Movable end for supporting steel supporting structure in foundation pit

Abstract

The utility model provides a movable end for supporting a steel supporting structure in a foundation pit. The movable end comprises an end plate, a lifting hook, a steel wedge, an adjusting bolt, a sleeve, a jack, a base plate, an outer box body, a stiffening rib, a flange plate, an anti-falling hook, straight teeth and a gear. Supporting axial force is transmitted through the center jack, an insertion type steel wedge is changed into front end two-face insertion, and the problems that due to the fact that the reserved width of a traditional single-compartment type adjustable end cannot be perfectly matched with a wedge block, and the structure is rough and rusted, eccentric stress is caused are solved. The side wall part of a traditional double-compartment type structure is optimized, so that damage caused by yielding of the end part and the side wall under the condition of high-pressure load is avoided; corresponding straight teeth and gears are arranged between the outer box body and the sleeve, so that the whole structure is convenient to assemble and disassemble, and the frictional resistance between the inner wall and the outer wall is reduced when displacement is generated due to axial load change; the supporting performance of the supporting structure can be conveniently adjusted by adjusting the positions of the primary and secondary wedges through the adjusting bolts at the upper and lower ends.

Description

Technical Field

[0001] The utility model relates to the technical field of foundation pit steel supports, in particular to a flexible end head used for supporting a steel support structure in a foundation pit. Background Art

[0002] With the increasing development of urban rail transit construction, there is a boom in the construction of underground space in major urban areas in my country. With the increasingly dense laying of various underground networks and underground pipelines, it is a test for the control of various indicators of the new foundation pit projects around these existing facilities. The requirements for deformation control and support effectiveness of these foundation pits have also risen. In various foundation pit excavation projects, the internal support retaining structure is an effective solution. Its support form includes external retaining structure and internal support structure. The most common materials are reinforced concrete support structure and steel support structure. Due to the fast construction speed, good support effect, stable quality and easy inspection and control, it is widely used.

[0003] As a component widely used in foundation pit retaining system, steel support structure has strong lateral deformation resistance, can effectively control the lateral deformation of the retaining structure as a whole, and at the same time has the advantages of small weight, high strength, easy installation and disassembly, and reusability. The overall steel support structure includes steel straight pipes, diagonal angle braces, triangular brackets, fixed ends and flexible ends. Since the length of the steel straight pipe is fixed but the size of the foundation pit is irregular, when the distance between the steel straight pipe and the purlin is not enough to install a steel straight pipe, a flexible end is required for adaptive compensation. At this time, the flexible end needs to bear great force and bending moment. Traditional steel wedge-type flexible ends are divided into single-chamber and double-chamber types. Among them, the end of the movable end box of the double-chamber flexible end is prone to end yielding and side wall yielding when subjected to excessive pressure, resulting in the destruction of the structure and loss of bearing capacity.

[0004] At present, the current research status in China is as follows:

[0005] (1) The Chinese patent authorization announcement is CN 216920377 U, the announcement date is 2022.07.08, and the utility model name is "A flexible end cap for supporting the side walls of large foundation pits". The patent discloses a flexible end cap for supporting the side walls of large foundation pits; however, the structure is a traditional single-chamber flexible end cap, which is easily damaged when subjected to huge pressure. The damage form is manifested as compressive yielding of the steel wedges inside the structure and the ribs of the radial structure.

[0006] (2) The article “Mechanical Properties and Improvement Measures of Steel Support Flexible Ends in Subway Foundation Pit Engineering” in Journal of Beijing Jiaotong University (2019, Vol. 43, No. 3) points out that when traditional double-box flexible ends are damaged, their damage state is mostly manifested as end yielding and side wall buckling of the movable end box.

[0007] (3) Shanxi Architecture (2023, Vol. 49, No. 11) pointed out in the article "Field Verification of the Foundation Pit Support Effect of the New Flexible End Steel Support" that after the prestress is applied to the traditional steel support end, the socket-type wedge block fills the gap and transmits the support axial force. However, due to the fact that the reserved width and the wedge block cannot perfectly fit and the structure itself is rough and corroded, the resulting stress is equivalent to eccentric stress. After the jack oil pressure is removed, the steel wedge block is difficult to effectively maintain the pre-applied support axial force, and the axial force loss is large. When the loss is serious, it cannot even meet the design requirements of the effective axial force of the steel support.

[0008] (4) Chinese patent authorization announcement CN 111305222 A, announcement date 2020.06.19, invention name "A foundation pit balance support device", the invention discloses a foundation pit support balance device, in which the lower part of the steel support push-pull rod structure has a structure that can achieve free displacement through the meshing and rolling of spur teeth and gears. However, this structure can only move and adjust the structure between the steel support and the steel purlin when the axial force is generated, and cannot well ensure the stability of the overall structure, especially when there is no stable anti-loosening structure under tension. Utility Model Content

[0009] The purpose of the utility model is to provide an active end for supporting a steel supporting structure in a foundation pit, which transmits the supporting axial force through a central jack and changes the inserted steel wedge to be inserted on both sides of the front end, thereby solving the problem that the reserved width of the traditional single-chamber active end cannot perfectly fit the wedge block, and the rough and rusted structure itself causes eccentric force; by optimizing the side wall part of the traditional double-chamber structure, the damage caused by the yielding of the end and the side wall when subjected to high-pressure load is avoided; by arranging corresponding spur teeth and gears between the outer box body and the sleeve, the loading and unloading of the overall structure is convenient, and the friction resistance between the inner and outer walls when it is displaced due to changes in axial load is reduced; by adjusting the position of the mother-and-child wedge by adjusting bolts at the upper and lower ends, the supporting performance of the supporting structure can be conveniently adjusted; at the same time, the yield load and stiffness of the mother-and-child wedge are higher than those of the single-sided wedge, and are more suitable for use in high-strength foundation pit projects to solve the problems raised in the above-mentioned background technology.

[0010] In order to achieve the purpose of this utility model, the technical solution adopted is:

[0011] A flexible end for supporting a steel supporting structure in a foundation pit comprises an end plate, a hook, a steel wedge, an adjusting bolt, a sleeve, a jack, a pad, an outer box, a stiffening rib, a flange plate, an anti-falling hook, a spur gear and a gear; the end plate is connected to the steel purlin on the surrounding underground retaining piles, the sleeve is welded to the end plate as a whole, a steel wedge is wedged between the outer box and the sleeve, a hook and an adjusting bolt are arranged on the outer wall of the sleeve, the adjusting bolt passes through the sleeve and is connected with the steel wedge; a jack is arranged inside the outer box, a pad is arranged inside the outer box at the rear end of the jack, the pad supports and connects the jack, a stiffening rib is arranged at the rear of the outer box, and is fixedly connected to the flange plate by bolts; gears are symmetrically arranged on the outer side of the front end of the outer box, a hook is arranged on the outer side of the front end of the rear end, an anti-falling hook is arranged on the side where the front and rear ends of the outer box are connected and located at the hook, and spur teeth are arranged on the inner wall of the sleeve where the sleeve and the outer box are sleeved and connected to the gears and work in coordination.

[0012] As a further solution of the utility model, the steel wedge arranged at the junction of the outer box body and the sleeve is composed of a sub-wedge and a sub-wedge. The distance between the sub-wedge and the sub-wedge can be freely adjusted by adjusting the bolts. The sub-wedge and the sub-wedge are connected to the sleeve and the outer box body at the same time.

[0013] As a further solution of the utility model, the inner cavity of the sleeve is provided with a box body mounting groove, the front end of the box body mounting groove is installed with a steel wedge, and the rear end is inserted into the outer box body for installation, and the inner wall surface of the rear end of the box body mounting groove is provided with straight teeth that are meshed and connected with the gear and work in cooperation.

[0014] As a further solution of the utility model, a sleeve mounting protrusion is arranged at the front end of the outer box body, gears are symmetrically arranged on the outer side of the sleeve mounting protrusion, and a hook is arranged at the root of the outer side of the sleeve mounting protrusion.

[0015] As a further solution of the utility model, a jack installation cavity is arranged inside the outer box body, a through hole is opened at the front end of the jack installation cavity, a jack and a pad are installed in the jack installation cavity, and the front end of the jack extends out from the through hole.

[0016] The utility model provides a flexible end for supporting a steel support structure in a foundation pit, which has the following advantages:

[0017] 1. In the utility model, the supporting axial force is transmitted through the central jack, and the inserted steel wedge is changed to be inserted on both sides of the front end, which solves the problem that the reserved width of the traditional single-chamber active end cannot perfectly fit the wedge block, and the eccentric force caused by the roughness and rust of the structure itself.

[0018] 2. In the utility model, by optimizing the side wall portion of the traditional double-chamber structure, damage caused by yielding of the end and the side wall when subjected to high pressure load is avoided.

[0019] 3. In the present invention, corresponding spur teeth and gears are arranged between the outer box and the sleeve, so as to facilitate the loading and unloading of the overall structure and reduce the friction resistance between the inner and outer walls when displacement occurs due to changes in axial load.

[0020] 4. In the utility model, the position of the mother-and-child wedges can be adjusted by adjusting the adjusting bolts at the upper and lower ends, so that the supporting performance of the support structure can be conveniently adjusted; at the same time, the yield load and stiffness of the mother-and-child wedges are higher than those of the single-sided wedges, and are more suitable for use in high-strength foundation pit projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the top view of the flexible terminal of the utility model;

[0022] Figure 2 This is a schematic diagram of the top view of the sleeve structure of the flexible end of the utility model;

[0023] Figure 3 This is a schematic diagram of the top view of the outer box body of the flexible terminal of the utility model;

[0024] Figure 4 This is a side view of the structure of the flexible terminal of the utility model;

[0025] Figure 5 This is a schematic diagram of the side view structure of the sleeve of the flexible end of the utility model;

[0026] Figure 6 This is a schematic diagram of the side view of the outer box body of the flexible terminal of the utility model;

[0027] Figure 7 This is a schematic diagram of the cross-sectional structure of the flexible end AA of the utility model;

[0028] Figure 8 This is a schematic diagram of the cross-sectional structure of the flexible end AA of the utility model;

[0029] Fig. 9 This is a schematic diagram of the gear structure of the utility model Figure 1 ;

[0030] Fig.10 This is a schematic diagram of the gear structure of the utility model Figure 2 .

[0031] In the figure: 1. end plate; 2. hook; 3. steel wedge; 4. adjusting bolt; 5. sleeve; 6. jack; 7. pad; 8. outer box; 9. stiffening rib; 10. flange plate; 11. anti-drop hook; 12. straight teeth; 13. gear. DETAILED DESCRIPTION

[0032] The utility model is further elaborated and illustrated below in conjunction with specific embodiments and the accompanying drawings of the specification.

[0033] In order to make the purpose, technical solution and advantages of the utility model more clear, the present invention is further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0034] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "horizontal", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0035] like Figure 1-10 As shown, a flexible end for supporting a steel supporting structure in a foundation pit comprises an end plate 1, a hook 2, a steel wedge 3, an adjusting bolt 4, a sleeve 5, a jack 6, a pad 7, an outer box 8, a stiffening rib 9, a flange plate 10, an anti-drop hook 11, a straight tooth 12, and a gear 13; the end plate 1 is connected to the steel purlin on the surrounding underground retaining piles, the sleeve 5 is integrally welded to the end plate 1, a steel wedge 3 is wedged between the outer box 8 and the sleeve 5, a hook 2 and an adjusting bolt 4 are arranged on the outer wall of the sleeve 5, and the adjusting bolt 4 passes through the sleeve 5 and is connected to the steel wedge 3.

[0036] like Figure 1-10 As shown, a flexible end cap for supporting a steel supporting structure in a foundation pit is provided, a jack 6 is arranged inside an outer box body 8, a pad 7 is arranged at the rear end of the jack 6 in the outer box body 8, the pad 7 supports and connects the jack 6, a stiffening rib 9 is arranged at the rear of the outer box body 8, and is fixedly connected to a flange plate 10 by bolts; gears 13 are symmetrically arranged on the outer side of the front end of the outer box body 8, a hook 2 is arranged on the outer side of the front end of the rear end, an anti-drop hook 11 is arranged on one side of the hook 2 where the front and rear ends of the outer box body 8 are connected, and straight teeth 12 that are engaged with the gear 13 and work in cooperation are arranged on the inner wall surface of the sleeve 5 and the outer box body 8.

[0037] like Figure 1-10As shown, a flexible end cap for supporting a steel supporting structure in a foundation pit, wherein the steel wedge 3 arranged at the junction of the outer box body 8 and the sleeve 5 is composed of a mother-and-child wedge, and the spacing between the mother-and-child wedges can be freely adjusted by adjusting the bolt 4, and the mother-and-child wedges are connected to the sleeve 5 and the outer box body 8 at the same time; the inner cavity of the sleeve 5 is provided with a box body mounting convex groove, and the mother-and-child wedges of the steel wedge 3 are installed at the front end of the box body mounting convex groove, and the rear end is inserted into the outer box body 8 for installation, and the inner wall surface of the rear end of the box body mounting convex groove is provided with a straight tooth 12 that is engaged and cooperates with the gear 13; the front end of the outer box body 8 is provided with a sleeve mounting protrusion, and the outer side of the sleeve mounting protrusion is symmetrically provided with gears 13, and the outer root of the sleeve mounting protrusion is provided with a hook 2; the interior of the outer box body 8 is provided with a jack mounting cavity, and the front end of the jack mounting cavity is opened with a through hole, and the jack 6 and the pad 7 are installed in the jack mounting cavity, and the front end of the jack 6 extends out from the through hole.

[0038] During operation, the sleeve mounting protrusion of the outer box body 8 is inserted into the box mounting protrusion groove of the sleeve 5, and the sleeve 5 and the outer box body 8 are hooked and connected by the anti-falling hook 11. At this time, the sleeve 5 is welded to the end plate 1 as a whole. In order to ensure the stability of the supporting structure, the end plate 1 is connected to the steel purlin on the surrounding underground retaining piles, and the sleeve 5 is welded to the end plate 1 as a whole. The rear part of the outer box body 8 is provided with stiffening ribs 9, and is fixedly connected to the flange plate 10 by bolts. In order to ensure the stability of the supporting structure, stiffening ribs 9 are added to the rear part of the outer box body 8, and are fixed to the flange plate 10 by bolts. At this time, the outer box body 8 is meshed and connected with the straight teeth 12 on the sleeve 5 through the gear 13 thereon. When the outer box body 8 is pushed into the sleeve 5, the sleeve 5 and the outer box body 8 are connected by the mother-and-child wedges of the steel wedge 3, and the size of the mother-and-child wedge spacing is freely adjusted by adjusting the bolt 4.

[0039] In the utility model, the supporting axial force is transmitted by the central jack, and the inserted steel wedge is changed to be inserted on both sides of the front end, which solves the problem that the traditional single-chamber flexible end cannot perfectly fit with the wedge block due to the reserved width, and the eccentric force caused by the roughness and rust of the structure itself; in the utility model, by optimizing the side wall part of the traditional double-chamber structure, the damage caused by the yielding of the end and the side wall under high pressure load is avoided; in the utility model, by arranging corresponding spur teeth and gears between the outer box body and the sleeve, the loading and unloading of the overall structure is convenient, and the friction resistance between the inner and outer walls when it is displaced due to the change of axial load is reduced; in the utility model, the position of the mother-and-child wedge is adjusted by the adjusting bolts at the upper and lower ends, so as to conveniently adjust the supporting performance of the support structure; at the same time, the yield load and stiffness of the mother-and-child wedge are higher than those of the single-sided wedge, which is more suitable for application in high-strength foundation pit projects.

[0040] The technical solutions disclosed in the embodiments of the present invention are introduced in detail above. The principles and implementation methods of the embodiments of the present invention are explained in detail using specific embodiments. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A flexible end for supporting a steel support structure in a foundation pit, characterized in that: It comprises an end plate (1), a hook (2), a steel wedge (3), an adjusting bolt (4), a sleeve (5), a jack (6), a pad (7), an outer box (8), a stiffening rib (9), a flange plate (10), an anti-drop hook (11), straight teeth (12) and a gear (13); The end plate (1) is connected to the steel purlin on the surrounding underground retaining piles, the sleeve (5) is integrally connected to the end plate (1) by welding, a steel wedge (3) is wedged between the outer box body (8) and the sleeve (5), a hook (2) and an adjusting bolt (4) are arranged on the outer wall of the sleeve (5), and the adjusting bolt (4) passes through the sleeve (5) and is connected to the steel wedge (3); The outer box (8) is provided with a jack (6) inside, a backing plate (7) is provided inside the outer box (8) at the rear end of the jack (6), the backing plate (7) supports and connects the jack (6), and a stiffening rib (9) is provided at the rear of the outer box (8) and is fixedly connected to the flange plate (10) by bolts; The front end of the outer box body (8) is symmetrically provided with a gear (13), and the front end of the rear end is provided with a hook (2). The front and rear ends of the outer box body (8) are connected to a side of the hook (2) to prevent it from falling off. The inner wall surface of the sleeve (5) and the outer box body (8) are provided with straight teeth (12) that are engaged with the gear (13) and work in coordination with each other.

2. The flexible end cap for supporting the steel support structure in the foundation pit according to claim 1 is characterized in that: The steel wedge (3) arranged at the junction of the outer box body (8) and the sleeve (5) is composed of a mother-and-child wedge. The distance between the mother-and-child wedges can be freely adjusted by adjusting the bolt (4). The mother-and-child wedges are connected to the sleeve (5) and the outer box body (8) at the same time.

3. The flexible end cap for supporting the steel support structure in the foundation pit according to claim 2 is characterized in that: The inner cavity of the sleeve (5) is provided with a box body installation convex groove, the front end of which is provided with a sub-wedge of a steel wedge (3), and the rear end is sleeved and installed in an outer box body (8), and the inner side wall surface of the rear end of the box body installation convex groove is provided with a straight tooth (12) which is meshed and connected with a gear (13) and works in cooperation with it.

4. The flexible end cap for supporting the steel support structure in the foundation pit according to claim 3 is characterized in that: The front end of the outer box body (8) is provided with a sleeve mounting protrusion, the outer side of the sleeve mounting protrusion is symmetrically provided with a gear (13), and the outer root of the sleeve mounting protrusion is provided with a hook (2).

5. The flexible end cap for supporting the steel support structure in the foundation pit according to claim 4 is characterized in that: A jack installation cavity is arranged inside the outer box body (8), a through hole is opened at the front end of the jack installation cavity, a jack (6) and a pad (7) are installed in the jack installation cavity, and the front end of the jack (6) extends out from the through hole.

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