高铁桥梁支座知识.doc

高铁桥梁支座知识The function and arrangement of bridge supportThe function and arrangement of bridge support2 、 the support is the support part of the bridge span structure. Its role is to bridge the load on the structure through the transfer to the pier bearing. The function of the bearing is mainly manifested in three aspectsOne 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 that the span of the bridge is deformed at the fulcrum according to the conditions specified in the calculation schemaThree, to ensure the bridge structure on the pier position fully fixed, not to fallClassification of bridge supportsThe bearings can be classified into fixed and movable supports according to whether they are fixed or notThe fixed support plays a role he allowed dumplings, the bridge structure rotates in the vertical plane along the line freely. Besides moving freely, the movable support can also allow the end of the beam to move horizontally when the live load and the temperature change. The simple supported beam bridge shall be provided with a fixed support at one end according to its static diagram, and a movable support is arranged at the other end. As for railway road beam bridge, due to the great influence of braking force, the arrangement of the fixed support and the movable support should be based on the principle1, on the bridge structure, the best beam bottom 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 compression 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, 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 according to the the effect of horizontal force effect is large, which should first meet the needs of the ramp5. For the multi span simply supported beam bridge, the two adjacent fixed supports should be placed on the same pier in order to distribute the longitudinal horizontal forces uniformly on each other6, for the highway multi span bridge, usually 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 wide roads and bridges, should support activities arranged along the longitudinal and transverse moving7, the anchor span of the cantilever beam bridge should also be provided with a fixed support at one end, and the other end is provided with a movable support, and the support arrangement of the hanging beam of the porous suspension bridge beam is the same as that of the simple beam8, 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 avoid, or to take special measures to avoid, body size bigMaterial composition of bridge supportThe material of the bearing is steel, rubber or reinforced concrete of not less than C30,Rubber bearings are most common on road bridges,But in recent years, rubber bearings have been widely adopted in railway bridges, and steel supports are widely adopted in earlier railway bridges. However, rubber bearings are widely adopted in newly-built Passenger Dedicated LinesReinforced concrete bearings have the characteristics of simple structure and low cost. They are widely used in small bridges on rural roads, bridges and non important roads. Because of their large size and low bearing capacity, they are adopted only on rural roads.Types and selection of rubber bearings for Highway BridgesPlate rubber bearing for Highway BridgeStructure and performance of plate type rubber bearingBridge plate rubber support is composed of multi banana slices and 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 displacement 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 the 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 advantages 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.Classification and representation methods of plate rubber bearingsSheet rubber bearings are classified according to their structural forms as follows:The plate rubber bearings consist of two types: plain plate rubber bearing and PTFE plate rubber bearingAmong them, the ordinary laminated rubber bearings can be divided into rectangular plate rubber bearing, circular normal rubber bearing, spherical normal rubber bearing three.PTFE laminated rubber bearings can be divided into rectangular PTFE laminated rubber bearing, round PTFE laminated rubber bearings, spherical PTFE laminated rubber bearing threeSheet rubber bearings, according to glue kind applicable temperature classification is as follows:A, neoprene: applicable temperature +60-25 degreesB, natural rubber: applicable temperature +60-40 degreesC, three yuan ethylene propylene rubber: applicable temperature +60-45Bridge bearings and their selection Part 2, followed by Part 11.2.3 bearing code representationThe bearing code is made up of four sections of symbols and numbers. Each section of the symbol and numeral has the following meanings:Example: GJZ300 * 400 * 47 (CR) stands for highway bridges, rectangular plain neoprene bearings, short side dimensions of 300mm, long side dimensions of 400mm, and thickness of 47mm.3. application scope of plate type rubber bearing3.1 ordinary rubber bearing is suitable for bridges whose span is less than 30m and less displacement. Different plane shapes are applicable to different bridge span structures: rectangular supports for orthogonal bridges, circular supports for Qu Xianqiao, skew bridges and cylindrical piers.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 is also availableAs a continuous beam and T beam traversing the top slider in the. Application of rectangular and circular fluoride plate rubber bearingDo not be the same as rectangular and round plain rubber bearings