Foundation pit supporting structure utilizing existing supporting piles
By setting up high-pressure rotary spray piles and H-shaped steel on existing support piles, SMW working piles are formed, and a unified crown beam is formed by planting reinforcement piles, the problem of insufficient stiffness and bending resistance of foundation pit support piles is solved. It improves structural safety, shortens construction periods and saves costs, and is in line with the concept of green, low-carbon and environmental protection.
Patent Information
- Application Number
- CN202420085179.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-01-12
AI Technical Summary
The stiffness and bending resistance of the existing foundation pit support piles are insufficient, and they cannot withstand the soil pressure outside the new foundation pit after the depth increases. Breaking the existing support structure will increase construction period and waste of resources.
High-pressure rotary spray piles and H-shaped steel are installed on the existing support piles to form SMW piles, and the bending resistance of the entire structure is enhanced by combining the reinforcement piles with the crown beam, forming a support closer to the double-row pile system structure.
It improves the structural safety of the foundation pit support system, shortens the construction period, saves economic costs, and can be recycled and utilized in the later stage, reducing the amount of concrete and steel, which is in line with the concept of green, low-carbon and environmental protection.
Smart Images
Figure CN222183366U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of foundation pit engineering, in particular to a foundation pit supporting structure utilizing existing supporting piles. Background Art
[0002] With the upgrading and renovation of municipal engineering, the land area in the factory area is limited, and the foundation pit of the new project has to be close to the existing structure. The existing support structure of the existing structure will invade the scope of the new foundation pit support system, causing the existing piles to occupy the position of the new foundation pit support piles. At the same time, the early structure was buried shallowly, and the upper slope was cut and the lower support piles were cantilevered. The existing support piles were small in diameter, length, and reinforcement, and the pile stiffness and bending resistance were weak, which could not withstand the larger soil pressure outside the new foundation pit after the depth increased. If the existing support structure is completely removed, it will not only increase the construction period, but also cause a great waste of resources. Therefore, in order to ensure the safety of the new foundation pit and the surrounding environment, a new support system can be built on the basis of the existing support piles to improve the stress state of the support structure. Utility Model Content
[0003] Based on the above description, the utility model provides a foundation pit support structure using existing support piles to solve the problem of insufficient stiffness and bending resistance of existing single support piles and increase the safety of the support system structure.
[0004] The technical solution of the utility model to solve the above-mentioned technical problems is as follows: a foundation pit support structure using existing support piles, comprising: existing support piles, and a first crown beam arranged on the upper part of the existing support piles, a plurality of high-pressure rotary jet piles are arranged adjacent to one side of the existing support piles, and H-shaped steels are arranged inside the plurality of high-pressure rotary jet piles; the plurality of high-pressure rotary jet piles are arranged side by side with the existing support piles, and the plurality of high-pressure rotary jet piles are staggered and connected to each other, and embedded bars are also arranged inside the first crown beam; first longitudinal main bars and first stirrups are arranged on both sides of the H-shaped steel, the first stirrups are fixedly connected to the first longitudinal main bars, second stirrups are arranged between the H-shaped steels, and concrete structures are arranged on the first longitudinal main bars, the first stirrups and the second stirrups to form a second crown beam as a whole.
[0005] On the basis of the above technical solution, the present invention can also be improved as follows.
[0006] Furthermore, the lengths of both ends of the high-pressure rotary jet pile are greater than those of the existing supporting piles, the first crown beam is lower than the height of the second crown beam, a first cavity is reserved between the second crown beam and the first crown beam, the embedded reinforcement is arranged in the first cavity, second longitudinal main reinforcement and third stirrups are arranged outside the embedded reinforcement, the third stirrups are fixedly connected to the embedded reinforcement and the second longitudinal main reinforcement, and the concrete structure is arranged on the embedded reinforcement, the second longitudinal main reinforcement and the third stirrups to form a pile connection section.
[0007] Furthermore, the first longitudinal main reinforcement and the first hoop reinforcement are also provided at the upper part of the pile connection section, the first longitudinal main reinforcement is provided with multiple layers, the second crown beam extends to the upper part of the pile connection section, and the embedded reinforcement extends to the inside of the second crown beam.
[0008] Furthermore, a joint section connected to the third stirrup is provided at the end of the embedded reinforcement, the length of the joint section does not exceed 10 cm, and an existing structure is arranged adjacent to the other side of the existing supporting pile.
[0009] Furthermore, the H-shaped steel is arranged inside the high-pressure jet grouting piles, the H-shaped steel is evenly arranged, and the bottom depth of the high-pressure jet grouting piles exceeds the bottom depth of the existing supporting piles.
[0010] Furthermore, the high-pressure jet grouting pile includes a core segment, and the unconfined compressive strength of the core segment is not less than 0.6 MPa.
[0011] Furthermore, the edge of the H-shaped steel on one side close to the existing supporting pile is arranged in contact with the first crown beam, the top of the H-shaped steel is arranged higher than the top of the high-pressure rotary jet pile, and the bottom depth of the H-shaped steel is less than the bottom depth of the high-pressure rotary jet pile.
[0012] Furthermore, a second cavity is provided on one side of the high-pressure jet grouting pile away from the existing supporting pile, a main structure is provided inside the second cavity, and the bottom depth of the main structure is higher than the bottom depth of the high-pressure jet grouting pile and the H-shaped steel.
[0013] Furthermore, a support is provided in the second cavity, and the support is fixedly connected to the second crown beam.
[0014] Furthermore, the high-pressure jet grouting piles and the H-shaped steel are combined to form SMW method piles, and the SMW method piles are arranged around the second cavity structure.
[0015] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:
[0016] The foundation pit support structure is formed by inserting H-shaped steel into a row of high-pressure rotary jet piles on the inner side of the existing supporting piles to form SMW method piles, and the existing supporting pile crown beams are used to plant reinforcement and connect the piles, which are cast together with the method piles to form a unified large crown beam, thereby enhancing the integrity of the two. In terms of structural force, it is closer to a double-row pile system, which solves the problem of insufficient stiffness and bending resistance of the existing single supporting piles and increases the safety of the support system structure. Compared with the conventional method of removing the existing supporting piles, the foundation pit support structure can not only shorten the construction period, but also save economic costs. At the same time, compared with cast-in-place piles, the method piles can be recycled in the later stage, reducing the use of concrete and steel, which is more in line with the development concept of green, low-carbon and environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 A schematic diagram of the elevation structure of a foundation pit support structure using existing support piles provided in an embodiment of the utility model;
[0018] Figure 2 A schematic diagram of the planar structure of a foundation pit support structure using existing support piles provided by an embodiment of the utility model;
[0019] Figure 3 A schematic diagram of the planar structure of the crown beam reinforcement provided by an embodiment of the utility model;
[0020] Figure 4 for Figure 3 Sectional view along AA;
[0021] Figure 5 for Figure 3 Section along BB;
[0022] In the accompanying drawings, the components represented by the reference numerals are listed as follows:
[0023] 1. Existing supporting piles; 11. Planted reinforcement; 111. Joint section; 12. Second longitudinal main reinforcement; 13. Third stirrups; 2. First crown beam; 3. High-pressure rotary jet piles; 4. H-shaped steel; 41. First longitudinal main reinforcement; 42. First stirrups; 43. Second stirrups; 5. Second crown beam; 6. Pile connection section; 7. Support; 8. Foundation pit; 9. Existing structures. DETAILED DESCRIPTION
[0024] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.
[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.
[0026] When used herein, the singular forms "a", "an" and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" etc. specify the presence of stated features, wholes, steps, operations, components, parts or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.
[0027] See also Figure 1-5 , the utility model provides a technical solution: a foundation pit support structure using existing support piles, comprising: an existing support pile 1, and a first crown beam 2 arranged on the upper part of the existing support pile 1;
[0028] A plurality of high-pressure rotary jet piles 3 are arranged adjacent to one side of the existing support pile 1, and H-shaped steels 4 are arranged inside the plurality of high-pressure rotary jet piles 3; the plurality of high-pressure rotary jet piles 3 are arranged side by side with the existing support piles 1, and the plurality of high-pressure rotary jet piles 3 are staggeredly connected to each other, and the first crown beam 2 is also provided with embedded reinforcement 11; the first longitudinal main reinforcement 41 and the first stirrup 42 are arranged on both sides of the H-shaped steel 4, and the first stirrup 42 is fixedly connected to the first longitudinal main reinforcement 41, and the second stirrup 43 is arranged between the H-shaped steel 4, and the first longitudinal main reinforcement 41, the first stirrup 42, and the second stirrup 43 are provided with a concrete structure and form a second crown beam 5 as a whole. It should be noted that the staggered connection between the plurality of high-pressure rotary jet piles 3 here means that the high-pressure rotary jet piles 3 are formed along the circumference by high-pressure spraying cement, and the positions of the two adjacent high-pressure rotary jet piles 3 overlap when the cement slurry is sprayed, and a staggered connection will be formed after the high-pressure rotary jet piles 3 are solidified.
[0029] Please see attached Figure 3 The H-shaped steel 4 is an I-shaped structure, the first longitudinal main reinforcement 41 is arranged along the left and right ends of the H-shaped steel 4, the second stirrups 43 are arranged along the upper and lower sides of the H-shaped steel 4, and the first longitudinal main reinforcement 41 and the second stirrups 43 are both steel bars arranged horizontally along a horizontal plane, the first longitudinal main reinforcement 41 and the second stirrups 43 are both arranged in multiple layers, and the first stirrups 42 bind and connect multiple first longitudinal main reinforcements 41 to form a stable structure.
[0030] Specifically, the H-shaped steel 4 is inserted after the construction of the high-pressure rotary jet pile 3 is completed but not completely solidified. The inner boundary of the H-shaped steel 4 is in contact with the first crown beam 2 of the existing supporting pile 1. The H-shaped steel 4 is arranged in a dense insertion manner, and the top is at a certain height from the ground to facilitate later extraction. The bottom of the H-shaped steel 4 is not higher than the high-pressure rotary jet pile 3; the H-shaped steel 4 relies on its own weight to be inserted, and when insertion is difficult, auxiliary measures can be used to sink it.
[0031] Please see attached Figure 1 , the length of both ends of the high-pressure jet grouting pile 3 is greater than the setting of the existing support pile 1, the first crown beam 2 is lower than the height of the second crown beam 5, a first cavity is reserved between the second crown beam 5 and the first crown beam 2, the first cavity is provided with the planting bar 11, the second longitudinal main bar 12 and the third hoop 13 are arranged outside the planting bar 11, the third hoop 13 is fixedly connected with the planting bar 11 and the second longitudinal main bar 12, the planting bar 11, the second longitudinal main bar 12, and the third hoop 13 are provided with the concrete structure to form the pile connection section 6. It should be noted that the length of both ends of the high-pressure jet grouting pile 3 is greater than the setting of the existing support pile 1, the first crown beam 2 is lower than the height of the second crown beam 5, which means that the top end of the high-pressure jet grouting pile 3 is higher than the setting of the existing support pile 1, and the bottom end of the high-pressure jet grouting pile 3 is lower than the setting of the existing support pile 1, and the existing support pile 1 is located between the high-pressure jet grouting pile 3. The first cavity is a certain area reserved between the first crown beam 2 and the second crown beam 5.
[0032] Specifically, the embedded reinforcement 11 is inserted into the bottom of the first crown beam 2 of the existing support pile 1, the second longitudinal main reinforcement 12 and the third hoop reinforcement 13 are tied and welded to the embedded reinforcement 11, and after the first crown beam 2 is roughened, the concrete structure is poured upward with the outer side of the first crown beam 2 as the boundary, and the existing support pile 1 is connected to form a pile connection section 6. The pile is connected by the embedded reinforcement 11, and is cast together with the high-pressure rotary jet pile 3 to form a unified second crown beam 5, which enhances the integrity of the two, and is closer to a double-row pile system in terms of structural stress, solving the problem of insufficient stiffness and bending resistance of the existing single support pile, and increasing the safety of the support system structure.
[0033] Please see attached Figure 4 The first longitudinal main reinforcement 41 and the first hoop reinforcement 42 are also provided on the upper part of the pile connection section 6 . The first longitudinal main reinforcement 41 is provided with multiple layers. The second crown beam 5 extends to the upper part of the pile connection section 6 , and the embedded reinforcement 11 extends to the inside of the second crown beam 5 .
[0034] A joint section 111 connected to the third stirrup 13 is provided at the end of the embedded reinforcement 11, and the length of the joint section 111 does not exceed 10 cm. The existing structure 9 is arranged adjacent to the other side of the existing support pile 1. It should be explained that the joint section 111 here refers to a distance provided at each end of the embedded reinforcement 11, and the distance between the top of the joint section 111 and the third stirrup 13 does not exceed 10 cm, so as to strengthen the strength of the embedded reinforcement 11. After the third stirrup 13 is welded and tied firmly to the embedded reinforcement 11, concrete is poured together with the support 7 for curing to form an integral crown beam and reach the designed strength.
[0035] Please refer to the attached Figure 2 The H-shaped steel 4 is arranged inside the high-pressure jet grouting pile 3 , and the H-shaped steel 4 is evenly arranged. The bottom depth of the high-pressure jet grouting pile 3 exceeds the bottom depth of the existing supporting pile 1 .
[0036] The high pressure jet grouting pile 3 comprises a core segment, and the unconfined compressive strength of the core segment is not less than 0.6 MPa. It should be noted that the unconfined compressive strength of not less than 0.6 MPa here means that the unconfined compressive strength of the pile body after 28 days of core extraction is not less than 0.6 MPa.
[0037] The edge of the H-beam 4 on one side close to the existing support pile 1 is arranged in contact with the first crown beam 2, the top of the H-beam 4 is arranged higher than the top of the high-pressure rotary jet pile 3, and the bottom depth of the H-beam 4 is less than the bottom depth of the high-pressure rotary jet pile 3. It should be noted that the top of the H-beam 4 is arranged higher than the top of the high-pressure rotary jet pile 3, and the H-beam 4 can be recycled in the later stage, which reduces the amount of concrete and steel, and is more in line with the development concept of green, low-carbon and environmental protection. Specifically, after the foundation pit 8 is excavated to the bottom and the main structure construction is completed, the H-beam 4 is vibrated and pulled out in an interval jump manner, and sand and gravel filling materials are poured and grouting are performed while pulling out to reduce the impact on the surrounding environment.
[0038] Please refer to the attached Figure 1 A second cavity is provided on one side of the high-pressure rotary jet pile 3 away from the existing supporting pile 1, and a main structure is provided inside the second cavity. The bottom depth of the main structure is higher than the bottom depth of the high-pressure rotary jet pile 3 and the H-shaped steel 4.
[0039] A support 7 is further disposed in the second cavity, and the support 7 is fixedly connected to the second crown beam 5 .
[0040] The high-pressure rotary jet piles 3 and the H-shaped steel 4 together form SMW construction piles, and the SMW construction piles are arranged around the second cavity structure. That is to say, a row of the high-pressure rotary jet piles 3 is added to the inner side of the existing support piles 1, and the H-shaped steel 4 is densely inserted in the piles. The high-pressure rotary jet piles 3 and the H-shaped steel 4 are densely inserted in the piles to form the SMW construction piles, so that the bending deformation resistance of the original support system is effectively improved. After the crown beam of the existing support pile 1 is raised by the embedded reinforcement 11, it is cast together with the SMW construction piles to form a reinforced concrete crown beam, thereby enhancing the overall force-bearing performance of the two. It should be noted that the second cavity structure is also the foundation pit area, and SMW construction piles are arranged around the foundation pit.
[0041] This embodiment also provides a construction method of a foundation pit support structure using existing support piles, comprising the following steps:
[0042] S1. Construction of high-pressure rotary jet piles: The high-pressure rotary jet piles 3 are arranged inside the existing support piles 1, closely attached to the existing support piles 1, the high-pressure rotary jet piles 3 overlap with each other by a certain width, the pile bottom exceeds the existing support piles 1 by a certain depth, and the unconfined compressive strength of the pile body after 28 days of core extraction is not less than 0.6 MPa;
[0043] S2, H-beam construction: insert the H-beam 4 within half an hour after the construction of the high-pressure jet grouting pile 3 is completed, the inner boundary of the H-beam 4 is in contact with the first crown beam 2, the H-beam 4 is arranged in a close-insertion manner, the top of the H-beam 4 is at a certain height from the ground, which is convenient for later extraction, and the bottom of the H-beam 4 is not higher than the high-pressure jet grouting pile 3; the H-beam 4 is inserted by its own weight, and when insertion is difficult, auxiliary measures can be used to sink it;
[0044] S3, the existing support pile connection construction: the said planting reinforcement 11 is implanted into the bottom of the first crown beam 2, the second longitudinal main reinforcement 12 and the third stirrup 13 are tied and welded to the said planting reinforcement 11, and the first crown beam 2 is roughened, and concrete is poured upward with the outer side of the first crown beam 2 as the boundary to form the pile connection part 6;
[0045] S4, construction of the integral crown beam: tie the first longitudinal main reinforcement 41 and the first stirrup 42 on both sides of the H-shaped steel 4, use the second stirrup 43 pulled through between the H-shaped steels 4, the distance between the implanted reinforcement 11 and the third stirrup 13 at the top of the second crown beam 5 is no more than 10 cm, and after welding and tying firmly, pour concrete together with the support 7 for curing, and reach the design strength;
[0046] S5. After the foundation pit is excavated to the bottom and the main structure is constructed, the H-shaped steel 4 is pulled out by vibration in an interval jumping manner. When pulling out, sand and gravel filling materials are poured and grouting is performed to reduce the impact on the surrounding environment.
[0047] To sum up, the foundation pit support structure forms SMW method piles by arranging a row of high-pressure rotary jet piles 3 and inserting H-shaped steel 4 on the inner side of the existing supporting piles 1, and connecting the piles through the existing supporting pile crown beam embedded reinforcement 11, and casting together with the method piles to form a unified large crown beam, thereby enhancing the integrity of the two. In terms of structural force, it is closer to a double-row pile system, which solves the problem of insufficient stiffness and bending resistance of the existing single supporting pile and increases the safety of the support system structure. Compared with the conventional method of removing the existing supporting piles 1, the foundation pit support structure can not only shorten the construction period, but also save economic costs. At the same time, compared with cast-in-place piles, the method piles can be recycled in the later stage, reducing the use of concrete and steel, which is more in line with the development concept of green, low-carbon and environmental protection.
[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.
Claims
1. A foundation pit support structure using existing support piles. It is characterized in that include: There are existing supporting piles, and a first crown beam arranged on the upper part of the existing supporting piles, a plurality of high-pressure rotary jet piles are arranged adjacent to one side of the existing supporting piles, and H-shaped steels are arranged inside the plurality of high-pressure rotary jet piles; the plurality of high-pressure rotary jet piles are arranged side by side with the existing supporting piles, and the plurality of high-pressure rotary jet piles are staggered and connected to each other, and embedded reinforcement is also arranged inside the first crown beam; first longitudinal main reinforcement and first stirrups are arranged on both sides of the H-shaped steel, the first stirrups are fixedly connected to the first longitudinal main reinforcement, second stirrups are arranged between the H-shaped steels, and concrete structures are arranged on the first longitudinal main reinforcement, the first stirrups and the second stirrups to form a second crown beam as a whole.
2. The foundation pit support structure using existing support piles according to claim 1, It is characterized in that The lengths of both ends of the high-pressure rotary jet pile are greater than the lengths of both ends of the existing supporting piles, the first crown beam is lower than the height of the second crown beam, a first cavity is reserved between the second crown beam and the first crown beam, the embedded reinforcement is arranged in the first cavity, the second longitudinal main reinforcement and the third stirrup are arranged outside the embedded reinforcement, the third stirrup is fixedly connected to the embedded reinforcement and the second longitudinal main reinforcement, and the concrete structure is arranged on the embedded reinforcement, the second longitudinal main reinforcement and the third stirrup to form a pile connection section.
3. The foundation pit support structure using existing support piles according to claim 2, It is characterized in that The first longitudinal main reinforcement and the first stirrup are also arranged on the upper part of the pile connection section. The first longitudinal main reinforcement is arranged in multiple layers. The second crown beam extends to the upper part of the pile connection section, and the embedded reinforcement extends to the inside of the second crown beam.
4. The foundation pit support structure using existing support piles according to claim 2, It is characterized in that A joint section connected to the third stirrup is provided at the end of the embedded reinforcement, and the length of the joint section does not exceed 10 cm. An existing structure is arranged adjacent to the other side of the existing support pile.
5. The foundation pit support structure using existing support piles according to claim 1, It is characterized in that The H-shaped steel is arranged inside the high-pressure jet grouting piles, and the H-shaped steel is evenly arranged. The bottom depth of the high-pressure jet grouting piles exceeds the bottom depth of the existing supporting piles.
6. The foundation pit support structure using existing support piles according to claim 1, It is characterized in that The high-pressure jet grouting pile comprises a core segment, and the unconfined compressive strength of the core segment is not less than 0.6 MPa.
7. The foundation pit support structure using existing support piles according to claim 1, It is characterized in that The edge of the H-shaped steel on one side close to the existing supporting pile is arranged in contact with the first crown beam, the top of the H-shaped steel is arranged higher than the top of the high-pressure rotary jet pile, and the bottom depth of the H-shaped steel is less than the bottom depth of the high-pressure rotary jet pile.
8. The foundation pit support structure using existing support piles according to claim 1, It is characterized in that A second cavity is provided on one side of the high-pressure jet grouting pile away from the existing supporting pile, a main structure is provided inside the second cavity, and the bottom depth of the main structure is higher than the bottom depth of the high-pressure jet grouting pile and the H-shaped steel.
9. The foundation pit support structure using existing support piles according to claim 8, It is characterized in that A support is also disposed in the second cavity, and the support is fixedly connected to the second crown beam.
10. The foundation pit support structure using existing support piles according to claim 8, It is characterized in that The high-pressure jet grouting piles and the H-shaped steel are combined to form SMW method piles, and the SMW method piles are arranged around the second cavity structure.