Stepped multi-row pile supporting structure

Abstract

The utility model belongs to deep foundation pit support technical field, specifically is a kind of stepped multi-row pile support structure, including outside row pile, intermediate row pile and inner row pile, outside row pile, intermediate row pile and inner row pile are sequentially arranged between ground and base from left to right, outside row pile, intermediate row pile and inner row pile top are commonly provided with corona beam component, corona beam component and outside row pile, intermediate row pile and inner row pile between are provided with link beam component, outside row pile and intermediate row pile between and intermediate row pile and inner row pile between are all provided with waist beam component;The support structure formed by the utility model has high safety factor, large rigidity and good lateral displacement resistance, compared with internal support structure, the structure is more suitable for large plane large-span foundation pit, and compared with pile anchor structure, the structure does not occupy adjacent underground space, compared with double-row pile support, the structure is more suitable for large excavation depth foundation pit.

Description

Technical Field

[0001] This utility model relates to the field of deep foundation pit support technology, specifically a stepped multi-row pile support structure. Background Technology

[0002] With the development of society and the economy, urban construction is no longer limited to above-ground space, and people are paying more and more attention to the development and utilization of underground space. Today, subways, intercity tunnels, and underground shopping streets are very common in many large cities, and the underground building environment is becoming increasingly complex. Modern deep foundation pit projects not only need to meet their own safety requirements but also need to consider the impact on the surrounding underground building environment.

[0003] Common deep foundation pit support structures include internal bracing with pile support, pile anchor support, and double-row pile support. However, these support designs often do not consider the impact of the surrounding underground building environment. Currently, the impact of foundation pit excavation on underground tunnels is not well understood. Therefore, improving the safety factor and lateral displacement resistance of the support structure is essential. To address these issues, a stepped multi-row pile support structure is proposed. Utility Model Content

[0004] In order to overcome the shortcomings of the existing technology and solve the problems in the background technology, this utility model proposes a stepped multi-row pile support structure.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a stepped multi-row pile support structure, including an outer row of piles, a middle row of piles and an inner row of piles, wherein the outer row of piles, the middle row of piles and the inner row of piles are arranged between the ground and the foundation from left to right.

[0006] The outer row of piles, the middle row of piles and the inner row of piles are all provided with a crown beam assembly at the top. A connecting beam assembly is provided between the crown beam assembly and the outer row of piles, the middle row of piles and the inner row of piles. A waist beam assembly is provided between the outer row of piles and the middle row of piles and between the middle row of piles and the inner row of piles.

[0007] Preferably, the top elevation of the middle row of piles is lower than that of the outer row of piles, and the top elevation of the inner row of piles is lower than that of the middle row of piles.

[0008] Preferably, the outer row of piles includes an outer double row of piles one and an outer double row of piles two, the top elevation of the outer double row of piles one and the top elevation of the outer double row of piles two are the same, the capping beam assembly includes an outer double row of piles capping beam one, an outer double row of piles capping beam two, a middle row of piles capping beam and an inner row of piles capping beam, the connecting beam assembly includes a first connecting beam, a second connecting beam and a third connecting beam, and the waist beam assembly includes a first waist beam and a second waist beam.

[0009] Preferably, the outer double-row pile top cap beam one and the outer double-row pile top cap beam two are respectively fixedly connected to the top of the outer double-row pile one and the outer double-row pile two, and the first connecting beam is fixedly connected between the outer double-row pile top cap beam one and the outer double-row pile top cap beam two.

[0010] Preferably, the middle row of piles and the outer double row of piles are connected by a first waist beam, a second connecting beam, and a capping beam of the middle row of piles to form a step, and the middle row of piles and the inner row of piles are connected by a second waist beam, a third connecting beam, and a capping beam of the inner row of piles to form a step.

[0011] Preferably, the number of intermediate piles can be set according to the depth of the foundation pit, and the elevation of the top of the intermediate piles decreases from the outside to the inside of the foundation pit.

[0012] Preferably, the middle part of the outer double-row piles and the middle part of the middle row piles are pre-bent and embedded with steel bars.

[0013] The advantages of this utility model are:

[0014] 1. The structure has a high safety factor, high stiffness, and good resistance to lateral displacement.

[0015] 2. This structure is more suitable for large-scale, large-span foundation pits compared to internally supported structures.

[0016] 3. Compared with pile-anchor structures, this structure does not occupy adjacent underground space.

[0017] 4. This structure is more suitable for foundation pits with large excavation depths compared to double-row pile support.

[0018] 5. Engineering monitoring showed that the foundation pit support effect was good in soft soil areas with underground tunnels in the surrounding area. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a front view structural diagram of Embodiment 1;

[0021] Figure 2 This is a schematic diagram of the construction structure of the waist beam component in Example 1;

[0022] Figure 3 This is a schematic diagram of the post-construction structure in Example 1;

[0023] Figure 4This is a schematic diagram of the first step of the working principle in Example 1;

[0024] Figure 5 This is a schematic diagram of the second step of the working principle in Example 1;

[0025] Figure 6 This is a schematic diagram of the third step of the working principle in Example 1;

[0026] Figure 7 This is a schematic diagram of the active sliding soil region structure in Example 1.

[0027] In the diagram: 1. Outer row of piles; 11. Outer double row of piles I; 12. Outer double row of piles II; 2. Middle row of piles; 3. Inner row of piles; 4. Crown beam assembly; 41. Outer double row of piles top crown beam I; 42. Outer double row of piles top crown beam II; 43. Middle row of piles top crown beam; 44. Inner row of piles top crown beam; 5. Connecting beam assembly; 51. First connecting beam; 52. Second connecting beam; 53. Third connecting beam; 6. Waist beam assembly; 61. First waist beam; 62. Second waist beam; 7. Embedded reinforcing steel. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Example 1

[0030] Please see Figure 1-7 As shown, a stepped multi-row pile support structure includes an outer row of piles 1, a middle row of piles 2 and an inner row of piles 3, which are arranged from left to right between the ground and the foundation.

[0031] The outer row of piles 1, the middle row of piles 2, and the inner row of piles 3 are all equipped with a crown beam assembly 4 at their tops. A connecting beam assembly 5 is provided between the crown beam assembly 4 and the outer row of piles 1, the middle row of piles 2, and the inner row of piles 3. A waist beam assembly 6 is provided between the outer row of piles 1 and the middle row of piles 2, and between the middle row of piles 2 and the inner row of piles 3. During operation, the crown beam assembly 4, the connecting beam assembly 5, and the waist beam assembly 6 can connect and fix the outer row of piles 1 to the middle row of piles 2 and the inner row of piles 3, and facilitate the connection between the outer row of piles 1 and the middle row of piles 2. A step is formed between pile 2 and inner pile 3, which makes outer pile 1, middle pile 2 and inner pile 3 form a stable stepped multi-row pile support structure. This structure has a high safety factor, high rigidity and good resistance to lateral displacement. Compared with the internal support structure, this structure is more suitable for large-span foundation pits with large planar area. Compared with the pile anchor structure, this structure does not occupy the adjacent underground space. Compared with the double-row pile support, this structure is more suitable for foundation pits with large excavation depth. At the same time, according to engineering monitoring, it has a good support effect on foundation pits in soft soil areas with underground tunnels in the surrounding area.

[0032] The top elevation of the middle row of piles 2 is lower than that of the top elevation of the outer row of piles 1, and the top elevation of the inner row of piles 3 is lower than that of the middle row of piles 2; during operation, this facilitates the formation of steps between the outer row of piles 1, the middle row of piles 2, and the inner row of piles 3.

[0033] The outer row of piles 1 includes an outer double row of piles 11 and an outer double row of piles 12. The top elevation of the outer double row of piles 11 and the top elevation of the outer double row of piles 12 are the same. The capping beam assembly 4 includes an outer double row of pile capping beam 41, an outer double row of pile capping beam 42, a middle row of pile capping beam 43, and an inner row of pile capping beam 44. The connecting beam assembly 5 includes a first connecting beam 51, a second connecting beam 52, and a third connecting beam 53. The waist beam assembly 6 includes a first waist beam 61 and a second waist beam 62. During operation, this facilitates the connection and fixation between the outer row of piles 1, the middle row of piles 2, and the inner row of piles 3.

[0034] The outer double-row pile top cap beam 41 and the outer double-row pile top cap beam 42 are respectively fixedly connected to the top of the outer double-row pile 11 and the outer double-row pile 2 12. The first connecting beam 51 is fixedly connected between the outer double-row pile top cap beam 41 and the outer double-row pile top cap beam 42. During operation, it is convenient to connect and fix the outer double-row pile 11 and the outer double-row pile 2 12 of the outer row pile 1.

[0035] The middle row of piles 2 and the outer double row of piles 12 are connected by the first waist beam 61, the second connecting beam 52 and the middle row of pile cap beam to form a step. The middle row of piles 2 and the inner row of piles 3 are connected by the second waist beam 62, the third connecting beam 53 and the inner row of pile cap beam to form a step. During operation, this facilitates the formation of stable steps between the middle row of piles 2 and the outer row of piles 1 and between the middle row of piles 2 and the inner row of piles 3.

[0036] The intermediate pile 2 can be set with different numbers of rows according to the depth of the foundation pit. The top elevation of the intermediate pile 2 decreases from the outside to the inside of the foundation pit. During operation, it can form a stepped multi-row pile structure with different numbers of steps.

[0037] Example 2

[0038] Please see Figure 2 As shown in the first embodiment, as another implementation of this utility model, the middle part of the outer double-row pile 2 and the middle part of the middle pile 2 are both pre-bent and embedded with steel bars 7; during operation, after excavation to the design depth, the protective layer is removed, the steel bars are straightened and combined with the waist beam component 6 for construction to ensure the node rigidity and structural integrity.

[0039] Working principle, step one: Figure 4 As shown, after the site is leveled, four rows of piles of equal length are pre-driven: outer double-row pile 11, outer double-row pile 2, middle pile 2, and inner pile 3. The outer double-row pile 1 and outer double-row pile 2 are then constructed as the outer double-row pile 1 and outer double-row pile 2 as the capping beam assembly 4. The outer double-row pile 1 capping beam 1 and outer double-row pile 2 capping beam 42 are then constructed. The first connecting beam 51 is then constructed to connect with the outer double-row pile 1 capping beam 1 and outer double-row pile 2 capping beam 42 of the capping beam assembly 4.

[0040] Step 2: As Figure 5 As shown, when excavating to the first step, the excess parts of the middle row of piles 2 and the inner row of piles 3 are cut off. Then, the top cap beam 43 of the middle row of piles 2 is constructed. The pre-embedded steel bars 7 in the middle of the outer double row of piles 12 are straightened to construct the first waist beam 61. Then, the second connecting beam 52 is constructed to connect with the first waist beam 61 and the top cap beam 43 of the middle row of piles.

[0041] Step 3: As Figure 6 As shown, when excavating to the second step, the excess portion of the upper part of the inner row of piles 3 is cut off. Then, the inner row of piles 2 is constructed with a top cap beam 44. The pre-embedded reinforcing bars 7 in the middle of the pile body of the middle row of piles 2 are straightened to form the second waist beam 62. Finally, a third connecting beam 53 is constructed to connect with the second waist beam 62 and the inner row of piles top cap beam 44. When the excavation reaches the designed depth of the foundation, the final effect is as follows: Figure 2 As shown, all the piles in this utility model are bored cast-in-place piles, and the capping beam, connecting beam, and waist beam are all reinforced concrete.

[0042] In summary, connecting the pile rows with coupling beams creates a stepped, multi-row pile support system with high rigidity and strong lateral displacement resistance. This stepped structure not only saves underground space and allows for the design of basements, but also significantly reduces soil load. Figure 7As shown, according to classical earth pressure theory, when there is no supporting structure, the sliding surface of the soil forms an angle with the vertical plane (where θ is the internal friction angle of the soil). It can be seen that when using a stepped multi-row pile structure, some of the actively sliding soil has been excavated, significantly reducing the soil load. Furthermore, different numbers of steps can be designed to be suitable for deep foundation pits. Using two or more rows of piles on the outer side, instead of a single row, provides better support for the free surface soil above the first step.

[0043] In summary, compared with existing foundation pit support structures, this stepped multi-row pile support structure has a higher safety factor and smaller structural displacement. It can be used for foundation pits with larger planar spans and deeper excavations, as well as for foundation pit support in areas with underground tunnels or soft soil.

[0044] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0045] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A stepped multi-row pile support structure, comprising an outer row of piles (1), a middle row of piles (2) and an inner row of piles (3), wherein the outer row of piles (1), the middle row of piles (2) and the inner row of piles (3) are arranged from left to right between the ground and the foundation; characterized in that The outer row of piles (1), the middle row of piles (2) and the inner row of piles (3) are all provided with a crown beam assembly (4). A connecting beam assembly (5) is provided between the crown beam assembly (4) and the outer row of piles (1), the middle row of piles (2) and the inner row of piles (3). A waist beam assembly (6) is provided between the outer row of piles (1) and the middle row of piles (2) and between the middle row of piles (2) and the inner row of piles (3).

2. The stepped multi-row pile supporting structure according to claim 1, characterized in that: The top elevation of the middle row of piles (2) is lower than that of the top elevation of the outer row of piles (1), and the top elevation of the inner row of piles (3) is lower than that of the middle row of piles (2).

3. The stepped multi-row pile supporting structure according to claim 2, characterized in that: The outer row of piles (1) includes an outer double row of piles one (11) and an outer double row of piles two (12). The top elevation of the outer double row of piles one (11) is the same as the top elevation of the outer double row of piles two (12). The capping beam assembly (4) includes an outer double row of pile top capping beam one (41), an outer double row of pile top capping beam two (42), a middle row of pile top capping beam (43) and an inner row of pile top capping beam (44). The connecting beam assembly (5) includes a first connecting beam (51), a second connecting beam (52) and a third connecting beam (53). The waist beam assembly (6) includes a first waist beam (61) and a second waist beam (62).

4. The stepped multi-row pile supporting structure according to claim 3, characterized in that: The outer double-row pile top cap beam one (41) and the outer double-row pile top cap beam two (42) are respectively fixedly connected to the top of the outer double-row pile one (11) and the outer double-row pile two (12), and the first connecting beam (51) is fixedly connected between the outer double-row pile top cap beam one (41) and the outer double-row pile top cap beam two (42).

5. The stepped multi-row pile supporting structure according to claim 4, characterized in that: The middle row of piles (2) and the outer double row of piles (12) are connected by the first waist beam (61), the second connecting beam (52) and the middle row of pile cap beam to form a step. The middle row of piles (2) and the inner row of piles (3) are connected by the second waist beam (62), the third connecting beam (53) and the inner row of pile cap beam to form a step.

6. The stepped multi-row pile supporting structure according to claim 5, characterized in that: The intermediate piles (2) can be set in different numbers according to the depth of the foundation pit, and the top elevation of the intermediate piles (2) decreases from the outside to the inside of the foundation pit.

7. The stepped multi-row pile supporting structure according to claim 6, characterized in that: The middle part of the outer double-row pile 2 (12) and the middle part of the middle pile (2) are both pre-bent and embedded with steel bars (7).

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