Background technology
As the bridge construction key member, the bridge pier seismic design is bridge field important subject all the time.The present railroad bridge of China and highway bridge mainly adopt reinforced concrete bridge pier.Should be noted that, reinforced concrete bridge pier is to have the rigidity of structure large, fatigue behaviour is good, when good the and cost of normability rationally waits feature performance benefit, also a little less than the ubiquity stirrup restraint, ductility is on the low side, the shortcomings such as the low and poor seismic behavior of shear strength, easily because of the bridge pier shearing resistance, Compressive Bearing Capacity and deformability are on the low side and shear failure occurs, Subjected To Compression, Bending, Shear And Torsion combined failure and toppling is collapsed and is waited the destruction form, at recent domestic repeatedly in the earthquake, all have reinforced concrete bridge pier to destroy serious and be difficult to repair the earthquake phenomenon to occur, reconstruction work has caused very large difficulty after earthquake centre disaster relief and rescue and the calamity over the ground.Therefore, when make great efforts improving and improving traditional seismic performance of reinforced concrete bridge piers, the composite steel concrete bridge pier form of innovative development new high-efficiency and the assembled pier Seismic Design Method that develops also day by day become current bridge engineering circle pay close attention to problem and study hotspot it
In building construction under the large quantity research of steel core concrete column and steel tube concrete superposed column and the application background, concrete pier of steel tube and steel tube concrete superposed column formula bridge pier (being called for short steel tube concrete superposed bridge pier) at home and abroad bridge engineering have also obtained some and have applied.Steel tube concrete superposed bridge pier in the steel tube confined concrete advantage, makes steel pipe corrosion-proof and pressurized cripling problem also obtain fine solution because steel pipe is built in reinforced concrete bridge pier inside in having concrete pier of steel tube.Existing result of study shows, steel tube concrete superposed bridge pier (post) intensity is high, ductility is large and consume energy, and has good anti-seismic performance.For effectively reducing after the bridge construction earthquake permanent set to make things convenient for repairing and reinforcement after the bridge shake, Chinese scholars proposes " vertical prestressing bridge pier " (or Self-resetting function) design reason recently, namely by at reinforced concrete bridge pier internal placement vertical prestressing bar, make bridge pier because vertical prestressing bar strains at the permanent set that acts on after the earthquake is effectively reduced.Existing result of study shows, vertical prestressing not only can effectively reduce the bridge pier permanent set and realize Self-resetting function after earthquake, and for improving bridge pier lateral deformation stiffness, shock resistance, overturning or slip resistance analysis and progressive collapse-resisting ability good contribution arranged all.
Summary of the invention
In order to overcome the shortcoming of above-mentioned prior art, the purpose of this utility model is to provide a kind of post-stressed high strength concrete filled steel tube superimposed bridge pier, existing bridge pier structure quake-resistant safety and validity have effectively been improved, have that supporting capacity is high, anti-seismic performance good, the characteristics of easy construction and Self-resetting, for bridge construction provides advanced technology.
In order to achieve the above object, the technical solution adopted in the utility model is:
The superimposed bridge pier of a kind of post-stressed high strength concrete filled steel tube, comprise steel pipe 2, be furnished with many unbonded prestressing tendons 3 in the steel pipe 2, pouring has pipe inner concrete 1 between steel pipe 2 inwalls and the unbonded prestressing tendon 3, steel pipe 2, unbonded prestressing tendon 3 and pipe inner concrete 1 form a stem stem 5, and concrete 4 forms superimposed bridge pier outside pipe has been built in stem stem 5 outsides.
Described superimposed bridge pier cross section is circular or square.
Described pre-unbonded prestressing tendon 3 covers have flexible pipe or parcel non-cohesive material.
Described stem stem 5 has the outer concrete 4 of equal gate spool between a plurality of, adjacent stem stem 5, forms the superimposed bridge pier of multicore post.
Described pipe inner concrete 1 is high-strength concrete, and managing outer concrete 4 is ordinary concrete or high-strength concrete.
The utility model compared with prior art has the following advantages:
(1) supporting capacity is high: because superimposed bridge pier stem stem adopts high-strength concrete and is positioned at bridge pier inside, high-strength concrete is subject to steel pipe and the outer concrete constraint of stem stem in the stem stem, strength of high strength concrete can be improved and give full play to, superimposed bridge pier cross section shear resistant capacity correspondingly, vertical compression supporting capacity and Subjected To Compression, Bending, Shear And Torsion composite force supporting capacity all can be significantly improved, effectively the little bias voltage of bridge pier destroys, shear failure and end Subjected To Compression, Bending, Shear combined failure supporting capacity, under same design load, the bridge pier sectional dimension can be effectively reduced, thereby can reach the saving material, increase attractive in appearance and increase under the bridge and pass through the space texts.
(2) anti-earthquake ductility is good: because high-strength concrete is subject to good constraint in the superimposed bridge pier stem stem, the high-strength concrete deformability is greatly improved, simultaneously because the high strength concrete filled steel tube stem stem bears most axial compressions, stem stem outer steel reinforced concrete partly bears axial compression less (being that outer steel reinforced concrete part Axial Compression Loads ratio is less), steel pipe is subject to the difficult secondary buckling unstable failure that occurs of inside and outside concrete constraint in addition, therefore, superimposed bridge pier has good ductility and energy-dissipating property.Good ability of elastic-plastic deformation, ductile performance and the energy dissipation capacity of the superimposed bridge pier of pre-stressed steel pipe high-strength concrete, can effectively prevent and avoid bridge pier heavy damage occuring and collapsing the effective lifting concrete pier anti-seismic performance of energy and quake-resistant safety under the shake greatly.
(3) elastic stiffness is large: the prestressing force stem stem is set in superimposed bridge pier can effectively increase bridge pier elasticity endurance and stiffness, thereby effectively reduce bridge pier train, when heavy vehicle travels bridge vibration and under little shake elastic deformation, can improve vehicle safety and comfortableness.
(4) Self-resetting is good: the prestressing force stem stem is set in superimposed bridge pier is equivalent to form the vertical prestressing bridge pier, vertical prestressing bar can effectively reduce the permanent set of earthquake rear abutment, make superimposed bridge pier after geological process, have good Self-resetting function (self-centering), make bridge pier after the small earthquakes effect, substantially return to the bridge pier initial position, under strong earthquakes, also can can't not repair even collapse because larger permanent set occurring.
(5) robustness is good: in recent years, normal generation vehicle, ship collision bridge pier cause bridge pier generation heavy damage even the phenomenon of collapsing (Guangzhou Jiujiang Bridge), at superimposed bridge pier pre-stressed steel pipe high-strength concrete stem stem is set, because inner pre-stressed steel pipe high-strength concrete stem stem and outer steel reinforced concrete double action, can Effective Raise bridge pier robustness, strengthen bridge pier antidetonation, anti-collision, shock resistance, overturning or slip resistance analysis and progressive collapse-resisting ability, improve the bridge pier security performance.
(6) good endurance: the conventional steel concrete pier that relative steel pipe exposes, because steel pipe is positioned at the concrete pier center in the pre-stressed steel pipe high-strength concrete bridge pier, need not consider the Anticorrosion of steel pipe in the superposed column, the bridge pier endurance quality effectively improves, and more is applicable to the higher bridge pier structure of environment category.
(7) pouring quality is good: because pre-stressed steel pipe high-strength concrete stem stem can prefabrication production, therefore, the high-strength concrete pouring quality can obtain fine assurance in the high strength concrete filled steel tube stem stem, can avoid cast in situs to cause the interior high-strength concrete of stem stem to build problems such as being difficult for closely knit and on-the-spot maintenance difficulty.
(8) good economy performance: high-strength concrete is subject to steel pipe and outside concrete good constraint in the superimposed bridge pier, can give full play to super high strength concrete performance advantage and a large amount of super high strength concrete that uses, bridge pier sectional dimension and concrete amount can reduce greatly, have good economic benefits.Existing use experience shows, compares with ordinary reinforced concrete structure, and the common steel tube concrete structure cost cost of same performance is basic and reinforced concrete structure is fair.And the superimposed bridge pier of pre-stressed steel pipe high-strength concrete is owing to adopting thin-wall steel tube, and steel using amount is very little, can remove the steel pipe corrosion-proof maintenance cost from addition, compares with the conventional steel concrete pier, has more obvious economic advantages.
In general, the superimposed bridge pier of pre-stressed steel pipe high-strength concrete is a kind of have good stress performance, anti-seismic performance and endurance quality and easy construction, cost novel bridge pier form reasonable and easy to control the quality, meet " firm, safe, durable " developing direction of the current civil engineering structure of China, have the applications well promotion prospect.
The specific embodiment
Below in conjunction with accompanying drawing the utility model is described in further details.
Embodiment one: the superimposed bridge pier of the single stem stem pre-stressed steel pipe high-strength concrete of circular cross-section
Referring to Fig. 1 and Fig. 2, the superimposed bridge pier of a kind of post-stressed high strength concrete filled steel tube, comprise steel pipe 2, be furnished with the pre-unbonded prestressing tendon 3 of the six roots of sensation in the steel pipe 2, pouring has pipe inner concrete 1 between steel pipe 2 inwalls and the pre-unbonded prestressing tendon 3, steel pipe 2, pre-unbonded prestressing tendon 3 and pipe inner concrete 1 form a stem stem 5, and concrete 4 forms superimposed bridge pier outside pipe has been built in stem stem 5 outsides, and superimposed bridge pier cross section is circular.
The preparation process of this superimposed bridge pier is at first determined strength grade and the outer concrete semi-finals degree grade of pipe of steel pipe 2 diameters and wall thickness, unbonded prestressing tendon 3 diameters, quantity and position and pipe inner concrete 1 referring to Fig. 3 according to designing requirement.Again steel pipe 2 is fixed, arrange unbonded prestressing tendon 3 by designing requirement in steel duct, build the pipe inner concrete 1 that vibrates with pumping method.Wait managing after inner concrete 1 reaches some strength and form pre-stressed steel pipe high-strength concrete stem stem 5, stem stem 5 is transported to the building site, is connected with stem stem suspension column base plate by basic cast-in fixing bolt, installation is fixed to the bridge pier center; Carry out the outer reinforcing bar binding of stem stem and outside concrete pouring construction, again unbonded prestressing tendon in the stem stem 3 is carried out stretch-draw and ground tackle anchoring, namely form the superimposed bridge pier of single stem stem pre-stressed steel pipe high-strength concrete.
Embodiment two: the superimposed bridge pier of the single stem stem pre-stressed steel pipe high-strength concrete in square-section
Referring to Fig. 4 and Fig. 5, the superimposed bridge pier of a kind of post-stressed high strength concrete filled steel tube, comprise steel pipe 2, be furnished with the pre-unbonded prestressing tendon 3 of the six roots of sensation in the steel pipe 2, pouring has pipe inner concrete 1 between steel pipe 2 inwalls and the pre-unbonded prestressing tendon 3, steel pipe 2, pre-unbonded prestressing tendon 3 and pipe inner concrete 1 form a stem stem 5, and concrete 4 forms superimposed bridge pier outside pipe has been built in stem stem 5 outsides, and superimposed bridge pier cross section is circular.
Its preparation process is consistent with embodiment one.
Embodiment three: the superimposed bridge pier of oval cross section multicore post pre-stressed steel pipe high-strength concrete
Referring to Fig. 6 and Fig. 7, stem stem 5 has three, and equal gate spool inner concrete 4 between the outer and adjacent stem stem 5 of stem stem 5 forms the superimposed bridge pier of multicore post, and the cross section of superimposed bridge pier be ellipse.
The utility model can also comprise the various embodiments such as twin-core post, three stem stems and the superimposed bridge pier of four-limbed pre-stressed steel pipe high-strength concrete, and pre-unbonded prestressing tendon 3 wherein can be embedded with flexible pipe, is convenient to isolate with surrounding concrete.