Bridge anti-ship collision active protection device and method of use thereof

Abstract

The application discloses a bridge anti-ship collision active protection device and a use method thereof, which comprises a laser range finder, a control assembly, a main bridge pier, a main bridge pile cap, a separated anti-ship collision facility structure, a polyurethane foam rotating drum and a riverbed. The upper portion of the main bridge pier is provided with the laser range finder and the control assembly, the bottom of the main bridge pier is provided with the main bridge pile cap, the periphery of the main bridge pile cap on the main bridge pier is provided with a plurality of separated anti-ship collision facility structures, the separated anti-ship collision facility structures are provided with the polyurethane foam rotating drum, and the other end of the polyurethane foam rotating drum away from the separated anti-ship collision facility structure is used for being embedded into the riverbed for fixation. When the distance between the ship and the main bridge pier detected by the optical range finder is less than a certain range, the control assembly controls the gas generator to inflate the gas bag to generate buoyancy, the polyurethane foam rotating drum is pulled to the water surface and contacted with the ship through the buoyancy, and the ship collision with the main bridge pier is prevented, so that the main bridge pier is not damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge anti-collision protection devices, in particular to a bridge anti-ship collision active protection device and a use method thereof. BACKGROUND

[0002] With the development of society, in order to connect the surrounding areas, many bridges are built in the water crossing range, the completion of the bridge drives the economic development of the region, and also causes a certain influence on water transportation, especially the navigation of ships. Due to the reasons such as underwater currents or human errors, the ship deviates from the channel and collides with the bridge pier and the pile cap, causing damage to the bridge and even collapse, causing extremely serious personnel casualties and economic losses, so it is necessary to prevent or reduce the damage caused by the collision of the ship with the bridge pier and the pile cap.

[0003] The existing bridge anti-ship collision facilities are mainly divided into fixed type and floating type. The anti-ship collision facility needs to be attached to the pier and the pile cap, and needs to be designed separately according to the shape of the bridge pier and the pile cap. The anti-ship collision facilities of various types of bridges cannot be universal, and cannot be industrialized to reduce costs. The floating type anti-ship collision facility is wrapped around the pier, and after being hit, it needs to replace the entire anti-collision device due to its integrated structure, causing great waste. The existing bridge anti-ship collision facilities are usually set above the water level, which will occupy the ship navigation width and affect the appearance of the bridge. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a bridge anti-ship collision active protection device and a use method thereof to solve the problems raised in the background art.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a bridge anti-ship collision active protection device, comprising a laser range finder, a control assembly, a main bridge pier, a main bridge pile cap, a separated anti-ship collision facility structure, a polyurethane foam rotating drum and a riverbed, the upper part of the main bridge pier is provided with a laser range finder and a control assembly, the bottom of the main bridge pier is provided with a main bridge pile cap, the periphery of the main bridge pile cap on the main bridge pier is provided with a plurality of separated anti-ship collision facility structures, the separated anti-ship collision facility structure is provided with a polyurethane foam rotating drum, and the other end of the polyurethane foam rotating drum away from the separated anti-ship collision facility structure is used for embedding into the riverbed for fixation.

[0006] Among them, the laser range finder and the control assembly are arranged on both sides of the main bridge pier.

[0007] Among them, the separated anti-ship collision facility structure comprises a steel pipe A and a steel pipe B; a large sliding cavity is formed in the inner side of the steel pipe A, a large cavity opening is formed in the top side wall of the steel pipe A, one end of the steel pipe B is provided with a large clamping rod, the large clamping rod of the steel pipe B is outwardly arranged, and the large clamping rod of the steel pipe B is used for being embedded in the inner wall of the large sliding cavity of the steel pipe A and sliding.

[0008] The steel pipe B is provided with a small sliding cavity inside, a small cavity opening is provided on the other end top wall of the steel pipe B away from the steel pipe A, the steel pipe C is provided with a small clamping rod at one end, the small clamping rod of the steel pipe C is outwardly arranged, and the small clamping rod of the steel pipe C is used for being embedded in the inner wall of the small sliding cavity of the steel pipe B and sliding.

[0009] The steel pipe C further comprises a gas generator and an air bag, the air bag is arranged inside the steel pipe C, the gas generator is arranged inside the steel pipe C and close to the lower side of the air bag, and the gas generator is used for being fixed on the lower inner wall of the steel pipe C.

[0010] The steel pipe A is provided with a steel pipe D below, the steel pipe A and the steel pipe D are provided with flanges, a plurality of bolt holes are provided on the flanges, the flanges comprise upper flanges and lower flanges, the upper flange is arranged on the other end bottom of the steel pipe A away from the steel pipe B, the lower flange is arranged on the top of the steel pipe D, and the bolt holes of the upper flange of the steel pipe A are used for being aligned with the bolt holes of the lower flange of the steel pipe D and being fixed by bolts.

[0011] The steel pipe D is provided with inner filled concrete inside, the other end of the steel pipe D away from the steel pipe A is used for being embedded in a riverbed, and the steel pipe A and the steel pipe D are arranged around a main bridge pile cap.

[0012] The main bridge pile cap is arranged with three rows and two rows of separated ship collision prevention facility structures respectively, and the separated ship collision prevention facility structures are arranged in a plum blossom shape.

[0013] The polyurethane foam rotating drum comprises a Teflon sliding plate, a high polymer material shell and polyurethane foam, the high polymer material shell is used for being arranged on the upper part of the steel pipe C, the high polymer material shell is provided with the polyurethane foam inside, and the high polymer material shell is provided with the Teflon sliding plate between the upper part of the steel pipe C.

[0014] The bridge ship collision prevention active protection device and the use method thereof comprise the following steps:

[0015] S1. A detection and signal sending stage: when the ship distance from the main bridge pier is less than a certain range, the separated ship collision prevention facility structure in the direction of the ship detected by the laser range finder sends a signal to the laser range finder through the control assembly.

[0016] S2. The lifting floating water surface stage: the gas generator in the separated ship anti-collision facility structure is started to inflate the air bag through the control assembly, the air bag generates buoyancy to drive the steel pipe C, the polymer material shell and the polyurethane foam to move upwards, so that the steel pipe C moves upwards from the small cavity of the steel pipe B, and the small clamp rod of the steel pipe C slides upwards along the inner wall of the small sliding cavity of the steel pipe B; after the steel pipe C slides upwards for a distance, the small clamp rod of the steel pipe C contacts the small cavity of the steel pipe B, the steel pipe C is continuously driven upwards by the buoyancy of the air bag, so that the steel pipe C drives the steel pipe B to move upwards through the contact of the small clamp rod and the small cavity, so that the steel pipe B moves upwards from the large cavity of the steel pipe A, and the large clamp rod of the steel pipe B slides upwards along the inner wall of the large sliding cavity of the steel pipe A; after the large clamp rod of the steel pipe B slides upwards for a distance, the large clamp rod of the steel pipe B contacts the large cavity of the steel pipe A, the large cavity of the steel pipe A blocks the large clamp rod of the floating steel pipe B, and at the same time, the small cavity of the steel pipe B blocks the small clamp rod of the steel pipe C; the steel pipe C, the polymer material shell and the polyurethane foam are floated out of the water surface by the buoyancy of the air bag;

[0017] S3. The protection stage: when the ship collides with the steel pipe C, the polymer material shell and the polyurethane foam, a part of energy is absorbed through the deformation of the polyurethane foam, and the kinetic energy of the ship is converted into collision force through the collision of the ship with the steel pipe C, the polymer material shell and the polyurethane foam, so that the tetrafluoro slide plate drives the polymer material shell and the polyurethane foam to rotate and push the bow along the upper part of the steel pipe C, and the kinetic energy of the ship is converted into collision force;

[0018] S4. The disassembly and replacement stage: the collision force of the ship causes the collision-affected part of the separated ship anti-collision facility structure to deform and be damaged, the bolts on the upper flange plate of the steel pipe A and the lower flange plate of the steel pipe D are screwed into the bolt holes of the upper flange plate of the steel pipe A and the lower flange plate of the steel pipe D through tools, the steel pipe A is disassembled and replaced, a newly made steel pipe A is hoisted to the installation position, and the bolt holes of the upper flange plate of the steel pipe A are aligned with the bolt holes of the lower flange plate of the steel pipe D through the bolts.

[0019] Compared with the prior art, the present application has the following advantages:

[0020] (1) The utility model is usually below water level through the separated ship anti-collision facility structure, when the laser range finder detects that the distance between the ship and the main bridge pier is less than a certain range, the control assembly sends a signal to the separated ship anti-collision facility structure in the direction, the gas generator in the separated ship anti-collision facility structure in the region starts to inflate the air bag, and the polyurethane foam rotating drum is pulled to the water surface and contacted with the ship through buoyancy, so that the ship colliding with the main bridge pier is prevented, and the main bridge pier is prevented from being damaged.

[0021] (2), the utility model adopts the separated type design, the separated type anti-ship collision facility structure is divided into replaceable part and non-replaceable part, when the collision occurs, only the replaceable part of the separated type anti-ship collision facility structure that collides is replaced, the use cost is saved, and the separated type anti-ship collision facility structure can be suitable for various shapes of bridge piers and bearing platform shapes; in the non-working state, the net width of the channel is not occupied.

[0022] (3), the polyurethane foam rotating drum part of the separated type anti-ship collision facility structure can rotate around the outside of the steel pipe C, when the ship collides, the ship head can be rotated and pushed to reduce the kinetic energy of the ship and convert the impact force, and the deformation energy dissipation of the polyurethane foam further reduces the kinetic energy of the ship. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the main bridge pier, the main bridge bearing platform and the separated type anti-ship collision facility structure plane structure schematic drawing of the application.

[0024] Figure 2 It is the separated type anti-ship collision facility structure plane structure schematic drawing of the application.

[0025] Figure 3 It is the overall plane structure schematic drawing of the separated type anti-ship collision facility structure working stage of the application.

[0026] Figure 4 It is the plane structure schematic drawing of the replaceable part of the separated type anti-ship collision facility structure non-working stage of the application.

[0027] Figure 5 It is the polyurethane foam rotating drum plane structure schematic drawing of the application.

[0028] Figure 6 It is the flange plate plane structure schematic drawing of the application.

[0029] Mark in the drawing: 1, laser range finder; 2, control assembly; 21, gas generator; 22, air bag; 3, main bridge pier; 4, main bridge bearing platform; 5, separated type anti-ship collision facility structure; 51, steel pipe A; 52, steel pipe B; 53, steel pipe C; 54, steel pipe D; 55, inner filling concrete; 56, bolt; 57, flange plate; 5701, bolt hole; 61, four fluorine sliding plate; 62, high molecular material shell; 63, polyurethane foam; 7, river bed. DETAILED DESCRIPTION

[0030] As Figure 1As shown, the present application provides technical solutions: a bridge anti-ship collision active protection device, including laser range finder 1, control assembly 2, main bridge pier 3, main bridge pile cap 4, separate anti-ship collision facility structure 5, polyurethane foam drum and river bed 7, the upper part of the main bridge pier 3 is provided with laser range finder 1 and control assembly 2, the bottom of the main bridge pier 3 is provided with the main bridge pile cap 4, the periphery of the main bridge pile cap 4 on the main bridge pier 3 is provided with a plurality of separate anti-ship collision facility structures 5, the polyurethane foam drum is arranged on the separate anti-ship collision facility structure 5, and the other end of the polyurethane foam drum away from the separate anti-ship collision facility structure 5 is used for embedding into the river bed 7 for fixation.

[0031] Wherein, the laser range finder 1 and the control assembly 2 are arranged on both sides of the main bridge pier 3, the front and the back; the height of the laser range finder 1 and the control assembly 2 can be adjusted according to actual requirements, but needs to be higher than the flood level position in order to measure the distance of the ship.

[0032] As shown in the figure, Figure 2 Wherein, the periphery of the main bridge pile cap 4 is respectively arranged with three rows and two rows of separate anti-ship collision facility structures 5, and the separate anti-ship collision facility structures 5 are arranged in the shape of plum blossom; the spacing between the separate anti-ship collision facility structures 5 is 1.5 times the maximum diameter of the separate anti-ship collision facility structure 5; the distance between the innermost separate anti-ship collision facility structure 5 and the main bridge pile cap 4 is equal to 0.6 times the maximum diameter of the separate anti-ship collision facility structure 5.

[0033] As shown in the figure, Figures 3-5 Wherein, the separate anti-ship collision facility structure 5 includes steel pipe A 51 and steel pipe B 52; the inside of the steel pipe A 51 is provided with a large sliding cavity, the top side wall of the steel pipe A 51 is provided with a large cavity opening, one end of the steel pipe B 52 is provided with a large clamping rod, the large clamping rod of the steel pipe B 52 is outwardly arranged, the large clamping rod of the steel pipe B 52 is used for embedding in the inner wall of the large sliding cavity of the steel pipe A 51 and sliding, the large cavity opening of the steel pipe A 51 is used for cooperating with the large clamping rod of the steel pipe B 52 to prevent the steel pipe B 52 from being pulled out of the large cavity opening of the steel pipe A 51.

[0034] Wherein, the inside of the steel pipe B 52 is provided with a small sliding cavity, the top wall of the other end of the steel pipe B 52 away from the connection with the steel pipe A 51 is provided with a small cavity opening, one end of the steel pipe C 53 is provided with a small clamping rod, the small clamping rod of the steel pipe C 53 is outwardly arranged, the small clamping rod of the steel pipe C 53 is used for embedding in the inner wall of the small sliding cavity of the steel pipe B 52 and sliding, the small cavity opening of the steel pipe B 52 is used for cooperating with the small clamping rod of the steel pipe C 53 to prevent the steel pipe C 53 from being pulled out of the small cavity opening of the steel pipe B 52.

[0035] Wherein, the steel pipe C 53 further includes a gas generator 21 and an air bag 22, the inside of the steel pipe C 53 is provided with the air bag 22, the inside of the steel pipe C 53 is provided with the gas generator 21 below the air bag 22, and the gas generator 21 is used for being fixed on the lower inner wall of the steel pipe C 53.

[0036] Among them, steel pipe D54 is provided below steel pipe A51, and flange 57 is provided on steel pipe A51 and steel pipe D54. Flange 57 has several bolt holes 5701. Flange 57 includes an upper flange and a lower flange. An upper flange is provided at the bottom of the other end of steel pipe A51 away from steel pipe B52, and a lower flange is provided at the top of steel pipe D54. The bolt holes 5701 of the upper flange of steel pipe A51 are aligned with the bolt holes 5701 of the lower flange of steel pipe D54 and fixed by bolts 56.

[0037] The inner side of the steel pipe D54 is filled with concrete 55, and the other end of the steel pipe D54 away from the connecting steel pipe A51 is used to be buried in the riverbed 7. The steel pipe A51 and the steel pipe D54 are arranged around the main bridge abutment 4.

[0038] like Figure 6 As shown, the polyurethane foam rotating cylinder includes a PTFE sliding plate 61, a polymer material shell 62, and a polyurethane foam 63. The polymer material shell 62 is used to be installed on the upper part of the steel pipe C53. The polyurethane foam 63 is provided inside the polymer material shell 62. The PTFE sliding plate 61 is provided between the polymer material shell 62 and the upper part of the steel pipe C53.

[0039] This application also provides a bridge anti-ship collision active protection device and its usage method, including the following steps:

[0040] S1. Detection and signaling stage: When the detection laser rangefinder 1 detects that the distance between the ship and the main bridge pier 3 is less than a certain range, the control component 2 sends a signal to the separated anti-ship collision facility structure 5 in the direction of the ship detected by the laser rangefinder 1.

[0041] S2. Lift the water surface stage: through the control assembly 2, the gas generator 21 in the separated ship anti-collision facility structure 5 starts to inflate the air bag 22, the air bag 22 generates buoyancy to drive the steel pipe C53, the polymer material shell 62 and the polyurethane foam 63 to move upwards, so that the steel pipe C53 moves upwards from the small cavity of the steel pipe B52, and the small clamping rod of the steel pipe C53 slides upwards along the inner wall of the small sliding cavity of the steel pipe B52, after the steel pipe C53 slides upwards for a distance, the small clamping rod of the steel pipe C53 contacts the small cavity of the steel pipe B52, the steel pipe C53 is continuously driven upwards by the buoyancy of the air bag 22, so that the steel pipe B52 moves upwards from the large cavity of the steel pipe A51, and the large clamping rod of the steel pipe B52 slides upwards along the inner wall of the large sliding cavity of the steel pipe A51 for a distance, then the large clamping rod of the steel pipe B52 contacts the large cavity of the steel pipe A51, the large cavity of the steel pipe A51 blocks the large clamping rod of the floating steel pipe B52, at the same time, the small cavity of the steel pipe B52 blocks the small clamping rod of the steel pipe C53, and the steel pipe C53, the polymer material shell 62 and the polyurethane foam 63 are floated out of the water by the buoyancy of the air bag 22;

[0042] S3. Protection stage: when the ship collides with the steel pipe C53, the polymer material shell 62 and the polyurethane foam 63, a part of energy is absorbed by the deformation of the polyurethane foam 63, and the ship collides with the steel pipe C53, the polymer material shell 62 and the polyurethane foam 63, so that the tetrafluoro slide plate 61 drives the polymer material shell 62 and the polyurethane foam 63 to rotate and push the bow along the upper part of the steel pipe C53, reducing the kinetic energy of the ship into collision force;

[0043] S4. Disassembly and replacement stage: the collision force of the ship will cause the collision part of the separated ship anti-collision facility structure 5 to deform and damage, the bolts 56 on the upper flange plate of the steel pipe A51 and the lower flange plate of the steel pipe D54 are rotated and screwed in by tools, the steel pipe A51 is disassembled and replaced, a newly made steel pipe A51 is hoisted to the installation position, and the bolt holes 5701 of the upper flange plate of the steel pipe A51 are aligned with the bolt holes 5701 of the lower flange plate of the steel pipe D54 and are fixed by tightening the bolts 56.

[0044] Although the embodiments of the present application have been shown and described, it is understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A bridge anti-ship collision active protection device, comprising a laser rangefinder (1), a control component (2), a main bridge pier (3), a main bridge abutment (4), a separate anti-ship collision facility structure (5), a polyurethane foam rotating cylinder, and a riverbed (7), characterized in that: The main bridge pier (3) is equipped with a laser rangefinder (1) and a control component (2) on its upper part. The main bridge pier (3) is equipped with a main bridge abutment (4) at its bottom. Several separate anti-ship collision facility structures (5) are provided around the main bridge abutment (4) on the main bridge pier (3). A polyurethane foam rotating cylinder is provided on the separate anti-ship collision facility structure (5). The other end of the separate anti-ship collision facility structure (5) away from the polyurethane foam rotating cylinder is used to be buried in the riverbed (7) for fixation. The separate anti-ship collision facility structure (5) includes steel pipe A (51) and steel pipe B (52); a large sliding cavity is opened on the inner side of steel pipe A (51), a large cavity opening is opened on the top side wall of steel pipe A (51), and a large clamping rod is provided at one end of steel pipe B (52). The large clamping rod of steel pipe B (52) is set outward, and the large clamping rod of steel pipe B (52) is used to slide on the inner wall of the large sliding cavity of steel pipe A (51); The inner side of the steel pipe B (52) is provided with a small sliding cavity. The top wall of the other end of the steel pipe B (52) away from the connection with the steel pipe A (51) is provided with a small cavity opening. One end of the steel pipe C (53) is provided with a small clamp rod. The small clamp rod of the steel pipe C (53) is set outward. The small clamp rod of the steel pipe C (53) is used to slide on the inner wall of the small sliding cavity of the steel pipe B (52). The steel pipe C (53) also includes a gas generator (21) and an airbag (22). The airbag (22) is provided on the inner side of the steel pipe C (53), and the gas generator (21) is provided on the inner side of the steel pipe C (53) near the lower part of the airbag (22). The gas generator (21) is used to fix it on the lower inner wall of the steel pipe C (53). Below the steel pipe A (51) is a steel pipe D (54). A flange (57) is provided on the steel pipe A (51) and the steel pipe D (54). Several bolt holes (5701) are provided on the flange (57). The flange (57) includes an upper flange and a lower flange. An upper flange is provided at the bottom of the other end of the steel pipe A (51) away from the steel pipe B (52). A lower flange is provided at the top of the steel pipe D (54). The bolt holes (5701) of the upper flange of the steel pipe A (51) are used to align with the bolt holes (5701) of the lower flange of the steel pipe D (54) and fix them by bolts (56). The inner side of the steel pipe D (54) is filled with concrete (55), and the other end of the steel pipe D (54) away from the connecting steel pipe A (51) is used to be buried in the riverbed (7). The steel pipe A (51) and the steel pipe D (54) are arranged around the main bridge abutment (4). The polyurethane foam rotating cylinder includes a PTFE sliding plate (61), a polymer material shell (62), and polyurethane foam (63). The polymer material shell (62) is used to be installed on the upper part of the steel pipe C (53). The inner side of the polymer material shell (62) is provided with polyurethane foam (63). The PTFE sliding plate (61) is provided between the polymer material shell (62) and the upper part of the steel pipe C (53).

2. The bridge anti-ship collision active protection device according to claim 1, characterized in that: The laser rangefinder (1) and control components (2) are located on both sides of the main bridge pier (3).

3. The bridge anti-ship collision active protection device according to claim 2, characterized in that: Around the main bridge abutment (4), three rows and two rows of separate anti-ship collision facility structures (5) are respectively arranged, and the separate anti-ship collision facility structures (5) are arranged in a quincunx pattern.

4. A method of using a bridge anti-ship collision active protection device, applied to the bridge anti-ship collision active protection device according to any one of claims 1-3, characterized in that: Includes the following steps: S1. Detection and signaling stage: When the laser rangefinder (1) detects that the distance between the ship and the main bridge pier (3) is less than a certain range, it sends a signal to the split anti-ship collision facility structure (5) in the direction of the ship detected by the laser rangefinder (1) through the control component (2); S2. Rising and Floating Stage: The gas generator (21) inside the separate anti-collision facility structure (5) is activated by the control component (2) to inflate the airbag (22). The buoyancy generated by the airbag (22) drives the steel pipe C (53), the polymer material shell (62), and the polyurethane foam (63) upward, causing the steel pipe C (53) to move upward from the small cavity of the steel pipe B (52). At the same time, the small lever of the steel pipe C (53) slides upward along the inner wall of the small sliding cavity of the steel pipe B (52). After the steel pipe C (53) slides upward for a certain distance, the small lever of the steel pipe C (53) will contact the small cavity of the steel pipe B (52). The buoyancy generated by the airbag (22) continues to drive the steel pipe C (53) upward, causing it to move upward. Steel pipe C (53) moves steel pipe B (52) upward together through the contact of the small clamp rod with the small cavity opening, so that steel pipe B (52) moves upward from the large cavity opening of steel pipe A (51). At the same time, the large clamp rod of steel pipe B (52) slides upward along the inner wall of the large sliding cavity of steel pipe A (51) for a distance, and then contacts the large cavity opening of steel pipe A (51) through the large clamp rod of steel pipe B (52). The large cavity opening of steel pipe A (51) blocks the floating large clamp rod of steel pipe B (52). At the same time, the small clamp rod of steel pipe C (53) is blocked through the small cavity opening of steel pipe B (52). The buoyancy generated by the airbag (22) drives steel pipe C (53), polymer material shell (62) and polyurethane foam (63) to float out of the water. S3. Protection phase: When the ship hits the steel pipe C (53), the polymer material shell (62) and the polyurethane foam (63), some energy is absorbed by the deformation of the polyurethane foam (63). At the same time, the force of the ship hitting the steel pipe C (53), the polymer material shell (62) and the polyurethane foam (63) causes the PTFE sliding plate (61) to drive the polymer material shell (62) and the polyurethane foam (63) to rotate along the upper part of the steel pipe C (53) and turn the bow of the ship, thereby reducing the conversion of the ship's kinetic energy into impact force. S4. Disassembly and Replacement Stage: The impact force of the ship will force the structure (5) of the separated anti-ship collision facility to deform and break. The bolts (56) on the upper flange of steel pipe A (51) and the lower flange of steel pipe D (54) are rotated and unscrewed by tools. Steel pipe A (51) is disassembled and replaced. The newly made steel pipe A (51) is hoisted to the installation position. The bolt hole (5701) of the upper flange of steel pipe A (51) is used to align with the bolt hole (5701) of the lower flange of steel pipe D (54) and tightened by bolts (56).

Images