Supporting structure free of inner support

Abstract

The utility model discloses a supporting structure free of an inner support. The supporting structure comprises supporting piles located along a foundation pit, a top beam connected between the top ends of the supporting piles, and composite outer supporting piles located on the outer side along the foundation pit. The composite outer supporting pile comprises a high-pressure jet grouting pile, a steel pipe pile and a tensioning assembly, the high-pressure jet grouting pile is inclined, the upper end of the high-pressure jet grouting pile is close to the supporting pile, the lower end of the high-pressure jet grouting pile is far away from the supporting pile, the pile tip of the steel pipe pile extends into the inner bottom of the high-pressure jet grouting pile, and the pile tail extends out of the high-pressure jet grouting pile to be connected with a pile head reinforcing steel bar of the supporting pile and is closed. The tensioning assembly comprises a steel base plate and a steel strand, the steel base plate is installed on the top face of the top beam, the steel strand is located in the steel pipe pile, the lower end of the steel strand is connected with the steel pipe pile tip, and the upper end sequentially penetrates through the steel pipe pile tail and the steel base plate and is tensioned on the steel base plate. According to the structure, an inner support does not need to be arranged in the foundation pit, great convenience is provided for in-pit operation, and the construction period is shortened.

Description

Technical Field

[0001] The utility model relates to deep foundation pit support, in particular to a support structure free of internal support. Background Art

[0002] With the continuous construction of urban underground space, deep foundation pit excavation and its support projects are becoming more and more numerous and complex. Conventional deep foundation pit support structures are often equipped with internal supports, which inevitably affect the excavation of earthwork in the pit and the construction of underground structures, so the construction period is relatively long. Utility Model Content

[0003] The purpose of the utility model is to provide a supporting structure without internal support, so that there is no need to set internal support inside the foundation pit, which greatly facilitates the operation in the pit and saves construction time.

[0004] The technical solution adopted by the utility model is:

[0005] A supporting structure without internal support, comprising supporting piles located along a foundation pit, a crown beam connected between the top ends of the supporting piles, and a composite external supporting pile located outside the foundation pit; the composite external supporting piles comprise high-pressure rotary jet piles, steel pipe piles and tensioning components, the high-pressure rotary jet piles are inclined with the upper end close to the supporting piles and the lower end away from the supporting piles, the tip of the steel pipe pile extends to the bottom of the high-pressure rotary jet pile, the tail of the pile extends out of the high-pressure rotary jet pile and is connected and sealed with the pile head steel bar of the supporting pile, barbs are distributed along the inner and outer walls of the high-pressure rotary jet pile, the tensioning component comprises a steel pad and a steel strand, the steel pad is installed on the top surface of the crown beam, the steel strand is located in the steel pipe pile and the lower end is connected to the tip of the steel pipe pile, the upper end passes through the tail of the steel pipe pile and the steel pad in sequence and is tensioned on the steel pad.

[0006] Preferably, a stress gauge for monitoring stress conditions is provided at the portion of the steel strand exposed from the steel backing plate.

[0007] Preferably, the composite external support piles correspond to the supporting piles one by one; or, the composite external support piles are arranged according to the spacing of the supporting piles.

[0008] Preferably, the diameter of the high-pressure rotary jet pile is not less than three times that of the steel pipe pile.

[0009] Preferably, the barbs are distributed in a plum blossom shape on the outer wall of the steel pipe pile, with a single barb no less than 25 cm in length, no less than three barbs on the same outer circle, and a spacing of no more than 20 cm along the length of the pile.

[0010] Preferably, the barbs are made of threaded steel and welded to the outer wall of the steel pipe pile.

[0011] Preferably, no less than three steel strands are used.

[0012] Preferably, the tail of the steel pipe pile is fixed to the pile head steel bar of the supporting pile by welding.

[0013] Preferably, the support piles are bored cast-in-place piles.

[0014] The beneficial effects of the utility model are:

[0015] The structure uses composite external support piles on the outside of the supporting piles to provide external support for the supporting piles. There is no need to set up internal supports inside the foundation pit, which greatly facilitates the work in the pit and saves construction time. In the structure, the high-pressure rotary jet piles can increase the lateral friction resistance of the steel pipe piles, and the barbs on the steel pipe piles can further increase the lateral friction resistance between them and the high-pressure rotary jet piles. Therefore, the composite external support piles can reduce the deformation of the foundation pit with a smaller length. In the structure, the stress on the foundation pit can be flexibly adjusted by adjusting the tensioning of the steel strands. In the structure, the steel pad can reduce the influence of the tensioning of the steel strands on the crown beam. In the structure, the steel pipe piles can be recycled after the support is completed, which reduces the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of a supporting structure without internal support in an embodiment of the utility model.

[0017] In the figure: 1-support pile; 2-crown beam; 3-high-pressure rotary jet pile; 4-steel pipe pile; 41-pile tip; 42-pile tail; 5-barb; 6-steel strand; 7-steel pad. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0020] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0021] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0022] Embodiment 1

[0023] This embodiment discloses a supporting structure without internal support, such as Figure 1 As shown, it includes supporting piles 1, crown beams 2 and composite external supporting piles; the supporting piles 1 are located along the foundation pit, and the crown beams 2 are connected between the tops of the supporting piles 1. The supporting piles 1 and the crown beams 2 belong to conventional settings; the composite external supporting piles are located outside the foundation pit, which belongs to the core setting of this application. Specifically: the composite external supporting piles include high-pressure rotary jet piles 3, steel pipe piles 4 and tensioning components. The high-pressure rotary jet piles 3 are inclined with the upper end close to the supporting piles 1 and the lower end away from the supporting piles 1. The steel pipe piles 4 are The pile tip 41 extends into the bottom of the high-pressure rotary jet pile 3, the pile tail 42 extends out of the high-pressure rotary jet pile 3 and is connected to the pile head steel bar of the support pile 1 and is closed, and barbs 5 are distributed along the inner and outer walls of the high-pressure rotary jet pile 3. The tensioning assembly includes a steel pad 7 and a steel strand 6. The steel pad 7 is installed on the top surface of the crown beam 2. The steel strand 6 is located in the steel pipe pile 4 and the lower end is connected to the pile tip 41 of the steel pipe pile 4. The upper end passes through the pile tail 42 of the steel pipe pile 4 and the steel pad 7 in sequence and is tensioned on the steel pad 7. Figure 1 .

[0024] In this embodiment, preferably: a stress gauge for monitoring the stress condition is set on the portion of the steel strand 6 exposed from the steel pad 7, so as to facilitate dynamic monitoring of the stress condition of the steel strand 6 during and after the excavation, and timely compensation and adjustment of the steel strand 6 according to the stress condition, thereby adjusting the stress condition of the foundation pit.

[0025] The composite external support piles can correspond to the supporting piles 1 one by one, or can be arranged at intervals according to the supporting piles 1. The specific distribution of the composite external support piles is determined according to the size of the foundation pit and the excavation depth.

[0026] In this embodiment, preferably: the diameter of the high-pressure rotary jet pile 3 is not less than three times that of the steel pipe pile 4; the barbs 5 are distributed in a plum blossom shape on the outer wall of the steel pipe pile 4, the length of a single barb 5 is not less than 25 cm, there are no less than three barbs on the same outer circle, and the spacing along the pile length direction is not more than 20 cm; the barbs 5 are made of threaded steel and welded to the outer wall of the steel pipe pile 4; no less than three steel strands 6 are used; the pile tail 42 of the steel pipe pile 4 is welded and fixed to the pile head steel bar of the support pile 1; the support pile 1 is a bored cast-in-place pile.

[0027] The construction method of the above-mentioned supporting structure without internal support is:

[0028] 1) Construct support piles 1 along the foundation pit, break the pile heads and expose the pile head steel bars;

[0029] 2) The high-pressure jet grouting pile 3 is constructed obliquely. Before the high-pressure jet grouting pile 3 is initially set, the steel pipe pile 4 is obliquely inserted into the inside thereof. Before the steel pipe pile 4 is inserted, the outer wall thereof has been installed with barbs 5 and the inside thereof has been connected with steel strands 6;

[0030] 3) Fix the pile tail 42 of the steel pipe pile 4 to the pile head steel bar of the support pile 1, seal the pile tail 42 of the steel pipe pile 4 and leave the steel strand 6, pour the concrete of the crown beam 2 and set the steel pad 7 on the top of the crown beam 2;

[0031] 4) After the strength of the high-pressure jet grouting pile 3 and the crown beam 2 reaches the design requirements, a tension test is carried out, and a stress gauge is set on the part of the steel strand 6 exposed from the steel pad 7 to monitor the stress condition of the composite external support pile in real time;

[0032] 5) Excavation of earthwork in the foundation pit, dynamically monitoring the stress condition of the steel strand 6 during and after the excavation, and timely compensating and adjusting the steel strand 6 according to the stress condition, thereby adjusting the stress condition of the foundation pit;

[0033] 6) After the foundation pit construction is completed, the steel pipe piles 4 are removed by a vibrating hammer for recycling.

[0034] It can be seen from the above scheme that: this structure uses the composite external support piles on the outside of the supporting piles to provide external support for the supporting piles, and there is no need to set up internal supports inside the foundation pit, which provides great convenience for the work in the pit and saves construction time; in this structure, the high-pressure rotary jet piles 3 can increase the lateral friction resistance of the steel pipe piles 4, and the barbs 5 on the steel pipe piles 4 can further increase the lateral friction resistance between them and the high-pressure rotary jet piles 3, so the composite external support piles can reduce the deformation of the foundation pit with a smaller length; in this structure, the force on the foundation pit can be flexibly adjusted by adjusting the tensioning of the steel strands 6; in this structure, the steel pads 7 can reduce the influence of the tensioning of the steel strands 6 on the crown beam 2; in this structure, the steel pipe piles 4 can be recycled after the support is completed, reducing costs.

[0035] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A supporting structure without internal support, comprising supporting piles located along the foundation pit and a cap beam connected between the top ends of the supporting piles, characterized in that: It also includes composite external support piles located on the outside along the foundation pit, the composite external support piles include high-pressure rotary jet piles, steel pipe piles and tensioning components, the high-pressure rotary jet piles are inclined with the upper end close to the supporting piles and the lower end away from the supporting piles, the tip of the steel pipe pile extends to the bottom of the high-pressure rotary jet pile, the pile tail extends out of the high-pressure rotary jet pile and is connected to the pile head steel bars of the supporting pile and is closed, barbs are distributed along the inner and outer walls of the high-pressure rotary jet pile, the tensioning component includes a steel pad and steel strands, the steel pad is installed on the top surface of the crown beam, the steel strand is located in the steel pipe pile and the lower end is connected to the tip of the steel pipe pile, the upper end passes through the steel pipe pile tail and the steel pad in turn and is tensioned on the steel pad.

2. The supporting structure without internal support as claimed in claim 1, characterized in that: A stress gauge for monitoring the stress condition is set on the part of the steel strand exposed from the steel base plate.

3. The supporting structure without internal support as claimed in claim 1, characterized in that: The composite external support piles correspond to the supporting piles one by one; or, the composite external support piles are arranged according to the spacing of the supporting piles.

4. The supporting structure without internal support as claimed in claim 1, characterized in that: The diameter of high-pressure rotary jet piles shall not be less than three times that of steel pipe piles.

5. The supporting structure without internal support as claimed in claim 1, characterized in that: The barbs are distributed in a plum blossom shape on the outer wall of the steel pipe pile. The length of a single barb is not less than 25 cm, there are no less than three barbs on the same outer circle, and the spacing along the length of the pile is not more than 20 cm.

6. The supporting structure without internal support as claimed in claim 1, characterized in that: The barbs are made of threaded steel and welded to the outer wall of the steel pipe pile.

7. The supporting structure without internal support as claimed in claim 1, characterized in that: No less than three steel strands are used.

8. The supporting structure without internal support as claimed in claim 1, characterized in that: The tail of the steel pipe pile is welded and fixed to the head of the supporting pile by steel bars.

9. The supporting structure without internal support as claimed in claim 1, characterized in that: The supporting piles are bored cast-in-place piles.

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