RU2604043C1 - Pontoon bridge - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to bridge means, namely to floating bridges and ferries. Floating bridge comprises two coastal parts, each of which consists of end pontoon and two coastal pontoons, rigidly interconnected by their sides and fixed on coastal braces, equipped with ramps, and inner part consisting of anchor and intermediate pontoons, rigidly interconnected with possibility of rotation of two sections in places of passage channel and having anti-different device and cable system attached to bottom anchors. Anti-different device is made in form of pin with cone-shaped end, fixed rigidly on one pontoon and receiving hole made in other pontoon, which forms gap along circumference from 5 mm to 1 cm at connection with pin, and rigid connection is made by cable ties belting oval-shaped supports arranged on fixed pontoons, and twisting of two threads in center with rigid fixation, rope ends are rigidly fixed by sleeve.

EFFECT: technical result is increase of carrying capacity of bridge owing to increasing its transverse strength.

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Description

The invention relates to ferry and bridge means, namely to floating bridges and ferries.

The term “floating bridge” means a bridge on floating supports. GOST 26775-97 (Large Normative and Technical Dictionary, Moscow, ACT, Astrel, 2007, p. 580). The floating bridge is a type of pontoon bridge. The main problems that are solved during the construction of such structures are an increase in the bearing capacity of the bridge, stability under the influence of wind and the speed of water flow, and ensuring navigation.

Known floating bridge (Pontoon Park PP-91 // Technical description and instruction manual, 05341 360080 007, TO, first book, page 30, second book, sheet 181, Fig. 183, OJSC KB Vympel, Nizhny Novgorod, 1991 ), including river links docked in the longitudinal direction, pairwise interconnected by means of butt assemblies located on rotary cowls, motor links placed in pairs by nose parts to each other between river links, and coastal links.

A disadvantage of the known floating bridge is that the motor links in pairs located in it, in contrast to the river links, are not interconnected. Consequently, the strength of the bridge decreases when passing vehicles.

Known floating bridge-tape (patent No. 2534133, application No. 2013107140, priority date 02/20/2013, publication date 11/27/2014, bull. No. 33, IPC class E01D 15/14). Known floating bridge-tape with three lanes of the roadway includes a connection in the longitudinal and transverse directions by means of butt assemblies consisting of articulated pontoons.

Similar articulated joints have been known for a long time, and their main disadvantage is the difficulty of their operation and manufacture.

It is more expedient to use such connections for bridges-belts from barges with a small carrying capacity.

The technical result of the invention is to increase the bearing capacity of the bridge by increasing its lateral strength.

A floating bridge is proposed, containing two coastal parts, each of which consists of an end pontoon and two coastal pontoons rigidly interconnected by sides and fixed to shore braces equipped with ramps, and an inner part consisting of anchor and intermediate pontoons rigidly articulated with the possibility of turning two sections in the places of passage of the ship and having an antidifferential device and a cable system for attaching to the bottom anchors.

The difference is that the antidifferential device is made in the form of a pin with a conical end fixed rigidly on one pontoon, and a receiving hole made on another pontoon, which when connected to the pin forms a circumference of 5 mm to 1 cm around the circumference, and a rigid joint is made by tightening the rope surrounding the oval-shaped supports located on the fixed pontoons and twisting its two threads in the center with rigid fixation, the ends of the rope are rigidly fixed by the sleeve.

A floating bridge of a continuous system is proposed on rigidly articulated pontoon supports.

The essence of the floating bridge is illustrated in FIG. 1, which shows the connection of the antidifferential device, FIG. 2 (screed formation), FIG. 3 (rigid joint by screed), FIG. 4 (fixing the ends of the rope).

One of the differences of the proposed floating bridge is that not serial transport barges are used, but specially designed pontoons.

The bridge consists of a pontoon belt, in which a movable section is provided for passing ships (not shown). The bridge is held in place by cable ropes fixed through buoys to the bottom anchors (not shown).

To eliminate the vertical movements of the pontoons relative to each other, an antidifferential device is used, which is a finger-sleeve connection (Fig. 1). The finger is a pin with a conical end 1, which is mounted on one pontoon, and on the other pontoon at the same level there is a hole 2 in the form of a sleeve. The connection itself is known in various branches of technology, but in this case, when used in the construction of a floating bridge around the circumference, a small gap of 5 mm to 1 cm is formed when the pin 1 and hole 2 are connected. Pin 1 is made of round steel with a diameter of about 82 mm . The presence of a conical end at the pin 1 is a prerequisite. The tapered end is convenient for docking the bridge and easily goes into the hole. Bridge assembly time is reduced. When vehicles pass through the bridge, the force from the traffic loads is calculated taking into account the dynamism of their application. When the equipment moves through the bridge, a bending moment arises, which is the result of the arising applied forces. The finger-sleeve connection transfers force from one part of the bridge to another in the form of concentrated forces. A gap of 5 mm to 1 cm in the event of a load gives a slight skew of the bridge at the junction, and there is no “sticking” of metal to metal and “biting” of the metal, and when the load is removed, the bridge connection smoothly returns to the opposite position. The gap allows you to create a smooth bend between the pontoons, and when removing the loads returns the base of the bridge to the desired position. The lateral strength of the bridge increases. A gap of more than 1 cm is not allowed, because the angle of inclination will increase and this may lead to a decrease in the carrying capacity of the bridge. Therefore, a clearance of 5 mm to 1 cm is optimal. In the event of waves and strong currents, the finger-sleeve connection prevents the bridge from swinging. When the water level drops on the river, a possible subsidence of the bridge occurs (since the coastal part of the bridge is fixed on the shore) the finger-sleeve connection protects the bridge from a break in the joints. In this case, the gap plays a very important role, the finger walks freely in the hole (sleeve), and a certain (permissible) angle of inclination is created, i.e. in case of subsidence of the bridge, deformation of the joint is prevented. In this case, the possibility of continuous traffic flow through the bridge.

The assembly itself is movable. When passing the equipment along the bridge, the magnitude of the applied force to the bridge changes and the magnitude of the bending moment changes. The presence of a conical end on the pin and the gap between the pin and the sleeve allows you to create a "smooth" bend, reduce the reaction to the load and provide a "smooth" return to its previous position. Pin 1 is made of steel, i.e. has a high degree of strength. Contact forces arising from the gravity of passing vehicles are transmitted to the surface of the hole 2. The presence of a gap between the pin 1 and the hole 2, as well as the presence of a cone-shaped end, make it possible to equalize the stresses, ensure the transmission of forces in the assembly and avoid the effect of “constraint” of the assembly elements. Otherwise, the hole 2 may be deformed under the arising loads, which will lead to a limitation of the carrying capacity of the bridge as a whole and the creation of an emergency. If these conditions are not observed, the entire assembly may be damaged, for example, wrinkled under the influence of loads. If there are loads on the bridge from the river, the finger-hub assembly also works by gently aligning the location of the bridge in a given place.

The elastic modulus E characterizes the ability of any body to elastically deform when a force is applied to it:

,

,

where σ is the stress caused in the sample by the acting force;

ε is the elastic deformation caused by stress.

The used finger-sleeve connection allows to reduce the elastic deformation index at the junction of two pontoons and thereby increase the elastic modulus of the connection. The reliability of the bridge and its carrying capacity increases.

The signs of the presence of the connection of the pin 1 with a conical end fixed rigidly on one pontoon and a receiving hole made on the other pontoon, which when connected to the pin forms a circumference of a gap of 5 mm to 1 cm, are in causal connection with the claimed technical result and are significant. Since, due to the equalization of the applied forces and the protection of the bridge joints from deformation, the load-carrying capacity of the bridge increases.

Pontoons are rigidly articulated with each other by six strands of rope 3 (Fig. 2). A steel rope with a diameter of 18 mm is used. Practical tests showed that the selected rope diameter of 18 mm in the proposed connection is optimal. A rope with a large diameter leads to the fact that the connection begins to work more rigidly.

Two strands of rope are twisted in the center, increasing the margin of safety, eliminating the possibility of sagging ropes. Ropes 3 are tightened with twisting in the center. For this, the simplest cross-shaped device 4 is used, which has two welded hollow pipes, the position of which is fixed with a rod (stop) 5. The simplicity of the proposed connection allows the pontoons to quickly merge without the use of additional mechanisms (winches), which reduces the time for their installation. The connection of the six strands of rope with a diameter of 18 mm with the twisting of two strands in the center acts on the principle of a "rigid spring" and provides a rigid pontoon pontoon. Twisting two ropes in the center increases strength, as two threads of 18 mm each work in a torsion with a diameter of 36 mm, and creates a cable tension, increasing its strength. The articulation of six strands of rope with a twist in the center of its two strands and a finger-sleeve connection works together according to the principle of a shock absorber that is simple in design. The vibrations are damped, sharp shocks are absorbed, and the effort is transferred smoothly from one pontoon to another. The effect of vibration is reduced. Both the finger-sleeve connections (pin 1 with a tapered end and hole 2) and the rigid joint of the six strands of rope work together as a rigid spring, absorbing part of the vibration energy. When a load occurs, the connection gently dampens, slightly stretched, when relieving stress, it returns to its original position. The lateral strength of the bridge increases.

The connection of six strands of rope according to the proposed method by twisting using a simple cross-shaped device allows you to quickly mount and disassemble the bridge, the connection itself allows the use of low-cost material, which reduces the cost of mounting the bridge.

A general view of the rigid joint is shown in FIG. 3. Pontoons come together (rigid joint) with each other by six strands of rope, which are laid on oval-shaped supports 6 located on both limbs of the pontoons. Two threads in the center are tightened with twisting using a cross-shaped device 4 with additional fixing by a bar 5. All six strands of the rope take up the force when they come together, while two threads in the center are used for twisting, ensuring joint strength, and they prevent sagging of the ropes. The force in the beginning is determined by the formula:

P _{c =} M _c / L _c ,

where M _s is the moment of forces perceived by a pair of forces (base counted)

L _c - shoulder counted.

P _{c is} perceived by all rope branches (total diameter 108 mm), and two of them (twisted in the center) work as one reinforced rope branch (diameter 36 mm), increasing the strength of the splice and excluding the fact of sagging ropes. Due to this, the breaking strength of the ropes increases. The lateral strength of the bridge and its bearing capacity increase. The cushioning ability of the entire connection allows you to increase the carrying capacity of the bridge by strengthening its connections. The signs are in a causal relationship with the claimed technical result.

As the actual tests of the floating bridge in action showed, its carrying capacity was almost doubled in comparison with analogues.

The ends of the ropes are rigidly fixed by the sleeve 7 (Fig. 4). Fixing the ends of the ropes with the sleeve allows you to increase the reliability of the connection. Fixing the ends of the rope with the sleeve and tightening the ropes with twisting allows you to create a reliable rigid articulation of the pontoons, and the presence of the anti-trim device on the principle of "finger-sleeve" allow you to perceive the bending moment, smoothly transmitting the arising forces in the direction of transport. All signs are significant and are in a causal relationship with the claimed technical result.

Claims (1)

A floating bridge containing two coastal parts, each of which consists of an end pontoon and two coastal pontoons rigidly interconnected by sides and fixed to shore braces equipped with ramps, and an inner part consisting of anchor and intermediate pontoons rigidly articulated with each other the ability to turn two sections in the passageways and having an anti-trim device and a cable system for attaching to the bottom anchors, characterized in that the anti-trim device molded in the form of a pin with a conical end fixed rigidly on one pontoon and a receiving hole made on the other pontoon, which when connected to the pin forms a circumference of 5 mm to 1 cm around the circumference, and a rigid joint is made by tightening the rope encircling oval-shaped supports located on the fixed pontoons, and twisting two of its threads in the center with rigid fixation, the ends of the rope are rigidly fixed by the sleeve.

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