CN106894346A - A kind of the continuous beam bridge construction method - Google Patents

Abstract

The invention provides a kind of the continuous beam bridge construction method, comprise the following steps：A precast beams are hole-specifically installed and are placed on temporary support；B sets Temporary Piers in prefabricated beam end, installs jack on Temporary Piers, and with the upper and lower levelling of steel plate；C uniformly exerts a force to each jack simultaneously, beam-ends top lifting height is met calculating and requires；D is poured after continuous joint concrete reaches design requirement intensity, tensioning hogging moment area prestressed strand；E removes temporary support, completes system transform；Removal, respectively across jack load, makes girder fall after rise to jack-up front position to F successively, and the final internal force status of structural system reach and once fall frame bridge completion state.Whole process of the present invention is simple to operate, and construction is quick；In addition, in work progress, system stress is clear and definite, structure is safe and reliable, can greatly improve final Internal force of bridge under completion stage state.

Description

A kind of the continuous beam bridge construction method

Technical field

The invention belongs to technical field of bridge construction, more particularly, to a kind of the continuous beam bridge construction method.

Background technology

At present, the construction method of Mid and minor spans continuous bridge mainly has two classes, after full framing built a bridge at once and first freely-supported Continuous system is changed.Full framing continuous bridge good integrity, into pontic architecture reasonable stress, span centre under a phase dead load Bending moment level is relatively low, but work progress is complicated, and the construction period is long, and cost is higher；Simply supported-to-continuous system bridge is by prefabricated Assembly, easy construction is quick, but under a phase dead load, span centre maximal bending moment is almost equal with the simply supported beam of same across footpath, passes through System transform also fails to improve into the internal force status of structural system after bridge, simply in structure " bridge floor is continuous ", for weight Traffic loading is carried, " bridge floor is continuous " in structure is also difficult to ensure that structural system has enough safety stocks.

The content of the invention

The technical problems to be solved by the invention are to solve Simply supported non-uniform system beam bridge to be stored up safely in operation phase inner structure Standby low problem.

In order to solve the above-mentioned technical problem, the technical solution adopted in the present invention provides a kind of the continuous beam bridge construction side Method, comprises the following steps：

A, precast beam set temporary support on pier cap beam and install permanent bearing, in advance after the completion of Liang Chang constructions Beam processed is hole-specifically installed and is placed on temporary support；

B, prefabricated beam end set Temporary Piers, jack is installed on Temporary Piers, each jack is upper and lower to use steel plate levelling；

C, while uniformly exerted a force to each jack, displacement meter monitored over time beam-ends jacking process, jacking to computed altitude；

After D, jack jacking to computed altitude, the continuous joint concrete of precast beam is poured, rear pouring concrete reaches design After desired strength, tensioning hogging moment area prestressed strand；

E, the continuous joint temporary support of precast beam is removed, complete Program for structural Transformation；

F, successively removal are each across jack load, girder is fallen after rise to jack-up front position, final structure system internal force status Reach and once fall frame bridge completion state.

In such scheme, in the step C, the computed altitude by etc. formula (I) be calculated：

Wherein, q is that precast beam is conducted oneself with dignity per linear meter(lin.m.)；L is calculating across footpath；E is concrete elastic modelling quantity；I is prefabricated beam section bending resistance The moment of inertia.

The present invention, jack-up construction is carried out using jack in prefabricated beam end, and finally falls after rise girder, whole process behaviour Make simple, construction is quick；In addition, in work progress, system stress is clear and definite, structure is safe and reliable, can greatly improve final Cheng Qiao Internal force status.

Brief description of the drawings

Fig. 1 is precast beam scheme of installation.

Fig. 2 is the prefabricated beam end jacking apparatus schematic diagram of jack.

Fig. 3 is jack jacking precast beam construction schematic diagram.

Fig. 4 is precast beam Simply supported non-uniform construction schematic diagram.

Fig. 5 is Program for structural Transformation schematic diagram.

Fig. 6 is that main back rises falling schematic diagram.

Fig. 7 is structural system end-state schematic diagram.

Fig. 8 is precast beam simply-supported state internal force diagram.

Fig. 9 is jack jacking precast beam mechanical model schematic diagram.

Figure 10 is that precast beam falls mechanical model schematic diagram after rise.

Figure 11 is that precast beam falls internal force diagram after rise.

Figure 12 is the final Internal force of bridge under completion stage figure of structural system.

Description of reference numerals：

Pier cap beam -1, precast beam -2, temporary support -3, permanent bearing -4, sagging moment area prestressing tendon -5, Temporary Piers - 6th, jack -7, steel plate -8, displacement meter -9, continuous joint -10, hogging moment area prestressing tendon -11.

Specific embodiment

Below by specific embodiment, the present invention will be described, but the invention is not limited in this.

Embodiment 1

As shown in Fig. 1~Figure 12, the present invention provides a kind of the continuous beam bridge construction method, comprises the following steps：

A precast beams 2 set interim branch after the completion of beam tensioning sagging moment area prestressing tendon 5 is constructed on pier cap beam 1 Seat 3 simultaneously installs permanent bearing 4, and precast beam 2 is hole-specifically installed and is placed on temporary support 3；

The freely-supported of precast beam 2 is installed and is placed on temporary support 3, and internal force status are shown in Fig. 8, respectively across span centre maximum sagging moment：

Beam-ends corner：

In formula：Q is that precast beam is conducted oneself with dignity per linear meter(lin.m.)；L is calculating across footpath；E is concrete elastic modelling quantity；I is prefabricated beam section bending resistance The moment of inertia.

B sets Temporary Piers 6 in the end of precast beam 2, and jack 7, the upper and lower use steel plate 8 of each jack 7 are installed on Temporary Piers 6 Levelling；

C uniformly exerts a force to each jack 7 simultaneously, and the monitored over time beam-ends jacking process of displacement meter 9 makes top lifting height meet meter Calculate and require.

Jack 7 in the work progress of jacking precast beam 2, the corner that prefabricated beam-ends is produced：

By ∑ θ_c'=0, ∑ θ_c=0 can obtain：

Jack 7 calculates top lifting height Δ in the work progress of jacking precast beam 2, sees Fig. 9：

After the jacking of D jack 7 to computed altitude, the continuous joint concrete 10 of precast beam is poured, rear pouring concrete 10 reaches After design requirement intensity, hogging moment area prestressing tendon 11 carries out tensioning；

E removes temporary support 3 at the continuous joint 10 of precast beam 2, completes Program for structural Transformation；

Removal is each across the load of jack 7 successively for F, girder 2 is fallen after rise to jack-up front position, final structure system internal force status Reach and once fall frame bridge completion state.

The load of removal B ends jack 7, make the beam-ends of girder 2 fall after rise height Δ, see Figure 10, cause in structural system in Power.

In formula：

After B ends are fallen after rise, removal A ends jack load, the accumulative internal force caused in structural system is shown in Figure 11：

Internal force diagram shown in Figure 11 is overlapped with the internal force diagram shown in Fig. 8, obtains final structure system internal force status, that is, reach To the frame bridge completion state that once falls, shown in Figure 12.

It is understood that above is example in order to illustrate principle of the invention and exploitativeness, the present invention not office It is limited to this.For those skilled in the art, without departing from the spirit and substance in the present invention, can be with All variations and modifications are made, these variations and modifications are also considered as protection scope of the present invention.

Claims (2)

1. a kind of the continuous beam bridge construction method, it is characterised in that comprise the following steps：

A, precast beam set temporary support on pier cap beam and install permanent bearing, precast beam after the completion of Liang Chang constructions Hole-specifically install and be placed on temporary support；

B, prefabricated beam end set Temporary Piers, jack is installed on Temporary Piers, each jack is upper and lower to use steel plate levelling；

C, while uniformly exerted a force to each jack, displacement meter monitored over time beam-ends jacking process, jacking to computed altitude；

After D, jack jacking to computed altitude, the continuous joint concrete of precast beam is poured, rear pouring concrete reaches design requirement After intensity, tensioning hogging moment area prestressed strand；

E, the continuous joint temporary support of precast beam is removed, complete Program for structural Transformation；

F, successively removal are each to make girder fall after rise to jack-up front position across jack load, and final structure system internal force status reach Once fall frame bridge completion state.

2. the continuous beam bridge construction method according to claim 1, it is characterised in that in the step C, the computed altitude By etc. formula (I) be calculated：

$\mathrm{\Δ}=\frac{{\mathrm{ql}}^4}{24EI}---\left(I\right)$

Wherein, q is that precast beam is conducted oneself with dignity per linear meter(lin.m.)；L is calculating across footpath；E is concrete elastic modelling quantity；I is prefabricated beam section bending resistance inertia Square.