Horizontal displacement auxiliary device for highway bridge erecting machine

Abstract

The application provides a highway bridge erecting machine horizontal movement auxiliary device, which comprises two groups of leveling supporting pads, a truss supporting beam, a distribution beam group and a track supporting surface; the two groups of leveling supporting pads are arranged on two bridge decks respectively; the truss supporting beam is arranged above the bridge decks and is supported on the surfaces of the two groups of leveling supporting pads respectively; the distribution beam group comprises multiple groups of I-shaped steel arranged along the width direction of the truss supporting beam, each group of I-shaped steel comprises multiple I-shaped steels arranged along the length direction of the truss supporting beam at intervals; and the track supporting surface is arranged on the upper side of the distribution beam group and is fixedly connected with each I-shaped steel. The upper side of the track supporting surface is provided with a horizontal movement platform for supporting the bridge erecting machine, and at least four I-shaped steels are located directly below the horizontal movement platform during movement of the horizontal movement platform, so that the load can be dynamically distributed in a surface area and the stress concentration phenomenon can be avoided. The highway bridge erecting machine horizontal movement auxiliary device provided by the application can uniformly distribute the load and improve the safety during operation of the device and the stability of the overall structure.

Description

Technical Field

[0001] This application belongs to the field of highway construction technology, specifically relating to a lateral movement auxiliary device for a highway bridge erecting machine. Background Technology

[0002] A highway bridge erecting machine is a large, temporary construction device specifically designed to precisely install precast box girders, T-beams, and other bridge beams onto bridge piers. During construction, to enable rapid transfer between different bridge spans and avoid complete disassembly, the bridge erecting machine needs to be moved laterally.

[0003] Currently, the mainstream technology for achieving this lateral movement operation is to lay guide rails between adjacent bridge spans and to use supports such as wooden blocks and steel components between the guide rails and the bridge deck to accommodate the height difference between adjacent bridge spans and ensure the flatness of the guide rails.

[0004] However, the inventors discovered that during this lateral movement, the overall center of gravity of the bridge erecting machine shifts along the guide rail surface, causing the load on the guide rail to concentrate in a localized area, resulting in significant stress concentration. This problem not only significantly increases the strength requirements of the guide rail material but also significantly shortens the service life of the guide rail due to localized overload. Utility Model Content

[0005] This application provides a lateral movement auxiliary device for a highway bridge erecting machine, which aims to distribute the load evenly, avoid stress concentration, and improve the safety and structural stability of the device during operation.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: A lateral movement auxiliary device for a highway bridge erecting machine is provided, comprising two sets of leveling supports for fixing respectively to two bridge decks; the lateral movement auxiliary device further includes: A truss support beam is used to be installed above the bridge deck, and its two ends are respectively supported on the surfaces of the two sets of leveling pads; A distribution beam assembly, disposed on the upper side of the truss support beam, includes at least two sets of I-beams arranged along the width direction of the truss support beam, each set of I-beams comprising a plurality of I-beams spaced apart along the length direction of the truss support beam; and A track support surface is fixedly installed on the upper side of the distribution beam group and is fixedly connected to each of the I-beams; above the track support surface is a transverse platform that is slidably connected to it, the top surface of the transverse platform is used to support the bridge erecting machine, and during the movement of the transverse platform, at least four of the I-beams are directly below it.

[0007] In one possible implementation, the truss support beam includes: Multiple sets of assembly bodies are arranged on the upper side of the leveling support along the lateral movement direction of the bridge erecting machine, and adjacent sets of assembly bodies are connected. Each assembly includes two assemblies spaced apart along the direction perpendicular to the transverse movement of the bridge erecting machine; the adjacent sides of the two assemblies each have a protrusion with a triangular cross-section, and the two protrusions are connected to form a reinforcing structure.

[0008] In one possible implementation, the bracket includes: A vertical reinforcing arm is fixedly connected to the assembled body, and its end abuts against an adjacent assembled body; and An oblique reinforcing arm, one end of which is connected to the abutting end of the vertical reinforcing arm, and the other end of which is connected to the assembled body, to form a right-angled triangular structure; When two adjacent assembly bodies are combined along a direction perpendicular to the lateral movement of the bridge erecting machine, the corresponding two oblique reinforcing arms are connected.

[0009] In one possible implementation, each of the inclined reinforcing arms has a through hole extending along the thickness direction, and when two of the inclined reinforcing arms are joined together, the corresponding two through holes are interconnected. Each assembly group also includes: A butt bolt, adapted to be inserted into two interconnected through holes, its head abutting against the outer side of one of the inclined reinforcing arms; and A mating nut is threaded onto the shank of the mating bolt and is adapted to abut against the outer side of the other inclined reinforcing arm to clamp the two inclined reinforcing arms in conjunction with the head of the mating bolt.

[0010] In one possible implementation, a positioning structure is provided between two adjacent assembled bodies along the lateral movement direction of the bridge erecting machine, the positioning structure comprising: Two positioning screws are respectively fixedly installed on the outer sides of the two assembled bodies; Alignment shims, disposed on the outer surface of the assembled body, having two alignment holes adapted for the passage of the two positioning screws respectively; and Two locking nuts are threaded onto the two positioning screws respectively and abut against the outer side of the alignment washer.

[0011] In one possible implementation, the junction of two adjacent assembled bodies along the lateral movement direction of the bridge erecting machine has an outwardly extending bend, and the two bends connect synchronously when the two assembled bodies connect.

[0012] In one possible implementation, the contact surface of the bent portion has a groove that extends in the vertical direction; When the two bends meet, the two adjacent grooves abut to form a plug hole for inserting welding wire or welding rod.

[0013] In one possible implementation, the lateral movement auxiliary device for the highway bridge erecting machine further includes: A reinforcing pad is used to be installed between two bridge decks, with its two ends respectively supporting the two bridge decks, and the upper side of the reinforcing pad supports the truss support beam.

[0014] In one possible implementation, the reinforcing support has two side wing plates that abut against the outer surfaces of the two bridge sections respectively, so as to restrict the movement of the reinforcing support along the lateral direction of the bridge erecting machine; Furthermore, the upper end of the side wing plate also has an upwardly extending and inwardly bent suspension portion, and the suspension portion is adapted to be fastened to the upper side of the reinforcing pad.

[0015] In one possible implementation, each set of leveling supports includes a plurality of leveling supports fixed between the truss support beam and the bridge deck; Of the plurality of I-beams located above the bridge deck, each I-beam has at least one leveling pad directly below it.

[0016] In this embodiment, the load applied by the bridge erecting machine is distributed step by step through the force transmission path of the transverse platform, the track support surface, the distribution beam group, the truss support beam, and the leveling pad. At the same time, since at least four I-beams are directly below the transverse platform during its movement, the load can be dynamically distributed to a surface area rather than a point at any time, which greatly reduces the pressure on a single support point.

[0017] The lateral movement auxiliary device for highway bridge erecting machines provided in this embodiment, compared with the prior art, effectively disperses the load, avoiding excessive local pressure and deformation in the structure, ensuring the stability of the highway bridge erecting machine during lateral movement, and effectively preventing jamming, impact, and other phenomena. Simultaneously, it transforms concentrated loads into uniformly distributed loads, greatly reducing the maximum compressive stress acting on the pier cap beam (i.e., the bridge deck in conjunction with this device), avoiding damage such as crushing and cracking of the newly constructed bridge deck concrete structure during lateral movement, and ensuring project quality. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1A three-dimensional structural schematic diagram of the lateral movement auxiliary device for a highway bridge erecting machine provided in the embodiments of this application; Figure 2 for Figure 1 Front view; Figure 3 for Figure 2 A magnified view of a portion of the middle circle A; Figure 4 This is an exploded structural diagram of the distribution beam group, track support surface, and transverse platform used in the embodiments of this application; Figure 5 This is an exploded structural diagram of the reinforcing support and side wing plate used in the embodiments of this application; Figure 6 This is a partial schematic diagram of the distribution beam assembly used in the embodiments of this application from a top view. Figure 7 This is an exploded view of the positioning structure used in the embodiments of this application; Figure 8 This is a partially enlarged schematic diagram of the distribution beam assembly used in the embodiments of this application from a stereoscopic perspective; Figure 9 This is an exploded view of the two assembled bodies used in the embodiments of this application; Explanation of reference numerals in the attached drawings: 1. Leveling support; 2. Assembled body; 21. Bending part; 211. Groove; 3. I-beam; 4. Track support surface; 5. Lateral platform; 6. Plug; 61. Vertical reinforcing arm; 62. Angled reinforcing arm; 621. Through hole; 7. Butt bolt; 71. Butt nut; 8. Positioning structure; 81. Positioning screw; 82. Alignment washer; 821. Alignment hole; 83. Locking nut; 9. Reinforcing support; 91. Side wing plate; 911. Suspension part. Detailed Implementation

[0020] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0024] Please refer to the following: Figures 1 to 9 The lateral movement auxiliary device for highway bridge erecting machines provided in this application will now be described. The lateral movement auxiliary device for highway bridge erecting machines proposed in this application includes two sets of leveling supports 1, truss support beams, distribution beam groups, and track support surfaces 4.

[0025] Two sets of leveling supports 1 are fixed to the two adjacent bridge decks respectively. During installation, the elevation of their top surfaces must be precisely controlled to ensure that the deviation between the two sets does not exceed 3mm, so as to guarantee the levelness of the subsequent support structure. In special cases, this value can be relaxed to 5mm, as long as the subsequent related components can maintain stable operation and the main body of the bridge erecting machine does not tilt.

[0026] The truss support beam is erected above the bridge deck, with its two ends supported on the upper surfaces of two sets of leveling pads 1, to bear the load transmitted by the superstructure and to have sufficient rigidity and stability.

[0027] The distribution beam group is arranged on the upper side of the truss support beam. In this embodiment, the distribution beam group includes at least two sets of I-beams 3, which are arranged along the width direction of the truss support beam, and each set of I-beams 3 includes multiple I-beams 3 spaced apart along the length direction of the truss support beam. Through the above structure, a uniformly distributed support grid can be formed to improve the load-bearing capacity and distribute the load.

[0028] The track support surface 4 is a panel structure, which is fixedly installed above the distribution beam group and firmly connected to each I-beam 3 (usually by welding). Two tracks are fixedly installed on the upper side of the track support surface 4, and the transverse platform 5 is slidably connected to the track support surface 4 through these tracks.

[0029] In actual use, the top of the transverse platform 5 is used to support the main structure of the bridge erecting machine, and at least four I-beams 3 are always kept below it to provide continuous support during the transverse movement, so as to ensure smooth and safe movement.

[0030] It should be noted that, under normal circumstances (without relying on the mobility of the bridge erecting machine itself), the transverse platform 5 is also equipped with drive components for moving it relative to the track support surface 4.

[0031] In this embodiment, the load applied by the bridge erecting machine is distributed step by step through the force transmission path of the transverse platform 5, the track support surface 4, the distribution beam group, the truss support beam, and the leveling pad 1. At the same time, since at least four I-beams 3 are directly below the transverse platform 5 during its movement, the load can be dynamically distributed to a surface area rather than a point at any time, which greatly reduces the pressure of a single support point.

[0032] The lateral movement auxiliary device for highway bridge erecting machines provided in this embodiment, compared with the prior art, effectively disperses the load, avoiding excessive local pressure and deformation in the structure, ensuring the stability of the highway bridge erecting machine during lateral movement, and effectively preventing jamming, impact, and other phenomena. Simultaneously, it transforms concentrated loads into uniformly distributed loads, greatly reducing the maximum compressive stress acting on the pier cap beam (i.e., the bridge deck in conjunction with this device), avoiding damage such as crushing and cracking of the newly constructed bridge deck concrete structure during lateral movement, and ensuring project quality.

[0033] In some embodiments, such as Figure 6 As shown, the truss support beam consists of multiple sets of assembled parts 2.

[0034] Multiple sets of assembly bodies 2 are arranged on the upper side of the leveling support 1 along the lateral movement direction of the bridge erecting machine, and adjacent sets of assembly bodies 2 are connected. Furthermore, each set of assembly bodies 2 includes two assembly bodies 2, which are spaced apart along a direction perpendicular to the lateral movement direction of the bridge erecting machine. The adjacent sides of the two assembly bodies 2 each have a protrusion 6 with a triangular cross-section, and the two protrusions 6 are connected to form a reinforcing structure to ensure the structural strength of the truss support beam when supporting the upper components.

[0035] In some embodiments, such as Figures 6 to 9 As shown, the bracket 6 includes a vertical reinforcing arm 61 and an oblique reinforcing arm 62.

[0036] The vertical reinforcing arm 61 is vertically installed on the assembly body 2. Its bottom is firmly connected to the assembly body 2, and its top directly abuts against the corresponding part of the adjacent assembly body 2. It mainly bears the vertical load to enhance the vertical stability of the structure.

[0037] The two ends of the oblique reinforcing arm 62 are connected to the abutting end of the vertical reinforcing arm 61 and the lower assembly body 2, respectively, thus forming a stable right-angled triangular support unit together with the vertical reinforcing arm 61 and the assembly body 2. This structure can effectively transfer horizontal forces to the main structure, significantly improving the overall lateral stiffness.

[0038] When two assembly bodies 2 are combined along a direction perpendicular to the lateral movement of the bridge erecting machine, their corresponding diagonal reinforcing arms 62 will connect to each other at the middle. This docking method connects adjacent triangular stabilizing units into one, forming a continuous reinforcement system spanning the two assembly bodies 2, ensuring overall stiffness and stability in this direction.

[0039] In some embodiments, such as Figure 9 As shown, each inclined reinforcing arm 62 has a through hole 621 extending along the thickness direction, and when two inclined reinforcing arms 62 are connected, the corresponding two through holes 621 are interconnected.

[0040] In this embodiment, each assembly 2 also includes a docking bolt 7 and a docking nut 71.

[0041] The butt bolt 7 is adapted to be inserted into two interconnected through holes 621, with its head abutting against the outer side of one of the inclined reinforcing arms 62.

[0042] The mating nut 71 is threaded onto the shank of the mating bolt 7 and is adapted to abut against the outer side of another oblique reinforcing arm 62 so as to clamp the two oblique reinforcing arms 62 with the head of the mating bolt 7.

[0043] In some embodiments, such as Figure 3 , Figure 7 and Figure 8 As shown, there is a positioning structure 8 between two adjacent assembly bodies 2 along the lateral movement direction of the bridge erecting machine; in this embodiment, the positioning structure 8 includes two positioning screws 81, alignment washers 82 and two locking nuts 83.

[0044] Two positioning screws 81 are pre-fixed vertically (e.g., welded) to the outer side of two adjacent assembly bodies 2; here, the outer side of the assembly body 2 refers to the side of the assembly body 2 that is away from the other assembly body 2 in the same group (i.e., another assembly body 2 that is vertically parallel to the other assembly body 2 along the transverse direction of the bridge erecting machine).

[0045] Alignment shims 82 are located on the outer side of the assembly body 2, and two alignment holes 821 are machined on them. The diameter and spacing of the holes must be such that two positioning screws 81 can be fitted in simultaneously. During actual assembly, the alignment shims 82 achieve initial positioning with the two assembly bodies 2 through the two alignment holes 821.

[0046] Two locking nuts 83 are screwed into the threaded ends of the two positioning screws 81 respectively, and after passing through the alignment washer 82, they are tightened from the outside, so that the alignment washer 82 is pressed tightly against the side of the assembly body 2, thereby completing the final connection and locking.

[0047] The alignment principle of this structure is as follows: when two adjacent assembly bodies 2 are connected, the operator inserts the two alignment holes 821 on the alignment pad 82 into the two positioning screws 81 respectively. This process completes the precise positioning of the assembly body 2 in the plane. Then, by tightening the locking nuts 83 on both sides, the alignment pad 82 can be firmly pressed, and the two assembly bodies 2 can be reliably connected.

[0048] In some embodiments, such as Figure 6 and Figure 8 As shown, the joint of two adjacent assembly bodies 2 along the transverse direction of the bridge erecting machine has an outwardly extending bend 21. This bend 21 is located at the end of the assembly body 2, and the two bends 21 are connected synchronously when the two assembly bodies 2 are connected.

[0049] By setting the bending part 21, the contact area between the two assembled bodies 2 and the total length of the edges can be increased; when welding the two assembled bodies 2, this structural design can increase the welding strength.

[0050] In some embodiments, such as Figure 6 and Figure 8 As shown, the contact surface of the bent portion 21 has a groove 211 that runs through the vertical direction.

[0051] When the two bends 21 are joined, the two adjacent grooves 211 are joined to form a plug welding hole for inserting welding wire or welding rod, so as to realize plug welding and improve the strength of the combined structure.

[0052] In some embodiments, such as Figure 1 and Figure 2 As shown, the lateral movement auxiliary device for highway bridge erecting machine also includes a reinforcing support 9, which is used to be installed between two bridge decks. Its two ends are respectively supported on the two bridge decks, and the upper side of the reinforcing support 9 supports the truss support beam to ensure that the suspended truss support beam has relevant accessories for support and to avoid breakage accidents at the suspended point.

[0053] In some embodiments, such as Figure 2 and Figure 5 As shown, the reinforcing support 9 has two side plates 91, each of which is securely attached to the reinforcing support 9 in the field by means of welding.

[0054] When the reinforcing support 9 and the truss support beam are fixed in the installation position at the same time, the two side wing plates 91 respectively abut against the adjacent sides of the two bridge bodies to restrict the movement of the reinforcing support 9 along the lateral movement direction of the bridge erecting machine.

[0055] The upper end of the side wing plate 91 also has an upwardly extending and inwardly bent suspension portion 911, which is adapted to be fastened to the upper side of the reinforcing support 9 to increase the contact area and ensure the stability of the welded structure.

[0056] In some embodiments, such as Figure 8 As shown, each set of leveling supports 1 includes multiple leveling supports 1, which are fixed in the gap between the truss support beam and the bridge deck to support the truss support beam. By selecting leveling supports 1 of different heights based on the pre-measured height difference of the bridge deck, the flatness of the overall structure can be ensured. Furthermore, the leveling supports 1 also serve to evenly distribute the superstructure load to the bridge deck.

[0057] Among the multiple I-beams 3 located above the bridge deck, each I-beam 3 has at least one leveling support 1 directly below it. Specifically, in the distribution beam group located directly above the bridge deck, each I-beam 3 has at least one leveling support 1 directly below it, forming a "one-beam-to-one-support" method. This ensures that the concentrated load transmitted by the I-beam 3 can be directly and efficiently transmitted to the bridge deck structure through the leveling support 1, avoiding excessive local stress on the truss support beam, thereby ensuring the stability and reliability of the overall support system.

[0058] The above content is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A lateral movement auxiliary device for a highway bridge erecting machine, comprising two sets of leveling supports respectively fixed to two bridge decks; characterized in that, The lateral movement assist device also includes: A truss support beam is used to be installed above the bridge deck, and its two ends are respectively supported on the surfaces of the two sets of leveling pads; A distribution beam assembly, disposed on the upper side of the truss support beam, includes at least two sets of I-beams arranged along the width direction of the truss support beam, each set of I-beams comprising a plurality of I-beams spaced apart along the length direction of the truss support beam; and A track support surface is fixedly installed on the upper side of the distribution beam group and is fixedly connected to each of the I-beams; above the track support surface is a transverse platform that is slidably connected to it, the top surface of the transverse platform is used to support the bridge erecting machine, and during the movement of the transverse platform, at least four of the I-beams are directly below it.

2. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 1, characterized in that, The truss support beam includes: Multiple sets of assembly bodies are arranged on the upper side of the leveling support along the lateral movement direction of the bridge erecting machine, and adjacent sets of assembly bodies are connected. Each assembly includes two assemblies spaced apart along the direction perpendicular to the transverse movement of the bridge erecting machine; the adjacent sides of the two assemblies each have a protrusion with a triangular cross-section, and the two protrusions are connected to form a reinforcing structure.

3. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 2, characterized in that, The protrusion includes: A vertical reinforcing arm is fixedly connected to the assembled body, and its end abuts against an adjacent assembled body; and An oblique reinforcing arm, one end of which is connected to the abutting end of the vertical reinforcing arm, and the other end of which is connected to the assembled body, to form a right-angled triangular structure; When two adjacent assembly bodies are combined along a direction perpendicular to the lateral movement of the bridge erecting machine, the corresponding two oblique reinforcing arms are connected.

4. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 3, characterized in that, Each of the inclined reinforcing arms has a through hole extending along the thickness direction, and when two of the inclined reinforcing arms are connected, the corresponding two through holes are interconnected. Each assembly group also includes: A butt bolt, adapted to be inserted into two interconnected through holes, its head abutting against the outer side of one of the inclined reinforcing arms; and A mating nut is threaded onto the shank of the mating bolt and is adapted to abut against the outer side of the other inclined reinforcing arm to clamp the two inclined reinforcing arms in conjunction with the head of the mating bolt.

5. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 2, characterized in that, A positioning structure is provided between two adjacent assembled bodies along the lateral movement direction of the bridge erecting machine, the positioning structure including: Two positioning screws are respectively fixedly installed on the outer sides of the two assembled bodies; Alignment shims, disposed on the outer surface of the assembled body, having two alignment holes adapted for the passage of the two positioning screws respectively; and Two locking nuts are threaded onto the two positioning screws respectively and abut against the outer side of the alignment washer.

6. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 2, characterized in that, The joint of two adjacent assembled bodies along the lateral movement direction of the bridge erecting machine has an outwardly extending bend, and the two bends are connected synchronously when the two assembled bodies are connected.

7. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 6, characterized in that, The contact surface of the bent portion has a groove that runs through the vertical direction. When the two bends meet, the two adjacent grooves abut to form a plug hole for inserting welding wire or welding rod.

8. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 1, characterized in that, The lateral movement auxiliary device for the highway bridge erecting machine also includes: A reinforcing pad is used to be installed between two bridge decks, with its two ends respectively supporting the two bridge decks, and the upper side of the reinforcing pad supports the truss support beam.

9. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 8, characterized in that, The reinforcing support has two side wing plates that abut against the outer surfaces of the two bridge sections respectively, so as to restrict the movement of the reinforcing support along the lateral direction of the bridge erecting machine; Furthermore, the upper end of the side wing plate also has an upwardly extending and inwardly bent suspension portion, and the suspension portion is adapted to be fastened to the upper side of the reinforcing pad.

10. The lateral movement auxiliary device for a highway bridge erecting machine as described in claim 1, characterized in that, Each set of leveling supports includes multiple leveling supports fixed between the truss support beam and the bridge deck; Of the plurality of I-beams located above the bridge deck, each I-beam has at least one leveling pad directly below it.

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