Active limiting device structure for foundation pit support replacement

Abstract

The utility model discloses an active limiting device structure for foundation pit support replacement. The structure comprises a limiting guide rod, a hydraulic jack, a fixed base plate, a support changing steel beam and a servo control system, wherein one end of the limiting guide rod is embedded in the side wall of the basement outer wall; the hydraulic jack sleeves one end of the limiting guide rod; a base of the hydraulic jack is fixedly connected with the side wall of the basement outer wall through a fixing base plate. The support changing steel beam is fixedly connected with the side wall of the enclosure wall body, the other end of the limiting guide rod penetrates through the support changing steel beam and then is fixedly installed in the side wall of the enclosure wall body, and an output shaft of the hydraulic jack makes contact with the support changing steel beam. And the servo control system is connected with the hydraulic jack. According to the structure, on the premise that the overall rigidity of the support changing structure is not changed, the capacity of actively controlling displacement of the enclosure structure is formed, and the construction risk in the support changing process is reduced; while the construction efficiency is improved, related parts can be repeatedly utilized, so that the construction cost is reduced, and the green construction level is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of foundation pit support replacement device in the technical field of foundation pit support replacement, specifically, a kind of foundation pit support replacement active limiting device structure. BACKGROUND

[0002] After deep foundation pit excavation is completed, the foundation pit enters the back construction phase, and the original support is gradually removed from bottom to top. To ensure the overall stability of the foundation pit and control the displacement and deformation of the retaining structure, the soil and water pressure on the retaining wall needs to be safely and orderly transferred to the basement structure through the support replacement structure. After the traditional support replacement structure is laid out, a "passive" force structure system is formed, which only serves as a transmission medium for force and displacement, and cannot actively control the deformation of the foundation pit retaining structure. The traditional support replacement structure usually uses concrete cast-in-place support replacement blocks and support replacement bars. When laying out, multiple construction processes such as steel bar binding, formwork erection, and maintenance need to be carried out in advance, and the main structure needs to be connected to ensure normal soil pressure transmission, which results in a long construction period. In addition, in areas with high requirements for foundation pit retaining deformation control, traditional support replacement structures need to be laid out densely, which limits the subsequent construction operation space of the basement exterior wall and affects the construction quality and efficiency of the main structure. SUMMARY

[0003] The utility model aims to solve the problems of traditional support replacement structures, such as passive displacement control of retaining structures, complex construction preparation steps, and long installation period. It proposes a foundation pit support replacement active limiting device structure, which effectively addresses the shortcomings of traditional support replacement structures and is suitable for foundation pit support replacement construction. The structure proposed by the utility model is composed of reinforced I-beams and hydraulic jacks. Without changing the overall stiffness of the support replacement structure, it forms the ability to actively control the displacement of the retaining structure and reduces the construction risk during the support replacement process. The structure can be prefabricated and assembled according to the design drawing size, improving construction efficiency and being reusable, which reduces construction costs, improves green construction level, and produces good economic and social benefits in practical construction.

[0004] To achieve the above technical purpose, the utility model adopts the following technical solutions:

[0005] The utility model discloses a limiting guide rod, one end of which is embedded in the side wall of the basement exterior wall. It also includes a hydraulic jack, which is sleeved at one end of the limiting guide rod. It also includes a fixed backing plate, which connects the base of the hydraulic jack and the side wall of the basement exterior wall. It also includes a support replacement steel beam, which is fixedly connected with the side wall of the retaining wall. The other end of the limiting guide rod passes through the support replacement steel beam and is fixedly installed in the side wall of the retaining wall. The output shaft of the hydraulic jack is in contact with the support replacement steel beam.

[0006] The supporting steel beam includes an I-beam, stiffening plates, and pressure pads; the first flange of the I-beam is fixedly connected to the side wall of the retaining wall, and a pressure pad is installed on the outer end face of the second flange of the I-beam. The output shaft of the hydraulic jack contacts the pressure pad, and one end of the limiting guide rod passes through the pressure pad, the second flange, and the first flange in sequence and is then placed inside the side wall of the retaining wall; multiple stiffening plates are installed at intervals on the web of the I-beam, and the stiffening plate near the limiting guide rod is connected to the limiting guide rod.

[0007] Stiffening plates are fixedly installed on the web of the I-beam. Each stiffening plate is arranged vertically, and its three sides are welded to the web, first flange, and second flange of the I-beam through weld seams.

[0008] The limiting guide rod includes a spring pin, an end plate, a slide rod, a piston limiting cylinder, limiting teeth, and an enlarged head. One end of the slide rod is fixedly connected to the end plate, and both the slide rod and the end plate are embedded in the end plate. A fixing pad and a hydraulic jack are provided on the outer sleeve of the slide rod. The piston limiting cylinder is embedded in the side wall of the retaining wall, and an enlarged head is placed inside the piston limiting cylinder. The other end of the slide rod passes through the replacement support steel beam and is connected to the enlarged head. Limiting teeth are arranged on the circumferential side of the slide rod inside the replacement support steel beam. The spring pin is fixedly installed inside the replacement support steel beam, and the elastic end of the spring pin is engaged between two limiting teeth. The spring pin is arranged facing the retaining wall.

[0009] The limiting tooth is an oblique tooth that tilts towards the side of the enclosure wall, and the angle between the axial direction of the spring bolt and the slide rod is set to an acute angle.

[0010] The limiting teeth are threaded teeth.

[0011] The spring pins are provided in multiple quantities.

[0012] The enlarged head is cylindrical in shape.

[0013] The structure of the active limit device for foundation pit support replacement also includes a servo control system, which is connected to the hydraulic jack.

[0014] The installation gaps between the I-beams and the enclosure wall are filled with plain concrete.

[0015] Pre-embedded bolts are installed inside the side walls of both the enclosure wall and the basement exterior wall.

[0016] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects:

[0017] (1) The active limiting device for foundation pit support replacement applies the jacking force through the servo system, which can actively control the displacement and deformation of the retaining structure into the pit in real time during the support replacement stage, so that the retaining structure can achieve "micro-deformation" control during the support replacement stage.

[0018] (2) By setting up an active limit device for the foundation pit support replacement, the number of support replacement nodes can be reduced, improving safety while reducing the use of materials, increasing the space for subsequent construction operations, and improving the overall efficiency of construction work.

[0019] (3) The active limiting device structure for foundation pit support replacement adopts a factory prefabrication and on-site assembly / installation method, which effectively improves the construction accuracy. Compared with the traditional concrete support replacement method, which requires waiting for the concrete strength to reach 100% before the support can be removed, this method effectively improves the construction efficiency.

[0020] (4) Hydraulic jacks can be dismantled and reused after construction, saving materials and reducing construction costs.

[0021] (5) The stress of each support node can be monitored in real time through the servo control system, which can improve construction safety and the reliability of the retaining structure. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the active limiting device for foundation pit support replacement;

[0023] Figure 2 This is a schematic diagram of the central section of the active limiting device for foundation pit support replacement;

[0024] Figure 3 This is a top view of the active limit device structure for foundation pit support replacement;

[0025] Figure 4 This is a detailed diagram of the contact between the spring pin and the limiting tooth;

[0026] Figure 5 This is a detailed drawing of the limit guide rod.

[0027] In the diagram: 1. Replacement support steel beam, 1-1. I-beam, 1-2. Stiffening plate, 1-3. Pressure pad, 1-4. Spring bolt, 2. Limiting guide rod, 2-1. End plate, 2-2. Sliding rod, 2-3. Piston limiting cylinder, 2-4. Limiting tooth, 2-5. Cylindrical enlarged head, 3. Fixing pad, 4. Hydraulic jack, 5. Embedded bolt, 6. Servo control system, 6-1. Servo host, 6-2. Connecting cable, 7. Enclosure wall, 8. Basement exterior wall, 9. Floor structure. Detailed Implementation

[0028] To further understand the content of this utility model, the present utility model will be described in detail with reference to the embodiments. The following embodiments are for the purpose of explaining the present utility model and are not limited to the following embodiments.

[0029] like Figure 1 , Figure 2 and Figure 3As shown, the structure of the active limiting device for foundation pit support replacement proposed in this utility model includes a limiting guide rod 2, a hydraulic jack 4, a fixing plate 3, a support replacement steel beam 1, and a servo control system 6. One end of the limiting guide rod 2 is embedded in the side wall of the basement exterior wall 8; the hydraulic jack 4 is sleeved on one end of the limiting guide rod 2; the base of the hydraulic jack 4 is fixedly connected to the side wall of the basement exterior wall 8 at the floor slab structure 9 through the fixing plate 3. The fixing plate 3 is circular and has four bolt holes in a cross-shaped symmetrical direction. It is fixed to the basement exterior wall together with the hydraulic jack 4 by pre-embedded bolts 5. The bottom of the hydraulic jack 4 has four bolt holes in a cross-shaped symmetrical direction, and the bolt hole positions are consistent with the bolt holes on the fixing plate 3; the support replacement steel beam 1 is fixedly connected to the side wall of the retaining wall 7, and the other end of the limiting guide rod 2 passes through the support replacement steel beam 1 and is fixedly installed in the side wall of the retaining wall 7. The output shaft of the hydraulic jack 4 is in contact with the support replacement steel beam 1. The servo control system 6 is connected to the hydraulic jack 4. The servo control system 6 includes a servo host 6-1 and a connecting cable 6-2. The hydraulic jack 4 is connected to the servo host 6-1 via the connecting cable 6-2 and is used to control the operation of the hydraulic jack 4.

[0030] The supporting steel beam 1 includes an I-beam 1-1, stiffening plates 1-2, and pressure pads 1-3. The first flange of the I-beam 1-1 is fixedly connected to the side wall of the retaining wall 7 by pre-embedded bolts 5. The installation gap between the I-beam 1-1 and the retaining wall needs to be filled with plain concrete. A pressure pad 1-3 is fixedly installed on the outer end face of the second flange of the I-beam 1-1. The output shaft of the hydraulic jack 4 contacts the pressure pad 1-3. One end of the limiting guide rod 2 passes through the pressure pad 1-3, the second flange, and the first flange in sequence and is then placed inside the side wall of the retaining wall 7. Multiple stiffening plates 1-2 are installed at intervals on the web of the I-beam 1-1. The stiffening plates 1-2 near the limiting guide rod 2 are connected to the limiting guide rod 2. That is, the spring pins 1-4 are welded to the inner side of the two middle stiffening plates 1-2 and contact the limiting teeth 2-4. The length of the I-beam should be controlled between 2.5 and 3 meters, with the specific length determined based on the side length of the foundation pit. The coverage rate of each supporting steel beam on each side of the foundation pit should not exceed 50%. The spacing between the stiffening plates at both ends of the I-beam should be controlled between 0.35 and 0.45 meters, and the spacing between the two middle stiffening plates should be controlled between 0.75 and 0.85 meters, ensuring that the two middle stiffening plates do not contact the limiting guide rods. The length and width of the pressure pad should be 0.5 to 0.6 times the length and width of the I-beam flange. The pressure pad should be fully welded to the center area of ​​the outer side of the I-beam flange, ensuring that the pressure pad is tightly attached to the outer side of the I-beam flange without warping or loosening.

[0031] Stiffening plates 1-2 are fixedly installed on the web of the I-beam 1-1. Each stiffening plate 1-2 is arranged vertically, and the three sides of the stiffening plate 1-2 are welded to the web, the first flange and the second flange of the I-beam 1-1 through welds.

[0032] like Figure 4 and Figure 5 As shown, the limiting guide rod is positioned and installed during the pouring of the main structure. The limiting guide rod 2 includes a spring pin 1-4, an end plate 2-1, a sliding rod 2-2, a piston limiting cylinder 2-3, limiting teeth 2-4, and an enlarged head 2-5. One end of the sliding rod 2-2 is fixedly connected to the end plate 2-1, and both the sliding rod 2-2 and the end plate 2-1 are embedded in the end plate 2-1. A fixing pad 3 and a hydraulic jack 4 are fitted over the sliding rod 2-2. The piston limiting cylinder 2-3 is embedded in the side wall of the retaining wall 7. The piston limiting cylinder 2-3 is made of iron or steel and is welded and fixed to the reinforcing steel bars inside the retaining wall. The central axis of the piston limiting cylinder 2-3 is aligned with the central axis of the limiting guide rod. The spacing between the limiting teeth 2-4 is 0.5 mm. An enlarged head 2-5 is placed inside the piston limiting cylinder 2-3. The enlarged head 2-5 is cylindrical in shape, and its outer diameter is the same as the inner diameter of the piston limiting cylinder 2-3. The other end of the slide rod 2-2 passes through the pressure pad 1-3, the second flange and the first flange of the replacement support steel beam 1 in sequence and is connected to the enlarged head 2-5. The I-beam 1-1 and the pressure pad 1-3 can slide freely on the limiting guide rod 2. The limiting guide rod 2 is positioned and installed during the construction and pouring of the main structure. The circumferential side of the slide rod 2-2 in the replacement support steel beam 1 is provided with limiting teeth 2-4 (that is, the limiting teeth 2-4 are located between the upper and lower flanges of the I-beam 1-1). The limiting teeth 2-4 and the slide rod 2-2 are integrally forged. Multiple spring pins 1-4 are fixedly installed in the internal stiffening plate 1-2 of the replacement support steel beam 1. The elastic end of the spring pin 1-4 is locked between two limiting teeth 2-4. The spring pins 1-4 are arranged facing the enclosure wall 7. Among them, the limiting tooth 2-4 is a threaded tooth, which is an oblique tooth inclined towards the side of the enclosure wall 7, and the angle between the axial direction of the spring bolt 1-4 and the slide rod 2-2 is set to an acute angle.

[0033] The foundation pit of a certain project has dimensions of 30m×25m and a depth of 15m. It is equipped with two support structures and adopts an active limit device structure for the foundation pit support.

[0034] Combined with appendix Figure 1 and attached Figure 2This utility model relates to an active limiting device structure for foundation pit support replacement, which includes a support steel beam 1, a limiting guide rod 2, a fixing pad 3, a hydraulic jack 4, pre-embedded bolts 5, and a servo control system 6. The support steel beam 1 includes an I-beam 1-1, a stiffening plate 1-2, a pressure pad 1-3, and a spring pin 1-4. The I-beam 1-1 is fixed to the retaining wall by the pre-embedded bolts 5. The I-beam 1-1 is made of 28#B steel, and the pre-embedded bolts 5 are of M20, M22 or higher specifications, with a bolt length of 100mm, and are tightened with nuts. Stiffening plates 1-2 are welded to both sides and ends of the I-beam 1-1. Pressure pads 1-3 are welded to the outer flanges of the I-beam 1-1. Spring pins 1-4 are welded to the inner sides of the two middle stiffening plates 1-2 and contact the limiting teeth 2-4. The limiting guide rod 2 includes an end plate 2-1, a sliding rod 2-2, a piston limiting cylinder 2-3, and limiting teeth 2-4. One end of the sliding rod 2-2 is welded to the center of the end plate 2-1, and the other end is connected to the piston limiting cylinder 2-3 via a cylindrical enlarged head 2-5 (the outer diameter of the cylindrical enlarged head 2-5 is the same as the inner diameter of the piston limiting cylinder 2-3). The limiting teeth 2-4 are located in the middle of the sliding rod 2-2 (limiting...). Positioning teeth 2-4 are located between the upper and lower flanges of the I-beam 1-1 and are integrally forged with the sliding rod 2-2. The limiting guide rod 2 passes through the upper and lower flanges of the I-beam 1-1 and the pressure pad 1-3, and the I-beam 1-1 and the pressure pad 1-3 can slide freely on the limiting guide rod 2. The limiting guide rod 2 is positioned during the main structure construction pouring. The fixing pad 3 is circular, with four bolt holes in a cross-symmetrical direction. It is fixed to the basement exterior wall together with the hydraulic jack 4 using pre-embedded bolts 5. The bottom of the hydraulic jack 4 has four bolt holes in a cross-symmetrical direction, and the bolt hole positions are consistent with the bolt holes on the fixing pad 3. The servo control system 6 controls the displacement and jacking force of the hydraulic jack 4 in real time and displays the force at each support point in real time. The hydraulic jack 4 can be removed and reused after construction.

[0035] Combined with appendix Figure 1 and attached Figure 3 The length of I-beam 1-1 is 3.5m. The installation gap between I-beam 1-1 and the retaining wall needs to be filled with plain concrete. The distribution spacing of stiffening plates 1-2 at both ends of I-beam 1-1 should be controlled at 0.35m, and the spacing between the two middle stiffening plates 1-2 should be 0.85m, ensuring that the two middle stiffening plates 1-2 do not contact the limiting guide rod 2. The length and width of the pressure pad are 1.75m × 0.14m. The pressure pad 1-3 should be fully welded to the center area of ​​the outer flange of I-beam 1-1, ensuring that the pressure pad 1-3 is tightly attached to the outer flange of I-beam 1-1 without warping or loosening.

[0036] Combined with appendix Figure 1 and attached Figure 4The spring pins 1-4 should ensure that the pin heads are tightly engaged with the limiting teeth 2-4 and are in a compressed state. Two spring pins 1-4 are arranged on each side, one above the other. When the supporting steel beam 1 moves outward from the pit, the spring pins 1-4 disengage from the current limiting tooth 2-4 and move to the next limiting tooth 2-4; when the supporting steel beam 1 moves inward from the pit, the spring pins 1-4 press against the limiting teeth 2-4 to restrict the movement of the supporting steel beam 1, forming a "one-way" limiting device.

[0037] Combined with appendix Figure 1 and attached Figure 5 The piston limiting cylinder 2-3 is made of iron or steel. It is welded and fixed to the reinforcing steel bars inside the retaining wall. The central axis of the piston limiting cylinder 2-3 is aligned with the central axis of the limiting guide rod. The spacing between the limiting teeth 2-4 is 0.5mm.

[0038] The present invention has been described in detail above with reference to the embodiments. However, the description is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made in accordance with the claims of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A foundation pit bracing active limiting device structure, characterized in that, The utility model provides a basement outer wall supporting device, including limit guide rod (2), one end of limit guide rod (2) is buried in the lateral wall of basement outer wall (8);Still including hydraulic jack (4), the hydraulic jack (4) is sleeved in one end of limit guide rod (2);Still including fixed backing plate (3), the base of hydraulic jack (4) is fixedly connected with the lateral wall of basement outer wall (8) through fixed backing plate (3);Still including support steel beam (1), support steel beam (1) is fixedly connected with the lateral wall of retaining wall (7), the other end of limit guide rod (2) is fixedly installed in the lateral wall of retaining wall (7) after passing through support steel beam (1), and the output shaft of hydraulic jack (4) is in contact with support steel beam (1).

2. The foundation pit bracing active limiting device structure according to claim 1, characterized in that, The support steel beam (1) includes I-steel (1-1), stiffened plate (1-2), pressurizing backing plate (1-3);The first flange of I-steel (1-1) is fixedly connected with the lateral wall of retaining wall (7), the outer end surface of the second flange of I-steel (1-1) is provided with pressurizing backing plate (1-3), the output shaft of hydraulic jack (4) is in contact with pressurizing backing plate (1-3), and the one end of limit guide rod (2) is sequentially arranged in the lateral wall of retaining wall (7) after passing through pressurizing backing plate (1-3), the second flange and the first flange;A plurality of stiffened plates (1-2) are sequentially and spacedly arranged at the web of I-steel (1-1), and the stiffened plate (1-2) near limit guide rod (2) is connected with limit guide rod (2).

3. The foundation pit bracing active limiting device structure according to claim 2, characterized in that, The web of I-steel (1-1) is fixedly provided with stiffened plate (1-2), each stiffened plate (1-2) is vertically arranged, and the three side surfaces of stiffened plate (1-2) are welded to the web, the first flange and the second flange of I-steel (1-1) by welds.

4. The foundation pit bracing active limiting device structure according to claim 1, characterized in that, The limit guide rod (2) includes spring pin (1-4), end plate (2-1), slide rod (2-2), piston limiting cylinder (2-3), limit tooth (2-4) and enlarged head (2-5);One end of slide rod (2-2) is fixedly connected with end plate (2-1), and one end of slide rod (2-2) and end plate (2-1) are both buried in end plate (2-1), slide rod (2-2) is provided with fixed backing plate (3) and hydraulic jack (4) in a sleeved mode, piston limiting cylinder (2-3) is buried in the lateral wall of retaining wall (7), piston limiting cylinder (2-3) is provided with enlarged head (2-5) in a placed mode, and the other end of slide rod (2-2) is connected with enlarged head (2-5) after passing through support steel beam (1);The circumferential side surface of slide rod (2-2) in support steel beam (1) is provided with limit tooth (2-4), spring pin (1-4) is fixedly installed in support steel beam (1), the elastic end of spring pin (1-4) is clamped between two limit teeth (2-4), and spring pin (1-4) is arranged towards retaining wall (7).

5. The foundation pit bracing active limiting device structure according to claim 4, characterized in that, The limit tooth (2-4) is an inclined tooth inclined to one side of retaining wall (7), and the included angle between the axial direction of spring pin (1-4) and slide rod (2-2) is an acute angle.

6. The foundation pit bracing active limiting device structure according to claim 4, characterized in that, The limit tooth (2-4) is a threaded tooth.

7. The foundation pit bracing active limiting device structure according to claim 4, characterized in that, The spring pin (1-4) is provided with a plurality of spring pins.

8. The foundation pit bracing active limiting device structure according to claim 4, characterized in that, The shape of the enlarged head (2-5) is cylindrical.

9. The foundation pit bracing active limiting device structure according to claim 1, characterized in that, The foundation pit bracing active limiting device structure further comprises a servo control system (6) connected with the hydraulic jack (4).

10. The foundation pit bracing active limiting device structure according to claim 2, characterized in that, The mounting gap between the I-shaped steel (1-1) and the enclosure wall (7) is filled with plain concrete.

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