[summary of the invention]
The objective of the invention is to overcome the defective that exists in the prior art, provide a kind of and can adapt to that height of support is limited, weight is big, lifting hydraulic device require flank width high, the case beam less, stride the continuous box girder in footpath greatly, realize safety, position high-span overweight continuous box girder integral lifting reconstruction method accurately.
The technical scheme that the present invention adopts for achieving the above object: a kind of high-span overweight continuous box girder integral lifting reconstruction method, it is characterized in that, this method comprises following construction sequence: cut the bridge pier top (1), wherein earlier pressure-bearing being carried out at the pier stud top calculates, the pressure-bearing value satisfies the jacking requirement and then directly the bridge pier top is cut, the pressure-bearing value does not satisfy the jacking requirement pier stud of bridge pier is carried out the concrete overstriking, implement again the bridge pier top to be cut after the steel hoop construction, carry out in that the bridge pier top is cut in two steps: a. bores to combine with golden steel chain rope saw and water bridge pad bridge pier top concrete is all around cut, after cutting finishes, adopt the high-strength polymer cement mortar that the concrete that cuts the bottom is carried out levelling, the jacking jack is installed in the intact back of levelling, after installing the jacking jack, the jacking jack is added 70% power and in advance screwing from screw device that the jacking jack carries; B. behind the Lifting Equipment pretension bridge superstructure, the bridge pier top concrete under the bridge pad is cut, take the fixing or sliding support of bridge then away, the concrete after the cutting of bearing bottom is carried out levelling, the servo-actuated jack is installed in the intact back of levelling; (2) the upper tank beam is carried out strengthening construction, be specially: steel concrete is newly built in the rib both sides at main socle case beam; (3) at column thick pillar hoop outside welded limiting device, position limiting structure and concrete pier post are formed integral body, and it is spacing to utilize the rigidity of the rigidity of former concrete column and stopping means self that bridge is carried out jacking; (4) the jacking jack is installed at the bridge pier top, the jacking jack holds out against in advance, Installation and Debugging servo-actuated jack; (5) formal jacking is specially: set the instruction displacement earlier; The jacking jack is according to the capable jacking of command bits shift-in; The servo-actuated jack follows up automatically, and the top lifting height error of jacking jack is at 1mm; The jacking of jacking jack is after the instruction displacement, and the jacking jack stops jacking, and the servo-actuated jack stops follow-up; The jacking jack is received cylinder, and servo-actuated this moment jack is stressed; The jacking jack is placed tool-type steel case cushion block down; After tool-type steel case cushion block placed under the jacking jack, the jacking jack was stretched cylinder and is held out against tool-type steel case cushion block; Screw on the jacking jack from screw device; The servo-actuated jack shrinks keeps in the center; At servo-actuated jack bottom place tool formula steel case cushion block; Servo-actuated jack setting pressure holds out against superstructure; (6) repeating step (5), until jacking to being higher than design elevation 1cm position, screw the jacking jack from screw device, remove the servo-actuated jack, erection support and permanent cushion block; (7) unclamp on the jacking jack from screw device, jack whereabouts 1cm is to design elevation; (8) remove Lifting Equipment, anchor ear, stopping means, the bridge pier after the jacking is connect height.
Be the counter-force basis with the bridge pier end face in the wherein said step (1), and the pier stud of bridge pier carried out the concrete overstriking, implements the steel hoop construction and be specially: to bridge pier pier shaft surface cutter hair, the reinforcing bar that enlarges pier shaft carries out bar planting and reinforcing bar binding, the formwork erection encased steel plate, by pumping fluid concrete on the bridge floor, steel plate is installed outside concrete again, is connect high position and get final product to cutting.
At the bridge pier top, utilize existing bridge pier planar dimension that jacking jack and servo-actuated jack are installed in the wherein said step (1), and when jacking jack and servo-actuated jack respectively at the steel plate of placement up and down of jacking jack and servo-actuated jack.
Bridge pier in the wherein said step (8) after the jacking connects high order: after 1) jacking puts in place, earlier bearing is installed and whole bridge is fallen cushion block under the servo-actuated jack, remove jacking jacking jack and following cushion block thereof then; 2) to being welded to connect between each the interim lip block under the bearing, uppermost cushion block carries out antirust processing; 3) reinforcing bar to pier stud connects height, and pier is connect high reinforcing bar carries out colligation (welded reinforcement on cushion block); 4) the pier stud concreting is connect height.
Because adopt said structure, the present invention's high-span overweight continuous box girder integral lifting reconstruction method has following beneficial effect:
1. the continuous box girder that the safe jacking height of support of energy is limited, weight is striden the footpath greatly, greatly solves the problem that reliable jacking underpin system is set in limited planar dimension.
2. can be good at solving in the jacking process because the danger that the superstructure that jacking jack unstability may cause is caved in, solve the whole stressed problem of servo-actuated jack, have very high safety.
3. can be good at solving the synchronous heavily loaded whereabouts of the big continuous box girder of a weight difficult problem.
4. the jacking underpin system is simple, and is stressed clear and definite, cost performance and degree of safety height.
Below in conjunction with drawings and Examples a kind of high-span overweight continuous box girder integral lifting reconstruction method of the present invention is further described.
[description of drawings]
Fig. 1 to Fig. 3 is that the present invention carries out first step cutting schematic diagram to the bridge pier top:
Fig. 1 is bridge pier cutting section figure, and Fig. 2 is that bridge pier cuts off elevation, and Fig. 3 is bridge pier cutting planes figure.
Fig. 4 to Fig. 6 is that the present invention carries out second step cutting schematic diagram to the bridge pier top:
Fig. 4 is bridge pier cutting section figure, and Fig. 5 is that bridge pier cuts off elevation, and Fig. 6 is bridge pier cutting planes figure.
Fig. 7 adopts steel hoop construction back schematic diagram to pier stud.
Fig. 8 is that bridge pier upper tank beam is reinforced elevation.
Fig. 9 is that bridge pier upper tank beam is reinforced profile.
Figure 10 is the floor map behind the welded limiting device of the column thick pillar hoop outside.
Figure 11 is the elevational schematic view behind the welded limiting device of the column thick pillar hoop outside.
Figure 12 is a bridge pier jacking profile.
Figure 13 is a bridge pier jacking elevation.
Figure 14 is a bridge pier jacking plan view.
Figure 15 is that bridge pier connects high plan view.
Figure 16 is that bridge pier connects high elevation one (the 1-1 direction sectional view of Figure 15).
Figure 17 is that bridge pier connects high elevation two (the 2-2 direction sectional view of Figure 15).
Figure 18 is that bridge pier connects high elevation three (the 3-3 direction sectional view of Figure 15).
[specific embodiment]
Extremely shown in Figure 180 as Fig. 1, a kind of high-span overweight continuous box girder integral lifting reconstruction method of the present invention, this method comprises following construction sequence:
(1) the bridge pier top being cut (is example with the bridge pier, as shown in Figure 1 to Figure 3, cut coverage 2, as shown in the figure), its reason is that the less jacking jack that is unfavorable for of headroom of considering abutment pier and case beam top is installed and operated, the bridge pier top is cut, so that jacking jacking jack is installed and is followed jack, form jacking counter-force basis, earlier pressure-bearing being carried out at the pier stud top before construction calculates, the pressure-bearing value satisfies the jacking requirement and then directly the bridge pier top is cut, the pressure-bearing value does not satisfy the jacking requirement pier stud of bridge pier is carried out the concrete overstriking, implement again the bridge pier top to be cut after the steel hoop construction, for guaranteeing that structure underpins safety, carry out in that the bridge pier top is cut in two steps: a. bores to combine with golden steel chain rope saw and water bridge pad bridge pier top concrete is all around cut, after cutting finishes, adopt the high-strength polymer cement mortar that the concrete that cuts the bottom is carried out levelling, jacking jack 3 is installed in the intact back of levelling, after installing jacking jack 3, the jacking jack is added 70% power and in advance screwing from the screw device (not shown) that the jacking jack carries; B. behind the Lifting Equipment pretension bridge superstructure, it (is example with the bridge pier that bridge pier top concrete under the bridge pad is cut, extremely shown in Figure 6 as Fig. 4, cut coverage 4, as shown in the figure), take the fixing or sliding support of bridge then away, concrete after the cutting of bearing bottom is carried out levelling, servo-actuated jack 5 is installed in the intact back of levelling, wherein when jacking jack and servo-actuated jack are installed respectively at the steel plate of placement up and down 16 of jacking jack and servo-actuated jack, can be implemented on the existing bridge pier top plan space by above two steps, corresponding Lifting Equipment and servo-actuated jack are installed, need not as traditional handicraft, need around bridge pier, carry out ground and handle, excellent economy and safety are arranged;
(2) the upper tank beam is carried out strengthening construction, be specially: steel concrete is newly built in the rib both sides at main socle case beam;
(3) at column thick pillar hoop outside welded limiting device, position limiting structure and concrete pier post are formed integral body, and it is spacing to utilize the rigidity of the rigidity of former concrete column and stopping means self that bridge is carried out jacking;
(4) the jacking jack is installed at the bridge pier top, the jacking jack holds out against in advance, Installation and Debugging servo-actuated jack;
(5) formal jacking is specially: set the instruction displacement earlier; The jacking jack is according to the capable jacking of command bits shift-in; The servo-actuated jack follows up automatically, and the top lifting height error of jacking jack is at 1mm; The jacking of jacking jack is after the instruction displacement, and the jacking jack stops jacking, and the servo-actuated jack stops follow-up; The jacking jack is received cylinder, and servo-actuated this moment jack is stressed; The jacking jack is placed tool-type steel case cushion block down; After tool-type steel case cushion block placed under the jacking jack, the jacking jack was stretched cylinder and is held out against tool-type steel case cushion block; Screw on the jacking jack from screw device; The servo-actuated jack shrinks keeps in the center; At servo-actuated jack bottom place tool formula steel case cushion block; Servo-actuated jack setting pressure holds out against superstructure;
(6) repeating step (5), until jacking to being higher than design elevation 1cm position, screw the jacking jack from screw device, remove the servo-actuated jack, erection support and permanent cushion block;
(7) unclamp on the jacking jack from screw device, jack whereabouts 1cm is to design elevation;
(8) remove Lifting Equipment, anchor ear, stopping means, the bridge pier after the jacking is connect height.
Bridge pier intensity can't satisfy bearing requirements in step (1), be the counter-force basis with the bridge pier end face when pressure-bearing value does not satisfy the jacking requirement, and the pier stud of bridge pier carried out the concrete overstriking, implements the steel hoop construction and be specially: earlier to bridge pier pier shaft surface cutter hair, the reinforcing bar that enlarges pier shaft carries out bar planting and reinforcing bar binding, formwork erection encased steel plate 11 by pumping fluid concrete on the bridge floor, carries out pier stud is adopted the steel hoop construction, adopt slightly expanded concrete to irritate real between circular corner post and the anchor ear, as shown in Figure 7.Each steel hoop is assembled by three to four, connects by the prestressed high-strength bolt between the each several part, and the design power of anchor ear has the prestressing force of high-strength bolt to come really.External wrapping concrete around original main pier, concrete is installed steel plate 11 outward again, connects high position to cutting and gets final product.
When in step (2), the upper tank beam being carried out strengthening construction (as Fig. 8, shown in Figure 9), newly build steel concrete 13 in the rib both sides of main socle case beam; Reinforcing bar 14 parts that newly add need to be connected with the bar planting of original case beam; The 15d degree of depth in the case beam is implanted in bar planting, need adopt the reinforcing bar survey meter to survey during bar planting, avoids reinforcing bar and prestressing force pore in the case beam; The position concrete that newly adds needs be connected with former concrete chisel hair, and performs and connect the face processing; Newly add the position and adopt high-strength grout, above material all need add micro-expanding agent.Personnel come in and go out in the following manhole of case beam base plate during construction, and grouting material gravity vent from the side enters builds.
At column thick pillar hoop outside welded limiting device, the position limiting structure of abandoning tradition utilizes the steel thick pillar hoop in the pier stud outside by bar planting and former suspended deck structure ways of connecting, and position limiting structure and concrete pier post are formed integral body in step (3).This design can be saved the steel using amount of position limiting structure, but safety improves a lot than conventional method, has very high cost performance.
Because Large-Span Continuous case beam is subjected to variations in temperature, thermal stresses can produce horizontal movement.Its structure Design of stopping means should consider to guarantee the horizontal movement that the temperature of pontic is freely stretched, and considers again to overcome because the skew that jacking may cause.So the installation preset clearance of stopping means and beam body will accurately be reserved by after calculating.In the gap of present embodiment engineering longitudinal spacing reservation 3cm, cross spacing is reserved the gap of 1cm, and spacing gap can suitably be adjusted by increasing steel plate.
The installation of stopping means 12 should be noted following problem: 1) assembling of member should be carried out after correcting in component-assembled, welding, and assembling sequence should be determined according to factors such as structural shape, welding method and welding sequences.2) behind the member installation in position of steel work, should proofread and correct immediately, fix.3) spacing steel work need be installed vertically.4) coating butter between case beam and the stopping means contact site is to reduce to grind resistance.Stopping means is installed the back shown in Figure 10,11.
The jacking jack provides equipment as the top power of bridge jacking in step (4), the protective device of servo-actuated jack jacking jack during as jacking and the supporting apparatus when receiving cylinder as the jacking jack.Respectively at the steel plate of placement up and down 16 of Lifting Equipment and servo-actuated jack, jacking jack and servo-actuated jack are simultaneously stressed in the jacking process when Lifting Equipment and servo-actuated jack are installed.Jacking jack and servo-actuated jack are mechanically stressed respectively when changing cushion block replaces replacing.
Jacking jack selected parameter: 200 tons, 63Mpa, high 366mm, end footpath 244mm, the maximum 140mm of stroke; Arrange many jacking jack on each bridge pier, so that satisfy jacking from heavy load, the characteristics of this engineering jacking jack are that a balanced protection valve all has been installed on each oil cylinder jack.The balanced protection valve is not for there being the cone valve structure of leakage, and 4 major functions are arranged: first function is the load pressure of balancing cylinder, makes band carry the unlikely decompression of the jacking cylinder that descends and glides, even can not allow workpiece fall when pipeline rupture yet; Second function is that the protection oil cylinder does not transship, when in-oil cylinder pressure surpasses set pressure, all carrying valve can open automatically, lay down too high oil pressure, make each oil cylinder load equalization, all carrying valve is board-like connection, can be directly installed on the oil cylinder, has reduced the trouble that external pipe brings to greatest extent; The 3rd function is the oil-feed speed-regulating function, avoids system to switch the excessive significant impact that load is caused of hydraulic pressure fluctuation when synchronization of jacking up and landing synchronously.The 4th is that when needs descended synchronously, the oil cylinder that load is bigger can be opened (function is held in heavy duty earlier) earlier when the oil cylinder of a plurality of band equalizing valves supports a heavy duty simultaneously, has truly guaranteed the reliably synchronous landing function of system.More than 4 functions are problems that common hydraulic control one-way valve (hydraulic lock) cann't be solved.
Jacking jack, cylinder body band are from the screw thread mechanical device, and behind jack jacking to a stroke, the jacking jack is opened from screw device and screwed, and jacking this moment jack is except that being used as the hydraulic pressure top or a machinery pushes up.Even hydraulic failure, hydraulic pressure top still can be used by the machinery top, guaranteed to change being perfectly safe when following the top cushion block.
Still can effectively support heavy load workpiece when the servo-actuated jack provides a kind of oil pressure at oil cylinder to suddenly disappear, avoid the mechanical type follow-up supporting mechanism of workpiece landing, one or several servo-actuated mechanical support jack are arranged near the jacking cylinder, servo-actuated mechanical support jack props up heavy load workpiece and synchronous with the jacking process of oil cylinder gently, the servo-actuated heavy duty is moved, and the structure servo-actuated of background screw rod is supported in servo-actuated; Hang with a carrying round nut on the servo-actuated mechanical support jack, gear is made in the outside of round nut, and a servomotor drives heavily loaded nut rotation by tooth-like transmission mechanism; Micrometer is installed on bearing, constantly measures the gap between heavily loaded nut and bearing, to judge the tracking mode of screw rod and heavy load workpiece, the tracking error signal that micrometer records is input to control loop, drives servomotor and drives the nut rotation, tracking error is constantly eliminated in the lead-screw lifting.In case having little time rotation, oil cylinder rapid decompression, nut follow the tracks of, but the just self-locking maintenance of servo-actuated studdle, and effectively the rest heavy load workpiece is avoided heavily loaded landing, has guaranteed the safety of heavy load workpiece jacking.Servo-actuated mechanical support jack machine herein still can effectively support the mechanical type follow-up supporting mechanism that the top bridge rises bridge, avoids top bridge landing also as temporary support when providing a kind of oil pressure at oil cylinder to suddenly disappear.So overcome the problems such as leakage of hydraulic pressure, the servo-actuated top must be that mechanical screws is stressed when being subjected to heavy duty.
Install jack when (comprising jacking jack and servo-actuated jack) because of noting: for ease of jacking operation (cushion block is had bad luck convenience), all jack all are inverted and are installed in case beam bottom, be that jack base is fixed on the continuous beam below, jack rises with the rising of case beam.Jack should guarantee the axis normal of jack when installing.In order to avoid produce horizontal component because of the jack installation is tilted in the jacking process.Behind the cutting pier stud top, Dun Ding and case beam gap are less, so can't be as traditional approach be connected by the bar planting or the method for beating expansion bolt with the upper tank beam during jack inversion.
Note when jack (comprising jacking jack and servo-actuated jack) is arranged: jack is placed the bridge pier top after the cutting, weight according to each bridge pier upper load, the top power load configuration of jacking jack will guarantee that jacking safety stock coefficient is not less than 1.7 times of load, according to the horizontal space restriction of Dun Ding, arrange the jack of different model simultaneously.The same support position jack in pier stud top is divided into one group, and each pier stud is divided into two groups, and each jack group is as a displacement control point; Full-bridge is divided into n * 2 displacement point according to pier stud quantity.Jacking is carried out at all displacement control points synchronously during the full-bridge jacking.Servo-actuated screw machine jack and the corresponding grouping of jacking jack grouping have an individual system of one's own, and jack is arranged can be referring to shown in Figure 14.
Jack is installed as follows in the present embodiment: (steel plate is connected by countersunk bolt with jack in the jack bottom one steel plate to be installed earlier, bolt head does not expose), steel plate and jack are fused, steel plate and upper tank beam are lived (jack stretches out precompressed) with steel bonding is gluing then, after jacking is finished, remove jack (steel plate on the jack still sticks together with superstructure at this moment), at last to the steel plate cutting disassembling.Transportation for main pier servo-actuated jack: main pier servo-actuated jack is far away in the outer part, and only there is 40cm in the space, so steel plate slippage is installed to assigned address down at it when installing.
In step (8), the bridge pier after the jacking is connect when high (is example with the bridge pier, as Figure 15 to shown in Figure 180), after jacking puts in place, interim lip block is not removed, after former column reinforcing bar connect height, the steel lip block wrapped in form the combination pillar construction within the concrete column, finish jacking work.Jacking connects high order: after 1) jacking puts in place, earlier bearing is installed and whole bridge is fallen cushion block under the servo-actuated jack, remove jacking jack and following cushion block thereof then; 2) to being welded to connect between each the interim lip block under the bearing, uppermost cushion block carries out antirust processing; 3) reinforcing bar to pier stud connects height, and pier is connect high reinforcing bar carries out colligation (welded reinforcement on cushion block); 4) the pier stud concreting is connect height.