SE188773C1

SE188773C1 -

Info

Publication number: SE188773C1
Authority: SE
Publication date: 1963-01-01

Description

KLASS I NTERNATI ONELLSVENSK B 61 d19 d:11 /00 PATENT- OCH REGISTRERINGSVERKET Ans. 5100/1961 den 15/5 1961Harlin en ritning; G ROBERTS, LONDON, STORBRITANNIEN Hangbro Prioritet begard fran den 16 maj 1960 ( Storbritannien) Foreliggande uppfinning avser en hangbro med medelst bajliga hdngstag fran barkablarna upphangd brobana i form. av en ihalig, sluten lada. Enligt uppfinningen aro hangstagen, som yart och ett bestar air tva, sidor i en triangel bildande komponenter, som traffas i sina fastpunkter pa kablarna och som dro atskilda vid fastpunkterna i brobanan, sa anordnade, ati yinkeln mellan de hada komponenterna ingenstades Overstiger °milling 0. CLASS I NTERNATI ONELLSVENSK B 61 d19 d: 11/00 PATENT AND REGISTRATION AGENCY Ans. 5100/1961 on 15/5 1961Harlin a drawing; G ROBERTS, LONDON, UNITED KINGDOM Suspension bridge Priority requested from 16 May 1960 (Great Britain) The present invention relates to a suspension bridge with flexible suspension tracks suspended from the bar cables by means of flexible suspension struts. of a greedy, closed barn. According to the invention, the suspension struts, which yart and one consist of air two, sides of a triangle forming components, which meet at their fixed points on the cables and which are pulled apart at the fixed points in the bridge path, are arranged so that the angle between the hated components is nowhere. .

Bland pakanningarna pa en hangbro kunna aven: upptrada Adana, som alstras genom torsionssvdngningar pa grund av inverkan av aerodynamiska krafter. Warm torsionssvangningar kunna endast upptagas genom att dampning anordnas i systemet, och i de konventionella hdngbroarna ãr den enda till buds stdende dompningen den som fororsakas genom hysteresis i den barande stalkopstruktionen och den lilla glidning som kan. 5ga rum i nitfbrbanden. Den pa detta sdtt erhallna dampningen dr mycket liten och kan inte mdtas. Among the gaps on a suspension bridge may also appear: Adana, which is generated by torsional oscillations due to the influence of aerodynamic forces. Hot torsional oscillations can only be absorbed by arranging steaming in the system, and in the conventional suspension bridges the only available damping is that caused by hysteresis in the load-bearing steel structure and the small slip that can. 5ga rum i nitfbrbanden. The steam obtained in this way is very small and cannot be met.

Genom torsionssvangningar pa grund av vindk.rafter pa bran erhalles lingdrorelse mellan kablarna och brobanan. Amplitude has denna rorelse är ett maximum vid mitten av brospannet och minskar successivt mot tornen. Hangstag bestaende av stallinor som hanga ned yertikalt fran barkablarna till brobanan nava en oyasentlig hamning p6 sadana svangningar, en5r de inte motverka den ovannamnda langdrorelsen. Dampning av torsionssvangningar pa bran kan emellertid astadkommas till en. bestdmd och berdkningsbar utstrdekning genom anvandning pa vardera sidan av bron av triangelstag, dvs, stag som vart och ett bestar av tva. delar som traf fas yid sin ovre fastpunkt vid kalreln och som aro atskilda vid nedre an:darna, dar de dro infasta i brobanan. Med triangelstag astadkommer relativ langdrorelse ay kablarna och brobanan en minskning av spanningen i en kompon.ent av vane stag och en okning av spanningen i den andra komponenten. Denna vaxling i stagens pakanningar innebar att energi upptages genom hysteresis, endr hangstagen inte 5.ro i verklig mening elastiska och darfor verka som dampningsorgan genom att absorbera en del av energin has brons av vindkraft framkallade svangningar. Due to torsional fluctuations due to wind forces on the bridge, longitudinal movement between the cables and the bridge deck is obtained. Amplitude has this movement is a maximum at the center of the bridge span and gradually decreases towards the towers. Suspension struts consisting of stable ropes that hang down vertically from the bar cables to the bridge deck create an insignificant end to such oscillations, but they do not counteract the above-mentioned longitudinal movement. Evaporation of torsional oscillations on fire can, however, be achieved to a. determined and calculable extension by using on each side of the bridge of triangular struts, ie, struts that each consist of two. parts which met at their upper fixed point at the caldera and which were separated at the lower ends, where they were attached to the bridge deck. With triangular struts, relative longitudinal rotation of the cables and the bridge path causes a reduction in the voltage in one component of the usual strut and an increase in the voltage in the other component. This waxing in the stays' pans meant that energy is absorbed by hysteresis, the hang stays do not change in the real sense elastic and therefore act as steaming means by absorbing part of the energy has bronze of wind-induced oscillations.

Skillnaden i pakanning mellan de bada delarna av ett hangstag och darmed effektiviteten hos triangelstaget mad betraffar svangningsdampning okar med vink.eln mellan stagkomponenterna. Av hansyn till -sakerhetsfaktorn: maximeras emellertid vinkeln ifraga till normalt c:a 0, ty om vinkeln gores storre finns en ydsentlig risk for att spanningen i den ena stagkomponenten skall bli nail, trots den statiska belastningen am brobanan, varvid denna komponent salunda skulle bli slak. Den kritiska vinkeln mellan stagdelarna varierar med amplituden has de relativa langdrorelserna av brobanan i den del av kabeln, vid yilken h5.ngstaget är fast, och är dadar ett minimum vid mitten av spannet. Det an omoj ligt att utan risk anvanda triangel-; stag, liar brobanan är am balkkonstruktion, nar i detta fall de undre andarna pa stagen maste vara fasta yid brobanan vid del stalle dar balkelement traffas for att brobanan skall kunna upptaga de palagda pakanningarna. Dessa punkter ligga normalt i jarnn delning, och ehuru de kunna medge, att triangelstag, forenade med hogre punkter pa kablarna nara tornen bilda mindre yinklar an 35% kravs for 2— — stagen .ndra mitten av spannet, som aro forenade med de ldgre delarna av kablarna, vinklar mellan stagdelarna som aro mycket starre dn 0. The difference in packing between the two parts of a suspension strut and thus the efficiency of the triangular strut mad concerns oscillation damping increases with the angle between the strut components. For the sake of safety factor: however, the angle in question is maximized to normally about 0, because if the angle is made larger, there is a significant risk that the tension in one of the stay components will become nail, despite the static load on the bridge deck, whereby this component would thus be slack. The critical angle between the tie rods varies with the amplitude of the relative longitudinal movements of the bridge deck in the part of the cable at which the hinge rod is fixed, and is a minimum at the center of the span. It is impossible to use triangle- without risk; stays, liar the bridge deck is of beam construction, when in this case the lower spirits on the stays must be fixed to the bridge deck at the part where beam elements are met in order for the bridge deck to be able to receive the paved packages. These points are normally in iron division, and although they may allow triangular strands, joined to higher points on the cables near the towers, to form smaller angles than the 35% requirement for the second struts in the middle of the span, which are joined to the older parts. of the cables, angles between the tie parts which are much more rigid dn 0.

N5.r emellertid enligt uppfinningen brobanan Si utford i ladkonstruktion kunna de nedre andarna pa hangstagen vara forenade med brobanan pa onskade punkter efter langden, och dessa punkter behova inte ligga Amu delning. Det Si dad& majligt att an-. vanda triangelstag for upphangning av brobanan I kablarna. However, according to the invention, when the bridge track is challenged in load construction, the lower spirits of the suspension struts can be united with the bridge track at desired points along the length, and these points need not lie in the Amu division. It Si dad & majligt to an-. use triangular brackets for hanging the bridge deck in the cables.

Triangelstag med liten toppvinkel, c:a 15°, anvandas vid mitten av spannet, dar ampliladen hos den relativa langdrOrelsen Si starst. Narmare tornen okas denna vinkel, I. ex. till c:a 0, men utover detta och nar man kommer narmare tornen minskas pa nytt vinkeln. Detta beror pa att det är oldmpligt att korsa stagen, och for att man mom dessa zoner skall kunna anordna tillräckligt med hangstag for att med erforderlig sakerb.et uppbdra brobanan är del nodvandigt, att fastpunkterna for vane triangelstag ligga tiara varandra. Triangular struts with a small top angle, approx. 15 °, are used in the middle of the span, where the amplitude of the relative longitudinal Si Si starts. Closer to the towers increase this angle, I. ex. to about 0, but beyond this and when you get closer to the towers the angle is reduced again. This is because it is impossible to cross the struts, and in order to be able to arrange enough suspension struts in these zones in order to erect the bridge deck with the necessary objects, it is necessary for the fixed points for the usual triangle struts to be close to each other.

Ett utforingsexempel pa en hangbro enligt uppfinningen skall nedan beskrivas under hdnvisning till bifogade ritning, pd. vilken fig. 1 visar en sidovy av bron, fig. 2 i storre skala visar en tvarsektion, fig. 3 visar ett schema Over anordningen av hdngstagen langs brons huvudspann, och fig. 4 i stone skala perspektiviskt visar en del av bron i narheten av spannets mitt. An exemplary embodiment of a suspension bridge according to the invention will be described below with reference to the accompanying drawing, pd. Fig. 1 shows a side view of the bridge, Fig. 2 on a larger scale shows a cross section, Fig. 3 shows a diagram of the arrangement of the suspension struts along the main span of the bridge, and Fig. 4 in stone scale perspective view shows a part of the bridge near the middle of the team.

Brobanan bestar av ett huvudspann 10 och sidospann 11 stodda pa tornen 12 medelst leder 13. Brobanan dr upphangd frail kablarna 14 i bade huvud- och sidospannen me-deist hangstag 15. Vart och ett av spannen 10, 11 bestar, sasom visas, av en sluten lad-balk med strOmlinjeformade sidor bildade av byre och undre utatlutande platar 16, 17, vilka motas i skarpa kanter 18, som ligga nagot ovanfOr ladbalkens halva hajd. Ladbalkarna aro forsedda med inre, tvdrforstyvande ramar 19, som p. vissa mellanrum aro forsedda med hal 20 och ha vertikala forstyvningar 21 och langsgertde balkelement 22. The bridge deck consists of a main span 10 and side span 11 standing on the towers 12 by means of joints 13. The bridge track there is suspended from the cables 14 in both the main and side spans by means of suspension struts 15. Each of the span 10, 11 consists, as shown, of a closed loading beam with streamlined sides formed by girders and lower sloping plates 16, 17, which are formed in sharp edges 18, which lie slightly above half the height of the loading beam. The load-bearing beams are provided with inner, double-stiffening frames 19, which at certain intervals are provided with a slat 20 and have vertical stiffeners 21 and longitudinal girder elements 22.

Bron är forsedd med korbanor 23, vilkas ytbeldggning anbringas direkt pa brobanans Oversida, rack 24 samt yttre gangbanor 25 och cykelbanor 27, anordnade pa brobanan i niva med kanterna 18 och farsedda med rack 26. The bridge is provided with cross tracks 23, the surface covering of which is applied directly to the upper side of the bridge track, rack 24 and outer walkways 25 and cycle paths 27, arranged on the bridge track at the level of the edges 18 and provided with racks 26.

Normalt stracka sig hangstagen i en hangbro vertikalt mellan kablarna och brobanan. Ehuru triangular anordning av hangstagen dr onskvdrt for att aka styvheten hos konstruktionen och darigenom dess naturliga vibrationsfrekvens, an delta inte mojligt d. brobanan uppbares pa en fackverkskonstruktion eftersom hangstagens undre andar maste fastas vid knutpunkterna i fackverket, vilka ligga for langt ifran varandra i narheten av mitten pa spannet. Normally, the suspension struts in a suspension bridge extend vertically between the cables and the bridge deck. Although the triangular arrangement of the suspension struts is difficult to achieve the rigidity of the structure and thereby its natural vibration frequency, it is not possible to participate as the bridge deck is supported on a truss structure as the lower ends of the suspension struts must be attached to the truss junctions which are too far apart. in the middle of the team.

Vid brobanan enligt uppfinningen kart emellertid fastsattningen av hangstagen 15 ske var som heist i langdled, och i enlighet med ett kdnnetecken pa uppfinningen an vane hdngstag 15 sasom visat, delat i tvâ delar som bilda en vinkel med varandra ej overstigande c:a 0 i planet for kablarna 14, varvid de hada delarna aro fastade i samma punkt pa kabeln. Salunda är vane fastpunkt pa kabeln 11 forbunden med tvà punkter pa brobanan av det delade hdngstaget 15 och relativ langdrorelse mellan: kabeln och brobanan motverkas darigenom churn den icke helt forhindras. At the bridge deck according to the invention, however, the attachment of the suspension struts 15 takes place anywhere as a longitudinal lift, and in accordance with a characteristic of the invention a customary suspension strut 15 as shown, divided into two parts which form an angle with each other not exceeding about 0 in the plane for the cables 14, the hot parts being fixed at the same point on the cable. Thus, the usual fixed point on the cable 11 is connected to two points on the bridge path by the divided suspension strut 15 and relative longitudinal movement between: the cable and the bridge path is thereby counteracted by churn it is not completely prevented.

Motstandet mot relativ langdrarelse och den ddrav fororsakade spanningen i kablarna kan varieras gertom ldmpligt val av yinkeln la (fig. 3) mellan de hada delarna av varje hangstag och,valjes normalt sadant att inte vid nd.gra belastningsfall den av brons egenvikt fororsakade spdnningen i endera de-lea av staget kan minskas till noll, och aven sa att den maximala spanning som kan uppstâ i endera delen av staget begrdnsas till ett lampligt, sakert och ekonomiskt varde. Variationen i lutningen hos hangstagen langs mittspannet som Si vald att passa far utfaringsexemplet visas i fig. 3. For omkring en tredjedel A av spannet, matt i riktning mot brons mitt fran vartdera tornet 12 mOtas hAngstagen 15 (som aro anordnade pa samma avstand fran varandra) vid sina fastpunkter i brobanan, varvid salunda deras vinkel mot vertikalen blir storre ,da avstandet fran tor-net akar. Pa den mittre tredjedelen av span-net (av vilken ena halften betecknas med B i fig. 3) motas hangstagen inte vid fastpunkterna i brobanan, och langs denna mittdel av spannet minskar hangstagens lutning mot mitten. The resistance to relative elongation and the deadly voltage in the cables can be varied by simply selecting the angle 1a (Fig. 3) between the hot parts of each tie rod and, normally selected so that in some case of load the voltage caused by the bronze dead weight in either part of the strut can be reduced to zero, and also said that the maximum tension that can occur in either part of the strut is limited to a suitable, safe and economical value. The variation in the inclination of the suspension struts along the center span as Si has been chosen to suit the exemplary embodiment is shown in Fig. 3. For about one third A of the span, measured in the direction of bronze in the middle of each tower 12, the suspension struts 15 (arranged at the same distance from each other) are formed. ) at their fixed points in the bridge path, whereby their angle towards the vertical becomes greater, as the distance from the tower akar. On the middle third of the span (one half of which is denoted by B in Fig. 3) the suspension struts are not received at the fixed points in the bridge path, and along this middle part of the span the inclination of the suspension struts towards the center decreases.

Claims

Patent claim:

Suspension bridge with flexible suspension rods suspended from the support cables in the form of a continuous, closed layer, characterized by the suspension struts (15), each consisting of two sides in a triangle forming components, which are met at their fixed points on the cables ( 14) and which are separated at the former points in the bridge track (10), are so arranged that the angle (a) between the had components nowhere exceeds about 0.

Suspension bridge according to claim 1, characterized in that adjacent suspension struts (15) in the bronze main span are met at their fixed points in the bridge path (10) over a part (A) of the span, extending from each tower (12) towards the center, the angle ( a) between the components of the suspension stays 6kar with the distance of the stays from the part adjacent to the tower Over this part (A) of the span, while the suspension points fixed points in the bridge path (10) lie at - - —3 different over the middle part (B) of the span, the angle (a) between the stay components decreases Over this part of the span at the middle to. Request Publications: U.S. Patent Nos. 1,454,772. Other Publications: Mehrtens, G C, Lectures on IngenieurWissenschaften. T. 2. Eisenbrikkenbau. Leipzig 1908, pp. 95, 526.