Straight web member-free triangular truss type steel truss girder erection method

Abstract

The invention provides a method for erecting a triangular truss type steel truss girder without a straight web member, and belongs to the field of bridge construction. The problems that the horizontal projection length of a triangular truss type steel truss girder structure without a straight web member is long, and the gravity center position is difficult to determine, so that the aerial posture cannot be controlled are solved. And the operation of the cable crane is influenced by the water level height. The temporary inclined rods and the balance cables are effectively connected with the triangular truss type steel truss girder without the straight web members, so that the triangular truss type steel truss girder is changed into a parallelogram type steel truss girder, the gravity center of the steel truss girder is conveniently determined, the stability of the aerial posture of a steel truss girder section is ensured, and the safety degree during hoisting and erecting is improved; the problem that the length of the horizontal projection of the section is long after the section of the triangular truss type steel truss girder without the straight web member is divided is solved by utilizing secondary swinging and shifting; due to the arrangement of the high-position sliding support and the low-position sliding support, the use amount of support steel is reduced, the construction cost is reduced, the construction of the cable crane is not limited by the height of the water level, and the method is very wide in market prospect.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a method for erecting a triangular truss steel truss without a straight web member. Background Art

[0002] A suspension bridge is a large-span flexible structure bridge. For suspension bridges across large rivers, cable-mounted cranes are often used to erect stiffening beams. Usually, the cable-mounted crane lifts the segment on the beam transport ship vertically, swings it to the sliding bracket once, and then slides the segment to the predetermined position. With the continuous development of bridge construction, the structural types of stiffening beams are also diverse, such as steel box beams, composite beams, steel trusses, etc. Among them, the structural types of steel trusses also vary. Some designs have straight webs, while others do not. For triangular truss steel trusses without straight webs, an unstable triangular truss structure is presented after segment division. The horizontal projections of the upper and lower chords are misaligned, and the horizontal projection length of the segments is long, resulting in the steel trusses needing to be lifted and swung twice before they can fall to the sliding bracket, and the center of gravity position is difficult to determine. The length of the lifting truss structure of a conventional cable-mounted crane is 15m, but in reality it is much longer than 15m. During the lifting process, the upper chord of the beam to be lifted is very likely to collide with the lower chord of the beam that has been lifted, making it difficult to lift into place.

[0003] In addition, the operation of cable-mounted cranes is often restricted by the water level. The practice of "waiting for the water to rise" makes it difficult to guarantee the construction period. If the sliding bracket is extended to the deep water area, the construction cost will increase greatly. In summary, how to improve the stress of the triangular truss steel truss structure without straight webs during the lifting process, and control its aerial posture under the premise that the center of gravity is difficult to determine, to ensure that the lifting and erection operations can be carried out in an orderly manner regardless of the dry season or the flood season, is an issue that needs to be urgently addressed. For the triangular truss steel truss structure without straight webs, how to meet the stress safety during the lifting and erection process, minimize the use of sliding brackets, and ensure that the construction is not affected by the water level, this series is directly related to the structural safety and affects the construction cost.

[0004] Therefore, it is particularly important to develop a construction method for erecting triangular truss steel trusses without straight web members.

[0005] Existing patents, such as a suspension bridge steel truss lifting and swinging device (application number: CN201910065307.2), include a lifting winch installed on the top of the cable tower, a swinging winch installed on the river bank, a lifting rope connected to the lifting winch at one end and fixed to the main cable at the other end through an anchoring cable clamp, an upper pulley located in front of the anchoring cable clamp and fixed to the main cable through the main cable clamp and suspending the lifting rope, a lower pulley suspended on the lifting rope, a sling suspended on the lower pulley, an adjustable sling rope and a fixed-length sling rope connecting the sling and the steel truss, and a swinging cable connected to the lower pulley and the sling at one end and the swinging winch at the other end. It has the advantages of good economy and high reliability. However, it is not suitable for triangular truss steel trusses without straight webs whose center of gravity is difficult to determine, which will make the shape difficult to control during the swinging process, seriously affecting the construction safety, and the influence of water level on the cable-mounted crane is not considered. Summary of the invention

[0006] The technical problems to be solved by the present invention are:

[0007] In order to solve the problem that the triangular truss steel truss structure without straight webs has a long horizontal projection length and the center of gravity is difficult to determine, resulting in the inability to accurately control its aerial posture; and the operation of the cable-mounted crane is affected by the water level.

[0008] The present invention adopts the following technical solutions to solve the above technical problems:

[0009] The present invention provides a method for erecting a triangular truss steel truss without a straight web member, comprising the following steps:

[0010] S100, assembling a temporary diagonal rod for a triangular truss steel truss without a straight web member, wherein the temporary diagonal rod is parallel to the diagonal rod of the triangular truss steel truss and is used to stabilize the position of the triangular truss steel truss in the air;

[0011] S200, construct the cable tower, set up the main cable, install the sling, install the low-position sliding bracket and the high-position sliding bracket, and install the high-position sliding bracket and the low-position sliding bracket in sequence near the cable tower and on both sides of the water area;

[0012] S300. Use beam transport vessels and cable-mounted cranes to symmetrically erect steel trusses from the middle of the span to the side span within normal waters. Use two swing shifts to place the steel trusses at the predetermined positions on the high-position sliding brackets. Then assemble the steel trusses. After installation, remove the temporary diagonal bars. Finally, carry out the steel beam jointing construction.

[0013] Furthermore, the triangular truss-type steel truss beam without a straight web includes an upper chord, a lower chord and a diagonal bar, wherein the upper chord and the lower chord are arranged in parallel with each other in an offset manner, and three diagonal bars arranged in a Z shape are arranged between the upper chord and the lower chord, and two ends of the middle diagonal bar of the three diagonal bars arranged in the Z shape are respectively connected to the upper chord and the lower chord.

[0014] Furthermore, the other two oblique rods are arranged in parallel and the ends thereof are respectively connected to the connection points between the middle oblique rod and the upper chord rod and the lower chord rod.

[0015] Furthermore, the added temporary diagonal rod is arranged parallel to the middle diagonal rod and crosses with the longer diagonal rod of the other two diagonal rods.

[0016] Furthermore, the low-level sliding support includes low-level guide hole anchor piles, low-level bored piles, low-level steel pipe piers, a low-level connecting system, a low-level lateral distribution beam and a low-level longitudinal slideway. The low-level guide hole anchor piles and the low-level bored piles are both used to be fixed in the underwater ground. The low-level guide hole anchor piles and the low-level bored piles are both connected to the low-level longitudinal slideway located in the same plane through the low-level steel pipe piers, and a low-level connecting system is provided between the low-level steel pipe piers.

[0017] Furthermore, the high-level sliding support includes high-level hole-drawing anchor piles, high-level bored piles, high-level steel pipe piers, a high-level connecting system, a high-level transverse distribution beam and a high-level longitudinal slideway. The high-level hole-drawing anchor piles and the high-level bored piles are both used to be fixed in the underwater ground. The high-level hole-drawing anchor piles and the high-level bored piles are both connected to the high-level longitudinal slideway located in the same plane through the high-level steel pipe piers, and a high-level connecting system is provided between the high-level steel pipe piers.

[0018] Furthermore, in step S300, it specifically includes:

[0019] S310. The steel truss beam is transported to the lifting position by a beam transport ship, and a protective pile is set at the lifting position. The cable-mounted crane moves to the A# sling clamp position and lifts the beam segment to the designed height. During this process, the front and rear ends of the steel truss beam segment are connected to one end of the balance cable, and the other end of the balance cable is connected to the main cable. A temporary sling is connected to the lower end of the B# sling, and the lower anchor head of the sling is connected to the ear plate of the segment beam hoist. After the installation is completed, the cable-mounted crane is slowly unloaded to swing the steel truss beam segment to the B# sling position, completing the first swing of the segment.

[0020] S320, the cable-mounted crane moves to the position of the C# sling clamp and is anchored with the sling, slowly loads the steel truss through the cable-mounted crane, and makes the segment swing to the position of the C# sling, releases the connection between the B# sling and the temporary sling and the steel truss, and lowers the steel truss to the low-level longitudinal slideway of the low-level sliding bracket by the cable-mounted crane, slides the steel truss to the side span on the low-level sliding bracket to the predetermined position, repeats the above arrangement, and sequentially hoists the steel truss segments outside the water area to the low-level sliding bracket;

[0021] S330. Similarly, the steel truss beam segments are swung to the high-position sliding bracket in sequence through secondary swinging, and are slid to a predetermined position on the high-position longitudinal sliding track on the high-position sliding bracket, thereby completing the placement of all the steel trusses.

[0022] S340, install steel trusses from the middle of the span and both sides toward the tower area. During installation, first hinge the upper chord, and after the linear adjustment is stable, rigidly connect the upper chord, and then remove the temporary diagonal bars; adjust the position and elevation of the side span steel trusses by jacks, and carry out the steel beam joint construction.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a method for erecting a triangular truss steel truss without a straight web. The method utilizes a temporary diagonal rod and a balancing cable to effectively connect the triangular truss steel truss without a straight web, so that the triangular truss steel truss is transformed into a parallelogram-shaped steel truss, which is convenient for determining the center of gravity thereof, thereby ensuring the stability of the aerial posture of the steel truss segment and improving the safety during hoisting and erection. The method utilizes "secondary swing", that is, the conversion of the force system from a cable-mounted crane → a sling (temporary sling) → a cable-mounted crane, thereby solving the problem of long horizontal projection length of the segment after the triangular truss steel truss without a straight web is divided. The provision of high and low position sliding brackets reduces the amount of bracket steel material used, reduces the construction cost, and enables the construction of the cable-mounted crane to be not restricted by the water level. The method has a very broad market prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of a triangular truss steel truss girder segment without a straight web member in an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the segment division of the triangular truss steel truss beam in the embodiment of the present invention;

[0027] Figure 3 The process of the method for erecting a triangular truss steel truss without a straight web member in an embodiment of the present invention is as follows Figure 1 ;

[0028] Figure 4 The process of the method for erecting a triangular truss steel truss without a straight web member in an embodiment of the present invention is as follows Figure 2 ;

[0029] Figure 5 The process of the method for erecting a triangular truss steel truss without a straight web member in an embodiment of the present invention is as follows Figure 3 ;

[0030] Figure 6 The process of the method for erecting a triangular truss steel truss without a straight web member in an embodiment of the present invention is as follows Figure 4 ;

[0031] Figure 7 It is a schematic diagram of the structure of the low-position sliding bracket and the high-position sliding bracket in an embodiment of the present invention.

[0032] Description of reference numerals:

[0033] 1. Cable-mounted crane; 2. Balance cable; 3. Lifting rope; 4. Temporary lifting rope; 5. Hoisting equipment; 6. Steel truss; 7. Beam transport ship; 8. Protective piles; 9. Cable tower; 10. Main cable; 11. Low-level sliding bracket; 12. High-level sliding bracket; 61. Upper chord; 62. Lower chord; 63. Diagonal rod; 64. Temporary diagonal rod; 111. Low-level lead hole anchor pile; 112. Low-level bored pile; 113. Low-level steel pipe pier; 114. Low-level connecting system; 115. Low-level transverse distribution beam; 116. Low-level longitudinal slideway; 121. High-level lead hole anchor pile; 122. High-level bored pile; 123. High-level steel pipe pier; 124. High-level connecting system; 125. High-level transverse distribution beam; 126. High-level longitudinal slideway. DETAILED DESCRIPTION

[0034] In the description of the present invention, it should be noted that the terminology nouns in the various embodiments, such as "up", "down", "front", "back", "left", "right", etc., which indicate directions, are only for simplifying the description of the positional relationship based on the drawings in the specification, and do not mean that the referred elements and devices must be operated according to the specific directions and defined operations and methods and structures in the specification. Such directional nouns do not constitute a limitation on the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Specific implementation plan 1: Combine Figures 1 to 7 As shown, the present invention provides a method for erecting a triangular truss steel truss without a straight web member, comprising the following steps:

[0037] S100, assemble temporary diagonal rods 64 on the triangular truss steel truss beam 6, and combine Figure 1 As shown, the conventional triangular truss steel truss beam 6 without a straight web member comprises an upper chord 61, a lower chord 62 and an oblique rod 63, wherein the upper chord 61 and the lower chord 62 are arranged in parallel and offset, and three oblique rods 63 arranged in a Z shape are arranged between the upper chord 61 and the lower chord 62, wherein the two ends of the middle oblique rod of the three Z-shaped oblique rods 63 are respectively connected to the upper chord 61 and the lower chord 62, and the other two oblique rods 63 are arranged in parallel and the ends are respectively connected to the middle oblique rod 63 and the connection between the upper chord 61 and the lower chord 62, and the sum of the lengths of the two oblique rods 63 is equal to the length of the middle oblique rod 63. Figure 2 As shown, the triangular truss steel truss beam 6 segment can be divided into a plurality of equal-length triangular truss steel truss beams 6 without straight web members; the added temporary diagonal rod 64 is arranged parallel to the middle diagonal rod 63 and crosses with the longer diagonal rod 63 of the other two diagonal rods 63; it is used to make the triangular truss steel truss beam 6 a parallelogram-like structure, and its center of gravity position is easy to determine, so as to control its posture in subsequent steps;

[0038] S200, installing a low-position sliding bracket 11 and a high-position sliding bracket 12, and sequentially installing a high-position sliding bracket 12 and a low-position sliding bracket 11 on both sides of the cable tower 9 and the water area, and combining Figure 7 As shown, the low-position sliding support 11 includes a low-position guide hole anchor pile 111, a low-position bored pile 112, a low-position steel pipe pier 113, a low-position connecting system 114, a low-position transverse distribution beam 115 and a low-position longitudinal slideway 116. The low-position guide hole anchor pile 111 and the low-position bored pile 112 are both used to be fixed in the underwater ground, and the fixing method is determined according to the hardness of the ground. The low-position guide hole anchor pile 111 and the low-position bored pile 112 are connected to the low-position longitudinal slideway 116 located in the same plane through the low-position steel pipe pier 113, and a low-position connecting system 114 is provided between the low-position steel pipe piers 113; Similarly, the high-position sliding support 12 includes a high-position hole anchor pile 121, a high-position bored pile 122, a high-position steel pipe pier 123, a high-position connecting system 124, a high-position transverse distribution beam 125 and a high-position longitudinal sliding way 126. The high-position hole anchor pile 121 and the high-position bored pile 122 are both used to be fixed in the underwater ground, and the fixing method is determined according to the hardness of the ground. The high-position hole anchor pile 121 and the high-position bored pile 122 are connected to the high-position longitudinal sliding way 126 located in the same plane through the high-position steel pipe pier 123, and a high-position connecting system 124 is provided between the high-position steel pipe piers 123;

[0039] S300, construct the cable tower 9, erect the main cable 10, install the sling 3, use the beam transport ship 7 and the cable crane 1 to symmetrically erect the steel truss 6 from the middle of the span to the side span in the normal waters, place the steel truss 6 at the predetermined position of the high-position sliding bracket 12 by swinging twice, then assemble the steel truss 6, remove the temporary diagonal rod 64 after the installation is completed, and finally carry out the steel beam joint construction, which specifically includes:

[0040] S310, combined Figures 3 to 5 As shown, the cable tower 9 is constructed, the main cable 10 is erected, the sling 3 is installed, the steel truss 6 is transported to the lifting position by the beam transport ship 7, and the protective pile 8 is set at the lifting position. The cable-carrying crane 1 moves to the cable clamp position of the A# sling 3 to lift the beam segment to the designed height; in this process, the front and rear ends of the steel truss 6 segment are connected to one end of the balance cable 2, and the other end of the balance cable 2 is connected to the main cable 10; the temporary sling 4 is connected to the lower end of the B# sling 3, and the lower anchor head of the temporary sling 4 is connected to the ear plate of the segment beam hanger 5; after the installation is completed, the cable-carrying crane 1 is slowly unloaded to swing the steel truss 6 segment to the position of the B# sling 3, completing the first swing of the segment;

[0041] S320, combined Figure 6As shown, the cable crane 1 moves to the position of the cable clamp of the C# sling 3 and is anchored with the sling 5. The cable crane 1 slowly loads and lifts the steel truss 6, so that the segment is swung to the position of the C# sling 3, and the connection between the B# sling 3 and the temporary sling 4 and the segment is released. The cable crane 1 lowers the steel truss 6 to the low-level longitudinal slideway 116 of the low-level sliding bracket 11, and slides the segment to the side span on the low-level sliding bracket 11 to a predetermined position. Repeat the above arrangement, and sequentially hoist the steel truss 6 segments outside the water area to the low-level sliding bracket 11;

[0042] S330, similarly, by secondary swinging, the steel truss beam 6 segments are swung to the high-position sliding bracket 12 in sequence, and slide to a predetermined position on the high-position longitudinal slideway 126 on the high-position sliding bracket 12, thereby completing the placement of all the steel truss beams 6;

[0043] S340, install the steel truss 6 from the mid-span and both banks toward the tower area, that is, install the steel truss 6 symmetrically from the mid-span toward the cable tower, and install the steel truss from the shore toward the cable tower. During installation, first hinge the upper chord 61, that is, hinge the adjacent upper chords 61 between segments, and after the linear adjustment is stable, rigidly connect the upper chord 61, and then remove the temporary diagonal rods 64; adjust the position and elevation of the side span steel truss 6 by using a jack, and carry out the steel beam joint construction.

[0044] It should be noted that the construction of the cable tower 9, the installation of the main cable 10, the installation of the suspension cable 3, and the closure construction are all prior arts well known in the art, and will not be elaborated in detail in the present invention.

[0045] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for erecting a triangular truss steel truss without a straight web member, characterized in that: The following steps are involved: S100, assembling a temporary diagonal rod (64) on a triangular truss steel truss beam (6) without a straight web member, wherein the temporary diagonal rod (64) is parallel to the diagonal rod (63) of the triangular truss steel truss beam (6) and is used to stabilize the position of the triangular truss steel truss beam (6) in the air; S200, constructing the cable tower (9), erecting the main cable (10), installing the sling (3), installing the low-position sliding bracket (11) and the high-position sliding bracket (12), and sequentially installing the high-position sliding bracket (12) and the low-position sliding bracket (11) on both sides near the cable tower (9) and near the water area; S300. In normal waters, a beam transport ship (7) and a cable-mounted crane (1) are used to symmetrically erect steel trusses (6) from the middle of the span to the side span, and the steel trusses (6) are placed at predetermined positions of high-position sliding brackets (12) by means of two swing shifts. The steel trusses (6) are then assembled. After the installation is completed, the temporary diagonal rods (64) are removed, and finally the steel beam joint construction is carried out.

2. The method for erecting a triangular truss steel truss beam without a straight web member according to claim 1, characterized in that: The triangular truss steel truss beam (6) without a straight web member comprises an upper chord (61), a lower chord (62) and an oblique rod (63), wherein the upper chord (61) and the lower chord (62) are arranged in parallel and staggered, and three oblique rods (63) arranged in a Z shape are arranged between the upper chord (61) and the lower chord (62), and two ends of the middle oblique rod (63) of the three oblique rods (63) arranged in the Z shape are respectively connected to the upper chord (61) and the lower chord (62).

3. The method for erecting a triangular truss steel truss beam without a straight web member according to claim 2, characterized in that: The other two oblique rods (63) are arranged in parallel and their ends are respectively connected to the connection points between the middle oblique rod (63) and the upper chord rod (61) and the lower chord rod (62).

4. The method for erecting a triangular truss steel truss beam without a straight web member according to claim 3, characterized in that: The additional temporary inclined rod (64) is arranged parallel to the middle inclined rod (63) and cross-arranged with the longer inclined rod (63) of the other two inclined rods (63).

5. The method for erecting a triangular truss steel truss beam without a straight web member according to claim 1, characterized in that: The low-position sliding support (11) comprises a low-position guide hole anchor pile (111), a low-position bored pile (112), a low-position steel pipe pier (113), a low-position connecting system (114), a low-position transverse distribution beam (115) and a low-position longitudinal sliding track (116). The low-position guide hole anchor pile (111) and the low-position bored pile (112) are both used to be fixed in the underwater ground. The low-position guide hole anchor pile (111) and the low-position bored pile (112) are both connected to the low-position longitudinal sliding track (116) located in the same plane through the low-position steel pipe pier (113). A low-position connecting system (114) is provided between the low-position steel pipe piers (113).

6. The method for erecting a triangular truss steel truss beam without a straight web member according to claim 5, characterized in that: The high-position sliding support (12) comprises a high-position hole-drawing anchor pile (121), a high-position bored pile (122), a high-position steel pipe pier (123), a high-position connecting system (124), a high-position transverse distribution beam (125) and a high-position longitudinal sliding way (126). The high-position hole-drawing anchor pile (121) and the high-position bored pile (122) are both used to be fixed in the underwater ground. The high-position hole-drawing anchor pile (121) and the high-position bored pile (122) are both connected to the high-position longitudinal sliding way (126) located in the same plane through the high-position steel pipe pier (123). A high-position connecting system (124) is provided between the high-position steel pipe piers (123).

7. The method for erecting a triangular truss steel truss beam without a straight web member according to claim 1, characterized in that: In step S300, specifically including: S310, transport the steel truss beam (6) to the lifting position by means of a beam transport ship (7), set a protection pile (8) at the lifting position, and move the cable-carrying crane (1) to the position of the cable clamp of the A# sling (3) to lift the beam segment to the designed height; during this process, the front and rear ends of the steel truss beam (6) segment are connected to one end of the balance cable (2), and the other end of the balance cable (2) is connected to the main cable (10); a temporary sling (4) is connected to the lower end of the B# sling (3), and the lower anchor head of the temporary sling (4) is connected to the ear plate of the segment beam hoist (5); the lower anchor head is connected to the ear plate of the segment sling (3); after the installation is completed, slowly unload the cable-carrying crane (1), so that the steel truss beam (6) segment is swung to the position of the B# sling (3), and the first swing of the segment is completed; S320, the cable-mounted crane (1) moves to the position of the cable clamp of the C# sling (3) and is anchored with the sling (5), and the steel truss (6) is lifted by the cable-mounted crane (1) so that the segment is swung to the position of the C# sling (3), and the connection between the B# sling (3) and the temporary sling (4) and the steel truss (6) is released. The cable-mounted crane lowers the steel truss (6) to the low-position longitudinal slideway (116) of the low-position sliding bracket (11), and slides the steel truss (6) on the low-position sliding bracket (11) to the side span to a predetermined position, and repeats the above arrangement, and sequentially lifts the steel truss (6) segments outside the water area to the low-position sliding bracket (11); S330. Similarly, the steel truss beam (6) segments are swung to the high-position sliding bracket (12) in sequence through secondary swinging, and are slid to a predetermined position on the high-position longitudinal sliding slideway (126) on the high-position sliding bracket (12), thereby completing the placement of all the steel trusses (6); S340, installing the steel truss beam (6) from the middle of the span and both sides toward the tower area. During installation, first hinge the upper chord (61), and after the linear adjustment is stable, rigidly connect the upper chord (61), and then remove the temporary diagonal rod (64); adjust the position and elevation of the side span steel truss beam (6) by using a jack, and carry out the steel beam joint construction.

Images