CN106498839A - A kind of bi-directional folded truss bridge construction - Google Patents

Abstract

The invention discloses a two-way folding truss bridge structure, which is composed of a support structure and a panel structure located on the support structure. The support structure is a folded truss, and the folded truss includes square prism units connected in the span direction, and the folded truss is folded and folded. Expanded cables; a cable is set on the upper chord node and the lower chord node of each quadrangular prism unit forming the folded truss; the eight folded rigid plate units are unfolded into a rectangle and form four edge nodes at the four corners of the rectangle ; The four edge nodes of the rigid bridge deck element are hinged to the four upper chord nodes of the quadrangular prism element. The folding dome mechanism of the present invention is a single-degree-of-freedom system, which reduces the number of driving devices; the number of components formed by the present invention is far less than that of the general folding structure, which overcomes the shortcomings of many and messy rods in the sense of structure; it is easy to move And relocation, reusable, reasonable structure, simple design and construction, especially suitable for bridges with small and medium spans.

Description

A two-way folding truss bridge structure

technical field

The invention relates to a folding truss structure, in particular to a bidirectional folding truss bridge structure.

Background technique

Since the Spanish architect Pinero first successfully applied the concept of expandable structure to the design of "movable theater" in the 1960s, the application of openable roofs in large-span spatial structures has increased rapidly. On the other hand, with the acceleration of people's exploration of outer space, deployable structures have received extensive attention, and relevant research results have been applied to space solar panels and satellite antennas. At present, the most widely used one is the expandable structure based on scissor like element. From a geometric point of view, the basic principle of this type of deployable structure is that each pair of connecting rods is connected by a column hinge, and each pair of connecting rods can only rotate relative to the axis perpendicular to the plane where the pair of connecting rods are located, while the other pair of connecting rods are free to rotate. The degree is completely restricted; at the same time, the connection between the scissor elements is realized by the joints at the end nodes of the elements. The scissor elements are connected to form a folded truss.

The geometry of existing movable structures mostly only considers two states of "start" and "end", that is, folded state and unfolded state. The conversion mode between these two states is roughly: horizontal movement type, horizontal rotation movement type, space movement type, central pivot rotation type, folding movement type and combined movement type, etc. However, these openable roof structures only have the ability to translate or rotate, and in fact the shape of the entire roof structure does not change. So these movable structures are not really geometrically variable structures.

The deployment of deployable structures is usually realized by the relative rotation between the members of the scissor unit, which has the advantages of short construction period, easy relocation and reusability, and has aroused great interest of modern engineers. However, it is rarely used in long-span structures due to the complexity of the nodes involved and poor stiffness.

Contents of the invention

The technical problem to be solved by the present invention is to provide a two-way folded truss bridge structure with few connecting nodes and good structural rigidity, which has the advantages of convenient design and construction, and can better meet the needs of temporary bridges. The flexible bridge is convenient to build and move, and the folding function of the long-span bridge is required.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A two-way folding truss bridge structure, consisting of a support structure and a panel structure on the support structure, characterized in that: the support structure is a folded truss, the folded truss includes quadrangular prism units connected in the span direction and the folded The truss is folded and unfolded by cables; the quadrangular prism unit is composed of four scissor units connected in the ring direction; After the two scissor units are connected end to end, four upper chord nodes and four lower chord nodes are formed, and one said drag cable is respectively arranged on the upper chord nodes and lower chord nodes of each quadrangular prism unit forming the folded truss;

The panel structure is composed of rigid bridge deck units; the rigid bridge deck unit is composed of eight folded rigid plate units, and the eight folded rigid plate units are unfolded into a rectangle and form four edge nodes at the four corners of the rectangle; The four edge nodes of the rigid bridge deck unit are hinged with the four upper chord nodes of the quadrangular prism unit; the eight folded rigid plate units are divided into four triangular plates and four pentagonal plates, which are respectively counterclockwise The first triangular plate, the first pentagonal plate, the second pentagonal plate, the second triangular plate, the third triangular plate, the third pentagonal plate, the fourth pentagonal plate and the fourth triangular plate, among them The common sides between them are respectively the first common side, the second common side, the third common side, the fourth common side, the fifth common side, and the sixth common side. In addition, the common side of the first triangular plate and the fourth triangular plate is the first Seven common sides, the common side of the first pentagonal plate and the fourth pentagonal plate is the eighth common side, wherein the common side of the second pentagonal plate and the third pentagonal plate is the ninth common side; Among them, the first common side to the sixth common side are parallel to each other, and the seventh common side to the ninth common side are collinear; the first triangular plate, the first pentagonal plate, the second pentagonal plate, the second triangular plate and The third triangular plate, the third pentagonal plate, the fourth pentagonal plate, and the fourth triangular plate are always symmetrical about the plane formed by the seventh common side to the ninth common side.

The first common side, the third common side, the fourth common side, the sixth common side and the eighth common side are peak lines, the second common side, the fifth common side, the seventh common side and the ninth common side are Valley line, adjacent triangular plates are folded outward along the peak line, and folded inward along the valley line. The outward folding means that the angle between the outer normals of adjacent triangular plates becomes larger, and Folding means that the angle between the outer normals of adjacent triangular plates becomes smaller.

The angles between the edges of the first triangular plate on both sides of the first common side and the seventh common side are respectively the first angle and the second angle; the edges on both sides of the second common side and the eighth common side The included angles are respectively the third included angle and the fourth included angle; the included angles between the sidelines on both sides of the second common side and the ninth common side are respectively the fifth included angle and the sixth included angle; the first included angle and the third included angle The included angles are equal, the second included angle and the fifth included angle are 90°; the first included angle and the fourth included angle are complementary, and the third included angle and the sixth included angle are complementary.

The straight rod is a plane rod or a rod of a space structure.

The beneficial effect of the present invention is that, during the opening and closing process, the mechanisms are compatible with each other, no additional internal force will be generated, and its mechanical performance is superior; moreover, the folding truss of the present invention is a single degree of freedom system, which reduces the The number of driving devices; in addition, because the number of components formed by the present invention is far less than that of the general folding structure, it gives people a simple and clear effect, and overcomes the shortcomings of many and messy rods in the structural sense; it is convenient for movement and relocation , reusable, reasonable in structure, simple in design and construction, especially suitable for bridges with small and medium spans.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is described in further detail:

Fig. 1 is the structural representation of scissor unit;

Fig. 2 is the structural representation of quadrangular prism unit;

Figure 3 is a schematic diagram of the fully expanded structure of the rigid bridge deck unit;

Figure 4 is a schematic diagram of a half-expanded structure of a rigid bridge deck unit;

Fig. 5 is the structural representation of the folded truss of cloth cable;

Fig. 6 is a structural schematic diagram of the overall structure expansion;

Fig. 7 is a structural schematic diagram of the half-expanded overall structure.

detailed description

Below with reference to accompanying drawing of description, the specific embodiment of the present invention is described in more detail:

The basic unit of a folded truss is a scissor unit. As shown in Figure 1, a scissor unit is formed by pinning two straight rods 21 and 22 at the midpoint of the two rods. Scissor unit 1 has two straight rods 21 and 22 Equal length and pinned at the midpoint of the rod. As shown in FIG. 2 , the scissor units 1 are connected in a circular direction from end to end to form a quadrangular prism unit 4 .

The structure unfolds and the cable 3 is tensioned, and the folded truss 4 of the cable 3 is shown in FIG. 5 .

The rigid bridge deck 5 is composed of rigid bridge deck units 6 connected together. Wherein eight folding plates 7 are foldable. Rigid bridge deck units 6 are arranged on the folded trusses 4 . When the rigid bridge deck unit 6 is fully deployed, it is shown in FIG. 3 , and when it is half-deployed, it is shown in FIG. 4 . Each rigid bridge deck unit 6 is composed of four triangular plates and four pentagonal plates, which are the first triangular plate 71, the first pentagonal plate 72, the second pentagonal plate 73, the second A triangular plate 74 , a third triangular plate 75 , a third pentagonal plate 76 , a fourth pentagonal plate 77 , and a fourth triangular plate 78 . The common sides between them are respectively the first common side 79, the second common side 710, the third common side 711, the fourth common side 712, the fifth common side 713, and the sixth common side 714. In addition, the first triangular plate and The fourth triangular plate common side is the seventh common side 715, the first pentagonal plate and the fourth pentagonal plate common side is the eighth common side 716, wherein the second pentagonal plate and the third pentagonal plate common The side is the ninth common side 717; during the movement, the first common side 79 to the sixth common side 714 are parallel to each other, and the seventh common side 715 to the ninth common side 717 are collinear. The first triangular plate 71, the first pentagonal plate 72, the second pentagonal plate 73, the second triangular plate 74 and the third triangular plate 75, the third pentagonal plate 76, the fourth pentagonal plate 77, The fourth triangular plate 78 is symmetrical about a plane formed by the seventh common side 715 to the ninth common side 717 . The two upper common nodes of two adjacent scissor elements are hinged to the outer edge of the rigid deck.

The first common side 79, the third common side 711, the fourth common side 712, the sixth common side 714 and the eighth common side 716 are peak lines, the second common side 710, the fifth common side 713, and the seventh common side 715 and the ninth common side 717 is a valley line, adjacent plates are folded outward along the peak line, and folded inward along the valley line, the outward fold refers to the angle between the outer normal lines of adjacent plates Getting bigger and folding inwards means that the angle between the outer normals of adjacent plates gets smaller. The included angles between the edge of the first triangular plate on both sides of the first common side and the seventh common side are respectively the first included angle 718 and the second included angle 719; The angles between the common side 79 and the second common side 710 and the eighth common side 716 are respectively the third included angle 720 and the fourth included angle 721; The included angles are respectively the fifth included angle 722 and the sixth included angle 723; the first included angle 718 and the third included angle 720 are equal, the second included angle 719 and the fifth included angle 722 are 90°; the first included angle and The fourth included angle 721 of 718 is complementary, and the third included angle 720 and the sixth included angle 723 are complementary.

The four outer nodes 723-726 of each mid-span rigid bridge deck unit 7 are hinged to the four upper chord nodes 41-44 of the folded truss 4 below (as shown in FIG. 5 ). During the movement, the structure can expand and contract along the span direction and perpendicular to the span direction. The overall structure is shown in Figure 6 when unfolded. Cables are arranged on the upper and lower edges of the folded truss 4. When unfolded, the cables 3 are tightened and fixed at the side spans. When contracted, the cables 3 are loosened (as shown in Figure 7). Global single-degree-of-freedom motion.

Claims (3)

1. a kind of bi-directional folded truss bridge construction, is made up of supporting construction and the panel construction in supporting construction, and which is special Levy and be：The supporting construction is folded truss, and the folded truss is included in the quadrangular unit that span direction is connected and by institute State the drag-line that folded truss is folded and launched；The quadrangular unit is by four scissors units in the connected group of head and the tail ring Into；The scissors unit is formed in respective midpoint pin joint by two equal length straight-bars；After four scissors units join end to end Four upper chord nodes and four lower-chord panel points are formed with, in the upper chord node of each the quadrangular unit for constituting the folded truss Be respectively provided with a drag-line on lower-chord panel point；

The panel construction is made up of mud jacking by duct Slab element；The mud jacking by duct Slab element is by eight pieces of folded plates unit groups Four fringe nodes are formed for rectangle and at four angles of rectangle after launching into, eight pieces of folded plates units；The rigid bridge Four fringe nodes of panel unit are hinged with four of the quadrangular unit upper chord nodes；Eight pieces of folded plates lists Unit is divided into four triangular plates and four pentagonal panels, according to be respectively counterclockwise the first triangular plate, the first pentagonal panel, the Two pentagonal panels, the second triangular plate, the 3rd triangular plate, the 3rd pentagonal panel, the 4th pentagonal panel and the 4th triangular plate, Common edge between them be respectively the first common edge, the second common edge, the 3rd common edge, the 4th common edge, the 5th common edge, 6th common edge, the first triangular plate and the 4th triangular plate common edge are the 7th common edge in addition, the first pentagonal panel and the Four pentagonal panel common edges are the 8th common edge, and wherein the second pentagonal panel and the 3rd pentagonal panel common edge are public for the 9th Side；In motor process, the first common edge is parallel to each other to the 6th common edge, and the 7th common edge is conllinear to the 9th common edge；The One triangular plate, the first pentagonal panel, the second pentagonal panel, the second triangular plate and the 3rd triangular plate, the 3rd pentagonal panel, 4th pentagonal panel, the 4th triangular plate are to remain symmetrical with regard to the 7th common edge to the plane that the 9th common edge is formed 's；

First common edge, the 3rd common edge, the 4th common edge, the 6th common edge and the 8th common edge are crest line, and second is public Side, the 5th common edge, the 7th common edge and the 9th common edge are valley line altogether, and adjacent triangular plate is foldable outwardly along crest line, Along valley line to interior folding, the outward folding refers to that the angle between the exterior normal of adjacent triangular plate becomes big, to infolding Angle between the folded exterior normal for referring to adjacent triangular plate diminishes.

2. bi-directional folded truss bridge construction according to claim 1, it is characterised in that：First triangular plate is first The sideline of common edge both sides is respectively the first angle and the second angle with the angle of the 7th common edge；In the second common edge both sides Sideline is respectively the 3rd angle and the 4th angle with the angle of the 8th common edge；Public with the 9th in the sideline of the second common edge both sides The angle on side is respectively the 5th angle and the 6th angle altogether；First angle and the 3rd angle are equal, the second angle and the 5th angle For 90 °；First angle and the 4th angle are complementary, and the 3rd angle and the 6th angle are complementary.

3. bi-directional folded truss bridge construction according to claim 1 and 2, it is characterised in that：The straight-bar be plane link or The rod member of space structure.