A front-arranged steel support system suitable for small-sized super-deep foundation pit

Abstract

This invention discloses a pre-positioned steel support system suitable for small, ultra-deep foundation pits, comprising several lattice columns, several connecting devices, pre-positioned steel supports, several steel strands, several through-hole jacks, several servo cylinders, and a hydraulic system. The pre-positioned steel supports include a steel waler and several corner horizontal braces set at the four corners of the steel waler. Several servo cylinders are spaced along the circumference of the steel waler on its outer surface. The servo cylinders extend and retract under the action of the hydraulic system to achieve active deformation control of the diaphragm wall. Several through-hole jacks, under the action of the hydraulic system, simultaneously raise and lower the pre-positioned steel supports by synchronously extending and retracting the corresponding steel strands. This invention enables a construction method of pre-positioning concrete or steel supports for simultaneous excavation, lowering, and support, effectively shortening the construction period and reducing the time without support during over-excavation. It has advantages such as high mechanization, strong construction safety, and high turnover rate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of construction engineering machinery, and particularly relates to a front-mounted steel support system suitable for small super-deep foundation pits. BACKGROUND

[0002] Small super-deep foundation pits (such as subway end head wells) have the characteristics of small area, large depth, high deformation control requirements, etc., and usually adopt a support scheme of underground continuous walls plus steel supports (or concrete supports).

[0003] However, simply using traditional steel supports (or concrete supports) to support underground continuous walls has the disadvantages and deficiencies of too long over-excavation time without support, inability to actively control the deformation of underground continuous walls, and the need to wait for the strength of the concrete support to reach the standard before excavation after the construction of the concrete support, thereby affecting the construction period. SUMMARY

[0004] The present application aims to provide a front-mounted steel support system suitable for small super-deep foundation pits, which solves the problems of too long over-excavation time without support, inability to actively control the deformation of underground continuous walls, and the need to wait for the strength of the concrete support to reach the standard before excavation after the construction of the concrete support, thereby affecting the construction period.

[0005] To solve the above technical problems, the present application provides the following technical solutions:

[0006] The application discloses a front-arranged steel support system suitable for small-sized super-deep foundation pits, which comprises a plurality of lattice columns, a plurality of connecting devices, a front-arranged steel support, a plurality of steel strands, a plurality of through-type jacks, a plurality of jack foundations, a plurality of steel strand guide frames, a plurality of servo oil cylinders and a hydraulic system, wherein the front-arranged steel support comprises a steel enclosing purlin and a plurality of corner horizontal diagonal braces arranged at four corner portions of the steel enclosing purlin; a lattice column is correspondingly arranged at the inner side of the corner horizontal diagonal brace at the innermost side of each corner portion of the steel enclosing purlin; the lattice column is pre-pressed into a soil layer at a designed position; the corner horizontal diagonal brace at the innermost side of each corner portion of the steel enclosing purlin is connected with the corresponding lattice column through the corresponding connecting device; the plurality of jack foundations are arranged at four corner portion positions of a first layer ring beam of a continuous wall respectively; the through-type jacks are arranged on the corresponding jack foundations; the steel strand guide frames are arranged on the corresponding jack foundations or the first layer ring beam of the continuous wall; the steel strands are arranged on the corresponding steel strand guide frames; the inner side surface of the steel enclosing purlin and the two side surfaces of the corner horizontal diagonal brace are respectively provided with a plurality of adjustable struts at equal intervals through bolt connection; the hydraulic system is arranged on the first layer ring beam of the continuous wall, the ground or the front-arranged steel support; the plurality of servo oil cylinders are arranged on the outer side surface of the steel enclosing purlin along the circumferential direction of the steel enclosing purlin; the plurality of servo oil cylinders and the plurality of through-type jacks are connected with the hydraulic system respectively; the plurality of servo oil cylinders are stretched and contracted under the action of the hydraulic system, so that active deformation control of the underground continuous wall is realized; the plurality of through-type jacks are connected with four corner portions of the front-arranged steel support through the corresponding steel strands respectively; the plurality of through-type jacks realize the lifting of the front-arranged steel support through synchronous extension and retraction of the corresponding steel strands under the action of the hydraulic system.

[0007] Preferably, in the front-arranged steel support system suitable for small-sized super-deep foundation pits, the front-arranged steel support is arranged at the inner side of the underground continuous wall, and the front-arranged steel support is assembled below the first layer ring beam of the continuous wall.

[0008] Preferably, in the front-arranged steel support system suitable for small-sized super-deep foundation pit, the connecting device comprises a bearing tripod, a tripod support plate, two connecting angle steels, a plurality of welded nuts, a plurality of adjusting bolts, an adjusting support plate, two lattice column U-shaped bolts, two lattice column connecting plates, four lattice column connecting nuts, a horizontal diagonal bracing connecting plate, two horizontal diagonal bracing U-shaped bolts and four horizontal diagonal bracing connecting nuts, the bearing tripod is a right-angled triangular structure, the bearing tripod has a horizontal plane and a vertical plane, the horizontal diagonal bracing connecting plate is fixedly arranged on the horizontal plane, the tripod support plate is fixedly arranged on the vertical plane, the horizontal diagonal bracing connecting plate and the tripod support plate are perpendicular to each other, the two connecting angle steels are vertically arranged on the left and right sides of the tripod support plate respectively, the upper and lower parts of the two connecting angle steels are respectively provided with first through holes for the lattice column U-shaped bolts to pass through, the two lattice column U-shaped bolts are connected through the corresponding lattice column connecting plates and lattice column connecting nuts after being clamped around the lattice columns, a row of second through holes for the corresponding horizontal diagonal bracing U-shaped bolts to pass through are respectively arranged on the two sides of the horizontal diagonal bracing connecting plate along the longitudinal direction of the horizontal diagonal bracing connecting plate, the two horizontal diagonal bracing U-shaped bolts are connected with the horizontal diagonal bracing connecting plate and the corner horizontal diagonal bracing through the corresponding horizontal diagonal bracing connecting nuts, a third through hole is respectively arranged on the upper and lower parts of the tripod support plate, and a threaded hole matched with the adjusting bolt is arranged at the third through hole, one end of the adjusting bolt passes through the corresponding threaded hole of the tripod support plate and is hingedly connected with the adjusting support plate through a ball hinge, and rotation of the adjusting bolt can move the corresponding adjusting support plate, so that the adjusting support plate is attached to the side surface of the lattice column.

[0009] Preferably, in the front-arranged steel support system suitable for small-sized super-deep foundation pit, the bearing tripod comprises two tripod vertical rods, two tripod horizontal rods, two tripod inclined rods and three tripod cross rods, the tripod vertical rods, the tripod horizontal rods and the tripod inclined rods are connected to form a triangular structure, the ends of the two triangular structures are connected through the three tripod cross rods respectively, the horizontal diagonal bracing connecting plate is arranged on the upper part of the bearing tripod, the horizontal diagonal bracing connecting plate is rigidly connected with the tripod horizontal rods and the tripod cross rods respectively, and the tripod vertical rods and the tripod cross rods are rigidly connected with the tripod support plate, so that the bearing tripod is supported on the tripod support plate.

[0010] Preferably, in the front-arranged steel support system suitable for small-sized super-deep foundation pit, each adjusting support plate is hingedly connected with three adjusting bolts, and the three adjusting bolts are arranged at equal intervals along the horizontal direction.

[0011] Preferably, in the front-located steel support system suitable for small-sized super-deep foundation pit, the steel enclosing purlin of the front-located steel support comprises a plurality of straight steel beams and four L-shaped corner steel beams, the plurality of straight steel beams are assembled into four strip steel beams by bolt connection, the ends of the four strip steel beams are connected into a rectangular steel enclosing purlin by the L-shaped corner steel beams, the strip steel beams and the corresponding L-shaped corner steel beams are connected by bolt connection, the two ends of the corner horizontal diagonal brace are respectively connected with the inner side wall of the steel enclosing purlin through the corner horizontal diagonal brace connecting segment, a plurality of parallel corner horizontal diagonal braces are arranged at each corner of the steel enclosing purlin, and a plurality of connecting beams are arranged at the two parallel corner horizontal diagonal braces on the inner side.

[0012] Preferably, in the front-located steel support system suitable for small-sized super-deep foundation pit, the connecting beam comprises a connecting beam steel beam and two connecting beam end connecting plates, the two connecting beam end connecting plates are fixedly arranged at the two ends of the connecting beam steel beam, bolt holes are arranged on the two connecting beam end connecting plates for the connecting beam U-shaped bolt to pass through, and the connecting beam U-shaped bolt clamps are fixed on the corresponding connecting beam end connecting plates through connecting beam connecting nuts.

[0013] Preferably, in the front-located steel support system suitable for small-sized super-deep foundation pit, the corner horizontal diagonal brace comprises a brace steel beam, two brace end connecting plates and a plurality of brace support foot connecting channel steels, the two brace end connecting plates are fixedly arranged at the two ends of the brace steel beam, the brace support foot connecting channel steels are symmetrically arranged on the two side faces of the brace steel beam at equal intervals along the longitudinal direction of the brace steel beam, bolt holes are arranged on the two brace end connecting plates for connecting the corresponding corner horizontal diagonal brace connecting segments, and a plurality of bolt holes are arranged on the brace support foot connecting channel steels at intervals for connecting the corresponding adjustable corner braces; the corner horizontal diagonal brace connecting segment comprises a connecting segment steel beam, a connecting segment corner brace connecting plate and a connecting segment steel enclosing purlin connecting plate, the connecting segment corner brace connecting plate and the connecting segment steel enclosing purlin connecting plate are rigidly connected at the two ends of the connecting segment steel beam, the connecting segment steel enclosing purlin connecting plate is arranged obliquely, the connecting segment corner brace connecting plate is arranged vertically, bolt holes are arranged on the connecting segment steel enclosing purlin connecting plate for connecting the steel enclosing purlin, and bolt holes are arranged on the connecting segment corner brace connecting plate for connecting the corresponding corner horizontal diagonal brace.

[0014] Preferably, in the front-located steel support system suitable for small-sized super-deep foundation pit, the cross section of the straight steel beam is a double-web H-shaped structure formed by fixed connection of a straight steel beam web and straight steel beam flange plates on both sides; the cross section of the L-shaped corner steel beam is a double-web H-shaped structure formed by fixed connection of an L-shaped corner steel beam web and L-shaped corner steel beam flange plates on the inner and outer sides; the L-shaped corner steel beam web is provided with a hole, and a steel strand anchor is arranged at the hole, and stiffening plates are arranged on both sides of the steel strand anchor.

[0015] Preferably, in the front steel support system suitable for small super-deep foundation pit, the servo oil cylinder comprises a cylinder sleeve box, an adjusting pad, a sleeve hook roller and a cylinder body, the cylinder body is arranged in the cylinder sleeve box, one end of the cylinder sleeve box is provided with a vertical end plate, the adjusting pad for adjusting the total elongation of the servo oil cylinder is arranged in the cylinder sleeve box, the adjusting pad is located between the vertical end plate and the cylinder body, the upper end of the vertical end plate is provided with a sleeve hook opening downward for hooking the steel enclosing purlin, a plurality of sleeve hook rollers are arranged between the vertical end plate and the sleeve hook, and bolt holes for connecting the steel enclosing purlin are formed in the vertical end plate.

[0016] From the above disclosed technical solutions, compared with the prior art, the beneficial effects of the present application are as follows:

[0017] The application discloses a front-arranged steel support system suitable for small-sized super-deep foundation pits, which comprises a plurality of lattice columns, a plurality of connecting devices, a front-arranged steel support, a plurality of steel strands, a plurality of through-type jacks, a plurality of jack foundations, a plurality of steel strand guide frames, a plurality of servo oil cylinders and a hydraulic system, the front-arranged steel support comprises a steel enclosing purlin and a plurality of corner horizontal diagonal braces arranged at four corner portions of the steel enclosing purlin, a lattice column is correspondingly arranged on the inner side of the corner horizontal diagonal brace located at the innermost side of each corner portion of the steel enclosing purlin, the lattice column is pre-pressed into a soil layer according to a designed position, the corner horizontal diagonal brace located at the innermost side of each corner portion of the steel enclosing purlin is connected with the corresponding lattice column through the corresponding connecting device, the plurality of jack foundations are arranged at four corner portion positions of a first layer ring beam of a continuous wall respectively, the through-type jacks are arranged on the corresponding jack foundations, the steel strand guide frames are arranged on the corresponding jack foundations or the first layer ring beam of the continuous wall, the steel strands are arranged on the corresponding steel strand guide frames, the inner side surface of the steel enclosing purlin and the two side surfaces of the corner horizontal diagonal brace are respectively provided with a plurality of adjustable angle braces at equal intervals through a bolt connection mode, the hydraulic system is arranged on the first layer ring beam of the continuous wall, the ground or the front-arranged steel support, the plurality of servo oil cylinders are arranged on the outer side surface of the steel enclosing purlin along the circumferential direction of the steel enclosing purlin, the plurality of servo oil cylinders and the plurality of through-type jacks are connected with the hydraulic system respectively, the plurality of servo oil cylinders are stretched and contracted under the action of the hydraulic system, thereby realizing active deformation control of the underground continuous wall, the plurality of through-type jacks are connected with the four corner portions of the front-arranged steel support through the corresponding steel strands respectively, the plurality of through-type jacks realize the lifting of the front-arranged steel support through the synchronous extension and retraction of the corresponding steel strands under the action of the hydraulic system. The front-arranged steel support system provided by the application can realize the construction method of front-arranging the concrete support or the steel support and lowering and supporting simultaneously with excavation, effectively shortens the construction period and the time of over-excavation without support, has the advantages of high mechanization degree, high construction safety and high turnover utilization rate, etc., the front-arranged steel support is lifted as a whole through the through-type jacks and the steel strands, has the advantages of stable lowering, safety and reliability and good synchronism, the adjustable angle braces arranged on the steel support can effectively transmit the self-weight of the front-arranged steel support and the self-weight of the upper cast concrete to the ground and keep the front-arranged steel support horizontal, and can ensure that the servo oil cylinders are not subjected to vertical torsional force when supporting the underground continuous wall in the horizontal direction, thereby improving the construction safety and the rationality of equipment stress. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of a front-arranged steel support system suitable for small-sized super-deep foundation pits in a construction state.

[0019] Figure 2 It is a plan view of a front-arranged steel support system suitable for small-sized super-deep foundation pits in a construction state.

[0020] Figure 3This is a 3D diagram of a pre-positioned steel support system suitable for small, ultra-deep foundation pits.

[0021] Figure 4 It is a three-dimensional diagram of a lattice column.

[0022] Figure 5 This is a front view of the connecting device.

[0023] Figure 6 This is a top view of the connecting device.

[0024] Figure 7 This is a side view of the connecting device.

[0025] Figure 8 It is a 3D diagram of the connecting device.

[0026] Figure 9 This is a 3D diagram of a straight steel beam section.

[0027] Figure 10 This is a 3D diagram of the L-shaped corner steel beam.

[0028] Figure 11 It is a 3D diagram of a servo hydraulic cylinder.

[0029] Figure 12 It is a 3D diagram of adjustable support legs.

[0030] Figure 13 This is a 3D diagram of the horizontal diagonal brace connection section at the corner.

[0031] Figure 14 This is a plan view of the horizontal diagonal brace connection section at the corner.

[0032] Figure 15 This is a three-dimensional diagram of the horizontal diagonal brace at the corner.

[0033] Figure 16 It is a 3D diagram of the connecting beam.

[0034] Figure 17 This is a structural diagram of step 1 of the usage method of a pre-positioned steel support system suitable for small ultra-deep foundation pits.

[0035] Figure 18 This is a structural diagram of step 2 of a method for using a pre-positioned steel support system suitable for small, ultra-deep foundation pits.

[0036] Figure 19 This is a structural diagram of step 3 of a method for using a pre-positioned steel support system suitable for small, ultra-deep foundation pits.

[0037] Figure 20 This is a structural diagram of step 4 of a method for using a pre-positioned steel support system suitable for small, ultra-deep foundation pits.

[0038] Figure 21 This is a structural diagram of step 5 of a method for using a pre-positioned steel support system suitable for small, ultra-deep foundation pits.

[0039] Figure 22 This is a structural diagram of step 6 of a method for using a pre-positioned steel support system suitable for small, ultra-deep foundation pits.

[0040] In the picture:

[0041] 1. Diaphragm wall,

[0042] 2. First-floor ring beam of diaphragm wall,

[0043] 3. Lattice column; 31. Lattice column angle steel; 32. Angle steel connecting plate;

[0044] 4. Connecting devices; 401. Triangular support plate; 402. Connecting angle steel; 403. Welding nut; 404. Adjusting bolt; 405. Adjusting support plate; 406. Lattice column U-bolt; 407. Lattice column connecting plate; 408. Lattice column connecting nut; 409. Triangular vertical rod; 410. Triangular horizontal rod; 411. Triangular diagonal rod; 412. Triangular horizontal bar; 413. Horizontal diagonal brace connecting plate; 414. Horizontal diagonal brace U-bolt; 415. Horizontal diagonal brace connecting nut.

[0045] 5. Front-mounted steel support,

[0046] 51. Straight steel beam section; 511. Straight steel beam section web; 512. Straight steel beam section flange plate.

[0047] 52. L-shaped corner steel beam, 521. L-shaped corner steel beam web, 522. L-shaped corner steel beam flange, 523. Steel strand anchor, 524. Stiffening plate.

[0048] 53. Servo cylinder; 531. Cylinder housing; 532. Adjusting pad; 533. Housing hook roller; 534. Cylinder body; 535. Vertical end plate; 536. Housing hook.

[0049] 54. Adjustable support legs; 541. Support leg connecting plate; 542. Support legs;

[0050] 55. Corner horizontal diagonal brace connection section; 551. Connecting section steel beam; 552. Connecting section corner brace connection plate; 553. Connecting section steel waler connection plate.

[0051] 56. Corner horizontal diagonal brace; 561. Corner brace steel beam; 562. Corner brace end connecting plate; 563. Corner brace support leg connecting channel steel.

[0052] 57. Tie beam; 571. Tie beam steel beam; 572. Tie beam end connecting plate;

[0053] 58. Connecting beam U-bolts,

[0054] 59. Connecting nut for connecting beam,

[0055] 510. Scaffold boards,

[0056] 6. Steel strand,

[0057] 7. Through-type jack,

[0058] 8. Jack foundation,

[0059] 9. Steel strand guide frame,

[0060] 10. Concrete or steel supports

[0061] 11. Soil layers,

[0062] 12. Concrete foundation. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The technical content and features of the present invention will be described in detail below with reference to the listed embodiments and the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention. For ease of description, the terms "upper" and "lower" used below are consistent with the upper and lower directions in the accompanying drawings, but this should not be construed as a limitation of the technical solution of the present invention.

[0064] Please see Figures 1 to 16This embodiment discloses a pre-positioned steel support system suitable for small ultra-deep foundation pits, including several lattice columns 3, several connecting devices 4, pre-positioned steel supports 5, several steel strands 6, several through-hole jacks 7, several jack foundations 8, several steel strand guide frames 9, several servo cylinders 53, and a hydraulic system. The pre-positioned steel supports 5 include steel walers and several corner horizontal braces 56 set at the four corners of the steel walers. A lattice column 3 is correspondingly set on the inner side of the innermost corner horizontal brace 56 at each corner of the steel walers. The lattice columns 3 are pre-pressed into the soil layer 11 according to the design position. The innermost corner horizontal brace 56 at each corner of the steel walers is connected to the corresponding lattice column 3 through the corresponding connecting device 4. The several jack foundations 8 are respectively set at the four corner positions of the first-layer ring beam 2 of the continuous wall; the through-hole jacks 7 are set on the corresponding jack foundations 8; the steel strand guide frames 9... The steel strands 6 are installed on the corresponding jack foundations 8 or the first-floor ring beam 2 of the diaphragm wall; the steel strands 6 are erected on the corresponding steel strand guide frames 9; the inner side of the steel waler and the two sides of the corner horizontal diagonal braces 56 are respectively provided with several adjustable bracing angles 54 at equal intervals by bolt connection; the hydraulic system is set on the first-floor ring beam 2 of the diaphragm wall, the ground, or the front-mounted steel support 5; the several servo cylinders 53 are arranged at intervals along the circumference of the steel waler on the outer side of the steel waler; the several servo cylinders 53 and several through-hole jacks 7 are respectively connected to the hydraulic system; the several servo cylinders 53 extend and retract under the action of the hydraulic system to realize active deformation control of the underground diaphragm wall 1; the several through-hole jacks 7 are respectively connected to the four corners of the front-mounted steel support 5 through the corresponding steel strands 6; the several through-hole jacks 7 realize the lifting and lowering of the front-mounted steel support 5 by synchronously retracting and extending the corresponding steel strands 6 under the action of the hydraulic system. The pre-positioned steel support 5 system provided by this invention enables a construction method of excavating, lowering, and supporting simultaneously with concrete supports or steel supports 10, effectively shortening the construction period and reducing the time of over-excavation without support. It has advantages such as high mechanization, strong construction safety, and high turnover rate. By using a through-hole jack 7 in conjunction with steel strands 6 to raise and lower the pre-positioned steel support 5 as a whole, it has the advantages of stable descent, safety and reliability, and good synchronization. By setting adjustable angle braces 54 on the steel support, the self-weight of the pre-positioned steel support 5 and the self-weight of the upper poured concrete can be effectively transferred to the ground, keeping the pre-positioned steel support 5 horizontal, and ensuring that the servo cylinder 53 is not subjected to vertical torsional force when supporting the underground continuous wall 1 in the horizontal direction, thereby improving construction safety and the rationality of equipment stress.

[0065] Preferably, in the aforementioned pre-positioned steel support system suitable for small ultra-deep foundation pits, the pre-positioned steel support 5 is located inside the underground continuous wall 1, and the pre-positioned steel support 5 is assembled below the first-layer ring beam 2 of the continuous wall. Specifically, bolt assembly is adopted for installation and disassembly, which improves the convenience of installation and disassembly and the turnover rate.

[0066] Please refer to the selected ones for more details. Figures 5 to 8 In the aforementioned pre-positioned steel support system suitable for small ultra-deep foundation pits, the connecting device 4 includes a load-bearing triangular frame, a triangular frame support plate 401, two connecting angle steels 402, several welded nuts 403, several adjusting bolts 404, an adjusting support plate 405, two lattice column U-bolts 406, two lattice column connecting plates 407, four lattice column connecting nuts 408, a horizontal diagonal brace connecting plate 413, two horizontal diagonal brace U-bolts 414, and four horizontal diagonal brace connecting nuts 415. The load-bearing triangular frame is a right-angled triangular structure with a horizontal plane and a vertical plane. The horizontal diagonal brace connecting plate 413 is fixedly installed on the horizontal plane, and the triangular frame support plate is fixedly installed on the vertical plane. The horizontal diagonal brace connecting plate 413 is perpendicular to the triangular frame support plate 401. The two connecting angle steels 402 are respectively vertically installed on the left and right sides of the triangular frame support plate 401. The upper and lower parts of the two connecting angle steels 402 are... A first through hole (not shown) is provided for the U-bolts 406 of the lattice columns to pass through. After the two U-bolts 406 of the lattice columns are clamped together, they are connected by the corresponding lattice column connecting plates 407 and lattice column connecting nuts 408. A second through hole (not shown) is provided on both sides of the horizontal brace connecting plate 413 along its own longitudinal direction for the corresponding horizontal brace U-bolts 414 to pass through. The two horizontal brace U-bolts 414 are connected by the corresponding horizontal brace connecting nuts 415 to the horizontal brace connecting plate. 413 is connected to the corner horizontal brace 56. The upper and lower parts of the tripod support plate 401 are respectively provided with a third through hole (not shown), and a threaded hole matching the adjusting bolt 404 is provided at the third through hole. One end of the adjusting bolt 404 passes through the corresponding threaded hole on the tripod support plate 401 and is hinged to the adjusting support plate 405 by ball joint. Rotating the adjusting bolt 404 can move the corresponding adjusting support plate 405, so that the adjusting support plate 405 fits against the side of the lattice column 3. Considering the possibility of torsion and vertical deflection of the lattice column 3, preliminary positioning is first performed during connection to ensure that the bottom surface of the horizontal brace connecting plate 413 is in contact with the corner horizontal brace 56. Then, the connecting device 4 is rotated, and the adjusting bolt 404 is rotated to ensure that the two adjusting support plates 405 are in contact with the side of the lattice column 3. Then, the lattice column U-bolt 406, the lattice column connecting plate 407, and the lattice column connecting nut 408 are used to connect and fix the connecting device 4 and the lattice column 3. Finally, the two horizontal brace U-bolts 414 are used to clamp the corner horizontal brace 56 and are tightened with the horizontal brace connecting nut 415, thereby realizing the connection between the corner horizontal brace 56 and the lattice column 3.

[0067] On the one hand, since the corner horizontal brace 56 and the connecting device 4 are connected by the horizontal brace U-bolt 414, when the horizontal brace connecting plate 413 is in contact with the bottom surface of the corner horizontal brace 56, the connection between the lattice column 3 and the connecting device 4 is ensured by rotating the connecting device 4 when there is torsional deviation and horizontal position deviation of the lattice column 3. Since multiple openings, namely two rows of second through holes, are provided on the horizontal brace connecting plate 413, even if the connecting device 4 is rotated, the appropriate second through hole can still be selected to insert the corresponding horizontal brace U-bolt 414 to realize the connection between the corner horizontal brace 56 and the connecting device 4.

[0068] On the other hand, since the two ends of the U-bolt 406 of the lattice column can rotate freely in the corresponding first through hole of the corresponding connecting angle steel 402, and by setting the adjusting bolt 404 and the adjusting support plate 405, one end of the adjusting bolt 404 passes through the corresponding threaded hole on the tripod support plate 401 and is hinged to the adjusting support plate 405 by ball joint. Therefore, by rotating the adjusting bolt 404, the two adjusting support plates 405 can be made to fit against the side of the lattice column 3, ensuring that the lattice column 3 and the horizontal diagonal brace have an effective force transmission connection, i.e., an effective support connection, when there is a verticality deviation of the lattice column 3. The connecting device 4 can always have an effective support connection with the lattice column 3 with the help of the adjusting support plate 405, so that the connecting device 4 has high adaptability and can adapt to the horizontal distance deviation, planar torsion, vertical tilt and other embedment errors of the lattice column 3.

[0069] Furthermore, since the adjusting support plate 405 is in close contact with the side of the lattice column 3, the vertical force of the corner horizontal brace 56 of the steel support can be effectively transferred to the lattice column 3. Moreover, since the connection between the connecting device 4 and the corner horizontal brace 56 is made by U-bolt clamping, and the connecting device 4 is not subject to horizontal constraint, the corner horizontal brace 56 can be effectively prevented from transferring the horizontal force to the lattice column 3, thus ensuring safety.

[0070] To improve the rigidity and load-bearing capacity of the load-bearing tripod, the load-bearing tripod includes two vertical rods 409, two horizontal rods 410, two diagonal rods 411, and three horizontal rods 412. The vertical rods 409, horizontal rods 410, and diagonal rods 411 are connected to form a triangular structure. The ends of the two triangular structures are connected by the three horizontal rods 412. A horizontal diagonal brace connecting plate 413 is placed on the upper part of the load-bearing tripod. The horizontal diagonal brace connecting plate 413 is rigidly connected to the horizontal rods 410 and the horizontal rods 412. The vertical rods 409 and the horizontal rods 412 are both rigidly connected to the tripod support plate 401, so that the load-bearing tripod is supported on the tripod support plate 401.

[0071] Preferably, in the aforementioned pre-positioned steel support system suitable for small ultra-deep foundation pits, each adjustable support plate 405 is hinged to three adjusting bolts 404, which are equally spaced along the horizontal direction, thereby making the adjustable support plate 405 fit tightly against the side of the lattice column 3 and improving the force transmission performance between them.

[0072] Preferably, in the aforementioned pre-positioned steel support system suitable for small ultra-deep foundation pits, the steel waler of the pre-positioned steel support 5 includes several straight steel beams 51 and four L-shaped corner steel beams 52. The several straight steel beams 51 are assembled into four strip steel beams by bolt connection. The ends of the four strip steel beams are connected by L-shaped corner steel beams 52 to form a rectangular steel waler. The strip steel beams and the corresponding L-shaped corner steel beams 52 are connected by bolt connection. The two ends of the corner horizontal brace 56 are respectively connected to the inner wall of the steel waler through corner horizontal brace connecting sections 55. Several parallel corner horizontal braces 56 are provided at each corner of the steel waler. Several connecting beams 57 are provided on the two parallel corner horizontal braces 56 located on the inner side to improve the overall stability of the pre-positioned steel support 5. Scaffold boards 510 are laid on the corner horizontal braces 56 as a working platform to facilitate construction workers to carry out construction work.

[0073] Preferably, in the aforementioned pre-positioned steel support system suitable for small ultra-deep foundation pits, an integral platform plate can be set on the pre-positioned steel support 5. This platform can serve as a working platform to support workers, engineering materials, and the side formwork for concrete support, as well as as the bottom formwork for the upper concrete pouring support. This avoids frequent installation and dismantling of the formwork, effectively improves the turnover efficiency of the formwork, and thus improves the construction efficiency of the foundation pit and shortens the construction period.

[0074] Please see Figure 4 The lattice column 3 is formed by connecting four lattice column angle steels 31 through several angle steel connecting plates 32.

[0075] Preferably, in the aforementioned pre-positioned steel support system suitable for small, ultra-deep foundation pits, please refer to the following: Figure 9 The cross-section of the straight steel beam 51 is H-shaped with double webs, and it is formed by the fixed connection between the web 511 of the straight steel beam and the flanges 512 of the straight steel beams on both sides; please refer to the following for details. Figure 10 The L-shaped corner steel beam 52 has a double-web H-shaped cross-section and is formed by the L-shaped corner steel beam web 521 and the L-shaped corner steel beam flange plates 522 on the inner and outer sides. The L-shaped corner steel beam web 521 has holes and steel strand anchors 523 are installed at the holes to form an effective connection between the through-hole jack 7 and the steel waler, so as to achieve stable lifting and lowering of the steel waler and improve construction safety. In addition, stiffening plates 524 are installed on both sides of the steel strand anchors 523 to further improve the stability and safety of the lifting and lowering of the steel waler.

[0076] Preferably, in the aforementioned pre-positioned steel support system suitable for small, ultra-deep foundation pits, please refer to the following: Figure 11 The servo cylinder 53 includes a cylinder housing 531, an adjusting pad 532, a housing hook roller 533, and a cylinder body 534. The cylinder body 534 is disposed inside the cylinder housing 531. A vertical end plate 535 is disposed at one end of the cylinder housing 531. An adjusting pad 532 for adjusting the total extension of the servo cylinder 53 is disposed inside the cylinder housing 531. The adjusting pad 532 is located between the vertical end plate 535 and the cylinder body 534. A downward-opening housing hook 536 for attaching to a steel waler is disposed at the upper end of the vertical end plate 535. A plurality of housing hook rollers 533 are disposed between the vertical end plate 535 and the housing hook 536. Bolt holes for connecting to the steel waler are opened on the vertical end plate 535. By setting the sleeve hook roller 533, the servo cylinder 53 can easily move along the steel waler, reducing the friction between the two. When the servo cylinder 53 reaches the predetermined position, it can be fixedly connected to the steel waler by bolts through the bolt holes opened on the vertical end plate 535 for connecting the steel waler.

[0077] Please refer to the selected ones for more details. Figure 12 In the aforementioned pre-positioned steel support system suitable for small ultra-deep foundation pits, the adjustable support leg 54 includes a support leg connecting plate 541 and a support leg body 542. The support leg connecting plate 541 is fixedly disposed on the upper part of the support leg body 542. The support leg connecting plate 541 is vertically arranged, and a plurality of bolt holes for adjusting the height of the adjustable support leg 54 are arranged vertically at intervals on the support leg connecting plate 541 so as to realize the support height of the adjustable support leg 54.

[0078] Preferably, in the aforementioned pre-positioned steel support system suitable for small, ultra-deep foundation pits, please refer to the following: Figure 15 The corner horizontal brace 56 includes a corner brace steel beam 561, two corner brace end connecting plates 562, and several corner brace support foot connecting channel steels 563. The two corner brace end connecting plates 562 are respectively fixedly installed at both ends of the corner brace steel beam 561. The corner brace support foot connecting channel steels 563 are symmetrically arranged in pairs at equal intervals on both sides of the corner brace steel beam 561 along its longitudinal direction. Bolt holes for connecting corresponding corner horizontal brace connecting sections 55 are provided on the two corner brace end connecting plates 562. Several bolt holes for connecting corresponding adjustable corner braces 54 are provided at intervals on the corner brace support foot connecting channel steels 563. Please refer to the following for details. Figures 13 to 14The corner horizontal brace connecting section 55 includes a connecting section steel beam 551, a connecting section corner brace connecting plate 552, and a connecting section steel waler connecting plate 553. The connecting section corner brace connecting plate 552 and the connecting section steel waler connecting plate 553 are respectively rigidly connected to both ends of the connecting section steel beam 551. The connecting section steel waler connecting plate 553 is obliquely arranged, and the connecting section corner brace connecting plate 552 is vertically arranged. Bolt holes for connecting the steel waler are opened on the connecting section steel waler connecting plate 553, and bolt holes for connecting the corresponding corner horizontal brace 56 are opened on the connecting section corner brace connecting plate 552. This realizes a detachable connection between the corner horizontal brace connecting section 55, the corner horizontal brace 56, and the steel waler, improving the convenience of installation and dismantling and the turnover rate.

[0079] Preferably, in the aforementioned pre-positioned steel support system suitable for small, ultra-deep foundation pits, please refer to the following: Figure 16 The connecting beam 57 includes a connecting beam steel beam 571 and two connecting beam end connecting plates 572. The two connecting beam end connecting plates 572 are fixedly installed at both ends of the connecting beam steel beam 571. The two connecting beam end connecting plates 572 are provided with through holes for connecting beam U-bolts 58 to pass through. The connecting beam U-bolts 58 clamp the corresponding corner horizontal brace 56 and are then fixed to the corresponding connecting beam end connecting plate 572 by connecting beam connecting nuts 59. This realizes a detachable connection between the connecting beam 57 and the corner horizontal brace 56, improving the convenience of installation and dismantling and the turnover rate.

[0080] The method of using the pre-positioned steel support system for small, ultra-deep foundation pits according to the present invention includes the following steps:

[0081] Step 1, please refer to it carefully. Figure 17 The construction of the diaphragm wall 1 and the first-floor ring beam 2 was completed. The lattice columns 3 were then driven into the soil layer 11 according to the design position. The soil layer 11 was excavated to a certain depth, and a concrete pad 12 was poured on top of it. A jack foundation 8 was installed on the first-floor ring beam 2 of the diaphragm wall. A through-type jack 7 and a steel strand guide frame 9 were also installed. Furthermore, during the excavation of the soil layer 11 to a certain depth, the earthwork was excavated in the order of first the center and then the surrounding areas. More excavation was carried out at the location of the lattice columns 3 to facilitate the installation of the horizontal bracing and the connection device 4 between the lattice columns 3 and the horizontal bracing. This increased the amount of earthwork excavation and improved the safety of the foundation pit construction.

[0082] Step 2, please refer to it carefully. Figure 18The components of the pre-positioned steel support 5 are hoisted onto the concrete pad 12 through the gap in the first-layer ring beam 2 of the diaphragm wall, and the assembly of the pre-positioned steel support 5 is completed. Steel strand anchors 523 are distributed at the four corners of the steel waler of the pre-positioned steel support 5. Each through-hole jack 7 is connected to the corresponding steel strand anchor 523 on the pre-positioned steel support 5 through the corresponding steel strand 6. The servo cylinders 53 and the through-hole jacks 7 are connected to the hydraulic system. The adjustable support feet 54 are adjusted so that they extend and support the concrete pad 12. The adjustable support feet 54 are finely adjusted to make the pre-positioned steel support 5 horizontal. The servo cylinders 53 are driven by the hydraulic system to extend and apply a certain pressure to the diaphragm wall 1 to actively control the deformation of the diaphragm wall 1. The adjustable support feet 54 make the overall leveling of the steel support more convenient and reliable, and can effectively transfer the weight of the front-mounted steel support 5 to the ground, avoiding the servo cylinder 53 from being subjected to vertical force and torsional damage when horizontally supporting the underground continuous wall 1, thus ensuring construction safety and reasonable equipment stress.

[0083] Step 3, please refer to it carefully. Figure 19 Concrete or steel supports 10 are installed above the pre-positioned steel support 5 at the designed position, while the soil layer 11 is excavated. The pre-positioned steel support 5 enables excavation while supporting, thus improving the construction efficiency of the foundation pit.

[0084] Step 4, please refer to it carefully. Figure 20 Excavate the soil layer 11 to a certain depth, and pour a concrete cushion layer 12 on top of the soil layer 11.

[0085] Please refer to step 5 carefully. Figure 21 The hydraulic system drives the servo cylinder 53 to retract, checks the descent path of the front steel support 5 to ensure it is unobstructed, drives the through-hole jack 7 through the pressure system to lower the front steel support 5 to a certain distance above the current concrete cushion 12, levels the front steel support 5 through the through-hole jack 7, adjusts the adjustable support feet 54 to support it on the concrete cushion 12, and extends the servo cylinder 53 through the control hydraulic system to apply a certain pressure to the underground continuous wall 11, actively controlling the deformation of the underground continuous wall 1. Connect each lattice column 3 to the corresponding corner horizontal diagonal brace 56 through the connecting device 4. The front steel support 5 is used to support as it is excavated, improving the construction efficiency of the foundation pit excavation and support, reducing the time of over-excavation without support, and thus improving the safety of foundation pit construction.

[0086] Please refer to step 6 carefully. Figure 22 Repeat steps 3 to 5 until the excavation and support construction of the small ultra-deep foundation pit is completed, and dismantle the front-mounted steel support 5 at the bottom and lift its components away from the foundation pit.

[0087] The principle and effects of the pre-installed steel support system for small ultra-deep foundation pits involved in this invention are as follows: The pre-installed steel support 5, together with the diaphragm wall 1, traditional concrete supports, or steel supports 10, forms a support system for small ultra-deep foundation pits; the pre-installed steel support 5 is arranged before the traditional concrete supports or steel supports 10, allowing for simultaneous excavation, lowering, and support, which can shorten the time without support during over-excavation and enhance construction safety; the pre-installed steel support 5 integrates a servo hydraulic cylinder 53, which can apply pressure to the inner wall of the diaphragm wall 1, realizing active control of foundation pit deformation; the pre-installed steel... The support 5 utilizes a through-hole jack 7 in conjunction with steel strands 6 for overall descent, which improves the stability and safety of the descent. The corner horizontal braces 56 of the front-mounted steel support 5 are connected using detachable, highly adaptable connecting devices 4, which improves overall stability and construction efficiency. The front-mounted steel support 5 is equipped with adjustable support legs 54, which can improve overall stability. A working platform is set on the upper part of the front-mounted steel support 5, which enhances the convenience of construction. All components of the front-mounted steel support 5 adopt a standard modular design and are assembled, which can effectively improve the convenience of installation and dismantling and the efficiency of component turnover.

[0088] In summary, this invention achieves active control of the deformation of the underground continuous wall 1 by setting servo cylinders 53 around the steel waler of the front-mounted steel support 5, improves the turnover rate by adopting a modular assembly design, and shortens the construction period and over-excavation time by adopting the construction method of excavating, lowering and supporting as the concrete support or steel support 10 is placed in front, which has the advantages of high mechanization, strong construction safety and high turnover rate. In addition, (1) the corner horizontal diagonal brace 56 of the front-mounted steel support 5 is connected to the lattice column 3 by a special connecting device 4. The connecting device 4 can adapt to the position error of the lattice column 3, can follow the front-mounted steel support 5 to descend, and can be quickly installed and removed; (2) the front-mounted steel support 5 is raised and lowered as a whole by using a through-hole jack 7 and steel strand 6, which has the advantages of stable descent, safety and reliability and good synchronization; (3) the steel support is equipped with an adjustable corner brace 54, which can effectively transfer the self-weight of the front-mounted steel support 5 and the self-weight of the upper concrete to the ground. The front steel support 5 is kept horizontal and the servo cylinder 53 is not subjected to vertical torsional force when it supports the underground continuous wall 1 in the horizontal direction, thereby improving construction safety and equipment stress rationality; (4) An integral platform plate is set on the front steel support 5, which can be used as a working platform to carry the side formwork of workers, engineering materials and concrete support, and can also be used as the bottom formwork for the upper concrete pouring support, thereby avoiding frequent installation and dismantling of the formwork, effectively improving the turnover efficiency of the formwork, thereby improving the construction efficiency of the foundation pit and shortening the construction period.

[0089] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A pre-installed steel support system suitable for small, ultra-deep foundation pits, characterized in that, The system includes several lattice columns, several connecting devices, front-mounted steel supports, several steel strands, several through-hole jacks, several jack foundations, several steel strand guide frames, several servo cylinders, and a hydraulic system. The front-mounted steel supports include steel walers and several corner horizontal braces located at the four corners of the steel walers. A lattice column is correspondingly installed on the inner side of the innermost corner horizontal brace at each corner of the steel walers. The lattice columns are pre-pressed into the soil according to the design position. The innermost corner horizontal brace at each corner of the steel walers is connected to the corresponding lattice column through a corresponding connecting device. The several jack foundations are respectively located at the four corners of the first-floor ring beam of the continuous wall. Through-hole jacks are installed on the corresponding jack foundations. Steel strand guide frames are installed on the corresponding jack foundations or on the first-floor ring beam of the continuous wall. Steel strands are laid on the corresponding steel strand guide frames.The outer side of the steel waler and the two sides of the horizontal diagonal braces at the corners are each provided with several adjustable support feet at equal intervals via bolt connections. The hydraulic system is installed on the first-floor ring beam of the diaphragm wall, the ground, or a front-mounted steel support. Several servo cylinders are spaced circumferentially along the outer side of the steel waler. These servo cylinders and several through-hole jacks are connected to the hydraulic system. The servo cylinders extend and retract under the action of the hydraulic system, achieving active deformation control of the diaphragm wall. The several through-hole jacks are connected to the front-mounted steel support via corresponding steel strands. The four corners of the front-mounted steel support are connected. Several through-hole jacks, under the action of the hydraulic system, synchronously raise and lower the front-mounted steel support by winding and releasing corresponding steel strands. The connecting device includes a load-bearing triangular frame, a triangular frame support plate, two connecting angle steels, several welded nuts, several adjusting bolts, an adjusting support plate, two lattice column U-bolts, two lattice column connecting plates, four lattice column connecting nuts, a horizontal diagonal brace connecting plate, two horizontal diagonal brace U-bolts, and four horizontal diagonal brace connecting nuts. The load-bearing triangular frame is a right-angled triangular structure. The load-bearing triangular frame has... The system comprises a horizontal plane and a vertical plane. A horizontal diagonal brace connecting plate is fixedly installed on the horizontal plane, and a triangular support plate is fixedly installed on the vertical plane. The horizontal diagonal brace connecting plate and the triangular support plate are perpendicular to each other. Two connecting angle steels are vertically installed on the left and right sides of the triangular support plate, respectively. First through holes for U-bolts of the lattice columns are respectively opened on the upper and lower parts of the two connecting angle steels. After the two U-bolts clamp the lattice columns, they are connected through corresponding lattice column connecting plates and lattice column connecting nuts. The horizontal diagonal brace connecting plate extends along both sides of the vertical plane. A second through hole is made longitudinally for the corresponding horizontal diagonal brace U-bolts to pass through. The two horizontal diagonal brace U-bolts are connected to the corner horizontal diagonal brace connecting plate via corresponding horizontal diagonal brace connecting nuts. A third through hole is made on the upper and lower parts of the tripod support plate, and a threaded hole matching the adjusting bolt is provided at the third through hole. One end of the adjusting bolt passes through the corresponding threaded hole on the tripod support plate and is hinged to the adjusting support plate via a ball joint. Rotating the adjusting bolt moves the corresponding adjusting support plate, allowing the adjusting support plate to fit against the side of the lattice column.

2. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 1, characterized in that, The pre-installed steel support is located inside the diaphragm wall, and the pre-installed steel support is assembled below the first-floor ring beam of the diaphragm wall.

3. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 1, characterized in that, The load-bearing tripod includes two vertical members, two horizontal members, two diagonal members, and three horizontal members. The vertical members, horizontal members, and diagonal members are connected to form a triangular structure. The ends of the two triangular structures are connected by the three horizontal members. A horizontal diagonal brace connecting plate is placed on the upper part of the load-bearing tripod. The horizontal diagonal brace connecting plate is rigidly connected to the horizontal members and horizontal members of the tripod. The vertical members and horizontal members of the tripod are rigidly connected to the tripod support plate, so that the load-bearing tripod is supported on the tripod support plate.

4. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 1, characterized in that, Each adjustment support plate is hinged to three adjustment bolts, which are evenly spaced along the horizontal direction.

5. The pre-positioned steel support system for small, ultra-deep foundation pits as described in claim 1, characterized in that, The front-mounted steel support waler includes several straight steel beams and four L-shaped corner steel beams. The several straight steel beams are assembled into four strip steel beams by bolt connection. The ends of the four strip steel beams are connected by L-shaped corner steel beams to form a rectangular steel waler. The strip steel beams and the corresponding L-shaped corner steel beams are connected by bolt connection. The two ends of the corner horizontal bracing are respectively connected to the inner wall of the steel waler through corner horizontal bracing connecting sections. Several parallel corner horizontal bracings are set at each corner of the steel waler. Several connecting beams are set on the two parallel corner horizontal bracings located on the inner side. Scaffold boards are laid on the corner horizontal bracings as a working platform.

6. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 5, characterized in that, The connecting beam includes a connecting beam steel beam and two connecting beam end connecting plates. The two connecting beam end connecting plates are fixedly installed at both ends of the connecting beam steel beam. The two connecting beam end connecting plates are provided with through holes for connecting beam U-bolts to pass through. The corresponding corner horizontal diagonal bracing of the connecting beam U-bolt clamp is fixed to the corresponding connecting beam end connecting plate by connecting beam connecting nuts.

7. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 1, characterized in that, The corner horizontal bracing includes a corner bracing steel beam, two corner bracing end connecting plates, and several corner bracing foot connecting channel steels. The two corner bracing end connecting plates are respectively fixedly installed at both ends of the corner bracing steel beam. The corner bracing foot connecting channel steels are symmetrically arranged in pairs at equal intervals on both sides of the corner bracing steel beam along its longitudinal direction. Bolt holes for connecting corresponding corner horizontal bracing connecting sections are provided on the two corner bracing end connecting plates. Several adjustable support feet are provided at intervals on the corner bracing foot connecting channel steels for connecting corresponding adjustable support feet. The bolt holes; the corner horizontal brace connection section includes a connecting section steel beam, a connecting section corner brace connection plate and a connecting section steel waler connection plate, the connecting section corner brace connection plate and the connecting section steel waler connection plate are respectively rigidly connected to both ends of the connecting section steel beam, the connecting section steel waler connection plate is obliquely arranged, the connecting section corner brace connection plate is vertically arranged, the connecting section steel waler connection plate is provided with bolt holes for connecting the steel waler, and the connecting section corner brace connection plate is provided with bolt holes for connecting the corresponding corner horizontal brace.

8. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 5, characterized in that, The cross-section of the straight steel beam is H-shaped with double webs, and it is formed by fixing the web of the straight steel beam to the flanges of the straight steel beams on both sides; the cross-section of the L-shaped corner steel beam is H-shaped with double webs, and it is formed by fixing the web of the L-shaped corner steel beam to the flanges of the L-shaped corner steel beams on both the inner and outer sides; the web of the L-shaped corner steel beam has a hole, and a steel strand anchor is installed at the hole, and stiffening plates are installed on both sides of the steel strand anchor.

9. The pre-installed steel support system for small, ultra-deep foundation pits as described in claim 1, characterized in that, The servo cylinder includes a cylinder housing, an adjusting pad, a housing hook roller, and a cylinder body. The cylinder body is housed within the cylinder housing. A vertical end plate is provided at one end of the cylinder housing. An adjusting pad for adjusting the total extension of the servo cylinder is provided inside the cylinder housing. The adjusting pad is located between the vertical end plate and the cylinder body. A downward-opening housing hook for attaching to a steel waler is provided at the upper end of the vertical end plate. Several housing hook rollers are provided between the vertical end plate and the housing hook. Bolt holes for connecting to the steel waler are provided on the vertical end plate.

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