Prestress applying device suitable for foundation pit inner support

Abstract

The invention relates to a prestress applying device suitable for supporting in a foundation pit. An adapter device comprises a pair of small lug plates fixed to a jack ejector rod and a large lug plate hinged to the pair of small lug plates through pin shaft nuts. The fixing plate is provided with prefabricated holes allowing enclosure beam embedded steel bars to be inserted therein and countersunk pull holes distributed in the face, close to a crown beam, of the fixing plate. A plurality of round holes for the slideable bolts to penetrate through are formed in the sliding base plate; a slidable bolt sequentially penetrates through the countersunk pull notch hole and the round hole and is fastened and connected through a first nut, so that the sliding base plate is attached to the fixed plate; the enclosure beam embedded steel bars penetrate through prefabricated holes in the fixing plates and are fixedly connected through second nuts. When the ejection degrees of a plurality of jacks in the jack system are different, the small lug plate and the large lug plate rotate through the pin shaft nut, and meanwhile, the slidable bolt can slide along the countersunk pull notch hole so as to achieve self-adaptive adjustment.

Description

Technical Field

[0001] The invention relates to a prestressing device suitable for supporting in a foundation pit, which can be suitable for both steel support and concrete support and is used in underground foundation pit supporting projects, belonging to the technical field of building construction. Background Art

[0002] In existing deep foundation pit projects, concrete or steel supports are commonly used for support. Due to the influence of the material expansion coefficient, steel and concrete supports can cause significant deformation in large-span supports due to thermal expansion and contraction, significantly impacting foundation pit safety. Servo-hydraulic systems are commonly used in the industry to compensate for the axial forces of steel and concrete supports. Prestressing devices are installed at the ends of these supports to reduce the impact of temperature by applying prestress.

[0003] For steel supports or concrete supports, there are two types of support structures: bracing and angle bracing. For the bracing form, conventional servo prestressed joints are relatively easy to install and adapt, while the diagonal bracing form has poor compatibility. When the steel support structure is used as an angle brace, concrete corbels are made at the crown beam and waist beam, and the corbel nodes are reinforced with reinforcement; when concrete support is used as an angle brace, there are currently no prestressed nodes on the market that cannot be directly installed at the end of the concrete support. The inner side of the grooved concrete purlin is rigidly connected to the concrete support, and the outer side of the grooved concrete purlin faces the foundation pit retaining wall. There are multiple grooves on the outer side of the grooved concrete purlin along the circumferential direction. The hydraulic jack is set in the groove, and the two ends are respectively against the foundation pit retaining wall and the grooved concrete purlin.

[0004] Both of the above-mentioned methods of applying prestressing require the production of a large amount of reinforced concrete, which has a great impact on the project cost. The subsequent demolition will generate a lot of construction material waste, and the excessive reinforcement is not conducive to cutting and disassembly. In addition, the jacks of the prestressed nodes are often in the form of ball joints. The eccentric load angle of the ball joint cannot generally exceed 2°, the eccentric load capacity is weak, and there are great limitations. Summary of the Invention

[0005] The purpose of the present invention is to provide a prestressing device suitable for support in foundation pits, so as to solve the problems of poor compatibility of foundation pit angle braces, the problem of generating a large amount of construction waste when the foundation pit angle braces are removed in the later stage, and the problem of small allowable eccentric load angle and large limitations caused by the use of spherical joints at prestressed nodes.

[0006] The present invention adopts the following technical solutions: A prestressing device suitable for supporting in a foundation pit, comprising a component connector 1, a hydraulic jack system 2, and an adapter device 4. The component connector 1 has a plurality of jack mounting slots 103, one end of the jack mounting slot 103 is closed and the other end is open, and the open end is used for the jack push rod to extend; the hydraulic jack system 2 includes a plurality of jacks placed in the jack mounting slots 103; the adapter device 4 includes: a pair of small ear plates 407 fixed on the jack push rod, a large ear plate 406 hinged to the pair of small ear plates 407 through a pin nut 405, a sliding pad 402 fixedly connected to the large ear plate 406, a fixed plate 408, a plurality of guard beam embedded in the concrete crown beam and extending vertically outward, and a plurality of slidable bolts 401; a fixed plate 408 is provided : The prefabricated holes for inserting the reinforcement bars of the guard beam are distributedly arranged on the countersunk holes on the side of the fixed plate 408 near the crown beam; the sliding pad 402 is provided with a number of circular holes for the sliding bolts 401 to pass through; the sliding bolts 401 pass through the countersunk holes and the circular holes in turn, and are fastened together by the first nut 404, so that the sliding pad 402 and the fixed plate 408 fit together; the guard beam reinforcement bars 409 pass through the prefabricated holes on the fixed plate 408 and are fixed together by the second nut 410, so that the fixed plate 408 is fit and fixed on the guard beam 3; when the ejection degrees of multiple jacks in the jack system 2 are different, the small ear plate 407 and the large ear plate 406 rotate through the pin nut 405, and the sliding bolt 401 can slide along the countersunk holes for adaptive adjustment.

[0007] This technical solution adopts a sliding pad and a fixed plate that cooperate with each other to connect with the embedded and partially extended guard beam reinforcement on the crown beam. The guard beam reinforcement needs to have its own thread and is directly fixed to the fixed plate through the second nut 410, so as to accurately locate and fix the position of the jack; by arranging a countersunk hole 408a on the fixed plate to cooperate with the sliding bolt 401 on the sliding pad, the lateral sliding of the sliding pad relative to the fixed plate is realized, thereby improving the adaptability; the hinged connection method of the large ear plate and a pair of small ear plates, on the one hand, has a larger adjustable range than the ball head hinge (the ball head hinge generally has an adjustment range of only 2°), and on the other hand, the rotation fine adjustment can be locked in the horizontal reverse direction and matched with the lateral sliding of the sliding pad.

[0008] Preferably, the countersunk hole is a stepped hole in the form of a horizontal waist-shaped hole.

[0009] Preferably, the jack mounting slot 103 of the component connector 1 is fixedly connected to the support pad 107, and the support pad 107 is fixedly connected to the main support anchor bar 106 with its own thread and the pre-buried bolt hole adapter plate 105 through the third nut 102; the main support anchor bar 106 is fixed to the steel support bolt, or is fixed to the steel support bolt and then cast in concrete. The "main support" in the "main support anchor bar 106" refers to the horizontal steel support or concrete support in the foundation pit, which can be a "straight support" perpendicular to the guardrail beam or a "diagonal support" inclined to the guardrail beam.

[0010] Furthermore, a plurality of jack bolt holes 104 for fixing the jack are provided on the bottom surface of the jack mounting slot 103 .

[0011] Preferably, the large ear plate 406 and the small ear plate 407 are arranged horizontally, and the pin nut 405 is arranged vertically.

[0012] Preferably, the sliding pad 402 corresponds to a single jack one-to-one, and the fixed plate 408 is a whole piece, the area of ​​which is larger than the sum of the areas of the multiple sliding pads 402; the sliding pad 402 and the fixed plate 408 are both metal plates.

[0013] Preferably, the lifting amplitudes of a row of jacks in the hydraulic jack system 2 increase linearly and are centrally controlled by a control system.

[0014] Preferably, a group of four guard beam embedded bars 409 distributed in a rectangular shape extend from the guard beam 3 and correspond to the four corners of the fixing plate 408.

[0015] Preferably, the enclosure beam 3 is a crown beam or a waist beam.

[0016] Furthermore, the main support is a "diagonal support" that is horizontal and inclined to the guard beam.

[0017] The beneficial effects of the present invention are: 1) It is suitable for two different material structures: steel support and concrete, and is compatible with two support forms: bracing and angle bracing.

[0018] 2) The front pin and lugs (one large lug and one pair of small lugs) of the jack can rotate freely according to the load surface (the rotation range is much larger than that of the ball joint) to prevent unbalanced loading and cooperate with the lateral sliding of the sliding plate to protect the safe use of the hydraulic equipment.

[0019] 3) Reduce the need to make more concrete corbels or grooved concrete purlins in traditional practices, significantly reduce costs, reduce concrete cutting and energy consumption and pollution, and have a positive impact on environmental protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1It is a schematic diagram of the prestressing device for supporting in a foundation pit according to the present invention after being connected to the crown beam / waist beam.

[0021] Figure 2 It is a structural diagram of component connectors.

[0022] Figure 3 The figure is a structural diagram of a prestressing device for supporting in a foundation pit according to the present invention from one perspective. The figure mainly marks and illustrates the adapter device.

[0023] Figure 4 This is a schematic diagram of the prestressing device for supporting in a foundation pit according to the present invention from another perspective. The figure mainly marks and illustrates components such as a fixing plate and a sliding bolt.

[0024] Figure 5 It is a top view of the prestressing device for supporting in a foundation pit according to the present invention when it is working.

[0025] In the figure, 1. component connector, 2. hydraulic jack, 3. guard beam (crown beam or waist beam), 4. adapter device, 101. threaded section of main support anchor bar, 102. third nut, 103. jack mounting slot, 104. jack bolt hole, 105. embedded bolt hole adapter plate, 106. main support anchor bar, 107. support pad, 108. fixing bolt, 201. jack, 202. piston rod, 401. sliding bolt, 402. sliding pad, 403. pin, 404. first nut, 405. pin nut, 406. large ear plate, 407. small ear plate, 408. fixing plate, 409. guard beam anchor bar (crown beam anchor bar or waist beam anchor bar). DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0027] See also Figure 1 The prestressing device for supporting in foundation pit mainly consists of three parts: component connector 1, hydraulic jack system 2, and adapter device 4. The support beam 3 in the figure can be a concrete crown beam or a concrete waist beam.

[0028] See also Figure 2 The component connector 1 is mainly used to connect with the steel support or concrete support, and is composed of a support pad 107 and a jack mounting groove 103.

[0029] In one embodiment, when a steel support is used as the inner support structure, the support pad 107 and the steel support can be directly connected and fixed by bolts; this is not specifically shown in the drawings.

[0030] In another embodiment, when concrete supports are used as the internal support structure, the anchor bolts need to be welded to the steel bars before the concrete supports are poured, and a pre-buried bolt hole adapter plate is added to align the anchor bolt hole positions with the support pad hole positions, effectively reducing the installation difficulty. This is not specifically shown in the accompanying drawings.

[0031] See also Figure 1 The hydraulic jack system 2 is the main power source of the prestressed joint and consists of three large-stroke jacks. The jacks are placed in the mounting grooves of the component connectors and fixed to the jack side walls with bolts. Two small ear plates 407 are welded to the piston rods of the large-stroke hydraulic jacks and connected to the adapter device using pin nuts 405, such as Figure 3 shown.

[0032] See also Figure 3 One side of the adapter device 4 is in contact with the crown (waist) beam, and the other side is connected to the jack piston rod pin.

[0033] See also Figure 4 The adapter device 4 mainly includes a fixed plate 408, a sliding pad 402 and a large ear plate 406.

[0034] Continue to see Figure 4 The fixing plate 408 is provided with a countersunk hole 408a. The countersunk hole 408a adopts a countersunk method to hide the sliding bolt 401 from hitting the crown waist beam. The countersunk hole 408a also adopts a sliding groove hole to facilitate the bolt to slide along with the rotation of the large ear plate 406. See also Figure 4 When tying the steel bars of the crown and waist beam, the embedded reinforcement 409 of the guard beam is pre-buried, and the exposed end of the embedded reinforcement adopts a threaded section to facilitate the connection of the fixing plate 408a and the guard beam (crown and waist beam) with bolts.

[0035] See also Figure 3 The sliding pad 402 is welded to the large ear plate 406 and connected to the fixed plate 408 via a sliding bolt 401 (combined with Figure 1 and Figure 4 ).

[0036] See also Figure 5 According to the different angles between the crown / waist beam and the support, the three hydraulic jack piston rods are lifted to different lengths respectively, which can flexibly adapt to the angle. The two ear plates on the hydraulic jack system are connected to the large ear plate 406 on the adapter device through a pin shaft, which can achieve a large angle rotation of -45° to 45°, solving the problem of eccentric load caused by the uneven contact surface between the jack and the jack.

[0037] In this embodiment, the sliding pad and the fixed plate cooperate with each other to connect with the embedded and partially extended guard beam reinforcement on the crown beam. The guard beam reinforcement needs to have its own thread and is directly fixed to the fixed plate through the second nut 410, so as to accurately locate and fix the position of the jack; the lateral sliding of the sliding pad relative to the fixed plate is achieved by providing a countersunk hole 408a on the fixed plate in conjunction with the sliding bolt 401 on the sliding pad, thereby improving the adaptability; the hinged connection method of the large ear plate and a pair of small ear plates, on the one hand, has a larger adjustable range than the ball head hinge (the ball head hinge generally has an adjustment range of only 2°), and on the other hand, the rotation fine adjustment can be locked in the horizontal reverse direction and matched with the lateral sliding of the sliding pad.

[0038] It should be noted that, see Figure 4 The countersunk hole is a stepped hole in the form of a horizontal waist-shaped hole, and the stepped structure inside the hole is not directly shown in the figure.

[0039] In this embodiment, see Figure 2 The jack mounting slot 103 of the component connector 1 is fixedly connected to a support block 107. The support block 107 is fixedly connected to a threaded main support anchor bar 106 and a pre-buried bolt hole adapter plate 105 via a third nut 102. The main support anchor bar 106 is fixed to the steel support bolts, or is fixed to the steel support bolts and then cast-in-place concrete support. The main support is a horizontal "diagonal brace" inclined to the enclosure beam, which is not shown in the attached figure.

[0040] Continue to see Figure 2 A plurality of jack bolt holes 104 for fixing the jack are provided on the bottom surface of the jack mounting groove 103 .

[0041] See also Figure 3 The large ear plate 406 and the small ear plate 407 are arranged horizontally, and the pin nut 405 is arranged vertically.

[0042] See also Figure 1 and Figure 5 The sliding pad 402 corresponds to a single jack one by one, and the fixed plate 408 is a whole piece, and its area is larger than the sum of the areas of multiple sliding pads 402; the sliding pad 402 and the fixed plate 408 are both metal plates.

[0043] See also Figure 5 The lifting amplitude of a row of jacks in the hydraulic jack system 2 increases linearly and is centrally controlled by the control system.

[0044] See also Figure 4 A group of four rectangularly distributed retaining beam reinforcement bars 409 extend from the retaining beam 3 , corresponding to the four corners of the fixing plate 408 .

[0045] The retaining beam 3 in this embodiment refers to the ring beam on the foundation pit retaining structure, which can be the crown beam located at the top first layer, or the waist beam of the lower layers.

[0046] In summary, the piston rod of the jack of the present invention is connected to the embedded fixing plate by an ear plate pin, which can realize a large angle rotation of -45° to 45°, is not limited to the structural form, and is flexibly adapted to the bracing structure and the angle bracing structure. It solves the problem that the eccentric load angle of the jack using the ball joint does not exceed 2°, and prevents the damage of the hydraulic equipment by eccentric load. According to the form of the supporting material, the reinforced concrete support adopts the form of embedded steel bars, and the steel support adopts the form of bolts, so that a set of equipment can be adapted to both the steel support and the concrete support at the same time, with strong compatibility and clearer force. It reduces the need to make more concrete corbels or grooved concrete purlins in traditional practices, significantly reduces costs, reduces concrete cutting and energy consumption and pollution, and has a positive impact on environmental protection. A countersunk hole (a combination of countersunk holes and countersunk holes) is provided above the fixing plate, which enables the sliding plate and the sliding bolt to be adjusted in position according to actual working conditions.

Claims

1. A prestressing device suitable for supporting in a foundation pit, characterized by: It includes a component connector (1), a hydraulic jack system (2), an adapter device (4), The component connector (1) has a plurality of jack mounting grooves (103), one end of the jack mounting groove (103) is closed and the other end is open, and the open end is used for the jack rod to extend; The hydraulic jack system (2) includes a plurality of jacks placed in the jack mounting slots (103); The adapter device (4) comprises: a pair of small ear plates (407) fixed on the jack rod, a large ear plate (406) hinged to the pair of small ear plates (407) via a pin nut (405), a sliding pad (402) fixedly connected to the large ear plate (406), a fixed plate (408), a plurality of retaining beam rebars pre-buried in the concrete retaining beam and extending vertically outward, and a plurality of slidable bolts (401); The fixing plate (408) is provided with: prefabricated holes for inserting the reinforcement bars of the enclosure beam, and countersunk holes distributed on one side of the fixing plate (408) near the crown beam; The sliding pad (402) is provided with a plurality of circular holes for the sliding bolts (401) to pass through; The slidable bolt (401) passes through the countersunk hole and the circular hole in sequence, and is fastened by a first nut (404) to fit the sliding pad (402) and the fixed plate (408); The retaining beam embedded reinforcement (409) passes through the prefabricated hole on the fixing plate (408) and is fixedly connected by a second nut (410), so that the fixing plate (408) is fixed on the retaining beam (3); When the ejection degrees of the multiple jacks in the jack system (2) are different, the small ear plate (407) and the large ear plate (406) rotate through the pin nut (405), and the sliding bolt (401) can slide along the countersunk hole to adjust adaptively.

2. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: The countersunk hole is a stepped hole in the form of a horizontal waist-shaped hole.

3. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: The jack mounting groove (103) of the component connector (1) is fixedly connected to the support pad (107), and the support pad (107) is fixedly connected to the main support anchor bar (106) with self-threaded thread and the pre-buried bolt hole adapter plate (105) through the third nut (102); The main support planting bars (106) are fixed to the steel support bolts, or are fixed to the steel support bolts and then cast in concrete for support.

4. The prestressing device for supporting in a foundation pit according to claim 2, characterized in that: A plurality of jack bolt holes (104) for fixing the jack are provided on the bottom surface of the jack mounting groove (103).

5. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: The large ear plate (406) and the small ear plate (407) are arranged horizontally, and the pin nut (405) is arranged vertically.

6. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: The sliding pad (402) corresponds to a single jack one by one, and the fixed plate (408) is a whole piece, the area of ​​which is larger than the total area of ​​the plurality of sliding pads (402); the sliding pad (402) and the fixed plate (408) are both metal plates.

7. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: The lifting amplitude of a row of jacks in the hydraulic jack system (2) increases linearly and is centrally controlled by a control system.

8. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: A group of four rectangularly distributed retaining beam reinforcement bars (409) extend from the retaining beam (3) and correspond to the four corners of the fixing plate (408).

9. The prestressing device for supporting in a foundation pit according to claim 1, characterized in that: The enclosure beam (3) is a crown beam or a waist beam.

10. The prestressing device for supporting in a foundation pit according to claim 3, characterized in that: The main support is a "diagonal brace" that is horizontal and inclined to the guard beam.

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