JP2589243B2 - Endless cable suspension bridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications] Simplify the design and construction of tower pillars and anchors, and suppress vibrations and lateral sway of suspension bridges necessary as conduits for water supply and gas, etc., for traffic routes over valleys, rivers, straits, etc. And an endless cable suspension bridge with improved stability.

[0002]

2. Description of the Related Art A conventional suspension bridge is constructed by suspending a bridge girder via a hanger rope to a main cable supported by anchors and tower columns. First, the height of the tower pillar is required to be 1/10 of the distance between the tower pillars, that is, the length of the center span as a standard height from the road surface. It became larger and the foundation needed scour prevention. It is important to conduct a geological survey of the installation location for the anchor anchoring the end of the main cable.
The distance of the position was a major factor affecting the overall design. Next, the main cable hangs in a bow between tower columns, and the bridge girder is hung via a hanger rope. We had to consider strengthening the structure of the bridge girder that could compete with the slab. Also, a proposal has been made to attach a hanger rope in a truss shape to reduce vibration and roll, but the suspended shape has not changed and has not been widely used thereafter. In addition, a "suspended floor slab", a method in which a number of steel wires or cables were stretched in parallel in tension and wound around concrete, was prototyped, and the tower pillars could be omitted. It is the current situation that the study on strategic issues has begun.

[0003]

The following problems have been pointed out with respect to the design of the conventional suspension bridge. First, high tower columns have been required.
Omit it. Regarding the installation position of the tower pillars, the design conditions shall be such that slopes and water areas can be avoided and easy-to-install locations can be selected. The location of the anchor must not be restricted by terrain or geology. Terminal fittings shall be alternative specifications that are easy to design and install. Secondly, rigidity is introduced into the conventional main cable stretching method and the hanging state of the hanger rope, so as to adopt a method capable of suppressing vibration and rolling. As mentioned above, the towers and anchors, which are difficult to design and construct, have been reviewed, and additional work to prevent vibration and rollover, such as wind-resistant construction or increase in bridge girder strength, has been simplified or omitted. It is desired to reduce the trouble and cost of the work.

[0004]

The structure of the suspension bridge of the present invention will be described in accordance with the progress of construction. A pair of side walls 4 are installed on the left bank and the right bank, and the terminal pulley 3 is attached to each side wall 4. With this terminal pulley 3 at both ends,
The main cable 1 is extended endlessly to form an upper chord and a lower chord. In place of a conventional tower and anchor supporting a main cable, a side wall 4 to which a terminal pulley 3 is attached is used. Next, the upper and lower chords of the main cable 1 stretched endlessly are connected by connecting ropes 2 arranged at predetermined intervals and squeezed into a drum shape, thereby forming a parabolic shape from both ends toward the center. A longitudinal gradient is formed and at the same time rigidity is introduced into the main cable 1. These crawling operations are performed in parallel on the upstream side and the downstream side. In the next step, the bridge girder 5 is supported by the lower chord of the main cable 1 and the connecting rope 2. That is,
The bridge girder 5 is tensioned in the vertical direction by the connecting rope 2 and horizontally by the lower chords of the main cable 1, and is held in three directions. The turnbuckles incorporated in each connecting rope 2 finely adjust the vertical gradient. Then, the installation of the bridge girder 5 is completed. The endless cable suspension bridge was constructed as described above.

[0005]

[Function] The upper and lower chords of the main cable 1 spanned in an endless manner are connected by a connecting rope 2 arranged at a predetermined interval, and the rigidity is introduced into a drum shape, thereby suppressing vibration and roll. At the same time, a vertical gradient is formed by the lower chord of the main cable 1. The bridge girder 5 is held by the lower chord of the main cable 1 and the connecting rope 2 from three directions, that is, the horizontal direction and the vertical direction.
Increased stability. The load on the bridge girder 5 pulls down the upper chord of the main cable 1 via the connecting rope 2, while the load is applied from the lower chord of the main cable 1 to the terminal pulley 3.
Then, the upper chord and the lower chord are attracted and harmonized with each other. Conventionally, vibrations and rolls, which were regarded as problems, were suppressed, and design and construction such as wind-resistant construction and increase in bridge girder strength were omitted, so that a great deal of work and cost could be saved. In addition, for the anchor construction required for geological surveys and tower pillar construction work involving high-altitude work, in the present invention,
Since it was concentrated only on the construction of the side wall 4 to which the terminal pulley 3 was attached, the design was simplified and the construction became easy. Therefore, although the selection of the bridge site was affected by the topography and the geology in the past, such restrictions were almost eliminated, and the bridge could be widely used.

[0006]

【Example】Example 1  The first embodiment is shown in FIG. 1 is the main cable
Then, the terminal pulley 3 attached to the side wall 4 provided on both right and left banks
Endlessly wrapped around both ends.
The number is not limited to one, but can be multiple depending on the scale
It shall be. 2 is the connecting rope and the main cable
1 at predetermined intervals, and the upper chord of the main cable 1
Connect the lower chord and squeeze it into a drum shape to introduce rigidity
At the same time, the lower chord forms a parabolic longitudinal gradient. What
Contact, the turnbuckle attached to the lower end of the vertical gradient
Adjustments shall be made. 3 is a terminal pulley,
In order to hang Bull 1 endlessly, both sides
It is rotatably attached to the wall 4. Terminal pulley 3
The diameter is determined according to the rules for the diameter of the hoisting drum.
More than 100 times the diameter of cable 1 or twisted
650 times or more the diameter of the element wire to be used. 4
Is installed on the left bank and right bank on the side wall.
It is a mounting base and acts as a gate to enter and exit the bridge. Obedience
It replaces anchors and towers in future specifications,
Can be concrete block or steel frame assembly
Possible, its shape can be triangular, polygonal, semicircular, etc.
Can be arbitrarily selected in consideration of aesthetics
You. A gate-type design is also possible by connecting the left and right upper parts.
Reference numeral 5 denotes a bridge girder.
Vertically by the lower chord of the main cable 1
Because it is supported in three directions from side to side, vibration and
It suppresses rolling and improves stability against wind pressure.
is there.Example 2  The second embodiment is shown in FIG. End to be attached to side wall 4
Regarding the end pulley, a plurality of small pulleys 31 were arranged in a semicircle.
To bridge the main cable 1 as a multiple pulley system
Can be.Example 3  The third embodiment is shown in FIG. Fixed on side wall 4
The main cable 1 on the surface or the side of the worn wheel 32
To the upper string cable 11 and the lower string cable 12,
Each terminal is fixed to the upper and lower tiers
is there. The rotation of the fixing wheel 32 causes the main cable
1 has the same function as when it is stretched endlessly
be able to.

[0007]

The endless cable suspension bridge of the present invention has the following effects and features. (1) Rigidity is introduced into the main cable 1, and the bridge girder 5 is supported in three directions by the main cable 1 and the connecting rope 2, forming a longitudinal gradient, and at the same time improving stability. (2) Since an anchor is not required, complicated work such as a geological survey for selecting the position of the anchor can be omitted, and terminal fittings are simplified at the same time. (3) There is no construction work on the tower pillars, and design and construction work on sloping lands and water bodies is not required. (4) The shape of the side wall 4 replacing the anchor and the tower post can be arbitrarily selected so as to conform to the environment. (5) Vibration and side contact are suppressed, wind-resistant cable design and construction are not required, and there is no need to specially strengthen bridge girders, which can greatly reduce the number of operations and costs. (6) Since almost all of the restrictions on the conventional construction site selection have been eliminated, the compatibility is expanded and the system is easily spread, and can be widely used not only as a transportation route but also as a gas / water supply conduit. As described above, the endless cable suspension bridge of the present invention
This is an extremely simplified bridge that does not require "anchors", "towers", "windproof ropes" and "piers".

[Brief description of the drawings]

FIG. 1 is a side view of the present invention.

FIG. 2 is a side view of a main part showing an embodiment.

FIG. 3 is a side view of a main part showing an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main cable 2 ... Connecting rope 3 ... Terminal pulley 4 ... Side wall 5 ... Bridge girder 11 ... Upper string cable 12 ... Lower string cable 31 ... Small pulley 32 ... Wheels for fixing

Claims (1)

(57) [Claims] 1. A pair of side walls (4) provided on both right and left banks,
With the terminal pulley (3) rotatably attached to the left and right ends, the main cable (1) is extended endlessly,
The upper and lower chords of the main cable (1) are connected by a connecting rope (2) arranged at a predetermined interval, the main cable 1 is squeezed in a drum shape, and the main cable (2) is vertically moved by the connecting rope (2). (1) An endless cable type suspension bridge characterized in that a bridge girder (5) is horizontally supported by a lower chord portion.