The utility model content
Technical problem to be solved in the utility model is to provide a kind of precast segment Concrete-Filled Rectangular Steel Tube Truss at the deficiencies in the prior art.Adopt following technical scheme:
A kind of precast segment Concrete-Filled Rectangular Steel Tube Truss, comprise upper chord, lower chord, montant and diagonal web member, upper chord, lower chord, montant and diagonal web member are the linear pattern light-walled rectangular pipe, wherein, or/and the inside fill concrete structure of lower chord, upper chord, lower chord, montant and diagonal web member weld together at upper chord.
Described precast segment Concrete-Filled Rectangular Steel Tube Truss, the inner prestressed reinforcement of tensioning of described lower chord.
Described precast segment Concrete-Filled Rectangular Steel Tube Truss, the cross section minimum dimension of described linear pattern light-walled rectangular pipe are more than or equal to 100mm, and wall thickness is more than or equal to 4mm, and the depth-width ratio in cross section is smaller or equal to 2.
Described precast segment Concrete-Filled Rectangular Steel Tube Truss, weld stud on the inwall of described linear pattern light-walled rectangular pipe.
Described precast segment Concrete-Filled Rectangular Steel Tube Truss is provided with longitudinal stiffener on the inwall of described linear pattern light-walled rectangular pipe.
The advantage of Concrete-Filled Rectangular Steel Tube Truss: (1) Concrete-Filled Rectangular Steel Tube Truss joint form is simple, surfacing, is convenient to connect.Compare with the circular cross-section encased structures, the friendship transversal between the encased structures member of square-section in a plane, be convenient to process and member between connection.In trussed construction, the advantage of square-section encased structures aspect node embodies more fully.(2) Concrete-Filled Rectangular Steel Tube Truss member section moment of inertia is big, stability good.Compare with circular cross-section concrete filled steel tube compressed member, the moment of inertia in concrete-filled rectangular steel tube compressed member cross section is relatively large, its stability is good, therefore, for the middle long member that is subjected to stability control, square-section concrete filled steel tube compressed member is better than circular cross-section concrete filled steel tube compressed member.(3) help the construction of bridge deck.Because the bar cross section of Concrete-Filled Rectangular Steel Tube Truss is a rectangle, becoming in the processing of bridge deck structure after girder builds up like this is more prone to.Bridge deck directly can be placed on the truss of square-section, just can obtain more stable effect, thus the joint construction of minimizing and bridge deck, and more economical.
The specific embodiment
Below in conjunction with specific embodiment, the utility model is elaborated.
The precast segment Concrete-Filled Rectangular Steel Tube Truss, as Fig. 1, shown in 2, comprise upper chord 10, lower chord 20, montant 30 and diagonal web member 40, upper chord 10, lower chord 20, montant 30 and diagonal web member 40 are linear pattern thin-walled rectangle (cross section is a rectangle) steel pipe, wherein, at upper chord 10 or/and lower chord 20 (can be separately at one of upper chord 10 or lower chord 20 fill concrete, also can all fill simultaneously) inside fill concrete structure 50, upper chord 10, lower chord 20, montant 30 and diagonal web member 40 weld together, form the truss sections, the truss sections is coupled together in the mode of welding or connector form whole truss then.
As shown in Figure 3, preferred, concrete filled steel tube can be combined with the advantage of prestressing technique, form pre-stressed steel pipe concrete combined member or structure, can expand its range of application.For example can adopt the loading scheme of pre-tensioning system, pre-tensioning system is exactly a pretensioning prestressed reinforcement 201, and then the method for concreting, after treating that concrete meets the requirements of intensity, cut off or loosen prestressed reinforcement, rely on the adhesion stress between prestressed reinforcement and the concrete on every side to transmit prestressing force.Adopt the drag-line method to apply prestressing force, flexible cable is anchored on the node in the structural system, produce prestressing force in inside configuration by the stretch-draw cable wire.The method of stretch-draw cable wire has jack tension method, jack pushing top process etc.Will symmetrical in batches stretch-draw during stretch-draw, to prevent unstability outside the truss plane.
Preferably, the structure of Concrete-Filled Rectangular Steel Tube Truss satisfies following the requirement:
1. the cross section minimum dimension of the rectangular steel pipe that adopted of upper chord 10, lower chord 20, montant 30 and diagonal web member 40 (being minimum dimension in the width of cross section or the height) is more than or equal to 100mm, the rectangular steel pipe wall thickness is more than or equal to 4mm, and the depth-width ratio in cross section is smaller or equal to 2.When the maximum limit of concrete-filled rectangular steel tube member section size is not less than 800mm, should takes on the rectangular steel pipe inwall weld stud or construction measure such as longitudinal stiffener is set.
2. the flakiness ratio of
upper chord 10, the
lower chord 20 steel pipe tube wall that adopts
B is the plate width; T is a panel thickness; f
yBe the yield strength of steel, the chord member thickness of steel pipe should not be less than the web member thickness of steel pipe.
3. the flakiness ratio of web member steel pipe should not greater than
Also should not less than
4. the angle between center line of the bar should not be less than 30 °.
5. node (position of chord member and web member handing-over is called node) locate big web member width should be greater than 1.5 times of the width of less web member.
6. the width of web member and chord member should be in following scope: T, Y type node (T, Y and N, the K type etc. fixed according to the shape of node location place rod member, just definition conforms to corresponding letter) 0.25≤β≤1.0, K type node or N type node 0.35≤β≤1.0 than β.
Application prospect:
Concrete-Filled Rectangular Steel Tube Truss is utilized the compression member of the good pressurized performance of concrete as truss, utilizes the tension member of steel pipe as truss itself, can give full play to the performance of steel pipe, concrete material, now its application prospect in bridge is summarized as follows:
(1) continuous girder bridge
Continuous girder bridge is good with its structure tension performance, distortion is little, the shrinkage joint is few, driving is smooth-going, handsome in appearance, maintenance is easy etc. and become one of most competitive main bridge type.In the actual engineering, girder generally adopts prestressed reinforced concrete construction, and box-type section has also obtained application widely owing to have bigger bending resistance torsional rigidity.Characteristics and advantage in conjunction with rectangular steel pipe are applied to Concrete-Filled Rectangular Steel Tube Truss in the continuous girder bridge, are fully feasible, mainly have following characteristics: 1. can alleviate the girder deadweight.The continuous girder bridge girder generally adopts prestressed reinforced concrete construction, and its deadweight is bigger, has limited further developing of bridge span.If adopt the Concrete-Filled Rectangular Steel Tube Truss girder, can effectively alleviate deadweight, reduce the girder section size, help the increase of bridge span.2. can make things convenient for main girder construction.Adopt the construction technology of precast segment, on-site consolidation to avoid the in-site pouring concrete to bring the control of steel pipe concrete filled difficult quality, working procedure increase, the slow shortcoming of speed of application, realized that batch production is prefabricated, accelerating construction progress is saved the duration, reduces cost; 3. help the construction of bridge deck.Because the bar cross section of Concrete-Filled Rectangular Steel Tube Truss is a rectangle, becoming in the processing of bridge deck structure after girder builds up like this is more prone to.Bridge deck directly can be placed on the truss of square-section, just can obtain more stable effect, thus the joint construction of minimizing and bridge deck, and more economical.
(2) application in the suspension bridge
Ratio in large span bridge scheme is chosen, and particularly when striding the footpath when km is above, suspension bridge often has overwhelming superiority.But along with striding advancing of footpath, its stiff girder focus on certainly ratio shared in the structure total load increase very fast, therefore in the large span suspension bridge, the closed cross-section that stiff girder all adopts steel case beam or plane steel truss to form.Although adopt steel case its bending resistance of beam and torsional rigidity big, wind resistance, moulding is succinctly slim and graceful, has problems such as steel using amount is big, cost of materials and processing charges height, piece spare is heavy, the assembly unit difficulty is big.And adopt the trussed construction on the plane of forming by shaped steel, although can utilize diagonal brace or transverse truss on the cross section at a certain distance strengthens, to improve the globality of its torsional rigidity and structure, also help transmitting the bridge floor load, but the torsional rigidity and the wind resisting stability of its direction across bridge bending resistance, cross section are still not good enough, and the joint structure complexity, steel using amount is also more.
In fact the main supporting member of suspension bridge is funicular system rather than stiff girder, but as an important component part of structure collectivity, can not ignore the beam action of putting more energy into, the requirement that must make it satisfy driving function and resist transverse wind and seismic forces.Simultaneously must provide torsional rigidity, to satisfy the aerodynamic stability requirement.Certainly necessary vertical bending rigidity also needs, be beneficial to mobile load suitable bridge to distribution.If adopt the stiff girder of Concrete-Filled Rectangular Steel Tube Truss girder structure, will have the following advantages: 1. help the stressed of girder as suspension bridge.Though girder of suspension bridge is not main supporting member, it is a kind of gauge structure of striding greatly, and the wind resistance antidetonation of girder just seems even more important.Adopt the Concrete-Filled Rectangular Steel Tube Truss girder, because it is conducted oneself with dignity greater than steel truss, this wind resistance seismic stability for bridge is favourable.In addition, the steel using amount of girder will greatly reduce, and satisfy under the prerequisite of main beam stress, can reduce construction costs effectively, reach a technical economic benefit preferably.2. help the stressed of king-tower.With respect to the steel concrete king-tower, the Concrete-Filled Rectangular Steel Tube Truss king-tower can also bear the moment of flexure effect that may exist in the king-tower preferably except the compressive load that can bear main push-towing rope and transmit.In addition, it can also reduce deadweight effectively, also will reduce greatly the basis and the requirement of ground.3. in self-anchored suspension bridge, girder also is subjected to coming from the bigger horizontal component of main push-towing rope except being subjected to the moment of flexure from deadweight and vehicular load, and this component will produce bigger pressure effect to main push-towing rope.The Concrete-Filled Rectangular Steel Tube Truss beam just in time has good axial compression resistance performance.
Should be understood that, for those of ordinary skills, can be improved according to the above description or conversion, and all these improvement and conversion all should belong to the protection domain of the utility model claims.