713results about "Suspension bridge" patented technology

The invention discloses a construction method of a single main cable inclined-suspender earth anchored suspension bridge, which is characterized by comprising the following steps of: respectively completing anchoring construction, main tower construction, steel box girder construction, main cable construction and suspender construction, then drawing a front anchor head of a suspender by adopting a jack, and fixing on a steel box girder; regulating the tensile force of the suspender till the tensile force of the suspender and the line shape of a main cable meet the requirements; disassembling all temporary supporting seats, and lowering the steel box girder to a main tower beam as a permanent supporting seat so as to complete the construction. The whole construction process has safety and reliability so as to provide a necessary precondition for ensuring project quality. The construction method has reasonability, high efficiency and concision, can not only ensure the project progress, but also effectively reduce the construction cost.

The invention relates to a continuous movable type cable climbing device, comprising at least a rack (12) and a climbing device (K) which is composed of an upper roller wheel (1), an upper chain wheel (2), a rotary hinge I (3), a rotary hinge II (4), a rotary hinge III (5), an upper linear driver (6), an upper chain (7), an upper connecting rod (8), a rotary hinge IV (9), a medium chain wheel (10), an electric motor (11), a rotary hinge V (13), a lower connecting rod (14), a lower chain (15), a rotary hinge VI (16), a lower linear driver(17), a rotary hinge VII (18), a rotary hinge VIII (19), a lower chain wheel (20), a lower roller wheel (21); wherein the rack is provided with at least three climbing devices (K).With the cable climbing device of the invention adopted, continuous movement of devices along the cable can be realized; in addition, the cable climbing device features obstacle detouring function.

The invention provides a process method for the construction of a steel-structured suspension bridge and a light type cable carrying crane specially used in the same, wherein the process flow comprises the steps of construction preparation, assembly of the light type cable carrying crane, the positioning and debugging of the light type cable carrying crane, the positioning of a ship carrying steelbeams, the lifting of the steel beams up to the hoisting point, the descent of a lifting device, the bolting connection of the lifting device and the steel beams, the first stage lifting of the steelbeams, the 30-percent load detection, the 70-percent load detection, the 100-percent load detection, the horizontal adjustment of the steel beams, the second stage lifting of the steel beams, the positioning of the steel beams and boiling connection of a lifting rod, the assembly of a security device, the lifting of the light type cable carrying crane, the movement positioning of the light type cable carrying crane; and the special light type cable carrying crane consists of a load-bearing mechanism, a load-lifting mechanism, a traveling mechanism, an anchoring mechanism and a weight-balancing beam. The process method and the special light type cable carrying crane have the advantages of light weight, simple structure, easy processing, convenient assembly and disassembly, no waterway occupation, big free space brought to transport barges and waterway traffic, high flexibility and maneuverability, high lifting speed, low construction cost, low labor intensity of workers and the suitability for the construction of the suspension bridge.

The invention provides an especial-big span suspension bridge of a uniparted hyperboloid space rope net main cable and a construction method thereof. A straight line character of the uniparted hyperboloid is used to change a vertical parallel cable rope system of an original suspension bridge. A thick and heavy centralized cable rope is changed into a dispersive space steel wire cable rope. Multiple strand of steel wire cable ropes are arranged in a cross mode. Space rope net main cable-cross nodes are fixed to form a space cable rope system of the uniparted hyperboloid type. An oval steel strengthening ring beam is arranged. A suspender and a stiffening beam are installed. A gate-type rigidity middle buckle is arranged. The especial-big span suspension bridge of the uniparted hyperboloid space rope net main cable system is built. The especial-big span suspension bridge of the uniparted hyperboloid space rope net main cable system has the advantages of being strong in span capacity, large in space structure rigidity, high in screw frequency ratio, good in wind resistance stability and the like. The novel space main cable system suspension bridge is capable of radically saving the problem of the wind resistance stability of the big span suspension bridge and used for projects of a striding sea connected island. The especial-big span channel suspension bridge of 3000-5000 meters is built.

A device having an anchor block having orifices therethrough, each accommodating a tendon of the cable and a means of immobilizing the tendon. The device further includes a bearing piece for the anchor block, and means of guiding the tendons between the anchor block and a running part of the cable. The guide means are connected to the bearing piece and include an individual guide passage for each tendon of the cable, allowing angular deviation thereof. Each guide passages have, in the direction of the anchor block, a transverse layout aligned with that of the orifices in the anchor block.

A cable-stayed suspension bridge having characteristics of a cable stayed bridge and those of a suspension bridge at the same and time and using one-box and two-box girders in combination is disclosed. The bridge grinder of the cable-stayed suspension bridge includes one-box girders that each extend to both sides through the respective one tower and a two-box girder set in a central portion of the center span between towers in the length direction of the bridge girder. The cable-stayed suspension bridge includes cable-stayed structures in which a respective one of the one-box girders is supported by the tower with plural cables and a suspension structure in which the two-box girder is supported by the plural towers with two main cables and plural hanger ropes. The two-box girder has a central ventilation opening in the central portion as viewed in a transverse direction thereof. The hanger ropes in the suspension structure extend from the main cables almost perpendicularly, and their lower end portions are connected to the end portions in the transverse direction of the central ventilation opening or in the vicinity thereof.

The invention discloses a self-anchored hybrid beam cable-stayed suspension cooperative system bridge, belongs to the technical field of constructional engineering, and particularly relates to a design for a large-span bridge in the bridge engineering. The bridge is characterized in that after a cable tower and side hole piers are manufactured, a cantilever is assembled to a concrete main bridge of the cable-stayed bridge; after the cantilever is assembled to a side hole, a main cable is hung, two ends of the main cable are anchored on an anchor block at the outer end of a concrete beam respectively, and the anchor block is pulled to a temporary anchor structure by a temporary anchor cable; a hanging rod is hoisted to span each section of steel main beam by a cable crane; after folding, the temporary anchor cables are detached in batch, and the main cables are completely anchored at two ends of the concrete main beam so as to finish the system conversion from temporary ground anchorage to self anchorage; and deck paving and rail construction are finished, the cable force of the whole bridge is adjusted, and the bridge is formed. The self-anchored hybrid beam cable-stayed suspension cooperative system bridge has the effects and advantages of solving the problems of the large-span bridge in design and construction, reducing the height of the tower, fully playing a role of materials, reducing the construction cost, shortening the construction period and reducing the risk in the construction process.

The invention relates to the field of construction of multi-tower suspension bridges, and particularly relates to a span-division erection construction method of a construction catwalk of a multi-tower suspension bridge. The construction method is characterized in that: a multi-span construction catwalk is divided into different spans, every two spans of the construction catwalk are taken as a construction segment, each construction segment is provided with a corresponding single-line reciprocating traction system, a catwalk bearing rope is independently erected for each single-line reciprocating traction system and finally, the catwalk bearing ropes which are erected segment by segment are fixed at the segment positions. In the invention, the span-division erection construction method of the construction catwalk of the multi-tower suspension bridge is provided, thus the erection efficiency of the catwalk bearing ropes of the construction catwalk of the multi-tower suspension bridge is improved.

The invention discloses a method for accurately computing unloaded cable shapes of suspension bridges with spatial cable planes. The method includes steps of setting preliminary deviation quantities;solving tangent points and horizontal force of various span main cables at main cable saddles at the moment; solving the difference delta H of horizontal force of mid-span and side span of the main cables under the preliminary deviation quantities; outputting the preliminary deviation quantities and the unloaded cable shapes under the preliminary deviation quantities if the delta H is smaller thanpermissible error values, or correcting the preliminary deviation quantities of the main cable saddles by the aid of influence matrix processes according to difference values and repeatedly carryingout the first, second, third and fourth steps until errors are smaller than the permissible error values. The method has the advantages that the method actually includes internal and external double-layer circulation, the tangent points of the various span main cables and the main cable saddles under the preliminary deviation quantities are solved by means of the inner-layer circulation, the preliminary deviation quantities are solved by means of the outer-layer circulation according to unbalanced force under the preliminary deviation quantities, only a single unknown number is available in each layer of circulation, and the method is excellent in solving efficiency and precision by the aid of the influence matrix processes under the condition that completed bridge tangent points are selected by initial values; correct results can be quickly solved by the aid of the method regardless of suspension bridges with parallel cable planes or the suspension bridges with the spatial cable planes.

The invention relates to the field of bridge construction and discloses a method for hoisting construction girder sections through cables. The method includes the steps: erecting a first main cable, a second main cable and a plurality of booms; taking a region at the bottom of each boom to arrange a hoisting device below the first main cable and the second main cable; transporting a to-be-mounted girder section to a hoisting position, and adjusting the to-be-mounted girder section to be perpendicular to the mounting direction; selecting one mounting region with no to-be-mounted girder section, enabling the hoisting device to move above the current mounting region after longitudinally hoisting the to-be-mounted girder section to a position 1-2m above a bridge deck, horizontally rotating the to-be-mounted girder section by 90 degrees, placing the to-be-mounted girder section at a designed elevation, and fixing the to-be-mounted girder section to the current mounting region and the bridge deck to form a mounted section. By adoption of the method for hoisting construction girder sections through cables, manufacturing cost can be reduced, arrangement of a girder section hoisting platform in a main span is avoided, and normal operation of a river channel is guaranteed.

A main cable wire wrapping machine and a wrapping method thereof relate to a device which can densely wrap galvanized mild steel wires on the main cables of a suspension bridge and a winding method thereof. The main cable wire wrapping machine is composed of a main machine, front and rear clamping holders and a guide girder. In the wrapping method, the wire wrapping of the main cable is first carried out on the end of a cable clip, then the internode wire wrapping is carried out, the wire wrapping of the main cable is carried out on the end of a terminal cable clip, a gear ring passes the cable clip, and finally the wire wrapping of the end of a second internode initiating terminal is prepared. The main machine of the present invention and the clamping holders can alternately travel on the main cable; the rotary speed and travelling speed of the main machine can be stepless regulated, matching is accurate and the main machine can carry out dense wire wrapping; the rotary gear ring is provided with a mobile gate, the cable clips and a suspension cable for convenient passing, and travelling wheels can automatically span the cable clips; applicable under different working conditions, the main cable wire wrapping machine has the advantages of stable and adjustable wire wrapping tension, convenient regulation, high wire wrapping efficiency and quality, easy operation, safety and reliability. The present invention is mainly used for forming a permanent protecting layer on the main cable by densely wrapping the galvanized mild steel wire on the main cable after the main cable is treated by antisepsis process at the last stage of the construction of the suspension bridge, so that the service life of the main cables is prolonged.

The invention discloses a suspender tensioning method of a double-tower single-span self-anchored suspension bridge with high-cross dip and spatial cable, which comprises the following steps: expanding a main cable to a certain degree by using temporary slings; tensioning permanent slings nearby the temporary slings to a preset tonnage or an unstressed sling length at the time forming a bridge in the process of tensioning the permanent slings; and stopping a part of the temporary slings or all temporary slings working by using the advantage that the allowable cable tension of the permanent slings are much greater than that of the temporary slings, thus ensuring that the cable tension of the temporary slings does not exceed the specified value. In the process, if the derivation of a tower top exceeds the limit, the main cable saddles are subject to incremental launching. In the suspender tensioning method of the double-tower single-span self-anchored suspension bridge with high-cross dip and spatial cable, the larger control cable tension of the permanent slings nearby the temporary slings is taken full advantage. The suspender tensioning method of the double-tower single-span self-anchored suspension bridge with high-cross dip and spatial cable has the following advantages of being in no need of regulating the cable tension of the temporary slings actively in the process of system conversion, thus ensuring safety in the construction process, and quickness and convenience, short construction period, and lower cost.

The invention discloses an erection method of a stiffening girder of a suspension bridge and a device thereof. The method comprises the following steps: 1) a track cable is erected below the position of a main cable of the suspension bridge; 2) a sling suspended on the main cable is taken as a middle suspension center of the track cable; 3) the middle suspension center is connected with the track cable by a saddle; 4) two ends of the track cable are arranged on anchorage systems at two banks; 5) a stiffening girder section is suspended by an overhead crane system supported on the track cable, and a traction system or a pushing system draws or pushes the overhead crane system to carry the stiffening girder section to a required position; and 6) the stiffening girder segment carried to the position is vertically lifted by a lifting device to be connected with the sling for achieving system transform. The method and the device have the obvious advantages of safe construction, cost saving, flexible and convenient operation, wide application range and the like, and help solve the problems of inconvenient transportation under a bridge in a mountainous area and hard stiffening girder erection of a super major suspension bridge in an area with extremely high vertical lifting height.

A connecting system for connecting a cable including at least one wire for a building work structure and an element of the structure. The connecting system comprises a clamping device which is connected to the element of the structure, and a load transmitting device which transmits a clamping load of the clamping device to the cable and which houses the at least one wire of the cable. The at least one wire is bonded into the load transmitting device.

A reinforcement for a building works structure comprising an assembly of solid wires. The wires are mutually parallel to form a bundle and the reinforcement comprises a sheath made of plastic material enclosing the bundle and providing it with cohesion.

The invention discloses a sling for a spatial cable structure, which comprises a sling body, an upper-end anchorage connected with the upper end of the sling body, and a lower-end anchor device connected with the lower end of the sling body, wherein the lower-end anchor device comprises a lower-end anchorage, a connecting rod, a base and a revolute pair positioned between the connecting rod and the base, the connection rod is a long rod with a cylinder head on the lower end, the revolute pair is a ring-shaped ball support with an inner spherical surface as the end surface of one end, the base is a tower-shaped body with a step hole, a small upper end and a large bottom end, the end surface of the bottom end of the base is an inclined surface or a plane, the upper end of the connecting rod passes through the step hole of the base and is connected with the lower-end anchorage, the cylinder head on the lower end of the connecting rod is locked on the end surface of the inner spherical surface of the revolute pair in the step hole of the base, and the lower end of the sling body is in anchoring connection with the lower-end anchorage of the lower-end anchor device. The sling can rotate larger angles, move, extend, and be adjusted with the length, and can fully adapt the demand of a suspension bridge adopting spatial cables to the structural form of the sling.

The invention discloses a propelled hydraulic cable carrying crane which comprises a power system, a control system and a mechanical executing mechanism, wherein the mechanical executing mechanism mainly comprises a main truss (100), walking type propelling systems (210 and 220) installed at both ends of the main truss, two sets of hydraulic lifting systems (310 and 320) installed on the main truss and a shoulder pole beam (400); the main truss and the shoulder pole beam both adopt length changeable structures; and the hydraulic lifting systems (310 and 320) comprise synchronous stepping continuous lifting jacks and continuous lifting steel strands (510 and 520). The whole crane realizes walking type propelling on a cable by controlling actions of a walking frame and a sliding end beam so as to alternately bear and alternately walk without additional traction equipment and manual disassembly, assembly and conveying of accessories at high altitude, such as clamping cables, hoops, and the like, and the invention has the advantages of high walking speed, high sliding resistance and high safety.

The invention discloses a method for stretching a single-tower double-span self-anchored suspension bridge sling of a side-span splay cable knot in a supportless way. The method is characterized by comprising the following steps of: alternately stretching slings at lateral span sides when a main-span sling is gradually stretched from a main tower to a splay cable saddle at a main tower side; firstly stretching a BK-M sling close to a splay cable knot at a lateral span side; then, sequentially and gradually stretching to the side-span splay cable knot; and sequentially and gradually stretching from the BK-M sling to the main tower and upwards pushing a main cable saddle if the deviation of a tower top exceeds a limit in the process. In the method, the characteristic of greater control sling force of a permanent sling close to the side-span splay cable knot is utilized, the vertical displacement of the splay cable knot can be basically controlled after the permanent sling is stretched, the sling force has little increment at a later period, and the whole quantity satisfies the safety requirement. The invention has the advantages of high safety factor, rapidness, convenience, cost saving by saving temporarily fixing facilities, such as a splay cable knot or a temporary sling, and the like.

The invention discloses an assembled cable saddle structure for a suspension bridge, which is composed of an upper part and a lower part, wherein the upper part is assembled into a saddle groove of a main cable saddle or a vice cable saddle by connecting and welding steel plates in various specifications through high-strength bolts, and the lower part is assembled into a bearing bracket of the main cable saddle or the vice cable saddle by welding the steel plates; the upper part is connected with the lower part through high-strength bolts or welded seams; and the bearing bracket can be in running fit, sliding fit or stationary fit with a base. Compared with the traditional casting or cast-weld combined saddle, the assembled cable saddle structure disclosed by the invention has the advantages of simpler processing, more convenient transportation, more flexible assembly and more reliable quality, can serve as the saddle of the suspension bridge, and is especially suitable for a large-span suspension bridge in a mountainous area with difficult transportation conditions.

The invention relates to a pre-stress steel structure rolling type tension cable node, which comprises a non-continuous cable end body, a continuous cable end body, a node waist, a cable cavity, a support rod, an ear plate, a rolling shaft, a continuous cable and a fixing briquetting. The non-continuous cable end body is connected with the continuous cable end body through the node waist, the ear plate is arranged on the non-continuous cable end body, the support rod is connect to the non- continuous cable end body; the cable cavity is provided in the continuous cable end body, the continuous cable passes through the cable cavity and rotates around the rolling shaft, the fixing briquetting is connected with the continuous cable end body through bolts to fix the continuous cable. The node has the advantages of being capable of freely sliding in the continuous cable tension process, thereby overcomes the disadvantages of uneven cable force caused by the friction force between the cable and the node, and meets the need of fixing after the cable is tensioned, the node is particularly applicable to the tension cable sliding nodes in the structures of suspended-domes, cable domes, beam strings, cable trusses and suspension bridges.

The invention provides a pneumatic control device for improving flutter stability of a steel trussed girder suspension bridge, which relates to the bridge technology. The device of the invention is a combination of bridge deck central slotting and pneumatic wing plates, wherein, the width of the slotting is 1 / 100-1 / 10 of the width of the steel trussed girder; thetwo pneumatic wing plates are symmetrically installed on two sides of the steel trussed girder and arranged longitudinally and continuously along the bridge, wherein, the total arrangement length is 1 / 2-1 time of the span length of a midspan area of a main span; the two pneumatic wing plates are arranged vertically along the bridge in a single layer, double layer or multilayer mode; the width of each pneumatic wing plate is 1 / 30-1 / 10 of the width of the steel trussed girder; the horizontal distance from the centers of the pneumatic wing plates to a center longitudinal axis of the bridge is 1 / 3-1 / 2 of the width of the steel trussed girder, and the vertical distance from the centers of the pneumatic wing plates to the bottom of the steel trussed girder is 1 / 4-1 / 2 of the height of the steel trussed girder; and the cross sections of the pneumatic wing plates are in an elliptic shape, or a flat plate shape with a round end or a triangle air nozzle. The pneumatic control device changes the air flow characteristic of the steel trussed girder, obviously improves the flutter stability of the steel trussed girder suspension bridge, and has simple structure, convenient installation and good economical efficiency.

The invention discloses a locally uncombined suspension bridge steel-concrete combined bridge deck system and a construction method of the combined bridge deck system, and belongs to the technical field of bridge structures. The bridge deck system consists of concrete slabs, longitudinal steel beams, cross steel beams, air nozzles and toggle pin connectors; and a suspension bridge section steel-concrete combined bridge deck system is prefabricated in a factory. The prefabricated concrete slabs and section steel main beams form a whole through concrete wet joints and the toggle pin connectors. The prefabricated concrete slabs and cast-in-place concrete joints are only connected with the cross steel beams to form a whole through the toggle pin connectors, the longitudinal steel beams are not provided with the toggle pin connectors, and meanwhile, the toggle pin connectors are not arranged in a certain area of the ends of the cross steel beams at hoisting points. The problems of cracking, complex structures of toothed grooves at the slab ends of the prefabricated concrete slabs and the like due to the factors of temperature, contraction, creep and the like of the concrete slabs of the traditional suspension bridge combined bridge deck system are solved by adopting a locally uncombined technology on the premise of keeping the consumption of steel, the manufacturing process of the prefabricated slabs is simplified, the bearing capacity, the rigidity and the cracking resistance of the structure are improved, and the durability of the structure is improved.

A system for suspending a structure from a tree comprising a collection of primary tension members interwoven to define a sleeve adapted to grip a portion of the tree, and at least one hanger assembly extending from the sleeve having an end connectable to the structure to be suspended. The suspension system accommodates different sizes of tree trunks and branches, and changes in diameter of the tree. The system of the present invention is mountable to a tree without damaging the tree or impeding its growth. The system accommodates the natural flexing of the tree due to wind while reliably retaining any supported structure suspended above the ground.

The invention discloses a method for reinforcing and strengthening a main cable of a suspension bridge, and belongs to the technical field of suspension bridge maintenance. The method comprises the steps of erecting a new main cable right above an original main cable along the original main cable in parallel, enabling cable saddles and anchorages of an original bridge to be used as installation fixing points of the new main cable, arranging cable clamps at two sides of a position, which corresponds to a cable clamp on the original main cable, on the mew main cable, respectively forming an installing groove in the middle part of the upper end of each cable clamp, respectively arranging a U-shaped suspension rod in the corresponding installing groove in a hanging way, enabling the U-shaped suspension rods to be in contact with and connected with the lower bottom surface of an original suspension rod anchor head by a connecting plate, and uniformly regulating the internal force of each U-shaped suspension rod. The method for reinforcing and strengthening the main cable of the suspension bridge, disclosed by the invention, has the advantages that the original main cable is uniformly reinforced, and an internal force balance state of an original bridge floor system is maintained; common load bearing of the new main cable and an old main cable is realized, and the problem that original rated load is difficultly borne due to the damage of the main cable of the original bridge is solved.

The invention relates to a combination hydraulic system of high-low pressure pumps, in particular to a combination hydraulic system of high-low pressure pumps used for tight rope equipment in the construction of a main cable and a tight rope of a suspension bridge. The invention is characterized in that an operation platform (14) is connected with a vertical jack (8) and a level jack (9); a hydraulic pump station (13) comprises two sets of hydraulic units consisting of a high pressure pump (1), a low pressure pump (2), a high pressure overflow valve (4) and a low pressure overflow valve (3); the high pressure pump (1) of each hydraulic unit is connected with the high pressure overflow valve (4); the low pressure pump (2) is connected with the low pressure overflow valve (3); the low pressure pump (2) is connected with the high pressure pump (1) through an one-way hydraulic control valve (12). The invention has the advantages of good tightening effect, high efficiency, leading the main cable to be uniformly forced within and outside, and ensuring porosity of the main cable to meet design requirements, thus realizing the purpose of high efficiency and quality tightening operation.

The invention discloses a construction method of non-floor stand of tower frame crossbeam of a suspension bridge. The method comprises the following steps of arranging a crossbeam construction platform on a bearing steel truss, wherein the bearing steel truss has two support manners. According to one support manner, the bearing steel truss is arranged on the bracket of a tower pillar and a deck-type crossbeam construction platform are arranged on the top of the bearing steel truss. According to the other support manner, the bearing steel truss is supported on the top of a tower frame, and a hanging crossbeam construction platform is hanged below the bearing steel truss by a hanger and arranged on the supports on both ends of an auxiliary bracket of the tower pillar.

The invention discloses an amending method of the mounting positions of rope clips of a suspension bridge. The amending method comprises the following steps of firstly, according to actually-measuredpre-deviator of a cable saddle and the coordinates of a lowest point of middle spans of free cables, determining the stress-free length of a main cable; then according to an actually-measured permanent loading capacity, amending hanging rod force; then according to the actual stress-free length of the main cable and the amended hanging rod force, determining the bridge forming line shape of the main cable, the bridge forming position of each rope clip and the stress-free length of every main cable rope section (between every two adjacent rope clips); and finally calculating the horizontal length of each rope section and the mounting position of each rope clip under a free cable condition. Through the adoption of the amending method disclosed by the invention, according to the actually-measured line shape of the free cable and the permanent loading and weighting result, the mounting position of each rope clip under the free cable condition can be amended, so that under the bridge forming condition, the accuracy of the position of each rope clip and the accuracy of the tilt angle of a hanging rod are guaranteed.

The invention relates to a combination line-shaped bearing cable suspension bridge which is formed by a carriageway beam, a bridge tower, an anchoring, a bearing cable, and suspender cables. The bearing cable is formed by two main cables. A main cable displacement pulling rod of the two main cables is arranged between the bridge tower and an anchoring point. The main cables between the bridge tower and the displacement pulling rod are parallel to each other. The main cables between the displacement pulling rod and the anchoring point are in curve shapes at different intervals. The suspender cables are connected at two sides of the main cables and stiff girders at different skew angles. A main cable plane locating process exists in a construction method of the combination line-shaped bearing cable suspension bridge. According to the combination line-shaped bearing cable suspension bridge and the construction method of the combination line-shaped bearing cable suspension bridge, a dip angle of the suspender cables of the suspension bridge can be enlarged, an approximate triangle structure is formed by the carriageway beam and a part of the suspender cables, and stability of the suspension bridge is strengthened.