utilizes a variable-section device to change the diameter to adapt to different apertures, so that a variable-section cast-in-place pile with higher strength can be cast to ensure the quality of the pile body. However, the technical solution proposed in the above invention also uses a bag directly placed in a cylindrical hole during the construction process. During the cement slurry pouring process, the bag will be deformed due to the gravity of the cement slurry and the flexible characteristics of the bag, which will affect the stability of the entire bag pile, causing local uneven force and leading to safety hazards. Summary of the invention

[0005] Therefore, in order to solve the above problems, the present invention proposes a variable-section steel frame bag pile structure and a construction method thereof, which solves the technical problem that the existing bag pile structure is unstable during construction, resulting in bag shaking during cement slurry pouring and thus causing instability of the bag pile structure.

[0006] To achieve the above object, the present invention adopts the following technical scheme: a variable-section steel frame bag pile structure, comprising a steel cage, a grouting pipe inserted into the steel cage, a bag sleeved outside the steel cage, and an auxiliary support structure arranged on the steel cage;

[0007] The steel cage comprises a supporting longitudinal beam group, an internal supporting crossbeam net, an internal supporting crossbeam, and an external supporting ring, wherein the supporting longitudinal beam group comprises a first supporting longitudinal beam group and a second supporting longitudinal beam group, wherein the first supporting longitudinal beam group and the second supporting longitudinal beam group are mutually sleeved, wherein the internal supporting crossbeam net is arranged in the first supporting longitudinal beam group, wherein the internal supporting crossbeam is arranged between the first supporting longitudinal beam group and the second supporting longitudinal beam group, and is used to define the relative position between the first supporting longitudinal beam group and the second supporting longitudinal beam group, wherein the external supporting ring is sleeved on the second supporting longitudinal beam group, wherein the supporting longitudinal beam group and the internal supporting crossbeam net are mutually perpendicular, wherein the supporting longitudinal beam group and the internal supporting crossbeam are mutually perpendicular, and wherein the internal supporting crossbeam net is provided with a through hole for the grouting pipe to pass through;

[0008] The cloth bag is provided with a plurality of flexible annular hoops, and the distance between two adjacent annular hoops is the same;

[0009] The auxiliary support structure includes a first connection part and a second connection part connected to each other, the first connection part is arranged on the external support ring, the second connection part is arranged on the annular hoop, and the connection mode of the first connection part and the second connection part is a movable connection.

[0010] Furthermore, the first connection portion and the second connection portion are connected in a detachable manner.

[0011] Furthermore, the first connecting portion includes a plurality of triangular grooves with a triangular vertical cross-section, and the second connecting portion includes a plurality of triangular protrusions with a triangular vertical cross-section, and the number of the first connecting portion and the second connecting portion is the same.

[0012] Furthermore, the first connecting portion includes a first clamping surface and a second clamping surface that are connected to each other, and the second connecting portion includes a third clamping surface and a fourth clamping surface that are connected to each other. When the first connecting portion and the second connecting portion are matched, the first clamping surface and the third clamping surface are in contact with each other, and the second clamping surface and the fourth clamping surface are in contact with each other.

[0013] Furthermore, the angle between the first clamping surface and the horizontal plane is 45-60°, the angle between the second clamping surface and the horizontal plane is 55-80°, the angle between the third clamping surface and the horizontal plane is 45-60°, and the angle between the fourth clamping surface and the horizontal plane is 55-80°.

[0014] Furthermore, a plurality of elastic clamping rings are arranged on the outer circumferential surface of the grouting pipe, and the elastic clamping rings include a plurality of elastic protrusions arranged around the outer circumferential surface of the grouting pipe, and the elastic protrusions are semicircular arc-shaped.

[0015] Furthermore, the elastic clamping ring and the edge of the through hole are mutually clamped.

[0016] A construction method for a variable-section steel frame bag pile structure comprises the following steps:

[0017] S1. Pile hole positioning: Position the pile hole according to the project layout drawing;

[0018] S2, drilling rig is in place; drilling is carried out after the drilling rig is in place and the preparation work is completed;

[0019] S3, lowering the bag pile; lowering the prefabricated bag pile vertically into the pile hole by a crane, and when the bag and the steel cage are matched, a plurality of grouting cavities of the same specifications are formed in the bag pile, and each of the grouting cavities has the same specifications;

[0020] S4, grouting; the grouting pipe is lowered from top to bottom through the through hole to the bottom of the bag pile, and the distance between the free end and the bottom of the bag pile is 15-20cm;

[0021] S5. Grouting is completed; the grouting pipe is pulled out from the bag pile, and the cement slurry in the bag pile is air-dried and solidified.

[0022] Furthermore, in step S4, when each grouting cavity is filled with cement slurry, the grouting pipe moves downward for a certain distance and is quickly reset.

[0023] Furthermore, when the grouting pipe is pulled out from the bag pile in step S5, the grouting pipe is pulled out by rotating itself synchronously during the lifting process.

[0024] By adopting the above technical solution, the beneficial effects of the present invention are:

[0025] 1. Compared with the existing bag pile structure, the present invention has structural improvements, specifically, by improving the connection relationship between the steel cage and the bag, so as to ensure that when the bag pile is poured with cement slurry, the overall structure of the bag pile can be relatively stable, thereby ensuring the uniformity of the structure of the bag pile after the overall pouring in the later stage, and being more stable. Specifically, the steel cage adopts the method of mutually nesting the first supporting longitudinal beam group and the second supporting longitudinal beam group, and the vertical cross-sections of the two are concentric circle structures, which ensures the superposition of double structures in the vertical direction, and at the same time, the first supporting longitudinal beam group and the second supporting longitudinal beam group are connected and reinforced by internal supporting cross beams, so as to form a structurally stable steel cage as a whole, and then an external supporting ring is sleeved on the outer circumferential surface of the second supporting longitudinal beam group, and the external supporting ring is used to perform a transverse reinforcement on the whole, thereby improving the steel cage. The overall stability of the reinforcement cage is improved, and the present invention further provides an auxiliary supporting structure on the reinforcement cage, and the connection relationship between the cloth bag and the reinforcement cage is adjusted through the auxiliary supporting structure, wherein the auxiliary supporting structure includes a first connecting part and a second connecting part connected to each other, and the cooperation of the first connecting part and the second connecting part can ensure that the cloth bag pile will be poured with cement slurry according to the grouting of each grouting cavity from bottom to top before the next grouting cavity is opened to fill the pile hole, such a segmented filling method ensures that the cement slurry can perfectly fill each grouting cavity during the filling process, and then the perfectly filled grouting cavities are spliced ​​one by one to form a completed cloth bag pile, and the separation of the first connecting part and the second connecting part is also self-realized by whether each grouting cavity is completely filled, and it is only realized by the mechanical structure without the help of other driving structures.

[0026] 2. In the present invention, the first connecting part and the second connecting part are connected by a triangular structure. Through the cooperation of the first connecting part and the second connecting part, it is ensured that the cloth bag and the steel cage are in a coordinated state during the construction process. Due to the coordination relationship between the cloth bag and the steel cage, it is ensured that the two form grouting cavities in the vertical direction.

[0027] 3. The present invention limits the angles among the first clamping surface, the second clamping surface, the third clamping surface and the fourth clamping surface, in order to ensure that when the first connecting part and the second connecting part are in contact with each other, if there is no external force acting on them, the two can keep matching, and when the horizontal plane of the cement slurry continuously moves upward and generates an upward and outward thrust on the bag, the two will separate, thereby ensuring that the cement slurry enters the next grouting cavity.

[0028] 4. In the present application, an elastic clamp ring is provided on the outer circumferential surface of the grouting pipe. By providing the elastic clamp ring, the degree of fit between the grouting pipe and the steel cage can be increased. At the same time, an elastic protrusion is used, which is elastically and movably connected to the through hole on the steel cage, that is, when the elastic protrusion is subjected to a certain degree of force, it will retract inward to ensure that the grouting pipe can be completely drawn out, and the elastic clamp ring can perform short intermittent up and down movements during the grouting process, which can drive the steel cage and the cloth bag to have relative displacement during the up and down movement, thereby ensuring better separation between the cloth bag and the steel cage, and ensuring that each grouting cavity can be quickly and smoothly opened. The principle is that the elastic protrusion will elastically retract inward only when subjected to a certain degree of force. If the force is not enough, it is a fixed protrusion, and it will bring The movable steel cage moves, and when the grouting cavity of the bottom layer is filled with cement slurry, the inner surface of the bag will be affected by the friction of the cement slurry and the gravity of the cement slurry itself, so it is relatively stable. At this time, the up and down movement of the steel cage can separate the first connection part and the second connection part of the area filled with cement slurry from each other, while the part without cement slurry, that is, the upper part, the bag is still in an unstressed state. Therefore, the short-distance up and down movement of the steel cage will not cause the bag to detach from the steel cage. Therefore, during the grouting process, the up and down short-distance displacement of the grouting pipe drives the up and down short-distance displacement of the steel cage, which can separate the bag and the steel cage of the grouting part from each other, while ensuring that the bag and the steel cage of the ungrouted part remain connected, which will not affect the overall grouting operation, and can ensure that the cement slurry in the bag pile is poured evenly and stably.

[0029] 5. In the construction method for bag piles proposed in the present invention, when the cement slurry has not filled a grouting cavity mentioned in step S3, the grouting pipe moves downward for a distance and quickly resets, so as to provide auxiliary separation for the bag and steel cage in the grouting cavity part where the cement slurry has been poured. In step S5, the reason why it is necessary to rotate itself and lift and pull it out synchronously after the cement pouring is to ensure that the grouting pipe has the least impact on the bag pile during the lifting process, and also considering that an elastic clamp ring is arranged on the outside of the grouting pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0031] Figure 1 This is a schematic diagram of the overall structure of the bag pile of the present invention (with a grouting pipe);

[0032] Figure 2 This is a schematic diagram of the three-dimensional structure of the steel cage of the present invention (with a grouting pipe);

[0033] Figure 3This is a schematic diagram of the front structure of the steel cage of the present invention (with grouting pipe);

[0034] Figure 4 It is a schematic diagram of the top view of the steel cage structure of the present invention (with grouting pipe);

[0035] Figure 5 This is a schematic diagram of the matching structure of the cloth bag and the steel cage of the present invention;

[0036] Figure 6 for Figure 5 Enlarged view of point A in the middle;

[0037] Figure 7 This is a schematic diagram of the structure of the grouting pipe of the present invention;

[0038] Figure 8 It is a flow chart of the construction method of the present invention. DETAILED DESCRIPTION

[0039] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0040] See also Figure 1-Figure 8 The present invention provides a variable-section steel frame bag pile structure, comprising a steel cage 1, a grouting pipe 2 inserted into the steel cage 1, a bag 3 sleeved outside the steel cage 1, and an auxiliary support structure is arranged on the steel cage 1;

[0041] The steel cage 1 includes a supporting longitudinal beam group, an internal supporting crossbeam net 13, an internal supporting crossbeam 15, and an external supporting ring 14. The supporting longitudinal beam group includes a first supporting longitudinal beam group 11 and a second supporting longitudinal beam group 12. The first supporting longitudinal beam group 11 and the second supporting longitudinal beam group 12 are mutually sleeved. The internal supporting crossbeam net 13 is arranged in the first supporting longitudinal beam group 11. The internal supporting crossbeam 15 is arranged between the first supporting longitudinal beam group 11 and the second supporting longitudinal beam group 12 to limit the relative position between the first supporting longitudinal beam group 11 and the second supporting longitudinal beam group 12. The external supporting ring 14 is sleeved on the second supporting longitudinal beam group 12. The supporting longitudinal beam group and the internal supporting crossbeam net 13 are perpendicular to each other. The supporting longitudinal beam group and the internal supporting crossbeam 15 are perpendicular to each other. The internal supporting crossbeam net 13 is provided with a through hole for the grouting pipe 2 to pass through, wherein the first supporting longitudinal beam group 11 and the second supporting longitudinal beam group 12 are both composed of a plurality of steel beams.

[0042] The cloth bag 3 is provided with a plurality of flexible annular hoops 31, and the distance between two adjacent annular hoops 31 is the same, wherein the annular hoops 31 are made of rubber material with telescopic deformation, and the specific number of the annular hoops 31 is determined according to the specific length of the cloth bag 3;

[0043] The auxiliary support structure includes a first connection part and a second connection part connected to each other, the first connection part is arranged on the external support ring 14, and the second connection part is arranged on the annular hoop 31, and the connection mode of the first connection part and the second connection part is a movable connection, specifically a detachable plug-in form.

[0044] The first connecting part includes a plurality of triangular grooves with triangular vertical cross-sections, the second connecting part includes a plurality of triangular protrusions with triangular vertical cross-sections, the number of the first connecting part and the second connecting part is the same, the first connecting part includes a first clamping surface 5 and a second clamping surface 6 connected to each other, the second connecting part includes a third clamping surface 7 and a fourth clamping surface 8 connected to each other, when the first connecting part and the second connecting part are matched, the first clamping surface 5 and the third clamping surface 7 are in contact with each other, and the second clamping surface 6 and the fourth clamping surface 8 are in contact with each other.

[0045] The included angle between the first clamping surface 5 and the horizontal plane is 60°, the included angle between the second clamping surface 6 and the horizontal plane is 80°, the included angle between the third clamping surface 7 and the horizontal plane is 60°, and the included angle between the fourth clamping surface 8 and the horizontal plane is 80°.

[0046] A plurality of elastic clamps are arranged on the outer circumferential surface of the grouting pipe 2, and the elastic clamps include a plurality of elastic protrusions 21 arranged around the outer circumferential surface of the grouting pipe 2. The elastic protrusions 21 are semicircular arc-shaped, and the elastic clamps are mutually clamped with the edge of the through hole 4. After being subjected to a certain degree of external force, the elastic protrusions 21 will elastically retract, and when the force is insufficient, they act as fixed protrusions, and the up and down movement of the grouting pipe 2 drives the steel cage 1 to descend, thereby ensuring that the cloth bag 3 of the part that has been grouted is separated from the steel cage 1.

[0047] This embodiment simultaneously proposes the above-mentioned bag pile construction method, a construction method of a variable-section steel frame bag pile structure, comprising the following steps:

[0048] S1. Pile hole positioning: Position the pile hole according to the project layout drawing;

[0049] S2, drilling rig is in place; drilling is carried out after the drilling rig is in place and the preparation work is completed;

[0050] S3, lowering the bag pile; lowering the prefabricated bag pile vertically into the pile hole by a crane, and when the bag and the steel cage are matched, a plurality of grouting cavities of the same specifications are formed in the bag pile, and each of the grouting cavities has the same specifications;

[0051] S4, grouting; the grouting pipe is lowered from top to bottom through the through hole to the bottom of the bag pile, and the distance between the free end and the bottom of the bag pile is 15 cm;

[0052] S5. Grouting is completed; the grouting pipe is pulled out from the bag pile, and the cement slurry in the bag pile is air-dried and solidified.

[0053] In step S4, when the cement slurry fills each grouting cavity, the grouting pipe moves downward for a distance of 3 cm and quickly resets.

[0054] Furthermore, when the grouting pipe is pulled out from the bag pile in step S5, the grouting pipe is pulled out by rotating itself synchronously during the lifting process.

[0055] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0056] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A variable cross-section steel frame bag pile structure, characterized in that: It includes a steel cage, a grouting pipe inserted into the steel cage, and a cloth bag sleeved outside the steel cage, and an auxiliary support structure is arranged on the steel cage; The steel cage comprises a supporting longitudinal beam group, an internal supporting crossbeam net, an internal supporting crossbeam, and an external supporting ring, wherein the supporting longitudinal beam group comprises a first supporting longitudinal beam group and a second supporting longitudinal beam group, wherein the first supporting longitudinal beam group and the second supporting longitudinal beam group are mutually sleeved, wherein the internal supporting crossbeam net is arranged in the first supporting longitudinal beam group, wherein the internal supporting crossbeam is arranged between the first supporting longitudinal beam group and the second supporting longitudinal beam group, and is used to define the relative position between the first supporting longitudinal beam group and the second supporting longitudinal beam group, wherein the external supporting ring is sleeved on the second supporting longitudinal beam group, wherein the supporting longitudinal beam group and the internal supporting crossbeam net are mutually perpendicular, wherein the supporting longitudinal beam group and the internal supporting crossbeam are mutually perpendicular, and wherein the internal supporting crossbeam net is provided with a through hole for the grouting pipe to pass through; The cloth bag is provided with a plurality of flexible annular hoops, and the distance between two adjacent annular hoops is the same; The auxiliary support structure comprises a first connection part and a second connection part connected to each other, the first connection part is arranged on the external support ring, the second connection part is arranged on the annular hoop, and the connection mode of the first connection part and the second connection part is a movable connection; The first connection part and the second connection part are connected in a detachable manner; The first connection part includes a plurality of triangular grooves with a triangular vertical cross section, and the second connection part includes a plurality of triangular protrusions with a triangular vertical cross section. The number of the first connection part and the number of the second connection part are the same.

2. The variable cross-section steel frame bag pile structure according to claim 1 is characterized by: The first connecting portion includes a first clamping surface and a second clamping surface connected to each other, and the second connecting portion includes a third clamping surface and a fourth clamping surface connected to each other. When the first connecting portion and the second connecting portion are matched, the first clamping surface and the third clamping surface are in contact with each other, and the second clamping surface and the fourth clamping surface are in contact with each other.

3. The variable cross-section steel frame bag pile structure according to claim 2 is characterized by: The included angle between the first clamping surface and the horizontal plane is 45-60°, the included angle between the second clamping surface and the horizontal plane is 55-80°, the included angle between the third clamping surface and the horizontal plane is 45-60°, and the included angle between the fourth clamping surface and the horizontal plane is 55-80°.

4. The variable cross-section steel frame bag pile structure according to claim 3 is characterized by: A plurality of elastic clamps are arranged on the outer circumferential surface of the grouting pipe, and the elastic clamps include a plurality of elastic protrusions arranged around the outer circumferential surface of the grouting pipe, and the elastic protrusions are in a semicircular arc shape.

5. The variable cross-section steel frame bag pile structure according to claim 4, characterized in that: The elastic clamping ring and the edge of the through hole are mutually clamped.

6. A construction method for a variable-section steel frame bag pile structure as claimed in claim 5, characterized in that: The following steps are involved: S1. Pile hole positioning: Position the pile hole according to the project layout drawing; S2, drilling rig is in place; drilling is carried out after the drilling rig is in place and the preparation work is completed; S3, lowering the bag pile; lowering the prefabricated bag pile vertically into the pile hole by a crane, and when the bag and the steel cage are matched, a plurality of grouting cavities of the same specifications are formed in the bag pile, and each of the grouting cavities has the same specifications; S4, grouting; the grouting pipe is lowered from top to bottom through the through hole to the bottom of the bag pile, and the distance between the free end and the bottom of the bag pile is 15-20cm; S5. Grouting is completed; the grouting pipe is pulled out from the bag pile, and the cement slurry in the bag pile is air-dried and solidified.

7. The construction method of a variable cross-section steel frame bag pile structure according to claim 6 is characterized by: In step S4, when each grouting cavity is filled with cement slurry, the grouting pipe moves downward for a certain distance and is quickly reset.

8. The construction method of a variable-section steel frame bag pile structure according to claim 7, characterized in that: When the grouting pipe is pulled out from the bag pile in step S5, it is pulled out by rotating itself synchronously during the lifting process.

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