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1、高铁桥梁支座知识（Knowledge of high speed bridge bearings）The role and arrangement of bridge supportThe role and arrangement of bridge support2, support is part of the cross bridge support structure. Its role is to bridge the load on the structure through the transfer to the pier bearing. The support effect
2、is mainly manifested in three aspects.One is to make the force clear role to the designated location of pier, and the concentrated force spread to a large enough area, in order to ensure the safe and reliable work of pierTwo, ensure the deformation of bridge structure in point according to the calcu
3、lation conditions stipulated by the schemaThree, to ensure the bridge structure on the pier position fully fixed, not to fallClassification of bridge supportAccording to the fixed bearing and whether the classification can be divided into fixed and moveable bearingsThe fixed support plays a role he
4、allowed dumplings, the bridge structure rotates in the vertical plane along the line freely. In addition to the movable support can rotate freely, also should be allowed in the live load and the change of the temperature, longitudinal beam end horizontal movement. Bridge, according to the static sch
5、ema should be set in one end of the fixed support is arranged at the other end of the movable support. For the railway bridge, due to power system influence, the fixed support and the movable support shall be arranged according to the following principles1, on the bridge structure, the best beam bot
6、tom pressure in the braking force under the action of vertical load and can offset a portion of bottom chord force;2, on the pier, let the best direction role of braking force to the center of the pier, and the pier concrete or mortar rubble compression, under the action of the braking force compres
7、sion rather than tension.3, on the abutment, make the best direction role of braking force to the river bank, the top of the concrete or mortar rubble abutment pressure, and can balance part of backfill pressure4, according to the principle of "railway bridge design regulations" provisions
8、, fixed support arranged on the ramp should be located in the lower end, in the vicinity of the station, the station should be located near one end of the interval, in the flat, should be located in the front heavy vehicle direction, when the above provisions conflict with each other, it should be a
9、ccording to the the effect of horizontal force effect is large, which should first meet the needs of the ramp5, for the multi span beam bridge, the longitudinal force distribution in London, should not be fixed bearing two adjacent piers located in the same6, for the highway multi span bridge, usual
10、ly adjacent fixed bearing two span is arranged in the same piers, when the pier is high, in order to reduce the level of function, can be considered in the layout of the adjacent bearing two span, the ramp is set on the bridge, will be fixed in the lower bearing arrangement the pier, especially on w
11、ide roads and bridges, should support activities arranged along the longitudinal and transverse movingAnchorage 7, cantilever bridge span should also set the fixed bearing at one end, the other end is provided with movable bearing, bearing arrangement suspension bridge hanging beam with the same bea
12、m porous8, continuous bridge each with only one fixed support, in order to avoid the beam moving end of the expansion joint is too large, the fixed support should be placed in the middle of each pivot on the body, such as high or because of the foundation stress condition, it should be considered to
13、 avoid, or to take special measures to avoid, body size bigA bridge bearing materialsBearing materials, rubber or steel reinforced concrete grade is not lower than C30,Rubber bearing in highway bridges using the most common,But in recent years, the railway bridge also uses a lot of rubber bearings,
14、the railway bridge earlier used a large number of steel bearings, but also uses a lot of new passenger line of rubber bearingsReinforced concrete bearing has the advantages of simple structure, low cost, small bridges are widely used in rural road bridge and non important roads, because of the large
15、 volume of bearing capacity is small, so the only on the road in the village.Types and selection of rubber bearings for Highway BridgesLaminated rubber bearing of Highway BridgeThe structure and properties of laminated rubber bearingsBridge plate rubber support is composed of multi banana slices and
16、 thin steel plates vulcanization bonding, it has enough vertical stiffness, the upper structure of the reverse force can be reliably transferred to the pier, with good flexibility, in order to adapt to the ends of the rotation, and a larger shear deformation capacity, to meet the horizontal displace
17、ment of superstructure theIn the surface of the rubber plate adhered to a Teflon plate thickness of 1.5mm - 3mm, is made of PTFE laminated rubber bearings, it has the vertical stiffness and elastic deformation, can withstand the vertical load and adapt to the rotation of the outer ends, because of t
18、he low friction coefficient of PTFE plate, the beam end in PTFE the surface free sliding, horizontal displacement is not restricted, especially suitable for medium and small load, large displacement bridge useLaminated rubber bearing not only excellent technical performance, but also has the advanta
19、ges of simple structure, low cost, no maintenance, easy replacement, vibration isolation, building height is low, so in the bridge area is very popular, widely used.The classification and representation method of laminated rubber bearingsThe classification of laminated rubber bearing in the form of
20、the structure are as follows:Laminated rubber bearing including ordinary laminated rubber bearing and PTFE laminated rubber bearing twoAmong them, the ordinary laminated rubber bearings can be divided into rectangular plate rubber bearing, circular normal rubber bearing, spherical normal rubber bear
21、ing three.PTFE laminated rubber bearings can be divided into rectangular PTFE laminated rubber bearing, round PTFE laminated rubber bearings, spherical PTFE laminated rubber bearing threeRubber plate rubber bearing according to applicable temperature classification as follows:A, neoprene: suitable t
22、emperature +60-25B, natural rubber: suitable temperature +60-40C, three yuan glue: suitable temperature +60-45Bridge support and selection of Part 2 Part 11.2.3 supports code representationBearing code using four digit symbol combination, each symbol and meaning of numbers are as follows:Example: GJ
23、Z300 * 400 * 47 (CR) said the highway bridge rectangular neoprene bearings, short edge size is 300mm, the long side size is 400mm, thickness of 47mm.The applicable scope of 3. laminated rubber bearings3.1 ordinary laminated rubber bearing applicable bridge in a span of less than 30m, the displacemen
24、t of small. The plane shapes for different bridge: Bridge with rectangular orthogonal support, Qu Xianqiao, skew bridge and pier bridge with circular bearings.3.2 PTFE laminated rubber bearing is suitable for large span and multi span continuous beam, continuous plate structure of the large displacement bridge. It can also beAs a continuous beam and T beam traversing the top slider in the. The application of rectangular and circular prison fluorine rubber bearing branchNot the same with rectangular or circular normal rubber bearing