Combined inclined inner support structure for foundation pit support

Abstract

The utility model relates to the field of underground engineering foundation pit support, in particular to a combined type inclined inner support structure for foundation pit support, which comprises a combined type inclined inner support system and a cantilever pile support system, the cantilever pile support system and the combined type inclined inner support system are connected and fixed at the top, the combined type inclined inner support system penetrates through a bottom plate to be supported in foundation soil, and the cantilever pile support system is connected with the cantilever pile support system. The combined inclined inner support system comprises an embedded section, a free section and a connecting section, and the cantilever pile enclosure system comprises an enclosure purlin and an enclosure pile. The scheme is reasonable and effective in structural design and high in safety coefficient; the combined inclined inner support structure is convenient to construct, and a pile tip is arranged at the bottom end of the embedded section so that the embedded section can be conveniently driven into the ground. The embedded section below the pit bottom of the combined inclined inner support is prefabricated through concrete, and a grouting pipe is arranged in the embedded section to facilitate post-grouting of the pile end.

Description

Technical Field

[0001] This utility model relates to the field of underground engineering foundation pit support, and in particular to a combined inclined internal bracing structure for foundation pit support. Background Technology

[0002] In foundation pit support engineering, traditional or single support methods have significant limitations for deep and large foundation pits. Combined support structures can effectively enhance the safety of the support. Currently, pile-anchor support systems, horizontal bracing systems, or inclined bracing systems are widely used. To ensure the safety of the foundation pit, the number and length of anchor bolts (cables) increase. Although foundation pit engineering is a temporary project, the anchor bolts (cables) used in the project remain for a long time after the project is completed, affecting the subsequent reuse of underground space. Traditional horizontal support methods have a long construction period, and the presence of horizontal supports makes foundation pit excavation difficult and costly. At the same time, the removal of steel horizontal supports results in resource waste. Conventional inclined bracing uses the bottom slab as the force transfer point, but the construction sequence is complex, the excavation of the soil retention area is slow, and the waiting time is long. If the foundation pit has high environmental protection requirements, the inclined bracing system needs to be retained indefinitely and needs to penetrate the underground structure, which makes the support system prone to water leakage.

[0003] Inclined bracing uses the soil layer below the pit bottom as the bearing layer. If the soil conditions are good, the spacing of the inclined bracing is often increased to make full use of the soil layer's advantages. In this case, the axial force on the inclined bracing may be too large, and the area above the pit bottom, being an open section, needs sufficient compressive stability. Utility Model Content

[0004] The purpose of this utility model is to provide a combined inclined internal bracing structure for foundation pit protection in order to solve the above-mentioned problems.

[0005] This utility model achieves the above objectives through the following technical solutions:

[0006] A combined inclined internal bracing structure for foundation pit protection includes a combined inclined internal bracing system and a cantilever pile retaining system. The cantilever pile retaining system is connected and fixed to the top of the combined inclined internal bracing system. The combined inclined internal bracing system passes through the bottom slab and is supported in the foundation soil. The combined inclined internal bracing system includes an embedded section, an exposed section, and a connecting section. The cantilever pile retaining system includes walers and retaining piles.

[0007] Preferably, the bottom end of the free-standing section is connected to the upper part of the buried section by a connector, and the connector is a fixed connection.

[0008] Preferably, the free-standing section is a steel structure component, the embedded section is a precast concrete component, the bottom of the embedded section is formed with a pile tip, and the top of the free-standing section is formed with a connecting section.

[0009] Preferably, the top of the connecting section is connected to the retaining pile via a waler, and the connecting section is welded with a number of end short steel bars, which are distributed in a quincunx pattern on the top of the connecting section, and an angle is provided between the end short steel bars and the connecting section. The retaining pile and the waler are cast and connected to the outside of the end short steel bars.

[0010] Preferably, the combined inclined internal bracing system is provided with grouting holes, which penetrate the embedded section, the free section and up to the bottom of the pile tip.

[0011] Preferably, the base plate is located in the middle of the free-space section, and the base plate is cast and connected to the free-space section. A water-stop ring is welded to the free-space section at the connection position with the base plate.

[0012] Preferably, a water-stop steel plate is provided on the side of the base plate near the retaining pile, a concrete cushion layer is provided at the bottom of the base plate, the bottom of the concrete cushion layer is a reinforced cushion layer, and a concrete force transmission strip is provided on the end face of the water-stop steel plate near the retaining pile.

[0013] Compared with existing technologies, the beneficial effects are as follows:

[0014] This design scheme features a reasonable and effective structure with a high safety factor. The combined inclined internal bracing structure is easy to construct, with pile tips at the bottom of the embedded section for easy driving into the ground. The embedded section below the pit bottom of the combined inclined internal bracing is precast concrete, with grouting pipes inside for post-grouting at the pile tip. The combined inclined internal bracing ensures the pile's bearing capacity, optimizes the stress pattern, saves costs, and allows the pile to be extended to the bearing layer, adapting to various soil layers. The compressive stability of the exposed section is enhanced. Post-grouting at the pile tip increases bearing capacity while reducing pile settlement. A water-stop ring is installed to reduce the risk of leakage after penetrating the basement structure. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a schematic diagram of a combined inclined internal bracing structure for foundation pit protection according to the present invention;

[0017] Figure 2 This is a schematic diagram of the combined inclined internal bracing system for foundation pit protection as described in this utility model.

[0018] Figure 3 This is a schematic diagram of the retaining pile structure of a combined inclined internal bracing structure for foundation pit protection according to this utility model;

[0019] Figure 4 This is a schematic diagram of a cantilever pile retaining system with a combined inclined internal bracing structure for foundation pit protection, as described in this utility model.

[0020] Figure 5 This is a schematic diagram of the water-stop ring structure of a combined inclined internal bracing structure for foundation pit protection as described in this utility model.

[0021] The annotations in the attached figures are explained as follows:

[0022] 1. Embedded section; 2. Free-standing section; 3. Connecting section; 4. Pile tip; 5. End short steel bar; 6. Connector; 7. Grouting hole; 8. Water-stop ring; 9. Base plate; 10. Concrete cushion layer; 11. Reinforced cushion layer; 12. Water-stop steel plate; 13. Retaining pile; 14. Waler; 15. Concrete force transmission strip. Detailed Implementation

[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] The present invention will be further described below with reference to the accompanying drawings:

[0025] like Figures 1-5 As shown, a combined inclined internal bracing structure for foundation pit protection includes a combined inclined internal bracing system and a cantilever pile retaining system. The cantilever pile retaining system is connected and fixed to the top of the combined inclined internal bracing system. The combined inclined internal bracing system passes through the bottom plate 9 and is supported in the foundation soil. The combined inclined internal bracing system includes an embedded section 1, an open section 2, and a connecting section 3. The cantilever pile retaining system includes a waler 14 and retaining piles 13. The cantilever pile retaining system is connected and fixed to the waler 14. The combined inclined internal bracing system passes through the bottom plate 9 and is supported in the foundation soil.

[0026] In this embodiment, the bottom end of the free section 2 is connected to the upper part of the buried section 1 by a connector 6, and the connector 6 is a fixed connection.

[0027] In this embodiment, the free-standing section 2 is a steel structure component, and the embedded section 1 is a precast concrete component. The free-standing section 2 can be a steel structure component such as a rectangular steel pipe pile, a circular steel pipe pile, a steel section pile, or a lattice column. The embedded section 1 is precast concrete and can be a precast square pile, a precast pipe pile, or other reinforced concrete pile.

[0028] The bottom of the embedded section 1 is formed with a pile tip 4, and the top of the free section 2 is formed with a connecting section 3.

[0029] In this embodiment, the top of the connecting section 3 is connected to the retaining pile 13 via the waler 14. The connecting section 3 is welded with several end short steel bars 5, which are distributed in a quincunx pattern on the top of the connecting section 3. An angle is set between the end short steel bars 5 and the connecting section 3. The retaining pile 13 and the waler 14 are cast and connected to the outside of the end short steel bars 5. The retaining pile 13 can be in the form of bored pile, SMW method pile, precast pile, steel pipe pile, underground continuous wall, etc.

[0030] In this embodiment, a grouting hole 7 is provided inside the combined inclined internal support system. The grouting hole 7 penetrates through the embedded section 1, the free section 2 and up to the bottom of the pile tip 4.

[0031] In this embodiment, the base plate 9 is located in the middle of the free section 2, and the base plate 9 is cast and connected to the free section 2. A water-stop ring 8 is welded to the free section 2 at the connection position with the base plate 9.

[0032] In this embodiment, a water-stop steel plate 12 is provided on the side of the base plate 9 near the retaining pile 13, a concrete cushion layer 10 is provided at the bottom of the base plate 9, and the bottom of the concrete cushion layer 10 is only a reinforced cushion layer 11. A concrete force transmission strip 15 is provided on the end face of the water-stop steel plate 12 near the retaining pile 13.

[0033] Working principle: The combined inclined internal bracing system is constructed after the retaining piles 13 are completed. The inclined pile driver is used to drive the embedded section 1 at an angle, and the pile head is exposed above the ground. The free section 2 is lifted and connected to the embedded section 1 through the connector 6. After the node connection is completed, the free section 2 is driven to the design elevation. The waler 14 is poured to form a whole.

[0034] The combined inclined internal bracing system is cut off after the structural base plate 9 and concrete force transmission strip 15 are constructed. When pouring the base plate 9, the 300m high basement exterior wall is poured at the same time, and a water-stop steel plate 12 is installed. A reinforced pad layer 11 is added under the concrete pad layer 10 within the connection range of the base plate 9.

[0035] 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 combined inclined internal bracing structure for foundation pit support, characterized in that: It includes a combined inclined internal bracing system and a cantilever pile retaining system. The cantilever pile retaining system is connected and fixed to the top of the combined inclined internal bracing system. The combined inclined internal bracing system passes through the bottom plate (9) and is supported in the foundation soil. The combined inclined internal bracing system includes an embedded section (1), an open section (2), and a connecting section (3). The cantilever pile retaining system includes a waler (14) and retaining piles (13).

2. The combined inclined internal bracing structure for foundation pit support according to claim 1, characterized in that: The bottom end of the free section (2) is connected to the upper part of the buried section (1) by a connector (6), and the connector (6) is a fixed connection.

3. The combined inclined internal bracing structure for foundation pit support according to claim 2, characterized in that: The free section (2) is a steel structure component, the embedded section (1) is a precast concrete component, the bottom of the embedded section (1) is formed with a pile tip (4), and the top of the free section (2) is formed with a connecting section (3).

4. The combined inclined internal bracing structure for foundation pit support according to claim 3, characterized in that: The top of the connecting section (3) is connected to the retaining pile (13) via the waler (14). The connecting section (3) is welded with a number of end short steel bars (5). The number of end short steel bars (5) are distributed in a plum blossom pattern on the top of the connecting section (3), and there is an angle between the end short steel bars (5) and the connecting section (3). The retaining pile (13) and the waler (14) are cast and connected to the outside of the end short steel bars (5).

5. A combined inclined internal bracing structure for foundation pit support according to claim 4, characterized in that: The combined inclined internal support system is provided with grouting holes (7), which penetrate the embedded section (1), the free section (2) and up to the bottom of the pile tip (4).

6. A combined inclined internal bracing structure for foundation pit support according to claim 5, characterized in that: The base plate (9) is located in the middle of the free section (2), and the base plate (9) is cast and connected to the free section (2). A water-stop ring (8) is welded to the free section (2) at the connection position with the base plate (9).

7. A combined inclined internal bracing structure for foundation pit support according to claim 6, characterized in that: A water-stop steel plate (12) is provided on the side of the base plate (9) near the retaining pile (13). A concrete cushion layer (10) is provided at the bottom of the base plate (9). The bottom of the concrete cushion layer (10) is a reinforced cushion layer (11). A concrete force transmission strip (15) is provided on the end face of the water-stop steel plate (12) near the retaining pile (13).

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