Open caisson cylinder wall structure capable of reducing frictional resistance and construction method thereof

Abstract

The invention provides an open caisson cylinder wall structure capable of reducing frictional resistance and a construction method thereof, and belongs to the technical field of open caisson construction. The open caisson cylinder wall structure comprises a first-section cylinder wall and a plurality of upper cylinder walls arranged above the first-section cylinder wall, the first-section cylinder wall comprises a first-section main body and a blade foot arranged at the bottom end of the first-section main body, and the upper end of the blade foot is flush with the first-section main body; a sinking formwork is arranged on the outer side of the first-section cylinder wall and used for concrete pouring of the first-section cylinder wall and reduction of frictional resistance during sinking. The open caisson has the beneficial effects that the sinking formwork is arranged on the outer side of the first section of cylinder wall, so that the friction resistance between the open caisson cylinder wall and a soil body is reduced, and the sinking efficiency is improved; a hard plastic template is used as a sinking template, so that the uniformity and balance of sinking can be better controlled; the sinking formwork is synchronously installed during construction of the first section of cylinder wall, extra installation time is not needed, and therefore the construction period is effectively shortened.

Description

Technical Field

[0001] The invention belongs to the technical field of caisson construction, and in particular relates to a caisson wall structure capable of reducing friction resistance and a construction method thereof. Background Art

[0002] In the field of industrial production, when some deep concrete structures are built underground due to process requirements, such as circulating water sedimentation tanks, cooling pits or equipment pits, the caisson method is usually used for construction. During the caisson construction, it is necessary to tie reinforcement and support the formwork in sections to cast concrete, and then dig out the soil layer in the well while relying on the self-weight of the structure to cut the soil and sink it until it sinks into place, and then seal the bottom. The resistance that the well body overcomes when sinking is mainly the friction resistance between the well body and the surrounding soil. In order to reduce the friction resistance during the sinking process, the prior art usually adopts the method of expanding the blade foot by 15-20mm. In this way, only the blade foot is in direct contact with the soil during sinking, and there is a gap of 15-20mm between the caisson body and the soil. Although this method can reduce the friction resistance, under some special process requirements, the blade foot of the caisson is flush with the caisson body, and this method cannot be used; especially under the working conditions of the caisson with a small inner diameter and a large well depth, it is necessary to backfill the earth during the sinking process, and the soil and the well body form a hoop effect, which has a greater friction resistance and is easy to cause uneven sinking and partial sinking, making the sinking more difficult to complete. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a caisson wall structure with reduced friction resistance and a construction method thereof, which solves the problem of large friction and uneven sinking during the sinking construction of the caisson wall structure with non-outwardly expanded blade feet.

[0004] The technical solution adopted by the present invention is: a caisson wall structure for reducing friction resistance, including a first section wall and several sections of upper wall arranged above the first section wall, the first section wall including a first section body and a blade foot arranged at the bottom end of the first section body, the upper end of the blade foot is flush with the first section body; a sinking template is provided on the outer side of the first section wall, which is used for pouring concrete of the first section wall and reducing friction resistance during sinking.

[0005] Furthermore, the sunken template is a hard plastic template.

[0006] Furthermore, the sinking template is manufactured by integrated shaping, and the inner side of the sinking template is densely covered with horizontal grooves.

[0007] Furthermore, the depth of the horizontal groove is 3-5 mm.

[0008] Furthermore, the opening size of the horizontal groove along the height direction is not less than 10 mm.

[0009] Furthermore, the spacing between adjacent horizontal grooves is no more than 20 mm.

[0010] Furthermore, the thickness of the sunken template is 15-20 mm.

[0011] Furthermore, the sinking template is formed by splicing and connecting a number of monomer templates.

[0012] A construction method for a caisson wall structure with reduced friction resistance as described above comprises the following steps:

[0013] Making a sinking template: making the sinking template according to the outer contour of the caisson wall;

[0014] Excavating a foundation pit: excavating the foundation pit, pouring the foundation pit cushion layer, and measuring the positioning center line and external contour line of the caisson wall;

[0015] Construction of the first section of the cylinder wall: tying the steel bars of the first section of the cylinder wall and installing tension bolts at preset positions; installing the sinking formwork on the outer contour line, installing the inner formwork on the inner contour line of the caisson cylinder wall, and fastening the sinking formwork and the inner formwork through the tension bolts; pouring the concrete of the first section of the cylinder wall;

[0016] Construction of the second section of the cylinder wall: tie the steel bars of the second section of the cylinder wall, and support the outer formwork and the inner formwork corresponding to the second section of the cylinder wall, and pour the concrete of the second section of the cylinder wall after tightening; when the concrete of the second section of the cylinder wall reaches the required strength, remove the inner formwork of the first section of the cylinder wall and the inner formwork and the outer formwork of the second section of the cylinder wall;

[0017] Sinking construction: excavating the soil inside the caisson to make the first section of the wall sink to the designed position;

[0018] Construction of the third section cylinder wall: tying the third section cylinder wall reinforcement, and supporting the outer formwork and the inner formwork corresponding to the third section cylinder wall, and pouring the third section cylinder wall concrete after tightening; when the third section cylinder wall concrete reaches the required strength, removing the inner formwork and the outer formwork of the third section cylinder wall;

[0019] The sinking construction and other upper cylinder wall construction are repeated until the caisson sinks to the designed position.

[0020] The advantages and positive effects of the present invention are:

[0021] The present application sets a sinking template on the outer side of the first section of the cylinder wall, and utilizes its thickness to make it bulge outward relative to the upper cylinder wall, so that during the sinking process, only the sinking template contacts the soil, while the first section of the cylinder wall and the upper cylinder wall are avoided from contacting the soil, thereby reducing the friction resistance between the caisson cylinder wall and the soil, and improving the sinking efficiency; by adopting a hard plastic template as the sinking template, utilizing the hard plastic template's smooth surface and good rigidity, strength and other characteristics, the friction resistance between the sinking template and the surrounding soil is reduced, and the uniform balance of the sinking can be better controlled; by reasonably designing the depth and opening height of the horizontal groove on the sinking template, it is ensured that the sinking template is firmly fixed on the outer side of the first section of the cylinder wall, the overall stability of the external structure of the first section of the cylinder wall is improved, and further ensured that it remains stable during the sinking process of the first section of the cylinder wall; at the same time, the sinking template can also be used as the outer template for concrete pouring of the first section of the cylinder wall, and can be installed simultaneously during the construction of the first section of the cylinder wall, without the need for additional installation time or dismantling, thereby effectively saving construction time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the first section of the cylinder wall structure of a specific embodiment of the present invention;

[0023] Figure 2 is a schematic diagram of a horizontal groove structure of a specific embodiment of the present invention;

[0024] Figure 3 It is a schematic diagram of a construction method of a specific embodiment of the present invention.

[0025] In the figure:

[0026] 1. First section wall 11, blade foot 2, sinking template

[0027] 21. Horizontal groove 3, foundation pit 4, second section wall DETAILED DESCRIPTION

[0028] The embodiments of the present invention are described below with reference to the accompanying drawings.

[0029] like Figure 1-Figure 3 As shown, the present invention proposes a caisson wall structure for reducing friction resistance, including a first section wall 1, and a plurality of upper sections of the wall arranged above the first section wall 1, the first section wall 1 including a first section body and a blade foot 11 arranged at the bottom end of the first section body, the upper end of the blade foot 11 is flush with the first section body; a sinking template 2 is provided on the outer side of the first section wall 1, which is used for pouring concrete of the first section wall 1 and reducing friction resistance during sinking.

[0030] The present application sets a sinking template 2 on the outside of the first section of the cylinder wall 1, and utilizes its thickness to make it protrude outward relative to the upper cylinder wall, so that during the sinking process, only the sinking template 2 is in contact with the soil, while the first section of the cylinder wall 1 and the upper cylinder wall are avoided from contacting with the soil, thereby reducing the friction resistance between the caisson cylinder wall and the soil and improving the sinking efficiency; in addition, the sinking template 2 also serves as the outer template for concrete pouring of the first section of the cylinder wall 1, and is installed simultaneously during the construction of the first section of the cylinder wall 1, without the need for additional installation time, thereby effectively saving construction time.

[0031] Preferably, the sinking template 2 is a hard plastic template. The surface of the hard plastic template is flat and smooth, far exceeding the flatness and smoothness of the concrete structure surface in the prior art, so its friction coefficient is much lower than that of the concrete structure surface, reducing the friction resistance with the surrounding soil, and can better control the uniform balance of the sinking.

[0032] The sinking formwork 2 made of hard plastic in this application has good adaptability and can be processed into various shapes according to needs to meet the requirements of different building formworks; the sinking formwork 2 in this application is made by integrated shaping, and the use of integrated shaping production process can guarantee the rigidity and strength of the formwork to the greatest extent, and can resist the lateral pressure during concrete pouring and the upward friction during the sinking process, and is not easy to deform and wear, thereby effectively protecting the caisson wall. In addition, as shown in the figure, dense horizontal grooves 21 are arranged on the inside of the sinking formwork 2, so that corresponding convex blocks are formed on the outside of the first section of the wall 1, and the convex blocks are tightly connected with the horizontal grooves 21 to resist the upward extrusion force transmitted by the sinking formwork 2 during the sinking process, so as to ensure that the sinking formwork 2 is firmly fixed on the outside of the first section of the wall 1 to avoid relative displacement.

[0033] Preferably, the depth of the horizontal groove 21 is 3-5 mm. It can be understood that the depth of the horizontal groove 21 corresponds to the thickness direction of the sinking template 2, so that the horizontal surface of the formed protrusion extends radially along the first section cylinder wall 1 by 3-5 mm to ensure that the protrusion forms effective support for the horizontal groove 21.

[0034] Furthermore, the opening size of the horizontal groove 21 along the height direction is not less than 10 mm, so that the formed protrusion reaches a length of not less than 10 mm along the height direction, thereby enhancing the rigidity and bearing capacity of the protrusion itself, and then improving the overall stability of the external structure of the first section of the cylinder wall 1, so that it can better withstand the extrusion pressure transmitted by the sinking template 2, ensuring that it remains stable and reliable during the sinking process of the first section of the cylinder wall 1.

[0035] Furthermore, the spacing between adjacent horizontal grooves 21 is no greater than 20 mm, so as to ensure sufficient bonding force between the concrete of the first section cylinder wall 1 and the sinking formwork 2, and further prevent relative displacement between the two during the sinking process.

[0036] Furthermore, the thickness of the sinking formwork 2 is 15-20 mm to ensure that the rigidity and strength of the sinking formwork 2 meet the requirements of concrete shaping and sinking.

[0037] In a specific embodiment, the sinking template 2 is composed of several single templates spliced ​​and connected. By splitting the sinking template 2 into several single templates and using hard plastic to shape and manufacture, the processing size of each single template can be accurately controlled, and these single templates are tightly connected together by splicing to finally form a complete sinking template 2. This method is conducive to reducing the overall processing cost, because the processing of the single template is relatively simple, and it can be more convenient to transport and install, which improves the efficiency and convenience of engineering construction.

[0038] The construction method of the caisson wall structure for reducing friction resistance proposed in this application is as follows: Figure 3 As shown, the specific steps include:

[0039] S1, making sinking template 2;

[0040] The sinking template 2 is manufactured according to the external contour of the caisson wall. Since the caisson wall is constructed in sections according to height, a design drawing of the sinking template 2 is drawn according to the external contour of the caisson wall before manufacturing, and it is divided into several single templates for easy processing and manufacturing according to certain principles. Preferably, the single templates have the same specifications and can be processed and manufactured using the same mold to reduce the manufacturing cost of the sinking template 2.

[0041] S2, excavation of foundation pit 3;

[0042] A foundation pit 3 is excavated at the designed position of the caisson wall. The depth of the foundation pit 3 is the same as the height of the first section wall 1. After leveling, a foundation pit 3 cushion is poured, and the positioning center line and external contour line of the caisson wall are measured on the cushion.

[0043] S3, construction of the first section of the cylinder wall 1;

[0044] First, the reinforcement of the first section of the cylinder wall 1 is tied, and tension bolts are installed at preset positions. Preferably, the tension bolts are evenly arranged according to the set spacing;

[0045] Subsequently, the sinking formwork 2 is installed on the outer contour line, and the inner formwork is installed on the inner contour line of the caisson wall, and the sinking formwork 2 and the inner formwork are fastened by tension bolts; when supporting the formwork and the inner formwork, a formwork support frame is used to support and reinforce the two.

[0046] Then pour the concrete of the first section of the cylinder wall 1. During pouring, the concrete should be vibrated frequently but should not touch the sinking formwork 2 and the inner formwork to prevent them from deformation or damage.

[0047] S4, construction of the second section cylinder wall 4;

[0048] Tie up the steel bars of the second section cylinder wall 4, and support the outer and inner formworks corresponding to the second section cylinder wall 4, fasten them with tension bolts, and then pour the concrete of the second section cylinder wall 4;

[0049] When the concrete of the second section cylinder wall 4 reaches sufficient strength, the inner formwork of the first section cylinder wall 1 and the inner and outer formworks of the second section cylinder wall 4 are removed; at the same time, the heads of the tension bolts in the first section cylinder wall 1 and the second section cylinder wall 4 are removed, and the outer surface of the sunken formwork 2 and the outer surface of the second section cylinder wall 4 are cleaned.

[0050] S5. Sinking construction:

[0051] Excavation equipment is used to excavate the soil inside the caisson. As the excavation proceeds, since the weight of the completed first and second sections of the shaft wall is greater than the friction resistance between the sinking template 2 and the soil, the two move downward synchronously until the first section of the cylinder wall 1 sinks to the designed position; preferably, the soil excavation depth and the sinking height are the same as the height of the first section of the cylinder wall 1. After the sinking is completed, the first section of the cylinder wall 1 is completely sunk into the excavated soil.

[0052] S5, the third section of the cylinder wall construction:

[0053] According to the same method as in step S4, the third section of the cylinder wall reinforcement is tied, and the outer and inner templates corresponding to the third section of the cylinder wall are supported, and the third section of the cylinder wall concrete is poured after being tightened; when the third section of the cylinder wall concrete reaches the required strength, the inner and outer templates of the third section of the cylinder wall are removed;

[0054] S6, repeat the sinking construction in step S5 and other upper wall construction until the caisson sinks to the designed position, remove the formwork support frame, clean the foundation pit 3 and then backfill the earth, and then the construction of the internal structure and facilities of the caisson can be carried out.

[0055] Embodiment 1

[0056] A caisson wall structure for reducing friction resistance, the caisson wall structure comprises a first section wall 1, and several sections of upper wall arranged above the first section wall 1, the height of the first section wall 1 and the upper wall are both 3m, the inner wall diameter is 15m, and the wall thickness is 500mm; wherein the first section wall 1 comprises a first section body and a blade foot 11 arranged at the bottom end of the first section body, the blade foot 11 in this embodiment is arranged in an inverted trapezoid, and the upper end of the blade foot 11 is flush with the first section body; a sinking template 2 is provided on the outside of the first section wall 1, and the sinking template 2 is made of a hard plastic template. The hard plastic template is made of polyvinyl chloride (PVC) material for integrated shaping, and its thickness is 15mm. A plurality of horizontal grooves 21 are provided on the inside thereof, the depth of the horizontal grooves 21 is 3mm, the opening height is 10mm, and the spacing between adjacent horizontal grooves 21 is 20mm. A plurality of monomer templates are assembled into an overall sinking template 2 that can match the outer contour of the first section wall 1, and the height of the assembled sinking template 2 is 3m.

[0057] Embodiment 2

[0058] A construction method for a caisson wall structure that reduces friction resistance, used to construct and form the caisson wall structure in Example 1 of the present application;

[0059] In this embodiment, both the inner and outer formworks are made of wooden formworks. The inner formwork of the first section of the cylinder wall 1 is fastened to the sinking formwork 2 by tension bolts and butterfly clips. The spacing between the tension bolts is 600mm and the diameter is 14mm. The sinking height of each time during the sinking construction process is 3m.

[0060] The present application sets a sinking template on the outer side of the first section of the cylinder wall, and utilizes its thickness to make it bulge outward relative to the upper cylinder wall, so that during the sinking process, only the sinking template contacts the soil, while the first section of the cylinder wall and the upper cylinder wall are avoided from contacting the soil, thereby reducing the friction resistance between the caisson cylinder wall and the soil, and improving the sinking efficiency; by adopting a hard plastic template as the sinking template, utilizing the hard plastic template's smooth surface and good rigidity, strength and other characteristics, the friction resistance between the sinking template and the surrounding soil is reduced, and the uniform balance of the sinking can be better controlled; by reasonably designing the depth and opening height of the horizontal groove on the sinking template, it is ensured that the sinking template is firmly fixed on the outer side of the first section of the cylinder wall, the overall stability of the external structure of the first section of the cylinder wall is improved, and further ensured that it remains stable during the sinking process of the first section of the cylinder wall; at the same time, the sinking template can also be used as the outer template for concrete pouring of the first section of the cylinder wall, and can be installed simultaneously during the construction of the first section of the cylinder wall, without the need for additional installation time or dismantling, thereby effectively saving construction time.

[0061] The embodiments of the present invention are described in detail above, but the contents described are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A caisson wall structure for reducing friction resistance, comprising a first section of the wall, and a plurality of sections of upper walls arranged above the first section of the wall, characterized in that: The first section cylinder wall includes a first section main body and a blade foot arranged at the bottom end of the first section main body, and the upper end of the blade foot is flush with the first section main body; a sinking template is provided on the outer side of the first section cylinder wall, which is used for pouring concrete of the first section cylinder wall and reducing friction resistance during sinking.

2. The caisson wall structure for reducing friction resistance according to claim 1 is characterized in that: The sinking template is a hard plastic template.

3. The caisson wall structure for reducing frictional resistance according to claim 2 is characterized in that: The sinking template is made by integrated shaping, and the inner side of the sinking template is densely covered with horizontal grooves.

4. The caisson wall structure for reducing frictional resistance according to claim 3 is characterized in that: The depth of the horizontal groove is 3-5 mm.

5. The caisson wall structure for reducing frictional resistance according to claim 3 or 4, characterized in that: The opening dimension of the horizontal groove along the height direction is not less than 10 mm.

6. The caisson wall structure for reducing frictional resistance according to claim 5 is characterized in that: The spacing between adjacent horizontal grooves is no more than 20 mm.

7. The caisson wall structure for reducing frictional resistance according to any one of claims 1 to 4 and 6, characterized in that: The thickness of the sunken template is 15-20 mm.

8. The caisson wall structure for reducing frictional resistance according to claim 7 is characterized in that: The sinking template is formed by splicing and connecting a number of monomer templates.

9. A construction method for a caisson wall structure with reduced friction resistance as claimed in any one of claims 1 to 8, characterized in that: The following steps are involved: Making a sinking template: making the sinking template according to the outer contour of the caisson wall; Excavating a foundation pit: excavating the foundation pit, pouring the foundation pit cushion layer, and measuring the positioning center line and external contour line of the caisson wall; Construction of the first section of the cylinder wall: tying the steel bars of the first section of the cylinder wall and installing tension bolts at preset positions; installing the sinking formwork on the outer contour line, installing the inner formwork on the inner contour line of the caisson cylinder wall, and fastening the sinking formwork and the inner formwork through the tension bolts; pouring the concrete of the first section of the cylinder wall; Construction of the second section of the cylinder wall: tie the steel bars of the second section of the cylinder wall, and support the outer formwork and the inner formwork corresponding to the second section of the cylinder wall, and pour the concrete of the second section of the cylinder wall after tightening; when the concrete of the second section of the cylinder wall reaches the required strength, remove the inner formwork of the first section of the cylinder wall and the inner formwork and the outer formwork of the second section of the cylinder wall; Sinking construction: excavating the soil inside the caisson to make the first section of the wall sink to the designed position; Construction of the third section cylinder wall: tying the third section cylinder wall reinforcement, and supporting the outer formwork and the inner formwork corresponding to the third section cylinder wall, and pouring the third section cylinder wall concrete after tightening; when the third section cylinder wall concrete reaches the required strength, removing the inner formwork and the outer formwork of the third section cylinder wall; The sinking construction and other upper cylinder wall construction are repeated until the caisson sinks to the designed position.

10. The construction method of a caisson wall structure with reduced friction resistance according to any one of claim 9, characterized in that: The sinking height of each sinking construction is the same as the height of the caisson wall of each section.

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