A steel cross-brace axial force system for controlling deformation of a foundation pit lattice column and a construction method thereof

Abstract

The application discloses a steel cross-bracing axial force system for controlling deformation of a foundation pit lattice column and a construction method, relates to the technical field of deep foundation pit construction, and discloses a steel cross-bracing axial force system for controlling deformation of a foundation pit lattice column, which comprises a foundation pit enclosure structure, a lattice column and a steel cross-bracing servo axial force system. The lattice column comprises angle steels and patch plates. The steel cross-bracing servo axial force system comprises a steel sleeve box, a plug-in steel cross-bracing, a deformation monitoring sensor, a monitoring system and a hydraulic jack. The application has good deformation control effect and high precision, can prevent the weakening of vertical stress capacity caused by the deformation of the lattice column, ensures the stability of the foundation pit, and guarantees the safety of the foundation pit construction.

Description

Technical Field

[0001] This invention relates to the field of deep foundation pit construction technology, specifically a steel cross bracing axial force system and construction method for controlling the deformation of foundation pit lattice columns. Background Technology

[0002] With the rapid development of my country's construction industry, the utilization rate of underground space is increasing, and deep foundation pit projects are becoming more and more common. As a crucial vertical load-bearing structure in the deep foundation pit support system, lattice columns play a vital role in maintaining the stability of deep foundation pits. In deep foundation pits, lattice columns are typically used to support horizontal supports and working platforms. Under pressure, lattice columns are prone to deformation. Eccentric compression deformation weakens the vertical load-bearing capacity of the lattice columns, severely affecting the stability of the deep foundation pit and posing safety risks. Eccentric compression deformation of lattice columns is often unavoidable and develops rapidly, bringing significant safety hazards to foundation pit construction. Therefore, there is an urgent need for a steel cross bracing axial force system to control the deformation of lattice columns in foundation pits to solve the above problems. Summary of the Invention

[0003] The purpose of this invention is to provide a steel cross bracing axial force system and construction method for controlling the deformation of lattice columns in foundation pits, so as to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A steel cross bracing axial force system and construction method for controlling the deformation of lattice columns in foundation pits include: a foundation pit retaining structure, lattice columns, and a steel cross bracing servo axial force system. Each of the foundation pit retaining structure, lattice columns, and steel cross bracing servo axial force system comprises several sets, with each set of lattice columns connected to one end of the steel cross bracing servo axial force system on all four sides, forming a large rectangular structure with a cross-section composed of several small rectangles. The other end of the outermost steel cross bracing servo axial force system is connected to the foundation pit retaining structure. The steel cross bracing servo axial force system is used to monitor the stress on the lattice columns and simultaneously provide support.

[0006] The lattice column includes: angle steel and connecting plates. Several sets of angle steel and connecting plates are provided. The several sets of angle steel are arranged in a biaxially symmetrical manner to form a column structure with a rectangular cross section. The connecting plates are arranged parallel to each other at equal intervals around the angle steel and connected to it.

[0007] The steel cross brace servo axial force system includes: a steel sleeve, plug-in steel cross braces, deformation monitoring sensors, a monitoring system, and hydraulic jacks. The steel sleeve is located in the middle section of the lattice column, and one end is connected to the middle section of the lattice column. The two ends of the plug-in steel cross braces are respectively plugged into the other ends of two sets of steel sleeves. The deformation monitoring sensors are installed in the middle of the lattice column and connected to the gusset plate for real-time monitoring of the bending deformation of the lattice column. The monitoring system and the hydraulic jacks are both located inside the steel sleeve and are electrically connected via a communication line. The deformation monitoring sensors and the monitoring system are electrically connected via a communication line. The output end of the hydraulic jack is connected to one end of the telescopic rod, and the other end of the telescopic rod abuts against the pressure plate. The pressure plate is installed on the plug-in steel cross braces.

[0008] As a further aspect of the present invention: the steel casing includes: an installation end and an interface end, the installation end being located in the middle section of the lattice column and connected to the outer wall of the upper gusset plate of the lattice column by welding, and the interface end being used to connect to the plug-in steel cross brace.

[0009] A construction method for a steel cross bracing axial force system for controlling the deformation of lattice columns in foundation pits includes the following steps:

[0010] S1. Lattice Column Preparation and Construction: The lattice column uses Q235B steel and E43XX welding rods. The welds are all 10-20mm thick. The center spacing of the lacing plates is 450mm. Four angle steels are arranged in a double-axis symmetrical manner to form a column structure with a rectangular cross-section. The lacing plates are welded from the bottom of the angle steel to the top. The distance between the last lacing plate and the top of the column structure is adjustable. During welding, the number of weld joints of a single lattice column shall not exceed two. Bevel welding is used. The joints of the single angle steels shall be staggered. The lattice column is positioned, the positioning point is determined, and it is hoisted and installed. After the lattice column is placed, it is reinforced and connected with steel sections and welded to the steel cage. Concrete is poured for fixation.

[0011] S2. Construction of the steel casing installation end: The two installation ends of the steel cross brace servo axial force system end structure are connected to the outer side of the gusset plate in the middle section of the adjacent lattice column by welding. Bevel welding is used. The installation end is symmetrically welded with four right-angle supports on the lattice column to ensure the stability of the connection between the installation end and the lattice column. The two installation ends of the steel cross brace servo axial force system end structure at the outer edge of the foundation pit can be connected to the lattice column and the foundation pit retaining structure respectively.

[0012] S3. Construction of plug-in steel cross brace: The two ends of the plug-in steel cross brace are respectively connected to the interface end of the steel sleeve box and set horizontally on the same axis. The plug-in steel cross brace can be freely inserted into the interface end, and a layer of lubricating oil is applied to the interface section. A pressure plate is installed inside the plug-in steel cross brace.

[0013] S4. Deformation monitoring sensor installation: The deformation monitoring sensor is installed on the inside of the gusset plate in the middle section of the lattice column to monitor the deformation of the lattice column in real time and transmit the monitoring data to the monitoring system.

[0014] S5. Control and Monitoring System Connection: The monitoring system connects to external deformation monitoring sensors and hydraulic jacks via communication lines. The deformation monitoring sensors can monitor the stress and deformation of the lattice column in real time. The monitoring system can process, analyze, and record the deformation data of the lattice column in real time, and send command signals to the hydraulic jacks to accurately control the bending deformation of the lattice column in real time. When the lattice column bends under the pressure of horizontal support or working platform in the deep foundation pit, the deformation monitoring sensors transmit the data to the monitoring system. After analyzing and processing the data, the monitoring system controls the hydraulic jacks to apply axial jacking force to ensure the stress safety of the lattice column.

[0015] S6. Applying prestress with hydraulic jacks: After the steel cross brace servo axial force system is installed, hydraulic jacks apply a certain amount of prestress to prevent the lattice column from bending and deforming.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. The present invention relates to a steel cross brace servo axial force system for controlling the deformation of deep foundation pit lattice columns. The system includes a steel sleeve, plug-in steel cross braces, deformation monitoring sensors, a monitoring system, and hydraulic jacks. The deformation monitoring sensors can monitor the deformation parameters of the foundation pit lattice columns and transmit the detected variables to the monitoring system. After the monitoring system receives and processes the deformation, it transmits the data to the hydraulic jacks to drive the telescopic rods forward. During this process, the deformation monitoring sensors adjust the axial pressure and feed speed of the steel cross braces according to the deformation status of the lattice columns. This automatically adjustable steel cross brace servo axial force system can fully ensure the effectiveness of the steel cross braces and improve their practicality.

[0018] 2. The steel cross bracing servo axial force system for controlling the deformation of lattice columns in deep foundation pits of this invention has a high level of automation, good deformation control effect, and high precision. It can prevent the deformation of lattice columns from weakening the vertical load-bearing capacity, ensuring the stability of the foundation pit and guaranteeing the safety of foundation pit construction. Attached Figure Description

[0019] Figure 1 This is a structural schematic diagram of a steel cross bracing axial force system and construction method for controlling the deformation of a lattice column in a foundation pit, as described in an embodiment of the present invention.

[0020] Figure 2 This is a side view of the steel cross brace servo axial force system in an embodiment of the present invention.

[0021] Figure 3 This is a top view of the steel cross brace servo axial force system in an embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the steel casing in an embodiment of the present invention.

[0023] Figure 5 This is a flowchart illustrating the construction process of the steel cross brace servo axial force system in an embodiment of the present invention.

[0024] Figure 6 This is a flowchart illustrating the control process of the servo axial force system for the steel cross brace in an embodiment of the present invention.

[0025] In the diagram: 1. Excavation pit retaining structure; 2. Lattice column; 3. Steel cross brace servo axial force system; 4. Angle steel; 5. Connecting plate; 6. Steel casing; 7. Plug-in steel cross brace; 8. Deformation monitoring sensor; 9. Monitoring system; 10. Hydraulic jack; 11. Installation end; 12. Interface end; 13. Communication line; 14. Right angle support; 15. Telescopic rod; 16. Bearing plate. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the embodiments of this invention, please refer to Figures 1 to 4 A steel cross bracing axial force system and construction method for controlling the deformation of lattice columns in a foundation pit, comprising: a foundation pit retaining structure 1, lattice columns 2, and a steel cross bracing servo axial force system 3. Each of the foundation pit retaining structure 1, lattice columns 2, and steel cross bracing servo axial force system 3 has several sets, and each set of lattice columns 2 is connected to one end of the steel cross bracing servo axial force system 3 on all four sides, forming a large rectangular structure with a cross-section composed of several sets of small rectangles. The other end of the outermost steel cross bracing servo axial force system 3 is connected to the foundation pit retaining structure 1. The steel cross bracing servo axial force system 3 is used to monitor the force on the lattice columns 2 and simultaneously provide support. Its distinguishing feature is...

[0028] The lattice column 2 includes: angle steel 4 and connecting plate 5. The angle steel 4 and connecting plate 5 are provided in several groups. The angle steel 4 is arranged in a biaxially symmetrical manner to form a column structure with a rectangular cross section. The connecting plate 5 is arranged parallel to the periphery of the angle steel 4 at equal distances and connected to it.

[0029] The steel cross brace servo axial force system 3 includes: a steel sleeve 6, a plug-in steel cross brace 7, a deformation monitoring sensor 8, a monitoring system 9, and a hydraulic jack 10. The steel sleeve 6 is located in the middle section of the lattice column 2, and one end is connected to the middle section of the lattice column 2. The two ends of the plug-in steel cross brace 7 are respectively plugged into the other ends of two sets of steel sleeves 6. The deformation monitoring sensor 8 is installed in the middle of the lattice column 2 and connected to the gusset plate 5 for real-time monitoring of the bending deformation of the lattice column 2. The monitoring system 9 and the hydraulic jack 10 are both located inside the steel sleeve 6 and are electrically connected through a communication line 13. The deformation monitoring sensor 8 and the monitoring system 9 are electrically connected through a communication line 13. The output end of the hydraulic jack 10 is connected to one end of the telescopic rod 15, and the other end of the telescopic rod 15 abuts against the pressure plate 16. The pressure plate 16 is installed on the plug-in steel cross brace 7.

[0030] The monitoring system 9 is connected to the deformation monitoring sensor 8 and the hydraulic jack 10 via the communication line 13. The deformation monitoring sensor 8 monitors the stress and deformation of the lattice column 2 in real time. The monitoring system 9 can process, analyze and record the deformation data of the lattice column 2 in real time, and send command signals to the hydraulic jack 10 to control the bending deformation of the lattice column 2 in real time and accurately. When the lattice column 2 bends under the pressure of horizontal support or working platform in the deep foundation pit, the deformation monitoring sensor 8 transmits the data to the monitoring system 9. After analyzing and processing the data, the monitoring system 9 controls the hydraulic jack 10 to apply axial jacking force to ensure the stress safety of the lattice column 2.

[0031] As one embodiment of the present invention, please refer to Figures 1 to 4 The lattice column 2 is formed by arranging four angle steels 4 in a biaxially symmetrical manner to form a column structure with a rectangular cross section. Multiple gusset plates 5 are welded parallel to each other at equal distances from the bottom to the top of the angle steels 4 to form the lattice column 2. The distance between the last gusset plate 5 at the top and the top of the column structure is adjustable.

[0032] In one embodiment of the present invention, the contact area between the upper lacing plate 5 and the angle steel 4 of the lattice column 2 is greater than half the area of ​​the lacing plate 5.

[0033] As one embodiment of the present invention, please refer to Figures 2 to 4 The steel casing 6 includes an installation end 11 and an interface end 12. The installation end 11 is located in the middle section of the lattice column 2 and is connected to the outer wall of the upper gusset plate 5 of the lattice column 2 by welding. The interface end 12 is used to connect to the plug-in steel cross brace 7.

[0034] As one embodiment of the present invention, please refer to Figure 1 Four sets of right-angle supports 14 are symmetrically welded on the mounting end 11. The four sets of right-angle supports 14 are welded to the outer wall of the lattice column 2 gusset plate 5 to ensure the stability of the connection between the mounting end 11 and the lattice column 2.

[0035] In one embodiment of the present invention, the welding method is bevel welding.

[0036] As one embodiment of the present invention, the inner wall of the interface end 12 and the outer wall of the plug-in steel cross brace 7 are both coated with a layer of lubricating oil to ensure a smooth connection between the two.

[0037] Please see Figure 5 and Figure 6 A construction method for a steel cross bracing axial force system for controlling the deformation of a foundation pit lattice column, comprising any one of the aforementioned steel cross bracing axial force systems for controlling the deformation of a foundation pit lattice column, including the following steps:

[0038] S1. Preparation and construction of lattice columns: The lattice column 2 is made of Q235B steel, the welding rod is E43XX, the weld is 10-20mm, the center spacing of the lacing plates is 450mm, and four angle steels 4 are arranged in a double-axis symmetrical manner to form a column structure with a rectangular cross section. The lacing plates 5 are welded from the bottom to the top of the angle steel 4. The distance between the last lacing plate 5 and the top of the column structure is adjustable. During welding, the number of weld joints of a single lattice column 2 shall not exceed two. Bevel welding is used. The joints of single angle steels shall be staggered. The lattice column 2 is positioned, the positioning point is determined, and it is hoisted and installed. After the lattice column 2 is placed, it is reinforced and connected with steel sections and welded to the steel cage. Concrete is poured for fixation.

[0039] S2. Construction of the steel casing installation end: The two installation ends 11 of the steel cross brace servo axial force system 3 end structure are connected to the outer side of the gusset plate 5 in the middle section of the adjacent lattice column 2 by welding. Bevel welding is used. Four right-angle supports 14 are symmetrically welded to the lattice column 2 at the installation end 11 to ensure the stability of the connection between the installation end 11 and the lattice column 2. The two installation ends 11 of the steel cross brace servo axial force system 3 end structure at the outer edge of the foundation pit can be connected to the lattice column 2 and the foundation pit retaining structure 1 respectively.

[0040] S3. Construction of the plug-in steel cross brace: The two ends of the plug-in steel cross brace 7 are respectively connected to the interface end 12 of the steel sleeve box 6 and are set horizontally on the same axis. The plug-in steel cross brace 7 can be freely inserted into the interface end 12, and a layer of lubricating oil is applied to the interface section. A pressure plate is installed in the plug-in steel cross brace 7.

[0041] S4. Deformation monitoring sensor installation: Deformation monitoring sensor 8 is installed inside the gusset plate 5 in the middle section of lattice column 2 to monitor the deformation status of lattice column 2 in real time and transmit the monitoring data to the monitoring system 9.

[0042] S5. Control and Monitoring System Connection: The monitoring system 9 is externally connected to the deformation monitoring sensor 8 and the hydraulic jack 10 via the communication line 13. The deformation monitoring sensor 8 can monitor the stress deformation of the lattice column 2 in real time. The monitoring system 9 can process, analyze and record the deformation data of the lattice column 2 in real time, and send command signals to the hydraulic jack 10 to control the bending deformation of the lattice column 2 in real time and accurately. When the lattice column 2 bends under the pressure of horizontal support or working platform in the deep foundation pit, the deformation monitoring sensor 8 transmits the data to the monitoring system 9. After analyzing and processing the data, the monitoring system 9 controls the hydraulic jack 10 to apply axial jacking force to ensure the stress safety of the lattice column 2.

[0043] S6. Applying prestress with hydraulic jacks: After the steel cross brace servo axial force system 3 is installed, the hydraulic jacks 10 apply a certain prestress to prevent the lattice column 2 from bending and deforming.

[0044] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0045] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A construction method for a steel cross bracing axial force system for controlling the deformation of lattice columns in foundation pits, comprising: The foundation pit retaining structure, lattice columns, and steel cross bracing servo axial force system are provided. Each of these components comprises several groups, with each group of lattice columns connected to one end of the steel cross bracing servo axial force system, forming a large rectangular structure with a cross-section composed of several small rectangles. The other end of the outermost steel cross bracing servo axial force system is connected to the foundation pit retaining structure. The steel cross bracing servo axial force system is used to monitor the stress on the lattice columns and provide support. Its distinguishing feature is... The lattice column includes: angle steel and connecting plates. Several sets of angle steel and connecting plates are provided. The several sets of angle steel are arranged in a biaxially symmetrical manner to form a column structure with a rectangular cross section. The connecting plates are arranged parallel to each other at equal intervals around the angle steel and connected to it. The steel cross brace servo axial force system includes: a steel sleeve, a plug-in steel cross brace, a deformation monitoring sensor, a monitoring system, and a hydraulic jack. The steel sleeve is located in the middle section of the lattice column, and one end is connected to the middle section of the lattice column. The two ends of the plug-in steel cross brace are respectively plugged into the other ends of the two sets of steel sleeves. The monitoring system and the hydraulic jack are both located inside the steel sleeve. The output end of the hydraulic jack is connected to one end of the telescopic rod, and the other end of the telescopic rod abuts against the pressure plate. The pressure plate is installed on the plug-in steel cross brace. It also includes the following steps: S1. Lattice Column Preparation and Construction: The lattice column uses Q235B steel and E43XX welding rods. The welds are all 10-20mm thick. The center spacing of the lacing plates is 450mm. Four angle steels are arranged in a double-axis symmetrical manner to form a column structure with a rectangular cross-section. The lacing plates are welded from the bottom of the angle steel to the top. The distance between the last lacing plate and the top of the column structure is adjustable. During welding, the number of weld joints of a single lattice column shall not exceed two. Bevel welding is used. The joints of the single angle steels shall be staggered. The lattice column is positioned, the positioning point is determined, and it is hoisted and installed. After the lattice column is placed, it is reinforced and connected with steel sections and welded to the steel cage. Concrete is poured for fixation. S2. Construction of the steel casing installation end: The two installation ends of the steel cross brace servo axial force system end structure are connected to the outer side of the gusset plate in the middle section of the adjacent lattice column by welding. Bevel welding is used. The installation end is symmetrically welded with four right-angle supports on the lattice column to ensure the stability of the connection between the installation end and the lattice column. The two installation ends of the steel cross brace servo axial force system end structure at the outer edge of the foundation pit can be connected to the lattice column and the foundation pit retaining structure respectively. S3. Construction of plug-in steel cross brace: The two ends of the plug-in steel cross brace are respectively connected to the interface end of the steel sleeve box and set horizontally on the same axis. The plug-in steel cross brace can be freely inserted into the interface end, and a layer of lubricating oil is applied to the interface section. A pressure plate is installed inside the plug-in steel cross brace. S4. Deformation monitoring sensor installation: The deformation monitoring sensor is installed on the inside of the gusset plate in the middle section of the lattice column to monitor the deformation of the lattice column in real time and transmit the monitoring data to the monitoring system. S5. Control and Monitoring System Connection: The monitoring system connects to external deformation monitoring sensors and hydraulic jacks via communication lines. The deformation monitoring sensors can monitor the stress and deformation of the lattice column in real time. The monitoring system can process, analyze, and record the deformation data of the lattice column in real time, and send command signals to the hydraulic jacks to accurately control the bending deformation of the lattice column in real time. When the lattice column bends under the pressure of horizontal support or working platform in the deep foundation pit, the deformation monitoring sensors transmit the data to the monitoring system. After analyzing and processing the data, the monitoring system controls the hydraulic jacks to apply axial jacking force to ensure the stress safety of the lattice column. S6. Applying prestress with hydraulic jacks: After the steel cross brace servo axial force system is installed, hydraulic jacks apply a certain amount of prestress to prevent the lattice column from bending and deforming.

2. The construction method of the steel cross bracing axial force system for controlling the deformation of the lattice column in the foundation pit according to claim 1, characterized in that, The lattice column is formed by arranging four angle steels in a biaxially symmetrical manner to form a columnar structure with a rectangular cross-section. Multiple gusset plates are welded parallel to each other at equal distances from the bottom to the top of the angle steels to form the lattice column. The distance between the last gusset plate at the top and the top of the columnar structure is adjustable.

3. The construction method of the steel cross bracing axial force system for controlling the deformation of the lattice column in the foundation pit according to claim 1, characterized in that, The contact area between the gusset plate and the angle steel on the lattice column is greater than half the area of ​​the gusset plate.

4. The construction method of the steel cross bracing axial force system for controlling the deformation of the lattice column in the foundation pit according to claim 2, characterized in that, The steel casing includes an installation end and an interface end. The installation end is located in the middle section of the lattice column and is connected to the outer wall of the upper gusset plate of the lattice column by welding. The interface end is used to connect to the plug-in steel cross brace.

5. The construction method of the steel cross bracing axial force system for controlling the deformation of the lattice column in the foundation pit according to claim 4, characterized in that, Four sets of right-angle supports are symmetrically welded on the installation end. The four sets of right-angle supports are welded to the outer wall of the lattice column gusset plate to ensure the stability of the connection between the installation end and the lattice column.

6. The construction method of the steel cross bracing axial force system for controlling the deformation of the lattice column in the foundation pit according to claim 5, characterized in that, The welding method used is bevel welding.

7. The construction method of the steel cross bracing axial force system for controlling the deformation of the lattice column in the foundation pit according to claim 4, characterized in that, Both the inner wall of the interface end and the outer wall of the plug-in steel cross brace are coated with a layer of lubricating oil to ensure a smooth connection between them.

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