Supporting system for small-space site foundation pit

Abstract

The utility model discloses a supporting system for a small-space site foundation pit, which comprises supporting wall bodies positioned at the edge of the foundation pit, latticed columns vertically arranged in the foundation pit and horizontal supporting steel pipes transversely supported between the supporting wall bodies on the opposite sides, a supporting platform used for being connected with the horizontal supporting steel pipes and vertically supporting the horizontal supporting steel pipes is arranged at the tops of the latticed columns. The supporting platform comprises a supporting plate which is horizontally arranged, the upper surface of the supporting plate is provided with a hoop used for fixing the horizontal supporting steel pipe, and the lower surface of the supporting plate is provided with a reinforcing structure used for reinforcing the connecting strength of the supporting plate and the latticed column; according to the utility model, the construction of the supporting system is carried out while excavation is carried out by adopting a horizontal steel pipe supporting mode, so that the supporting and excavation of the foundation pit are completed under the condition that the existing peripheral buildings are not influenced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a supporting system for small space site foundation pit. BACKGROUND

[0002] With the development of urbanization, the scale of underground space development is also getting larger and larger. At present, most of the foundation pit projects are located in the densely distributed urban areas of existing buildings, municipal roads and underground pipelines, but the influence of foundation pit excavation on the surrounding environment is very sensitive, and how to carry out reasonable foundation pit support construction in small space site has brought challenges to the technical personnel in the field and put forward new requirements for the foundation pit support of the construction industry.

[0003] In the prior art, common foundation pit excavation generally adopts the ways of slope excavation, setting anchor rod retaining wall support, setting anti-slide pile plate retaining wall, etc. However, slope excavation generally needs a larger site space, which is difficult to implement in a small space, and needs to ensure that the construction site has good soil quality and no important existing buildings around; although the foundation pit construction of anchor rod retaining wall support does not need a larger site space, the anchor rod is easy to damage the surrounding existing buildings, so it is not suitable for the case where there are important existing buildings around; as for the foundation pit construction of anti-slide pile plate retaining wall support, a larger diameter pile foundation is usually needed, and anchor rods still need to be set in the area with poor soil quality in the retaining wall. This kind of foundation pit support method consumes a lot of materials, and the process is relatively complex, with high cost.

[0004] Therefore, it is necessary to improve the structure of the existing foundation pit support system so that it can be applied to small space sites with important existing buildings around. INVENTION CONTENTS

[0005] Therefore, the purpose of the utility model is to provide a supporting system for small space site foundation pit, which can improve construction efficiency, ensure construction safety, reduce the influence on the surrounding environment, etc. by optimizing the way of underground structure foundation pit excavation and support system.

[0006] The supporting system for small space site foundation pit provided by the utility model comprises a supporting wall body located at the edge of a foundation pit, a lattice column vertically arranged in the foundation pit and a horizontal support steel pipe transversely supported between the supporting wall bodies on opposite sides, the top of the lattice column is provided with a support platform for connecting with the horizontal support steel pipe and vertically supporting the horizontal support steel pipe, the support platform comprises a support plate arranged horizontally, the upper surface of the support plate is provided with a clamp for fixing the horizontal support steel pipe, and the lower surface of the support plate is provided with a reinforcing structure for strengthening the connection strength of the support plate and the lattice column.

[0007] Further, the supporting wall is in U-shaped structure in the height direction and is formed by a plurality of supporting piles arranged at intervals, and the top of the plurality of supporting piles is connected by a crown beam to form a whole.

[0008] Further, the crown beam is provided with a hanging plate at the connection with the horizontal supporting steel pipe, and the hanging plate is used for temporarily placing the supporting end of the horizontal supporting steel pipe.

[0009] Further, the supporting plate is further provided with a circular arc plate for increasing the contact area of the supporting plate with the horizontal supporting steel pipe.

[0010] Further, a connecting rod is arranged between adjacent supporting platforms.

[0011] Further, a diagonal supporting steel pipe is arranged between adjacent supporting walls for strengthening the supporting strength of the foundation pit, and the diagonal supporting steel pipe is arranged at the earth outlet side of the foundation pit.

[0012] Further, the horizontal supporting steel pipe and the diagonal supporting steel pipe each include a fixed end connected with the crown beam and a movable end for adjusting the supporting strength.

[0013] Further, the horizontal supporting steel pipe and the diagonal supporting steel pipe are in segmented structure, and the movable end and the fixed end are fixed by a flange.

[0014] The supporting system for the small-space site foundation pit has the advantages that the supporting system for the excavation foundation pit of the underground structure is determined according to the site environment profile, the foundation structure type and the underground structure characteristics, the construction of the supporting system is performed by adopting the horizontal steel pipe supporting mode during the excavation, the supporting and the excavation of the foundation pit are completed without affecting the surrounding existing buildings and structures, the supporting platform is arranged on the lattice column to ensure the limiting and fixing of the horizontal steel pipe support or the diagonal steel pipe support in the horizontal direction and the height direction, and the supporting strength of the horizontal steel pipe support or the diagonal steel pipe support is ensured, and the hanging plate for temporarily placing the supporting end of the horizontal steel pipe support arranged on the crown beam helps to adjust the supporting strength according to the actual situation of the construction site, and the construction efficiency is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] The utility model will be further described in connection with the drawings and embodiments:

[0016] Figure 1 is the structure schematic view of the supporting system for the small-space site foundation pit in the utility model;

[0017] Figure 2 is the connection plan view of the supporting platform and the horizontal supporting steel pipe in the utility model;

[0018] Figure 3is the connection front view of the support platform and the horizontal support steel pipe in the utility model;

[0019] Figure 4 is the connection schematic view of the horizontal support steel pipe and the hanging plate in the utility model;

[0020] Figure 5 is the structure schematic view of the hanging plate in the utility model;

[0021] The sign explanation: 1 - support pile;2 - crown beam;3 - lattice column;4 - horizontal support steel pipe;5 - inclined support steel pipe;6 - connecting rod;7 - hoop;8 - arc plate;9 - support plate;10 - reinforcing structure;11 - hanging plate;12 - flange connection;13 - fixed end;14 - movable end. Specific implementation

[0022] As shown in the figure, the utility model provides a kind of support system for small space site foundation pit, including the support wall body in foundation pit edge, lattice column 3 being set up in foundation pit and horizontal support steel pipe 4 being supported between opposite side support wall body transversely, the top of lattice column 3 is provided with the support platform for being connected with horizontal support steel pipe 4 and the vertical support of horizontal support steel pipe 4;By using the support system of support wall body, lattice column 3 and horizontal support steel pipe 4 intercoordination, the construction of support system is carried out while excavating, to complete the support and excavation of small space site foundation pit without affecting surrounding existing building;And by setting support platform on lattice column 3, the horizontal direction and height direction of horizontal steel pipe support are guaranteed to be limited and fixed, to guarantee the support strength of horizontal steel pipe support;

[0023] The support platform includes the support plate 9 arranged horizontally, the upper surface of the support plate 9 is provided with the hoop 7 for fixing the horizontal support steel pipe 4, and the lower surface of the support plate 9 is provided with the reinforcing structure 10 for strengthening the connection strength of the support plate 9 and the lattice column 3;It also includes the arc plate 8 arranged on the support plate 9 for increasing the contact area of the support plate 9 and the horizontal support steel pipe 4; Figure 2 And Figure 3 As shown in the figure, reinforcing structure 10 is inclined reinforcing rod arranged between support plate 9 and lattice column 3, and the inclined reinforcing rod is made of channel steel.

[0024] In the embodiment, the support wall body is in U-shaped structure in height direction and is formed by a plurality of support piles 1 arranged at intervals, and the top of a plurality of support piles 1 is connected by crown beam 2 to form a whole; Figure 1As shown, the supporting wall is formed by a plurality of supporting piles 1 arranged at intervals. In this scheme, because there is an important existing building on the side opposite the excavation opening, the supporting wall is formed by the construction of supporting piles 1 on the side of the excavation opening and on the two sides adjacent to the side of the excavation opening, and finally a U-shaped structure is formed. The top of the supporting pile 1 is connected by a corbel 2 to form a whole.

[0025] In this embodiment, the corbel 2 is provided with a hanging plate 11 at the connection with the horizontal support steel pipe 4, which is used for temporarily placing the support end of the horizontal support steel pipe 4. Figure 4 and Figure 5 As shown, according to the elevation and positioning of the connection point of the horizontal support steel pipe 4 and the corbel 2, the corbel 2 is provided with a hanging plate 11 on the side close to the connection with the horizontal support steel pipe 4. The hanging plate 11 is mainly used for temporarily placing the support end of the horizontal steel pipe, which helps to adjust the support strength according to the actual situation on the construction site, greatly improving the construction efficiency. The overall structure of the hanging plate 11 is Z-shaped, and the hanging plate 11 is hung on the inside of the corbel 2 and fixed together with the corbel 2 by round steel dowel.

[0026] In this embodiment, a connecting rod 6 is arranged between adjacent support platforms to connect them. The connecting rod 6 is made of I-beam, mainly used to increase the connection strength between the support platforms, to ensure the overall connection strength of the support system.

[0027] In this embodiment, a diagonal support steel pipe 5 is arranged between adjacent support walls to strengthen the support strength of the foundation pit. The diagonal support steel pipe 5 is arranged on the side of the excavation opening of the foundation pit. Figure 1 As shown, because the number of horizontal support steel pipes 4 arranged in the foundation pit is not large, and because the side of the excavation opening of the foundation pit is often passed by equipment, vehicles and the like, it is easy to cause damage to the overall structural strength of the support system. Therefore, a diagonal support steel pipe 5 is arranged between adjacent support walls to strengthen the support strength of the foundation pit, and a lattice column 3 and a support platform are also arranged below the diagonal support steel pipe 5.

[0028] In this embodiment, the horizontal support steel pipe 4 and the diagonal support steel pipe 5 each include a fixed end 13 fixedly connected to the corbel 2 and a movable end 14 for adjusting the support strength. The horizontal support steel pipe 4 and the diagonal support steel pipe 5 are of a segmented structure, and the movable end is fixed between the fixed end 13 by a flange. Figure 4 As shown, the horizontal support steel pipe 4 and the diagonal support steel pipe 5 usually have a fixed end 13 at one end and a movable end 14 at the other end, and the fixed end 13 and the movable end 14 are connected by bolts at the flange. This is a prior art and will not be described here.

[0029] The embodiment also provides a construction method of the supporting system for the small-space site foundation pit.

[0030] S1. The construction of the supporting pile 1 and the crown beam 2 is completed according to the site edge size, and the construction of the lattice column 3 is completed inside the site;

[0031] S2. The foundation pit is excavated to the first design height position, and the lattice column 3 is cleaned; the lattice column 3 is arranged when the pile foundation is constructed, after the earthwork is excavated to the first design height position, the lattice column 3 is cleaned first, the center point of the horizontal support steel pipe 4 is accurately placed on the crown beam 2 and the lattice column 3 by the survey personnel according to the drawing coordinates, in order to facilitate the construction, the survey team draws a line in the horizontal and vertical directions at the center of the horizontal support steel pipe 4 by spraying paint, so as to facilitate the calibration of the position of the steel support after the steel support is installed;

[0032] S3. The support platform is arranged on the top of the lattice column 3, and the horizontal support steel pipe 4 is arranged on the opposite side of the supporting wall through the support platform, or the inclined support steel pipe 5 is arranged on the adjacent side of the supporting wall through the support platform; then the support platform is arranged on the column, and the actual length between the center points of the horizontal support steel pipes 4 is measured by using a tape measure after the installation of the hanging plate 11 on the crown beam 2 and the support platform of the lattice column 3 is completed, and the steel pipe is cut and assembled according to the actual length. One end of each horizontal support steel pipe 4 is a fixed end, and the other end is a loose end 14. In the case of conditions, the horizontal support steel pipe 4 is pre-assembled to the corresponding splicing length on the ground by using a crane and manual work, and the total length (when the active section is retracted) is 10-30 cm smaller than the net distance of the enclosure structure. Each connection is connected and spliced by using high-strength bolts, and the horizontal support steel pipe 4 is tightened, and the exposed bolts are not less than two teeth. Since the horizontal support steel pipe 4 is long, two-point lifting is adopted when lifting, and a cable wind rope is tied to achieve safe, stable and accurate lifting. The horizontal support steel pipe 4 is hoisted in place, the hook is not immediately loosened, the fixed end is hung on the support temporary hanging plate 11, the middle is placed on the support platform of the lattice column 3, and the other end is hung on the support embedded part by adjusting the length of the loose end 14; then the collar 7 and the I-shaped connecting rod 6 are welded to prevent the horizontal support steel pipe 4 from sliding horizontally; the horizontal support steel pipe 4 needs to be installed with an axial force meter, and the installation of the axial force meter is completed by the monitoring unit.

[0033] S4. Adjust the adjustable end of the horizontal support steel pipe 4 and the inclined support steel pipe 5, and gradually apply prestress until the horizontal support steel pipe 4 and the inclined support steel pipe 5 support on the support wall with a preset support strength; after the horizontal support steel pipe 4 is installed, the connection status of each node should be checked in time, and after it is confirmed that the elevation, plane position, pitch, and axis deviation meet the requirements, the prestress (150 kN) can be applied; 2 100T hydraulic jacks are placed in the adjustable end 14 top pressure position, and attention should be paid to keep the jacks consistent. After the prestress is applied in place, the gasket in the adjustable end 14 is tightened, and is fixed firmly, and after 2-5 minutes, the oil is returned to loosen the jack, the steel wire rope is untied, and the installation of the support is completed. Before the prestress construction, the oil pump and the jack must be calibrated and recorded. During the prestress application, the prestress must be applied step by step according to the design requirements, the first total prestress is 30%, after checking the bolts and nuts, if there is no abnormal condition, the second total prestress is 50%, after checking the bolts and nuts, if there is no abnormal condition, the third prestress reaches the design requirement of 150KN. When the support applies the prestress, the stress loss during operation should be considered, so the prestress value should be increased by 15% than the design axial force, and the prestress value is recorded for reference.

[0034] S5. Complete the excavation of the foundation pit to the target design height position.

[0035] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A support system for foundation pits in small spaces, characterized in that: The structure includes retaining walls located at the edge of the foundation pit, lattice columns erected within the foundation pit, and horizontal support steel pipes horizontally supporting the retaining walls on opposite sides. The top of the lattice columns is provided with a support platform for connecting to and vertically supporting the horizontal support steel pipes. The support platform includes a horizontally arranged support plate. The upper surface of the support plate is provided with a clamp for fixing the horizontal support steel pipes, and the lower surface of the support plate is provided with a reinforcing structure for strengthening the connection between the support plate and the lattice columns.

2. The support system for foundation pits in small spaces according to claim 1, characterized in that: The retaining wall has a U-shaped cross-section in the height direction and is formed by a number of spaced-apart retaining piles. The tops of the retaining piles are connected by a capping beam to form a whole.

3. The support system for foundation pits in small spaces according to claim 2, characterized in that: The cap beam is provided with a hanging plate at the connection with the horizontal support steel pipe, and the hanging plate is used to temporarily place the support end of the horizontal support steel pipe.

4. The support system for foundation pits in small spaces according to claim 1, characterized in that: It also includes an arc plate disposed on the support plate to increase the contact area between the support plate and the horizontal support steel pipe.

5. The support system for foundation pits in small spaces according to claim 1, characterized in that: A connecting rod is provided between adjacent support platforms to connect the two.

6. The support system for foundation pits in small spaces according to claim 2, characterized in that: An inclined support steel pipe is installed between adjacent retaining walls to strengthen the foundation pit support. The inclined support steel pipe is located on the soil outlet side of the foundation pit.

7. The support system for foundation pits in small spaces according to claim 6, characterized in that: Both the horizontal support steel pipe and the diagonal support steel pipe include a fixed end that is fixedly connected to the cap beam and a movable end for adjusting the support strength.

8. The support system for foundation pits in small spaces according to claim 7, characterized in that: Both the horizontal support steel pipe and the diagonal support steel pipe are segmented structures, and the movable end and the fixed end are fixed by flanges.

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