Small-area deep foundation pit collection pool construction method and structure based on open caisson method

Abstract

The invention relates to the field of deep foundation pit construction, in particular to a small-area deep foundation pit collecting pool construction method and structure based on an open caisson method.The small-area deep foundation pit collecting pool construction method comprises the steps that firstly, pit digging is conducted according to the depth of a main pool body, and then the position of a collecting pool is determined at the elevation of the pool bottom; then, a first well-shaped piece is arranged on the outer side of the position of the collecting pool through an open caisson method; the bottom of the inner side of the first well-shaped piece is subjected to underwater pouring and bottom sealing through a guide pipe method; a second well-shaped piece is placed in the position of the collecting pool, and the second well-shaped piece is inserted into the sealing bottom of the inner bottom of the first well-shaped piece; and a concrete layer is poured in the space between the first well-shaped piece and the second well-shaped piece. According to the construction method of driving the first well-shaped piece into the stratum and sealing the bottom, the defects of an open excavation masonry method can be effectively reduced and improved, and the purposes of shortening the construction period, reducing the cost, improving the safety, reducing the influence on surrounding soil structures and the like are achieved.

Description

Technical Field

[0001] The present invention relates to the field of deep foundation pit construction, and in particular to a construction method and structure of a small-area deep foundation pit collection pool based on the open caisson method. Background Technique

[0002] Traditional deep foundation pit collection pool construction uses the open cut method for construction. As Figure 1 shown, generally, the construction process of foundation pit excavation - dewatering - formwork support - concrete construction of the pool bottom and pool wall - waterproof layer construction is adopted. Figure 1 The outer contour line in the middle and outside is the scope of earthwork excavation required for construction; this construction method has the disadvantages of long construction period, high construction cost, great safety hazards, large impact on surrounding soil structures, large precipitation, large environmental impact, and difficulty in reversing and correcting when it does not conform to the design.

[0003] Most pool bodies such as garbage storage pools and clear water pools themselves have an excavation depth of less than 5 meters, but when the depth of the sump is added, the overall excavation depth exceeds 5 meters, which belongs to a dangerous and large project and requires expert demonstration. The increase in excavation depth increases the overall excavation volume, increases the incidence of safety risk accidents, increases the excavation floor area, increases the impact on surrounding soil and structures, and increases the precipitation. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a construction method and structure of a small-area deep foundation pit collection pool based on the open caisson method, which can effectively reduce and improve the disadvantages of the open cut masonry method, and achieve the purposes of shortening the construction period, reducing costs, improving safety, and reducing the impact on surrounding soil structures.

[0005] To achieve the above object, the present invention is realized according to the following technical solutions:

[0006] On the one hand, the present invention provides a construction method of a small-area deep foundation pit collection pool based on the open caisson method, including the following steps:

[0007] Step S1: Dig a pit according to the depth of the main pool body, and after completion, determine the position of the collection pool at the elevation of the pool bottom;

[0008] Step S2: Place the first well-shaped member outside the position of the collection pool by the open caisson method;

[0009] Step S3: Underwater seal the bottom of the inner side of the first well-shaped member by the conduit method;

[0010] Step S4: Place the second well-shaped member at the position of the collection pool, and make the second well-shaped member insert into the bottom seal inside the first well-shaped member;

[0011] Step S5: Pour a concrete layer in the space between the first well-shaped member and the second well-shaped member.

[0012] In one technical solution, the first well-shaped member and the second well-shaped member are made of threaded steel pipes, stainless steel pipes or reinforced concrete pipes.

[0013] In the above technical solution, the depth of the main pool body in step S1 < 5 meters.

[0014] In the above technical solution, the thickness of the bottom seal in step S2 is determined by anti-floating calculation according to the depth of the groundwater level.

[0015] In one technical solution, it further includes step S6: evacuating the accumulated water in the space between the first well-shaped member and the second well-shaped member.

[0016] In one technical solution, the first well-shaped member and the second well-shaped member are coaxial, and the distance between the first well-shaped member and the second well-shaped member is 20 cm.

[0017] In one technical solution, the first well-shaped member and the second well-shaped member are subjected to anti-corrosion and anti-oxidation treatments before use.

[0018] On the other hand, the present invention provides a deep foundation pit collection pool structure, including a main pool, a first well-shaped member and a second well-shaped member. A through hole is provided in the bottom wall of the main pool. A first well-shaped member is fixed downward at the inner edge side of the through hole at the bottom end of the bottom wall of the main pool. A second well-shaped member is fixed inside the first well-shaped member. A concrete layer is filled between the first well-shaped member and the second well-shaped member. A bottom seal is provided at the inner bottom of the first well-shaped member. A collection pool is formed in the space above the bottom seal inside the second well-shaped member.

[0019] In one technical solution, the first well-shaped member and the second well-shaped member are coaxial, and the distance between the first well-shaped member and the second well-shaped member is 20 cm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The construction method of the small-area deep foundation pit collection pool based on the open caisson method of the present invention aims at the disadvantages of the traditional open cut method, such as long construction period, high construction cost, great safety hazards, large impact on surrounding soil structures, large precipitation, large environmental impact, and difficulty in reversing and correcting when it does not conform to the design. By driving the first well-shaped member into the formation and constructing the bottom seal, it can effectively reduce and improve the disadvantages of the open cut masonry method, achieving the purposes of shortening the construction period, reducing the cost, improving safety, and reducing the impact on surrounding soil structures. It has the advantages of simple operation, no need for large-area earth excavation, dewatering, formwork construction, waterproof construction, low cost, short construction period, no deep foundation pit excavation, and high construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] Figure 1 It is a structural contour diagram of the traditional open cut method construction;

[0024] Figure 2 It is a longitudinal sectional schematic diagram of a deep foundation pit collection pool structure of the present invention;

[0025] Figure 3 It is a top view structural schematic diagram of a deep foundation pit collection pool structure of the present invention.

[0026] Reference numerals: 1 - main pool; 2 - first well-shaped member; 3 - second well-shaped member; 4 - concrete layer; 5 - bottom seal. Specific embodiments

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0028] Embodiment 1

[0029] A construction method for a small-area deep foundation pit collection pool based on the open caisson method in Embodiment 1 of the present invention includes the following steps:

[0030] Step S1: Dig a pit according to the depth of the main pool body 1. After completion, determine the position of the collection pool at the bottom elevation;

[0031] Most of the main pool body 1, such as pool bodies like garbage storage pools and clean water pools, whose excavation depth itself is less than 5 meters and does not require expert demonstration. Therefore, when digging a pit for the depth of the main pool body 1, according to the geological and hydrological data, combined with the situation of nearby buildings on site, formulate an excavation plan and do a good job in waterproofing and drainage;

[0032] Step S2: Place the first well-shaped member 2 outside the position of the collection pool by the open caisson method;

[0033] The transverse dimension of the first well-shaped member 2 should be larger than the transverse dimension of the collection pool; the height of the first well-shaped member 2 is specifically determined according to the depth of the collection pool; when specifically placing it, vertically position the first well-shaped member 2 outside the position of the collection pool, excavate the soil inside the first well-shaped member 2, and sink while tunneling to ensure that the first well-shaped member 2 sinks vertically until the sinking depth of the first well-shaped member 2 reaches the depth of the collection pool.

[0034] Step S3: Underwater grout the bottom inside the first well-shaped member 2 with a conduit method; the bottom seal 5 can be grouted with concrete;

[0035] The depth of the main pool body 1 plus the depth of the collection pool, the overall excavation depth exceeds 5 meters, that is, the lower part of the collection pool has reached below the groundwater level line. Therefore, the bottom inside the first well-shaped member 2 is underwater grouted with a conduit method to form the bottom wall of the collection pool.

[0036] Step S4: Place the second well-shaped member 3 at the position of the collection pool, and insert the second well-shaped member 3 into the bottom seal 5 at the inner bottom of the first well-shaped member 2;

[0037] The lateral dimension inside the second well-shaped member 3 is the lateral dimension of the collection pool, and the depth of the second well-shaped member 3 is specifically determined according to the depth of the collection pool; the shape of the second well-shaped member 3 is determined according to the specific shape design of the collection pool; before the bottom seal 5 hardens, insert the second well-shaped member 3 into the bottom seal 5 at the inner bottom of the first well-shaped member 2.

[0038] Step S5: Pour a concrete layer 4 in the space between the first well-shaped member 2 and the second well-shaped member 3.

[0039] Although the excavation depth of most pool bodies such as garbage storage pools and clear water pools themselves does not reach 5 meters, but adding the depth of the sump, the overall excavation depth exceeds 5 meters, which belongs to a major hazardous project and requires expert demonstration. The increased excavation depth leads to an increased overall excavation volume, an increased incidence of safety risk accidents, an increased excavation footprint, an increased impact on the surrounding soil and structures, and an increased precipitation. The construction method of the small-area deep foundation pit collection pool based on the open caisson method of the present invention aims at the disadvantages of the traditional open cut method construction method, such as long construction period, high construction cost, large safety hazards, large impact on the surrounding soil and structures, large precipitation, large environmental impact, and difficult to reverse and need to be corrected when not in line with the design. By driving the first well-shaped member 2 into the formation and constructing the bottom seal, it can effectively reduce and improve the disadvantages of the open cut masonry method, achieving the purposes of shortening the construction period, reducing the cost, improving the safety, and reducing the impact on the surrounding soil and structures. It has the advantages of simple operation, no need for large-area earth excavation, precipitation, formwork construction, waterproof construction, low cost, short construction period, and no deep foundation pit excavation, and high construction safety.

[0040] The shapes of the first well-shaped member 2 and the second well-shaped member 3 are appropriately selected according to the designed shape of the collection pool. For example, the transverse cross-sectional shapes of the first well-shaped member 2 and the second well-shaped member 3 can be circular, square, elliptical and other shapes.

[0041] The embodiments of the present invention are provided according to the construction conditions of the collection pool structure in the garbage comprehensive treatment project of Yudaokou Ranch Management Area. The transverse cross-sectional shapes of the first well-shaped member 2 and the second well-shaped member 3 are specifically designed to be circular; the first well-shaped member 2 and the second well-shaped member 3 need to be subjected to anti-corrosion and anti-oxidation treatments before use; according to the properties of the liquid stored in the collection pool, the materials of the first well-shaped member 2 and the second well-shaped member 3 and the anti-corrosion and anti-oxidation treatment methods are determined; the materials of the first well-shaped member 2 and the second well-shaped member 3 need to meet the strength requirements at the same time; further, the first well-shaped member 2 and the second well-shaped member 3 can be made of threaded steel pipes, stainless steel pipes or reinforced concrete pipes; using formed pipes such as threaded steel pipes, stainless steel pipes, and reinforced concrete pipes to replace support structures such as formwork can not only meet the support requirements but also play a water-stop role.

[0042] As a preferred technical solution of the present invention, the thickness of the bottom seal 5 in step S2 is determined by anti-floating calculation according to the depth of the groundwater level to ensure that the self-weight of the poured concrete meets the anti-floating requirements.

[0043] As a preferred technical solution of the present invention, it further includes step S6: evacuating the accumulated water in the space between the first well-shaped member 2 and the second well-shaped member 3; further, waterproof layer construction can be carried out.

[0044] As a preferred technical solution of the present invention, the first well-shaped member 2 and the second well-shaped member 3 are coaxial, and the distance between the first well-shaped member 2 and the second well-shaped member 3 is 20 cm.

[0045] After the concrete layer 4 is poured, the main pool body 1 is poured around the collection pool according to the design dimensions of the main pool body 1, that is, the collection pool of the main pool body 1 is formed.

[0046] Embodiment 2

[0047] A deep foundation pit collection pool structure according to Embodiment 2 of the present invention, such as Figure 2 、 Figure 3As shown, it is composed of a construction method of a small-area deep foundation pit collection pool based on the open caisson method according to Embodiment 1, including a main pool 1, a first well-shaped member 2, and a second well-shaped member 3. A through hole is opened on the bottom wall of the main pool 1. A first well-shaped member 2 is fixed downward at the bottom end of the bottom wall of the main pool 1 on the inner edge side of the through hole. A second well-shaped member 3 is fixed inside the first well-shaped member 2. A concrete layer 4 is filled between the first well-shaped member 2 and the second well-shaped member 3. A bottom seal 5 is provided at the inner bottom of the first well-shaped member 2. A collection pool is formed in the space above the bottom seal 5 inside the second well-shaped member 3; the transverse cross-sectional shapes of the first well-shaped member 2 and the second well-shaped member 3 are specifically designed to be circular. The first well-shaped member 2 and the second well-shaped member 3 are coaxial, and the distance between the first well-shaped member 2 and the second well-shaped member 3 is 20 cm; the first well-shaped member 2, the second well-shaped member 3, and the concrete layer 4 form a symmetrically surrounding construction wall of the collection pool; after the concrete layer 4 is poured, the main pool body 1 is poured according to the design dimensions of the main pool body 1 around the collection pool; under the connection action of each direction of the soil body, the concrete layer 4, the bottom seal 5, and the main pool body 1, a firm structure of the collection pool is formed.

[0048] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", "lateral", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0049] The terms "first", "second", etc. in the specification, claims, and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, product, or device that includes a series of steps is not limited to the listed steps, but optionally further includes steps not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0050] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for constructing a small-area deep foundation pit collection pool based on the caisson method, characterized in that: The following steps are involved: Step S1: dig a pit according to the depth of the main pool body (1), and after completion, determine the location of the collection pool at the pool bottom elevation; Step S2: placing a first well-shaped member (2) outside the collecting pool by using a caisson method; Step S3: using a catheter method to underwater perfuse and seal the bottom (5) of the inner bottom of the first well-shaped member (2); Step S4: placing a second well-shaped member (3) at the position of the collection pool, so that the second well-shaped member (3) is inserted into the bottom cover (5) at the bottom of the first well-shaped member (2); Step S5: pouring a concrete layer (4) in the space between the first well-shaped member (2) and the second well-shaped member (3).

2. The method for constructing a small-area deep foundation pit collection pool based on the caisson method according to claim 1, characterized in that: The first well-shaped member (2) and the second well-shaped member (3) are made of threaded steel pipes, stainless steel pipes or reinforced concrete pipes.

3. The method for constructing a small-area deep foundation pit collection pool based on the caisson method according to claim 1, characterized in that: In step S1, the depth of the main pool body (1) is less than 5 meters.

4. The method for constructing a small-area deep foundation pit collection pool based on the caisson method according to claim 1, characterized in that: In step S2, the thickness of the bottom cover (5) is determined by performing anti-floating calculation according to the depth of the groundwater level.

5. The method for constructing a small-area deep foundation pit collection pool based on the caisson method according to claim 1, characterized in that: The method further comprises step S6: evacuating the accumulated water in the space between the first well-shaped member (2) and the second well-shaped member (3).

6. The method for constructing a small-area deep foundation pit collection pool based on the caisson method according to claim 2, characterized in that: The first well-shaped member (2) and the second well-shaped member (3) are coaxial, and the distance between the first well-shaped member (2) and the second well-shaped member (3) is 20 cm.

7. The method for constructing a small-area deep foundation pit collection pool based on the caisson method according to claim 2, characterized in that: The first well-shaped member (2) and the second well-shaped member (3) are subjected to anti-corrosion and anti-oxidation treatments before use.

8. A deep foundation pit collection pool structure, characterized in that: The invention comprises a main body pool (1), a first well-shaped member (2) and a second well-shaped member (3), wherein the bottom wall of the main body pool (1) is provided with a through hole, the bottom end of the bottom wall of the main body pool (1) is downwardly located on the inner edge of the through hole and fixed with the first well-shaped member (2), the inner side of the first well-shaped member 2 is fixed with the second well-shaped member (3), a concrete layer (4) is filled between the first well-shaped member (2) and the second well-shaped member (3), the inner bottom of the first well-shaped member (2) is provided with a bottom seal (5), and the inner side of the second well-shaped member (3) is located in the space above the bottom seal (5) to form a collection pool.

9. A deep foundation pit collection pool structure according to claim 8, characterized in that: The first well-shaped member (2) and the second well-shaped member (3) are coaxial, and the distance between the first well-shaped member (2) and the second well-shaped member (3) is 20 cm.

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