Summary of the invention
The technical problem that the present invention will solve is to propose a kind of employing " shifting formwork block construction " new technology to build the concrete continuous girder bridge; The beam of a piece section case beam heavily alleviates half behind the piecemeal, has created condition for adopting existing military trusses of highway shellfish thunder and railway six or four or eight or seven military trusses.
Technical scheme of the present invention is: the template that a kind of method that adopts military truss shifting formwork block placement concrete continuous girder bridge comprises the horizontal steel truss that adopts on the steel hoop that is set up in bridge pier, be positioned at nose girder and the vertical steel truss on the horizontal steel truss and supported by vertical steel truss; The method of said shifting formwork block placement concrete continuous girder bridge, being called for short the shifting formwork block construction is to be divided into two piece section case beams striding the footpath for the whole hole concrete continuous beam of L, at first builds the A piece section case beam that is positioned on the bridge pier, and stretch-draw A piece section case beam upper limb prestressing force; The template that A piece section case beam is dismantled after building and accomplishing moves to the B piece section case beam that is positioned at span centre and builds; After waiting to reach the lower edge prestressing force of connection prestressing force and B piece section case beam of intensity post tensioning B piece section case beam and A piece section case beam, said horizontal steel truss, nose girder and vertical steel truss are moved to next bridge opening; Template moves to the A piece section case beam of next bridge opening and builds, and after repeating to accomplish the shifting formwork block construction operation of said previous bridge opening, changes next bridge opening over to again and carry out the shifting formwork block construction.The cross section type of concrete continuous beam comprises single box single chamber or single-box multi-cell, and wide requirement comprises single case two Room, single case three Room or single case four Room again to single-box multi-cell according to bridge.
Said horizontal steel truss and vertical steel truss adopt the different military truss of bearing load, comprise Bailey truss, six or four truss or eight or seven truss; Whole hole concrete continuous beam stride footpath L≤25m the time, the shifting formwork block construction adopts Bailey truss; During L=30~40m, the shifting formwork block construction adopts six or four truss; During L=40~50m, the shifting formwork block construction adopts eight or seven truss.The method of said shifting formwork block placement concrete continuous girder bridge comprises:
1. when whole hole concrete continuous beam stride footpath L<25m the time; Employing is set up in the horizontal steel truss of shellfish thunder on the steel hoop of bridge pier top, nose girder and the Bei Lei that is positioned on the horizontal steel truss of shellfish thunder indulges steel truss and indulge the template that steel truss supports by Bei Lei; Successively build A piece section case beam and B piece section case beam respectively; The length of the vertical steel truss of Bei Lei is 2.5L, crosses over two bridge piers.Build the A piece section case beam that is positioned at a bridge pier top earlier, A piece section case beam is a hogging moment area, and A piece section case beam length P=2 * 0.25L after concrete reaches intensity, gets final product the upper limb prestressing force of stretch-draw A piece section case beam.Subsequently, will move to span centre B piece section case beam and build B piece section case beam, wait to reach the associating prestressing force of intensity post tensioning B piece section case beam and A piece section case beam and the lower edge prestressing force of B piece section case beam from the template of A piece section case beam dismounting; B piece section case beam length Q=0.5L is the positive bending moment district.After the pre-stress construction of stretch-draw A piece section case beam and B piece section case beam finished, vertical steel truss of Bei Lei and nose girder shifted forward a bridge opening from pouring area, repeat aforementioned construction sequence, build next bridge opening.One time shifting formwork is built a bridge opening usually, i.e. the concrete continuous beam of single span length for can the extend length of the vertical steel truss of shellfish thunder of quickening progress reaches 3L, then can carry out the piecemeal shifting formworks construction simultaneously of two bridge openings.
2. when 25m<L<50m,, can the interim pier of steel pipe (9) be set at span centre according to the job site condition and carry out the shifting formwork block construction in order to save the consumption of stringers.Like this, the footpath of striding during construction is the half the of the continuous girder span of whole hole concrete footpath L, and concrete continuous beam deadweight moment of flexure can reduce four times, can carry out the construction of shellfish thunder shifting formwork by the scheme of the said L<25m of leading portion.The interim pier of said steel pipe can adopt the setting steel pipe column that enlarges the basis, on steel pipe temporary pier top a pair of hydraulic jack is set, and when the concrete continuous beam produced bigger amount of deflection in shifting formwork block placement construction, available vertical jack came straightening.After whole hole concrete continuous beam pouring construction is accomplished, the interim pier of steel pipe is dragged to installation again on the reposition well with rope coil.
3. when 25m<L<50m, if the interim pier of span centre is not set, then adopting length is that six or four steel trusss or eight or seven steel trusss of 3L carry out two simultaneously and stride the shifting formwork block construction.Because being " six or four " steel truss or " eight or seven " steel truss of 3L, length crosses over four bridge piers; Build earlier the A piece section case beam that is positioned at adjacent two bridge pier tops simultaneously; To move to span centre B piece section case beam from the template of A piece section case beam dismounting subsequently, build two B piece section case beams more simultaneously; Wait to reach the connection prestressing force of intensity post tensioning B piece section case beam and A piece piece section case beam and the lower edge prestressing force of B piece section case beam.Length is that six or four vertical steel trusss or eight or seven vertical steel trusss and the nose girder of 3L shifts forward two bridge openings from pouring area, repeats aforementioned construction sequence, and the method that shifting formwork block construction can be built the concrete continuous beam of two span length's degree simultaneously is called for short CMSS.
Said horizontal steel truss is formed one group of integrated member by military truss sheet and counterbracing, is installed on the steel hoop of bridge pier both sides by the direction perpendicular to the concrete continuous beam or the steel pipe pile top of middle interim pier.Sand tube, wedge or the jack that can be out of shape in vertical direction, be used to unload frame are housed between horizontal steel truss and the steel hoop, and the end face of horizontal steel truss is provided with the reinforcement chord member, in order to carry vertical steel truss.After vertical steel truss shifted forward, horizontal steel truss that will the completion back dismounting from pouring area repeated to be installed in next bridge opening position to be installed.Said vertical steel truss is formed one group of integrated member by military truss sheet and counterbracing, and the footpath decision is striden in the calculating of several case beam weight of building according to its carrying of the sheet of military truss sheet and vertical steel truss.Vertical steel truss is parallel to the concrete continuous beam, and vertically packet layout is positioned at the both sides and the two wide avris of bridge of bridge pier below the perpendicular rib of said section case beam that its carrying is built, is erected at the end face of horizontal steel truss.Set up template at the vertical steel truss top of each group, template comprises case beam bottom board plate and portable side template; Case beam bottom board plate is made up of gooseneck, steel plate or plank, and the length of case beam bottom board plate equals the footpath of striding of two hole concrete continuous beams, promptly equals 2L, but the double as operation platform.In the width range of bridge pier, case beam bottom board plate can be twitched to both sides, and is before vertical steel truss displacement, earlier that case beam bottom board plate is traversing to both sides; After the displacement of vertical steel truss, again with case beam bottom board plate from both sides traversing return; Space between case beam bottom board plate and the vertical steel truss is adjusted with jackscrew.Portable side template is formed by shape steel bracket and steel sheet weldering knot, because whole hole concrete continuous beam is divided into A, two section casees of B beam pouring construction successively, so the length of portable side template is striden half of L directly for whole hole concrete continuous beam; Portable side template moves to B piece section case beam again after A piece section case beam is built, reuse.
Described bridge pier adopts uncovered post and beam structure, comprises only columnar pier, two-columned pier or three pillar type bridge pier; The outside of steel hoop is provided with diagonal brace and is fastened on the top of bridge pier.
The invention has the beneficial effects as follows:
1. the used truss sheet of shifting formwork block construction all can reclaim repeated use; Especially " Bailey truss " is the military truss of war preparedness that China each province all stores in a large number, and it has from heavy and light, adopts keying installation, easy accessibility, versatility is good and rent is low advantage; It is convenient that military six or four truss of institute's use railway or eight or seven truss have assembling too in striding the footpath continuous beam greatly, and reusable advantage can reduce disposable equipment investment significantly.The present invention constructs, and equipment needed thereby is few, speed is fast, and the duration is short, quality good, and can reduce cost, practice thrift investment.
2. because beams and prestress concrete continuous has the characteristic of positive and negative two moments of flexure, be divided into A, two sections constructions successively of B; Build A piece section case beam earlier, A piece section case beam is a hogging moment area, after concrete reaches intensity, i.e. and the upper limb positive bending moment prestressing force of stretch-draw A piece section case beam; Thereby alleviated the load-bearing of military truss, increased to use and striden the footpath.
3. adopting length is three holes, six or four steel trusss or eight or seven steel trusss of 3L, and two stride and can construct simultaneously, have accelerated speed of application.Longitudinal stability is better in moving simultaneously.
4. compare with the single box single chamber cross section in the single-box multi-cell pattern continuous beam cross section of adopting, every chamber width 3~4m is close with lane width (3.75m), can accomplish not occur in the Room two traction engines; Therefore thickness that can the attenuate top board is saved the concrete amount more than 10%.In addition, top board can reduce one procedure because case top width degree does not need transverse prestress after reducing, and practices thrift good cost of engineering time.
5. the portable interim intermediate pier that the setting steel pipe column that adopt to enlarge the basis is done shifting formwork can make strides the footpath and reduces half thely, and continuous beam deadweight moment of flexure can reduce four times, can reduce shifting formwork total steel using amount of constructing significantly, when particularly striding the footpath greater than 30m, has better economic property.
The specific embodiment
Below in conjunction with accompanying drawing and embodiment the present invention is further specified.
Embodiment 1: adopt the vertical steel truss shifting formwork piecemeal in two holes builds the concrete continuous girder bridge by the hole method like Fig. 1-1 with shown in the 1-2:
A, service condition: when the shifting formwork block construction duration is not controlled; In order to save the consumption of steel truss; Vertical steel truss 1 length overall is 2.5L, carries out the technology that single span divides A, two section casees of B beam to build, and only waters one at every turn and strides; Vertically move the stable requirement of overturning or slip resistance analysis for satisfying vertical steel truss 1, will set up nose girder 6 on the horizontal steel truss 5 of shifting formwork front end.
B, be suitable for when striding footpath: L≤25m, the shifting formwork block construction adopts the vertical steel truss 1 of shellfish thunder, every high 1.5m, and long 3m, wide 0.23m weighs 270kg; Chord member 2 [10, can use artificial keying to install, it is very convenient to construct.Allow moment of flexure [M]=750 (KNm), quality g=0.13 (t/m); Laterally with the slivering of 0.25m (or 0.45m) spaced sets, cut after support forms integral body with angle steel between each bar, but longitudinal pull is to another hole.
When L increased 30~40m, the shifting formwork block construction adopted six or four vertical steel trusss 1; Every high 3.16m, long 4m, wide 0.52m; [16, easy construction is installed in the keying of the upper and lower layer of the work point of can choosing to chord member 2.Allow moment of flexure [M]=3220 (KNm), quality g=0.24 (t/m); Lateral stability is good, but the monolithic frame is upright.Link to each other spacing a=0.80m, several transverse set sliverings between two with bolt sleeve; But between each bar with angle steel cut support form integral body after longitudinal pull to another hole.
When L increased to 40~50m, the shifting formwork block construction adopted eight or seven vertical steel trusss 1; Every high 2.5m of light-duty eight or seven truss, chord member adopts H380x350x16, is bolt gusset plate structure, allows moment of flexure [M]=11280 (KNm), quality g=0.36 (t/m); Purlin sheet lateral stability is good, and 40 i iron is set between two, and establishing vertical i-beam track again carries out vertical shift down for it.
The vertical steel truss 1 of c, equipment: Bei Lei is formed one group of integral blocks spare by shellfish thunder frame sheet and counterbracing, strides the sheet number that the footpath determines shellfish thunder frame sheet according to case beam weight and stringers calculating that its carrying is built; The vertical steel truss 1 vertical packet layout of shellfish thunder that is parallel to continuous beam the case beam that its carrying is built erect rib below, be positioned at the both sides and the wide outside of bridge of bridge pier 3, be erected at the end face of the horizontal steel truss 5 of Bei Leishi; Set up template 2 at vertical steel truss 1 top of each group, template 2 comprises crossbeam soffit formwork 11 and mobile side template 10.
The horizontal steel truss 5 of shellfish thunder is formed one group of integral blocks spare by shellfish thunder frame sheet and counterbracing, and is horizontal about bridge pier perpendicular to continuous girder bridge, is bearing on the steel hoop 4 of bridge pier 3 both sides or the steel pipe pile top of middle interim pier 9; The steel hoop 4 that the outside is provided with diagonal brace is fastened on bridge pier 3 tops; Being equipped with between the horizontal steel truss 5 of Bei Leishi and the steel hoop 4 can vertical deformation, be used to unload sand tube, wedge or the jack of frame; The end face of the horizontal steel truss 5 of shellfish thunder is provided with the reinforcement chord member, in order to carry the vertical steel truss 1 of shellfish thunder; The horizontal steel truss 5 of a complete set of shellfish thunder has eight groups, is arranged on the current bridge pier of continuous beam and three bridge piers in vertical shift the place ahead of building; Use the horizontal steel truss 5 of shellfish thunder to remove after vertical steel truss 1 displacement of Bei Lei, can repeat to be installed in position to be installed, the place ahead.
Template 2 is device three bulk Steel-wood forming boards on horizontal steel truss 5, and every 2m is a sections.With 10 tons of jackscrew supporting traverse soffit formworks 11 and mobile side template 10, can build concrete after holding out against, get final product the demoulding behind the pine.Establish tail trimmer on the jack, when 1 reach of the vertical steel truss of Bei Leishi, it is taken apart be put on the shellfish thunder frame, load onto again again after waiting to move past bridge pier.During adjustment bed die absolute altitude, camber is set.Full-bridge is established the long L/2 template of two covers.
Support mobile system: comprise trundle, loop wheel machine 8, wire rope, assembly pulley and preceding anchor point etc., gross weight 18t.
Bridge pier steel hoop 4: be two semicircles, be clamped on the bridge pier 3 with 600t prestressing force with 12 pairs of Φ 32 fining twisted steels, support horizontal steel truss 5, do not damage concrete, mounting or dismounting are convenient.Full-bridge is installed steel hoop 4 on 7 bridge piers 3, nearly weigh 7t, can have enough to meet the need use.
D, segmentation casting craft main points are following:
1. striding with one is a construction period, at first builds the A piece section case beam length P=2 * 0.25L that is positioned at the bridge pier top, and A piece section case beam weight GA is half the many for whole hole continuous box girder weight ∑ G; A piece section case beam is a hogging moment area; After A piece section case beam is built in advance, get final product stretch-draw and can satisfy the hogging moment prestressing force that the upper limb of the permanent mobile load needs of full-bridge becomes bridge construction; To move to span centre B piece section case beam from the template 2 of A piece section case beam unloading subsequently, build B piece section case beam, wait to reach longitudinal prestressing and B piece case beam lower edge prestressing force that intensity post tensioning B piece and A piece interrelate; B piece section case beam length Q=0.5L, B piece section weight G
BLack for whole hole continuous box girder weight is half the; B piece section case beam is the positive bending moment district; A piece section case beam and B piece section box girder tensioning pre-stress construction finish the back and accomplish a construction period, and the vertical steel truss 1 of two hole Bei Leishi and nose girder 6 shift forward a bridge opening from pouring area 7, repeat aforementioned construction sequence, build next bridge opening.
2. zero moment of flexure; When the A piece watered and stretch-draw prestressing force after, its moment M of being produced of deadweight
gBy longitudinal prestressing M
TBalance is born, and both add up to total moment of flexure to be close to zero, and promptly on the heavy vertical steel truss 1 that does not act on Bei Leishi of A piece beam, thereby has reduced the suffered load of shellfish thunder trusses.
3. stringers reversal of the natural order of things; At 50cm place, A section two ends, with Φ 32 fining twisted steels reversal of the natural order of things I 36 crossbeams, the supporting stringers, the work that B section case beam is built is striden the footpath and is reduced 11m by 20m, can help amount of deflection control.
Embodiment 2 is as shown in Figure 3: the interim pier of a kind of employing span centre carries out concrete continuous girder bridge shifting formwork block placement method; When 25m<L<50m; At span centre the interim pier 9 of steel pipe is set and carries out the shifting formwork block construction; The footpath of striding during construction is the half the of the continuous girder span of whole hole concrete footpath L, and concrete continuous beam deadweight moment of flexure can reduce four times, can be by the scheme construction of the said L<25m of leading portion; Promptly adopt shellfish thunder trusses to do the interim pier 9 of the said steel pipe of longeron and adopt the setting steel pipe column that enlarges the basis; On the interim Dun9Dun of steel pipe top a pair of hydraulic jack is set; When the concrete continuous beam produced bigger amount of deflection in shifting formwork block placement construction, available vertical jack was adjusted; After whole hole reinforced concrete continuous beam pouring construction is accomplished, the interim pier 9 usefulness rope coils of steel pipe are dragged to installation again on the reposition well.
Embodiment 3 is shown in Fig. 2-1,2-2,2-3,2-4 and 2-5: the vertical steel truss shifting formwork piecemeal in a kind of employing three holes build simultaneously two stride the concrete continuous girder bridge method (being called for short CMSS); When 25m<L<50m is not provided with the interim pier of span centre again; Then adopting length is that " six or four " or " eight or seven " vertical steel truss 1 piecemeal shifting formwork, two of 3L is striden the method for construction simultaneously; The vertical steel truss 1 in " six or four " of 3L or " eight or seven " is crossed over four bridge piers 3, builds earlier the A piece section case beam that is positioned on adjacent two bridge piers 3 simultaneously, the template 2 that will remove from A piece section case beam subsequently; Move to span centre B piece section case beam, build two B piece section case beams simultaneously; After construction finished, vertical steel trusss 1 six or four formulas of 3L or eight or seven formulas and nose girder 6 shifted forward two bridge openings from pouring area 7, repeat aforementioned construction sequence, and a shifting formwork can be built two simultaneously and striden the concrete continuous beam.Steel truss 1 length overall ∑ L=3L+4m is indulged in three holes.Can guarantee most effectively that vertical unstability does not appear in the mould bases moving process, come the quickening progress and utilize 3L length can build two span continuous beam simultaneously.
Embodiment 4 is as shown in Figure 4: the lateral arrangement scheme of " shifting formwork block placement concrete continuous girder bridge " that the double width Four-Lane Road merges, single case six Room patterns and three pillar type bridge pier are adopted in the cross section of concrete continuous beam.Comprise among the bridge floor clear span 12m two row automobiles (2 * 3.75=7.5m), emergency stopping lane only band (3.25m), the crashproof railing of wheel back gauge (0.25m) and both sides (four parts such as 2 * 0.50m).
A, case beam: overall with B=12+2+12=26m, the wherein wide 2m of divided lane.Girder adopts single case six Room patterns, and the width of chamber is b=4m.Bridge pier is a three pillar type, is located at vertical rib below, limit, and column diameter is Φ 1.2m~Φ 1.5m.The post upper end is provided with laminated rubber bearing, apart from box plate height 0.5m, can supply the shifting formwork soffit formwork to go up and down.Bridge floor is an asphalt concrete, gross thickness 10cm.
B, mobile formwork structure: overall with 30m comprise:
1. the 10t straddle truck 8.Can be used for the installation of article such as reinforcing bar, template, small instruments and tools indulging vertically operation and horizontal handling crane gear on the steel truss 1.
2. crashproof railing and bridge floor are all built after girder closes up again.
3. cast-in-situ box girder side template, length 0.5L divides two positions to install, and can on vertical steel truss 1, move.
4. cast-in-situ box girder up-down soffit formwork is made up of I 16 goosenecks and angle iron frame bamboo glue pattern plate soffit formwork.
5. the vertical steel truss 1 of shifting formwork has three types of Bailey truss and six or four truss and eight or seven truss etc.Its number is decided by striding directly to vary in size.
6. bridge pier prestress steel anchor ear 4 is born the weight that crossyard transmits, on the rack device that unloads of adjustment height is arranged.
Embodiment 5 is as shown in Figure 5: " shifting formwork block placement concrete continuous girder bridge " lateral arrangement scheme of separate type single width, single case three Room pattern and two-columned piers are adopted in the cross section of concrete continuous beam.Case beam overall with B=12m, girder adopt single case three cell structures, the width b=3m of chamber.Bridge floor is the modified bitumen concrete, gross thickness 10cm.
Embodiment 6 is as shown in Figure 6: ramp bridge, overpass bridge, only stub, two chamber shifting formwork lateral arrangement scheme, the cross section of concrete continuous beam adopt single case two chamber-type formula and only columnar pier.
A, girder overall with 12m are generally three and stride; Be the two case cross sections of single chamber, the wide b=4m in chamber, owing to limited by underpass, middle pier can only adopt single pillar structure, abutment then is a queen post abutment structure, forms the rock-steady structure of three-point support.
Two organized totally six greatly about the vertical steel truss 1 of b, shifting formwork was divided into.Horizontal steel truss 5 removes and is bearing in the center pillar place, and two outsides will add the steel pipe pile supporting in addition.