Support structure and construction method for supporting a foundation pit in an arch

Abstract

The application discloses an arch-shaped supporting structure for a foundation pit, which comprises a lower-digging underground continuous wall, a concrete straight support, a steel column, a column pile, an arch-shaped supporting beam and a steel support, one end of the steel column is arranged in the column pile, and the other end is connected with the concrete straight support; the two sides of the steel column are provided with the arch-shaped supporting beams, the arch-shaped supporting beams are internally provided with embedded bolt holes; the arch-shaped supporting beams are provided with the steel supports on the back surfaces of the arch-shaped supporting beams, one end of each steel support is connected with the arch-shaped supporting beam, and the other end is connected with the underground continuous wall. The multiple segmented arch-shaped supporting beam assembly structures are mutually offset, the middle horizontal soil pressure is transmitted to the multiple segmented arch-shaped supporting beam assembly structures through the steel supports and is mutually offset, the pulling force received by the arch-shaped supporting beams is transmitted to the column pile through the steel columns and is offset through soil friction, the stability of the foundation pit is ensured, most of the core soil in the foundation pit is reserved while the foundation pit supporting system is completely formed, and the deformation of the foundation pit is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of subway foundation pit, in particular to a supporting structure of an arched support foundation pit and a construction method. BACKGROUND

[0002] In the construction of a subway foundation pit, in order to ensure the construction of conventional steel support, the steel support needs to be constructed after the excavation is completed, the core soil in the middle of the foundation pit cannot be preserved, and the stability of the steel support is poor when the lower force steel support is long, which easily leads to large deformation of the foundation pit as a whole and poor stability of the supporting system under the condition that the soil quality of the foundation pit is poor, thereby affecting the safety of the foundation pit. SUMMARY

[0003] In order to solve the problems in the background art, the present application provides a supporting structure of an arched support foundation pit.

[0004] The present application adopts the following technical solution:

[0005] A supporting structure of an arched support foundation pit, characterized in that it comprises a lower-excavated underground continuous wall, a concrete straight support, a steel column, a column pile, an arched support beam and a steel support, one end of the steel column is arranged in the column pile, and the other end is connected with the concrete straight support; the two sides of the steel column are provided with arched support beams, and the arched support beams are internally provided with embedded bolt holes; the back of the arched support beam is provided with a steel support, one end of the steel support is connected with the arched support beam, and the other end is connected with the underground continuous wall.

[0006] Further, the arched support beam connected with the steel support is internally provided with a pre-embedded arc-shaped steel plate, and the underground continuous wall connected with the steel support is internally provided with a pre-embedded steel plate.

[0007] Further, the arched support beam is composed of a plurality of segmented arched support beams which are connected by bolt holes and bolts. The arched support beam is an approximately 120° arched structure which is connected by a plurality of precast arc-shaped concrete blocks through a bolt connection system.

[0008] Further, the arched support beam and the steel column are connected and fixed by expansion concrete at the joint. The arched support beam and the column pile are connected and fixed by the expansion concrete.

[0009] Further, the arched support beam and the steel support are connected by a diagonal support seat at the joint, and the steel support and the underground continuous wall are connected by a steel diagonal support at the joint. The steel support and the arched support and the underground continuous wall are connected by the pre-embedded steel plate. The arched support beam and the underground continuous wall are fixed by the expansion concrete at the joint.

[0010] An arch support foundation pit support structure, the earth pressure of the underground continuous wall, the lowest horizontal earth pressure is offset by the segmented arch support beam assembly structure, the middle horizontal earth pressure is transmitted to the segmented arch support beam assembly structure by the steel support and offset, the uplift force received by the arch support beam is transmitted to the column pile by the steel column through the soil friction force, the formation of the above system ensures the stability of the foundation pit, while the foundation pit support system is formed, most of the core soil in the foundation pit is reserved, and the deformation of the foundation pit is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 A cross-sectional schematic view of an arch support foundation pit support system and construction method provided by the present application;

[0012] Figure 2 A first excavation step schematic view of an arch support foundation pit support system and construction method provided by the present application;

[0013] Figure 3 A second excavation step schematic view of an arch support foundation pit support system and construction method provided by the present application;

[0014] Figure 4 A third excavation step schematic view of an arch support foundation pit support system and construction method provided by the present application;

[0015] Figure 5 A fourth excavation step schematic view of an arch support foundation pit support system and construction method provided by the present application;

[0016] Figure 6 A fifth excavation step schematic view of an arch support foundation pit support system and construction method provided by the present application;

[0017] Figure 7 A first arch support beam 6 and column 3 connection detail view of an arch support foundation pit support system and construction method provided by the present application.

[0018] Figure 8 An arch support beam connection detail view of an arch support foundation pit support system and construction method provided by the present application.

[0019] Figure 9 A second arch support beam 7 and steel support 5 connection detail view of an arch support foundation pit support system and construction method provided by the present application.

[0020] Figure 10 An underground continuous wall 1 and steel support 5 connection detail view of an arch support foundation pit support system and construction method provided by the present application.

[0021] The numbers marked in the figure represent, in order: 1 - underground continuous wall; 2 - concrete straight support; 3 - steel column; 4 - column pile; 5 - steel support; 6 - arched support beam; 7 - second arched support beam; 8 - third arched support beam; 9 - final block arched support beam; 11 - embedded steel plate; 12 - expanded concrete; 13 - steel inclined support; 51 - inclined support bearing; 52 - steel support schematic; 62 - embedded bolt hole; 63 - bolt system; 71 - embedded arc steel plate DETAILED DESCRIPTION

[0022] The application will be further described in detail below in conjunction with the drawings and specific embodiments.

[0023] Referring to the drawings,

[0024] An arched support foundation pit support structure, comprising a dug underground continuous wall 1, a concrete straight support 2, a steel column 3, a column pile 4, an arched support beam 6 and a steel support 5, the steel column 3 is arranged in the column pile 4 at one end and connected with the concrete straight support 2 at the other end; the steel column 3 is provided with arched support beams 6 on both sides, and the arched support beams 6 are provided with embedded bolt holes 62 inside; the arched support beams 6 are provided with steel supports 5 on the arch back, and the steel supports 5 are connected with the arched support beams 6 at one end and connected with the underground continuous wall 1 at the other end.

[0025] The arched support beams 6 connected with the steel supports 5 are provided with embedded arc steel plates 71 inside, and the underground continuous wall 1 connected with the steel supports 5 is provided with embedded steel plates 11.

[0026] The arched support beams 6 are composed of a plurality of segmented arched support beams, the plurality of segmented arched support beams are provided with embedded bolt holes 62, and the plurality of segmented arched support beams are connected by a bolt system 63. The arched support beam is an about 120° arched structure, which is connected by a plurality of said prefabricated arc concrete blocks through a bolt connection system.

[0027] The arched support beams 6 are filled with expanded concrete 12 at the joint with the steel columns 3. The arched support beams 6 are connected and fixed with the column piles 4 through the expanded concrete 12

[0028] The arched support beams 6 are provided with inclined support bearings 51 at the connection with the steel supports 5, such as steel support schematic 52, and the steel supports 5 are provided with steel inclined supports 13 at the connection with the underground continuous wall 1. The steel supports 5 are connected at the connection with the arched support beams 6 and the underground continuous wall 1 through the embedded steel plates 11. The arched support beams 6 are fixed at the connection with the underground continuous wall 1 through the expanded concrete 12.

[0029] An arch support foundation pit support structure, the earth pressure of the underground continuous wall, the lowest horizontal earth pressure is offset by the segmented arch support beam assembly structure, the middle horizontal earth pressure is transmitted to the segmented arch support beam assembly structure by the steel support, the uplift force received by the arch support beam is transmitted to the column pile by the steel column through the soil friction force, the formation of the above system ensures the stability of the foundation pit, while the foundation pit support system is formed, most of the core soil in the foundation pit is reserved, and the deformation of the foundation pit is reduced.

[0030] The specific construction steps are as follows:

[0031] S1: first excavate the trench underground continuous wall 1, lower the ground wall steel reinforcement cage, set the embedded steel plate 11 in the ground wall steel reinforcement cage, and pour the underground continuous wall 1 into a whole by the embedded steel plate 11, construct the column pile 4, and put in the steel column 3;

[0032] S2: construct the first block arch support beam 6 and the second block arch support beam 7 of the prefabricated concrete structure according to the size specification of the foundation pit, and reserve the connecting bolt hole 62 according to the connection requirement, so as to facilitate the installation of the connecting bolt system 63;

[0033] S3: excavate the foundation pit to the elevation of the concrete straight support 2, pour the concrete straight support 2, and anchor into the steel column 3, as shown in Figure 2 ;

[0034] S4: after the concrete straight support 2 reaches the design strength, continue to excavate the foundation pit to the elevation of the first block arch support beam 6, assemble the two first block arch support beams 6 by using the connecting bolt system 63, and fill the expanded concrete 12, as shown in Figure 3 ;

[0035] S5: continue to excavate the foundation pit to the elevation of the second block arch support beam 7, assemble the first block arch support beam 6 and the second block arch support beam 7 by using the connecting bolt system 63, and set the steel support 5 at the predetermined height, as shown in Figure 4 ;

[0036] S6: continue to excavate the foundation pit to the elevation of the second block arch support beam 8, assemble the second block arch support beams 7 and 8 in turn by using the connecting bolt system 63, and set the steel support 5 at the predetermined height, as shown in Figure 5 ;

[0037] S7: continue to excavate the foundation pit to the elevation of the last block arch support beam 9, assemble the second block arch support beams 7 and the last block arch support beam 9 in turn by using the connecting bolt system 63, and fill the expanded concrete 12 at the joint with the underground continuous wall 1, as shown in Figure 6 ;

[0038] S8: excavate the foundation pit, as shown in Figure 1 , with the structure back to the construction, the support system is removed in turn, and the recycling work of the support system is completed.

[0039] Note that the above merely describes the preferred embodiments of the present application and the principles of the technology applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, modifications and substitutions can be made by those skilled in the art without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. A support structure for an arched foundation pit, characterized in that, The structure includes an excavated underground continuous wall, concrete supports, steel columns, column piles, arched support beams, and steel supports. One end of the steel column is installed inside the column pile, and the other end is connected to the concrete support. Arched support beams are provided on both sides of the steel column, and the arched support beams have pre-embedded bolt holes inside. A steel support is provided on the back of the arched support beam, and one end of the steel support is connected to the arched support beam, and the other end is connected to the underground continuous wall.

2. The support structure for an arched foundation pit according to claim 1, characterized in that, An embedded arc-shaped steel plate is installed inside the arched support beam connected to the steel support, and an embedded steel plate is installed inside the underground continuous wall connected to the steel support.

3. The support structure for an arched foundation pit according to claim 1, characterized in that, The arched support beam is composed of multiple segmented arched support beams spliced ​​together. The multiple segmented arched support beams are provided with bolt holes and are connected by bolts.

4. The support structure for an arched foundation pit according to claim 1 or 3, characterized in that, The connection between the arched support beam and the steel column is filled with expansive concrete.

5. The support structure for an arched foundation pit according to claim 2, characterized in that, The arched support beam is provided with a diagonal brace at the connection with the steel support, and the steel support is provided with a steel diagonal support at the connection with the underground continuous wall.

6. A construction method for a support structure for an arched foundation pit according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: First, excavate the trench to form a continuous wall, put in the steel cage, set the pre-embedded steel plate inside the steel cage, cast the whole structure, drive in the construction column piles, and put in the steel column. Step 2: Prefabricate the first arched support beam and the extended arched support beam according to the dimensions of the foundation pit, and prefabricate the connecting bolt holes at the joints of the arched support beams; Step 3: When the excavation pit reaches the concrete support elevation, pour the concrete support and anchor it to the steel column; Step 4: After the concrete supports reach the design strength, continue excavating the foundation pit to the elevation of the first arch support beam. Assemble the first arch support beam using a connecting bolt system, and fill the gaps with expansive concrete. Step 5: Continue excavating the foundation pit to the elevation of the second arched support beam, and extend and assemble it with the first arched support beam through a connecting bolt system, while setting steel supports at the predetermined height; Step Six: Continue excavating the foundation pit, and repeat Step Five based on the elevation of the arch support beam; Step 7: Continue excavating the foundation pit to the elevation of the end of the arched support beam. Connect the end of the arched support beam with connecting bolts, and connect the other end to the steel plate pre-embedded in the previous step. Fill the gap with expansive concrete. Step 8: After the foundation pit is excavated, the support system is dismantled in sequence as the structure is back-built, completing the recycling of the support structure system.

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