A high-stability support device based on deep foundation pit

Abstract

This utility model discloses a high-stability support device for deep foundation pits, including a central support beam assembly. Four sets of side support plate mechanisms are fixed in a circular array on the four sides of the central support beam assembly. The central support beam assembly of this design adopts a rigid-flexible composite structure of a double-layered cross-shaped concrete beam and steel columns. It utilizes a hollow cross-section and built-in X-shaped reinforcing ribs to optimize self-weight and enhance bending stiffness. The bottom concrete columns and cast-in-place piles form a vertically continuous load transmission chain, effectively dispersing the top construction load. The W-shaped support beams of the side support plate mechanisms improve out-of-plane torsional performance through a multi-corrugated web design. The support force adjustment mechanism achieves stepless adjustment of the support force through a screw pair transmission of an internal threaded sleeve and double lead screws. Combined with a ball-joint support seat, it automatically adapts to the micro-deformation of the support plate. During foundation pit excavation, it can dynamically balance the support stiffness according to changes in soil pressure, avoiding the risk of stress concentration in rigid support systems.

Description

Technical Field

[0001] This utility model relates to the field of foundation pit support equipment technology, specifically to a highly stable support device for deep foundation pits. Background Technology

[0002] With the acceleration of urbanization, the demand for high-rise buildings and underground engineering projects is constantly increasing. As a fundamental construction phase, the safety and stability of support technology are crucial for deep foundation pit engineering. However, traditional support systems, such as horizontal support structures, suffer from problems such as dense member configurations, limited excavation space, high costs, and long construction periods, making it difficult to meet the dual demands of efficiency and economic benefits in modern engineering. Specifically, the dense member configurations of traditional horizontal support systems result in limited working space within the foundation pit, affecting construction efficiency. In soft soil or complex geological conditions, traditional support systems are prone to deformation, leakage, and local instability. Furthermore, traditional support systems lack real-time dynamic adjustment capabilities, making it difficult to adapt to changes in soil pressure during foundation pit excavation, easily leading to imbalances in support stiffness. Therefore, those skilled in the art propose a solution for a highly stable support device for deep foundation pits. Utility Model Content

[0003] The purpose of this utility model is to provide a technical solution for a highly stable support device based on deep foundation pits, thereby addressing the shortcomings mentioned in the background art. To overcome the drawbacks and defects described in the background art, this technical solution includes the following:

[0004] It includes a central support beam assembly, and four sets of side support plate mechanisms are fixed in a circular array on the four sides of the central support beam assembly. Each side support plate mechanism has a support plate fixedly connected to its outer end face. Four support force adjustment mechanisms are fixedly connected between the inner bottom of the support plate and the outer bottom of the central support beam assembly.

[0005] The central support beam assembly includes two layers of cross-shaped concrete beams arranged vertically, several steel columns fixed between the cross-shaped concrete beams, and several concrete columns fixed below the bottom cross-shaped concrete beams, with concrete piles fixed at the bottom of the concrete columns.

[0006] The side support plate mechanism includes two layers of W-shaped support beams arranged vertically, and purlins fixed to the outer end face of the W-shaped support beams.

[0007] Each of the support force adjustment mechanisms includes an internally threaded sleeve, a lead screw that passes through and is screwed to both ends of the internally threaded sleeve, and a support seat hinged to one end of the lead screw that is far apart from the other.

[0008] As a preferred embodiment of this utility model: the cross-section of the cross-shaped concrete beams is cross-shaped, and the interior of the cross-shaped concrete beams is hollow. The interior space of the cross-shaped concrete beams is fixed with 4 X-shaped reinforcing ribs.

[0009] As a preferred embodiment of this utility model: the upper and lower end faces of the steel column are respectively fixed to the end face nodes of the cross-shaped concrete beam that are close to each other.

[0010] As a preferred embodiment of this utility model: the concrete pile is cast and buried in the soil at the bottom of the foundation pit, and the concrete pile and the cross-shaped concrete beam are supported by concrete columns to form a space for foundation pit operations.

[0011] As a preferred embodiment of this utility model, the inner end face of the W-shaped support beam is fixedly connected to the four outer end faces of the cross-shaped concrete beam.

[0012] As a preferred embodiment of this utility model, 2-4 bolts are screwed through and tightened between the outer surface of the W-shaped support beam and the inner end face of the purlin.

[0013] As a preferred embodiment of this utility model: the outer sidewall of the support plate is in contact with the inner surface of the foundation pit, and the height of the support plate is consistent with the depth of the foundation pit.

[0014] As a preferred embodiment of this utility model: a handle is fixedly connected to the outer ring surface of the internal threaded sleeve for rotating the internal threaded sleeve, and two mirror-symmetrical threads are opened in the inner cavity of the internal threaded sleeve for matching with the outer ring threads of the two lead screws.

[0015] As a preferred embodiment of this utility model: the end face of the top support away from the screw rod is fixedly connected to the bottom of the inner surface of the support plate, and the end face of the bottom support away from the screw rod is fixedly connected to the outer surface of the concrete column.

[0016] The technical effects and advantages provided by this utility model in the above technical solution are as follows:

[0017] The central support beam assembly of this scheme adopts a rigid-flexible composite structure of double-layer cross-shaped concrete beams and steel columns. The hollow cross-section and built-in X-shaped reinforcing ribs are used to optimize self-weight and enhance bending stiffness. The bottom concrete columns and cast-in-place piles form a vertically continuous load transmission chain, effectively dispersing the top construction load. The W-shaped support beam of the side support plate mechanism improves out-of-plane torsional performance through a multi-corrugated web design. The support force adjustment mechanism achieves stepless adjustment of support force through the helical transmission of internal threaded sleeves and double screws. With the ball joint support seat, it automatically adapts to the micro-deformation of the support plate. During the excavation of the foundation pit, the support stiffness can be dynamically balanced according to the changes in soil pressure, avoiding the risk of stress concentration in the rigid support system. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 A schematic diagram of the overall structure of a deep foundation pit support mechanism;

[0020] Figure 2 A schematic diagram of the internal structure of a deep foundation pit support mechanism;

[0021] Figure 3 A schematic diagram of the central support beam assembly inside a deep foundation pit support mechanism;

[0022] Figure 4 This is a schematic diagram of the side support plate mechanism;

[0023] Figure 5 A schematic diagram of the force adjustment mechanism.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Central support beam assembly; 11. Cross-shaped concrete beam; 12. Steel column; 13. Concrete column; 14. Concrete pile; 2. Side support plate mechanism; 21. W-shaped support beam; 22. Bolt; 23. Purlin; 24. Support force adjustment mechanism; 241. Internal threaded sleeve; 242. Screw rod; 243. Support seat; 3. Support plate. Detailed Implementation

[0026] To provide a clearer explanation and description of the technical solution and implementation of this utility model, several preferred specific embodiments for implementing the technical solution of this utility model are introduced below.

[0027] The following description is exemplary in nature and is not intended to limit the scope, application, or use of this disclosure. It should be understood that in all these figures, the same or similar reference numerals indicate the same or similar parts and features. The figures are merely schematic representations of the concept and principles of embodiments of this disclosure and do not necessarily show the specific dimensions and scale of each embodiment. Specific details or structures of embodiments of this disclosure may be exaggerated in particular portions of certain figures. The disclosures of various publications, patents, and published patent specifications cited herein are incorporated herein by reference in their entirety. The technical solutions of this utility model will be clearly and completely described below in conjunction with embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model.

[0028] Example 1: This high-stability support equipment was used in a rectangular deep foundation pit project with an excavation depth of 10 meters. The central support beam assembly 1 consists of two layers of cross-shaped concrete beams 11 vertically connected by four steel columns 12. The cross-section of the concrete beams 11 is hollow cross-shaped, with four X-shaped reinforcing ribs welded inside. Four concrete columns 13 extend below the bottom cross-shaped concrete beams 11, and concrete piles 14 are poured at their bottom ends to the bearing layer of the foundation pit. Four sets of side support plate mechanisms 2 are arranged in a circular array along the central support beam assembly 1. Each set consists of two layers of W-shaped support beams 21 connected to purlins 23 by four bolts 22 to form a frame structure. The inner side of the W-shaped support beams 21 is welded and fixed to the end face of the cross-shaped concrete beams 11. The support plate 3 is made of steel plate, with its outer wall fitting against the side wall of the foundation pit, and its inner bottom connected to the outside of the concrete columns 13 by four sets of support force adjustment mechanisms 24. During adjustment, by rotating the handle on the outer wall of the internal threaded sleeve 241, the screw rods 242 at both ends extend and retract synchronously, the top support seat 243 pushes the support plate 3 to fit tightly against the pit wall, and the bottom support seat 243 forms a stable support system through the concrete column 13.

[0029] Example 2: For complex conditions where the foundation pit has a trapezoidal cross-section, the cross-shaped concrete beam 11 in the central support beam assembly 1 adopts a variable cross-section design, wider at the top and narrower at the bottom to match the contour of the foundation pit. The steel column 12 is welded to the concrete beam 11 at joints with stiffening ribs to enhance shear resistance. The W-shaped support beam 21 of the side support plate mechanism 2 adjusts its installation angle according to the inclination angle of the foundation pit. The purlin 23 adopts a segmented splicing structure, and the curved surface fit is achieved by adjusting the connection position of the bolts 22. The support plate 3 adopts a segmented combined steel plate, and each segment is equipped with an independent support force adjustment mechanism 24 at the bottom. By adjusting the extension and retraction of the internal threaded sleeve 241 in different areas, the support plate 3 can form an adaptive fit with the side wall of the foundation pit, solving the problem of supporting irregular foundation pits.

[0030] Example 3: In an ultra-deep foundation pit with an excavation depth of 18 meters, a double-layer support system is adopted: the upper central support beam assembly 1 is 8 meters below the ground surface, and the lower assembly is 14 meters below the ground surface, with the upper and lower layers connected by steel columns 12. The diameter of the concrete columns 13 is increased to 1.2 meters, and the concrete piles 14 are embedded in the moderately weathered rock layer. The W-shaped support beam 21 of the side support plate mechanism 2 adopts a double-layer composite structure, with the inner and outer layers enhanced by welded joints to increase the overall rigidity. The support force adjustment mechanism 24 is made of high-strength alloy steel, and the surface of the internal threaded sleeve 241 is provided with anti-slip knurling. It can be quickly adjusted by an electric wrench, so that the support plate 3 can still maintain verticality under ultra-deep conditions.

[0031] Example 4: For silty soft soil foundations, the concrete columns 13 of the central support beam assembly 1 adopt an enlarged-base pile design, with the diameter of the concrete piles 14 gradually decreasing from 1 meter to 1.5 meters, and an enlarged head at the bottom to enhance pull-out resistance. Grouting pipes are pre-embedded inside the cross-shaped concrete beam 11, and pressure grouting is performed after construction to reinforce the surrounding soil. Shear-resistant grooves are added to the surface of the W-shaped support beam 21 of the side support plate mechanism 2, and high-strength friction bolts are used at the connection with the purlin 23. The support force adjustment mechanism 24 is equipped with a force sensor. When the force on the support plate 3 exceeds the warning value, the emergency locking device of the internal threaded sleeve 241 is automatically triggered. The mechanical interlocking mechanism prevents support failure and ensures the safety of deep foundation pit construction on soft soil foundations.

[0032] Based on the above-described preferred technical solution, the workflow of this technical solution is explained as follows:

[0033] The prefabricated upper and lower two-layer cross-shaped concrete beams 11 are hoisted to the designated height of the foundation pit. The steel columns 12 are then bolted to the concrete beams 11 to form an integral frame. The bottom concrete columns 13 extend vertically to the bottom of the foundation pit, and their bottom concrete piles 14 are compacted with the bearing soil using a vibration compaction process. Simultaneously, the side support plate mechanism 2 is assembled. The two layers of W-shaped support beams 21 are horizontally hoisted to the outside of the cross-shaped concrete beams 11. The inner end faces of the W-shaped support beams 21 are welded to fit and fix to the end faces of the concrete beams 11. Then, the purlins 23 are slid into place along the outer grooves of the W-shaped support beams 21 and secured with bolts. Bolt 22 passes through the pre-drilled holes in both and applies torque to complete the connection; when the support plate 3 is hoisted, keep the outer wall parallel to the pit sidewall and fix its initial position with temporary diagonal bracing. Then, place the internal threaded sleeve 241 of the support force adjustment mechanism 24 between the bottom of the support plate 3 and the concrete column 13. Rotate the handle on the outer wall of the internal threaded sleeve 241 to drive the screw rods 242 at both ends to rotate out synchronously, so that the ball joint end face of the top support seat 243 is welded to the bottom inner side of the support plate 3 and the bottom support seat 243 is welded to the outer side of the concrete column 13. By alternately rotating the internal threaded sleeve 241 in four directions, the support plate 3 is gradually pressed against the pit sidewall.

[0034] During the excavation of the foundation pit, the displacement data of the support plate 3 is monitored in real time. When the support plate 3 in a certain area is subjected to earth pressure and causes a small displacement, the internal thread sleeve 241 at the corresponding position is tightened with a torque wrench. The support force distribution is adjusted by axial movement of the screw 242 to achieve dynamic balance. During dismantling, the internal thread sleeve 241 is rotated in the opposite direction to retract the screw 242, thereby releasing the jacking constraint of the support seat 243 on the support plate 3. Then, the temporary diagonal brace is cut off and the support plate 3 is lifted away. Finally, the flange connection between the steel column 12 and the concrete beam 11 is separated by a hydraulic jacking device, and the central support beam assembly 1 and the side support plate mechanism 2 are lifted in sections to complete the equipment recovery.

[0035] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A high stability support equipment based on deep foundation pit comprising a central support beam assembly (1), characterized in that: The central support beam assembly (1) has four sets of side support plate mechanisms (2) fixed in a ring array on its four sides. Each side support plate mechanism (2) has a support plate (3) fixedly connected to its outer end face. Each support plate (3) has four support force adjustment mechanisms (24) fixedly connected to its inner bottom and the outer bottom of its outer side. The central support beam assembly (1) includes two layers of cross-shaped concrete beams (11) arranged vertically, several steel columns (12) fixed between the cross-shaped concrete beams (11), and several concrete columns (13) fixed below the bottom cross-shaped concrete beams (11), and concrete piles (14) are fixed at the bottom of the concrete columns (13). The side support plate mechanism (2) includes two layers of W-shaped support beams (21) arranged vertically, and purlins (23) fixed to the outer end face of the W-shaped support beams (21); Each of the support force adjustment mechanisms (24) includes an internal threaded sleeve (241), a lead screw (242) that is screwed through both ends of the internal threaded sleeve (241), and a support seat (243) that is hinged to one end of the lead screw (242) that is far apart from the other end.

2. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: The cross-section of each of the cross-shaped concrete beams (11) is cross-shaped, and the interior of each cross-shaped concrete beam (11) is hollow. Each of the cross-shaped concrete beams (11) has four X-shaped reinforcing ribs fixed in its interior space.

3. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: The upper and lower ends of the steel column (12) are respectively fixed to the end nodes of the cross-shaped concrete beam (11) that are close to each other.

4. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: The concrete piles (14) are poured and buried in the soil at the bottom of the foundation pit, and the concrete piles (14) and the cross-shaped concrete beams (11) are supported by concrete columns (13) to form a space for foundation pit operations.

5. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: The inner end face of the W-shaped support beam (21) is fixedly connected to the four outer end faces of the cross-shaped concrete beam (11).

6. A high-stability support device based on a deep foundation pit according to claim 1, characterized in that: Two to four bolts (22) are screwed through the outer surface of the W-shaped support beam (21) and the inner end face of the purlin (23).

7. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: The outer sidewall of the support plate (3) is in contact with the inner surface of the pit, and the height of the support plate (3) is consistent with the depth of the pit.

8. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: Each of the inner threaded sleeves (241) has a handle fixedly connected to its outer ring surface for rotating the inner threaded sleeve (241). The inner cavity of the inner threaded sleeve (241) has two mirror-symmetrical threads for matching with the outer ring threads of the two lead screws (242).

9. The high stability support equipment based on deep foundation pit according to claim 1, characterized in that: The end face of the top support (243) away from the screw rod (242) is fixedly connected to the bottom of the inner surface of the support plate (3), and the end face of the bottom support (243) away from the screw rod (242) is fixedly connected to the outer surface of the concrete column (13).

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