High speed railroad because speed load of tall, concussion precision of system of the big, path that do not have tiny fragments of stone asks tall, bridge designs use fixed number of year (100 years) long, because this is successive to be being crossed greatly,just sedimentationed after the construction precision of compose bridge, labour and the Xu in crossing changes deflection raised taller requirement. Aqueduct of sanded bay of special railway line of passenger traffic of railroad of wide deep harbor is especially big the bridge spans design of aqueduct of violet Ni river, sanded bay aqueduct is (104+168 × 2+112) M and (112+168 × 2+104) concrete of M prestressing force is successive firm compose bridge, c60 of Tong intensity grade, bridge ministry uses cantilever to irrigate the construction that build a way.
Graph aqueduct of 1.1 sanded bays is especially big the bridge spans aqueduct of violet Ni river (104+168 × 2+112) M
Successive firm compose bridge establishs face sketch map
One, labor law characteristic
1, 0# piece uses mound to carry bracket law construction on the head, on the safe side.
2, this labor law is used tailor-made hang basket without counterbalance, self-propelled, the structure designs stiffness
Big, suffer force to make clear, the operation is convenient, repeated usage sex is better.
3, this labor law optimized colligation of reinforcing steel bar, concrete to irrigate build, prestressing force is tensioning construction
Craft, will hang time of construction of section of the sheet that irrigate bridge to shorten to average 8-10 day (5 days
Tensioning) , improved work efficiency, accelerated construction plan.
4, program of construction of concrete of will high grade, high-powered, wear changes this work way,
Standardization.
5, hang form of the line that irrigate bridge and stress monitoring method advanced, the effect is good.
6, the social benefit with be versed in the law has better originally and economic benefits.
2, suitable scope
1, apply to tall mound of high speed railroad, big span arm of successive firm compose, successive Liang Xuan is irrigated build construction.
2, apply to the cantilever that big, time limit for a project tightens safe risk to irrigate build construction.
3, craft principle
Combinative headroom, cross level of channel, design tall, time limit for a project is close wait for a characteristic, use impending bracket construction to accumulating 0# piece roughly and use tensioning the method of steel skeining thread undertakes be pressinged beforehand. Hang fill to hanged basket to use LM-300 to hang basket without counterbalance self-propelled triangle. Become the quality after the bridge and construction line entity to assure bridge, pump of colligation of elevation of outfit, pattern plate, reinforcing steel bar, Tong is going all out to send to hanging basket in process of the construction that hang fill, irrigate build reach preserve one's health, prestressing force tensioning, press the link such as the oar to have pilot at the same time, still wait for section of process of software imitate construction, computation to throw a value beforehand through using SAP2000, MIDAS, make form of bridge internal force, line accords with a requirement. Pass the quality trace of each link in the process, safe to whole construction control, especially big bridge completes sanded bay water course smoothly closure, assured construction time limit for a project.
4, construction technological process and operation point
(one) total construction craft
This bridge advocate mound is located in in water, build from the bank set landing stage to mound, as the passageway. Mound place set tower crane, regard perpendicular promotion as machines and tools. Concrete is used carry pump pump to send to construction site. 0# piece uses mound to carry bracket law construction on the head, concrete is divided second irrigate build. Dangerous irrigate construction to use trigonometry to hang basket, closure order is first in cross behind cross, closure paragraph two side set cistern to deserve to weigh, use hang basket advocate truss forms hanger of glyph of closure Duan Jing. Click? Project data downloads freely
Total construction technological process pursues
(2) craft of 0# piece construction and technology
0# piece uses mound to carry bracket law construction on the head, odd piece trigonometry bracket uses profiled bar solder to make in the ground, tower crane installation, bury armor plate to be linked together beforehand with mound body coping, check of structure of 0# piece bracket calculates 5.2-1 seeing a picture.
Computation of structure of 0# piece bracket pursues
0# piece construction pursues
0# piece bracket uses steel skeining thread tensioning the law is pressed beforehand, from bracket the top installs steel skeining thread and bear the stage buries steel skeining thread to be linked together beforehand, in bracket the top uses jack to undertake by design load tensioning. 0# piece bracket presses load to be equal to beforehand bear 1.1 times of the biggest load. Click? Project data downloads freely
0# piece bracket is pressed beforehand
0# piece bracket is pressed beforehand bring to bear on load
(3) cantilever is irrigated build construction craft and technology
Working procedure of construction of the bridge that hang fill is: → of the perch that hang basket is adjusted blow mould bottom, outside → of reinforcing steel bar of motherboard of colligation of → of side model elevation, abdomen board installs vertical stroke to slip to system of the standard inside → of prestressing force reinforcing steel bar a perch → installation is fore-and-aft, transverse → of reinforcing steel bar of roof of colligation of → of prestressing force conduit is irrigated build → of concrete → conserve to wear → of steel skeining thread. Such loop construction, cycle of every section construction is 8-10 day on average.
1) the design that hang basket and construction
Successive bridge design is this bridge simple case cell, the heaviest dangerous irrigate section 286t, section end length spends 3m ～ 4m. Big tonnage Liang Duan hangs basket to use lozenge or triangle commonly tailor-made hang basket, this bridge uses LM-300 triangle to hang basket.
(1) hang basket
Hang basket main by trigonometry advocate truss, around is transverse system of carling of sill of beam of coupling department, top, around, bottom, pattern plate, condole takes away anchorage solid system, travel slippage system and tensioning the composition such as platform.
LM-300 triangle hangs basket design
Sill and condole belt use form of bore with a reamer after, be helpful for adjusting bridge bottom line form and make sure juncture is close twice. Hang basket to walk use without system of proper motion of solid of the anchor after deserving to weigh, reduced hang basket self-prossessed, every hang basket only self-prossessed 115t.
Hang basket advocate inclined condole takes a design to be able to use finish rolling steel and jack to undertake be tighteninged beforehand before truss, reduced greatly hang basket total construction deflection, ensured construction safety and construction quality. Hang the model inside basket system and inside Hua Liang uses gyro wheel to join, OK and convenient inside modular system slippage is taken out.
The check that hang basket calculates use SAP2000 to build a model to undertake whole is analysed, classics check calculates, advocate truss structure is stable, stiffness is big, deflection is small, hang basket to be fully loaded with condition to issue the biggest deflection to be 16.7mm.
Hang what basket 3D model and model suffer force hind to be out of shape
(2) hang basket to be pressed beforehand
Hang basket to be pressed in the ground to undertake beforehand, go up in flat above all tile carries crossbeam on the head 3 times to be made the same score as tone frame, use sruveyor's level attune to make the same score. Make the same score in tone next frame on go all out outfit advocate truss, two advocate truss is opposite, fulcrum O is in will before pedestal is superior, dot of back end A uses bridge of 3 carrying pole and 6 Φ anchor of steel of whorl of 32 finish rolling originallies. Bridge of 2 carrying pole is placed in place of front B node, use 4 Φ steel of whorl of 32 finish rolling crosses carrying pole bridge to join, use two YCW80B-200 jack to classification respectively tensioning. The biggest load falls by the most adverse condition hang basket advocate 1.2 times what truss gets power, . Press beforehand by 10% , 25% , 50% , 75% , 100% , the class difference of 120% classifications to load, every 6 hours of observation after to load ends, after stress and deflection value are stable, cent 50% , 10% , 0% 3 class are uninstalled. Before to load, in advocate the two condole belt of lever of truss OB, AC, OC and BC sticks strain gauge respectively, classification to load and when uninstalling, read respectively take stress to be worth. In A, O, B the dot installs displacement plan respectively, classification in order to measure to load and when uninstalling advocate truss nods deflection value each.
Hang basket to approach sketch map beforehand
The girder that hang basket is pressed beforehand
(3) hang basket to go all out outfit
After construction ends the 0# Liang Duan of T compose, clear above all Liang Duanding face, use 1: 2 cement mortar will spread pillow position make level, with lever of tower crane general condole comes 0# piece end face, go all out by following program semmetry next outfit hang basket: Before → of laid steel pillow installs orbit → , hind pedestal → hoisting advocate the mould bases inside mould bases of bottom of hoisting of → of belt of the condole after crossbeam → going up to install before truss → hoisting and hoisting of → of bottom pattern plate walks along travel bridge → installation.
(4) the shift that hang basket
① hangs basket shift flow:
Hang basket migratory
Carry face make level on the head in Liangduan above all and measure good orbit place, laid fills up pillow and orbit, next drawing of patterns, use blow mould bottom chain trochlear condole hangs outer model to take a roof beam, loose advocate the anchor after structural frame, the pedestal before using catenary drawing makes hang mould bases of basket, bottom, outside side model moves to book the position to pay equal attention to to below one section ahead together new anchorage firm is on orbit. The condole after installation is taken, wear blow mould bottom trice. Walk along the hanger after travel bridge in model of the side outside should be being installed on Liang Duan next, remove next a before one bridge paragraph go up hind hanger, move to had been installed to a narrow passage providing the only means of access to a certain place of obligate of this Liang Duan, remove again another. Take the pattern plate outside been adjust after travel bridge perch and level of blow mould bottom, the model is mixed in motherboard inside the ability after colligation of celiac board reinforcing steel bar is finished procrastinates piece, final Feng Duanmo.
② hangs basket reach note
A. The operation such as transfer to a lower level, reach, promotion should set person specially assigned for a task to unite direct, each reference point sends person specially assigned for a task to be in charge of monitoring.
B. Before loose bottom basket, should check pattern plate to whether keep clear of entirely to pulling screw, prevent transfer to a lower level, move block of the card when machine; Move before hanging basket, set wire rope of a group of insurance, pull hang basket hind, prevent to glide suddenly.
C. When basket of bottom of transfer to a lower level, operate jack to answer synchronous balance transfer to a lower level; Operation jack lower part forbids somebody to stay, prevent handle to drop harm; Boom needs to delimit mark.
D. Orbit wants laid firm, level off, suitable straight, do not get deflection.
E. In scale of staff guage of the lay off on orbit, in order to control reach rate; When hanging basket to walk, should slow undertake, speed should be controlled control in minutely journey 250px, the left and right sides must synchronous reach.
Two side register F.T form basket should synchronous semmetry undertakes, its reach is apart from poor value to must not be more than half of Liang Duan length. G. Should notice to hang basket when reach each lever be out of shape circumstance, strengthen accept power position to each (rope of the belt that be like condole, insurance) the examination of firm circumstance, discover hidden trouble is handled in time.
H. Move machine reach the designated position, adjust level, anchorage solid is reliable, wait for ability is accessibility after checking and accept qualification construction of next line working procedure.
(5) hang basket to demolish
Demolish order to be as follows: After complete bridge is shut, hang model of the side outside basket and blow mould bottom to use steel skeining thread to have transfer to a lower level to wadi on intermediate cargo ship, after the ship is received, move to be demolished to dock disintegrate. Hang basket advocate pillow of steel of truss, orbit and other component are retreated undertake demolishing to tower crane place; Closure paragraph the model inside unused, inside take a roof beam, in closure paragraph demolish before construction.
The pattern plate that hang basket is demolished
2) reinforcing steel bar, concrete and craft of prestressing force construction and technology
Basically include the following content: Oar of pressing of construction of reinforcing steel bar, concrete construction, prestressing force construction, a narrow passage providing the only means of access to a certain place, seal anchor.
(1) construction of reinforcing steel bar
A. Treatment of reinforcing steel bar is made
The attune before ① reinforcing steel bar is machined clears clean continuously, must not have oily be soiled, lacquer corrupt, grout.
When expecting below ② , according to number of bridge body reinforcing steel bar and the accident that offer makings measure, arrange as a whole, use the material below successive burden law in order to reduce the loss of reinforcing steel bar. Click? Project data downloads freely
③ turn makes appropriate of reinforcing steel bar from which the ministry begins, progressively turn to two end, curved hook should be finished.
Connect of ④ reinforcing steel bar uses glitter to wait to solder, arc welding solder form. Advanced before applying solder formally travel tries solder, had mastered each technology parameter, undertake batch is produced after qualification trying solder.
B. Colligation of reinforcing steel bar
① colligation order is: Abdomen of → of motherboard reinforcing steel bar board reinforcing steel bar of roof of → of reinforcing steel bar. Colligation reinforcing steel bar while the moire valve that installs corresponding place.
② reinforcing steel bar is semi-manufactured goods in workshop treatment, carry shapes to the colligation after the spot.
Reasonable arrangement wants in process of colligation of ③ reinforcing steel bar the colligation of different reinforcing steel bar is ordinal.
④ covering layer uses space block of fine stone Tong, intensity ≧ 60MPa, quincuncial decorate, every square metre not less than 4.
(2) concrete construction
A. Two symmetrical section of cantilever construction and its section semmetry balance perfusion.
B. Concrete perfusion method is section statified perfusion, statified ply appropriate is 750px. Perfusion order: First by celiac board pours wine cup, again motherboard is mid, next perfusion abdomen board, final perfusion roof,
C. The freedom of perfusion concrete falls to be not gotten high be more than 2m, when exceeding 2m, should use chute, string together the appliance such as canister, funnel.
D. Concrete perfusion wants to undertake continuously, on, lower level time interval cannot coagulate first more than time.
E. In concrete perfusion process, should prevent collision pattern plate, reinforcing steel bar, bury beforehand reach prestressing force steel bundle conduit.
F. Concrete brace up pound give priority to in order to insert type vibrator, should prevent to leak brace up, also should have avoided brace up. Person specially assigned for a task should be set to wait for crucial position to undertake to pattern plate, anchorage bolster plate when construction brace up pound and check.
(3) prestressing force construction
A. Prestressing force a narrow passage providing the only means of access to a certain place
A narrow passage providing the only means of access to a certain place of ① prestressing force uses plastic and moire pipe,
② is make sure obligate a narrow passage providing the only means of access to a certain place is expedite, to fore-and-aft ripple the appropriate inside the canal inserts the canal of large wall glue of smaller than moire canal internal diameter 3~6mm or plastic pipe, it is in concrete perfusion process until before coagulating first, often should go there and back to twitch or rotate, pull out in time after coagulating at the beginning of concrete.
③ reachs grout felt to assure moire canal and concrete good, there must not be smeary, clay to wait outside moire canal.
The bolster plate below moire canal and anchor should keep homocentric, backing plate face should perpendicular at conduit axes.
Prestressing force a narrow passage providing the only means of access to a certain place is installed
B. Should expect below steel skeining thread beforehand and wear bundle
After the steel skeining thread after ① cut should undertake combing arranging, wear bundle, use the every other that plunge into silk next colligation of 2 ～ 3m together, its plunge into silk to buckle should park key link in the space of skeining thread, make up bundle hind classification is deposited.
② is worn bundle before, application compresses air the seeper inside cleared conduit and contamination.
③ basis steel bundle length can choose a person to be versed in or windlass cooperates to wear bundle.
C. Prestressing force bundle (muscle) tensioning.
To ensure prestressing force bundle tensioning the accuracy that controls stress, in prestressing force bundle undertake tensioning before, need to undertake frictional resistance of a narrow passage providing the only means of access to a certain place experiments, make 2 contain the prestressing force conduit, anchorage bolster plate, test specimen that deserves to have reinforcing steel bar, the steel of 2 kinds of types in choosing bridge body blueprint respectively wrings wiring harness to have a test. Conduit is decorated with successive bridge agree in blueprint, the requirement is suitable straight, strengthen fixed position (detailed sees graph 5.3.2-2) . Concrete strength grade and intensity of bridge style design are consistent, strength of demand of the concrete before the experiment is achieved 100% . Xian Qingkong needs before the experiment, the installation after waiting for experimental personnel to reach the designated position detects piece hind, fang Kean holds ground tackle, clip piece. If inadequacy of test specimen intensity, conduit is rough straight or position of anchor mouth, horn opening is malcontent full test condition, must make test specimen afresh. To load order divides 4 level in all, various load is a design respectively tensioning control stress 10% , 30% , 50% , 70% , to load arrives maximum (those who design piece of pulling force 70% ) hind, tensioning jack answers oil, uninstall 10% what design piece of pulling force, had made each record of stretchy quantity. Click? Project data downloads freely
Discovery is like to check data in experiment process unusual or other is accident circumstance, answer to stop to load instantly, wait for a circumstance to find out rear can restore to load afresh. According to prestressing force steel bundle with the U of coefficient of friction of conduit wall and conduit every meters of local deviation is opposite the influence coefficient K of attrition defines loss of frictional resistance of prestressing force a narrow passage providing the only means of access to a certain place. Have consideration by following formula commonly:
θ of Con[1-e-(u of σ of σ of σ η = + Kx) ]
In type:
σ σ Con, what anchor of prestressing force reinforcing steel bar falls is tensioning control stress (MPa) ;
θ , from tensioning end comes calculate the included angle the sum of tangent of part of sectional curve conduit (Rad) ;
X, from tensioning end comes the conduit length with sectional computation, the umbriferous length that can take this conduit to go up in component part x-axis approximately (M) ;
U, prestressing force steel bundle the coefficient of friction with conduit wall;
K, every meters of local deviation checks pipeline the influence coefficient of attrition.
Test block of frictional resistance experiment installs a plan (Mm)
Prestressing force bundle tensioning and main note is as follows:
Demarcate undertakes according to relevant standard before ① jack and oil pressure gauge are used and form a complete set is used.
② is tensioning and ordinal: By the design tensioning and ordinal undertake.
One by one answers to whether the examination has flaw or be out of shape before clamping apparatus of ③ ground tackle is installed, the concrete below anchor is close-grained, on face of cleared bearing sundry.
④ is tensioning give priority to with stress, with stretchy quantity school nucleus undertakes double accuse, actual and stretchy quantity and computation are stretchy the difference of the quantity must not be more than ± 6% . Fore-and-aft bundle tensioning undertake at the same time for two end.
⑤ is tensioning program: 0.1 σ of 0 → 0.5 σ of K → → of 1 σ K holds K → carry on his shoulder or back 5 minutes → is slow computation of → of solid of the anchor that answer oil is stretchy quantity → answers oil to uninstall to 0.
D. A narrow passage providing the only means of access to a certain place presses an oar
1) prestressing force a narrow passage providing the only means of access to a certain place presses an oar to use vacuum to assist the technology that press an oar. Technological process is: → of valve of installation of mouth of a narrow passage providing the only means of access to a certain place joins vavuum pump in blame pressing oar mouth → presses oar pump join to be in → of the mouth that press an oar in order to establish ties container of means general negative pressure, 3 press oar aperture join to rise to valve and anchorage bolster plate,
2) all drain tap are shut before pressing an oar (the except of join vavuum pump) , vacuumize of the vavuum pump that start, make pressure is achieved - 0.08MPa. While vavuum pump runs, open pump of dynamic pressure oar to begin to press an oar, till press an oar,grout appears in the transparent and plastic pipe of end, open press an oar 3 to valve, close valve when valve mouth pours out of thick oar, continue to press an oar and protect below 0.7MPa pressure press 2min.
3) the performance demand of grout: Water ash compares 0.3 ～ 0.35; Secrete water is led 2% , secrete water should be absorbed by oar body inside 24 hours; Flow spends 14 ～ 18s; Expand rate ＜ 3% ; Time coagulates to answer first ≥ 4 hours, coagulate eventually time ≤ 10 hours; Temperature of the air when pressing an oar should be in 5 ℃ ～ 30 ℃ .
4) the personnel that press an oar should record the process that press an oar in detail, ash of the date pressing an oar that includes every pipeline, water compares detail of accident of intensity of the feed in raw material that reach mix into, pressure that press an oar, test block, obstacle and need to fill the work that do.
5) press an oar to should be in tensioning after finishing undertake inside 24 hours.
E. Seal anchor
Interior of box roof beam is fore-and-aft prestressing force bundle, transverse prestressing force bundle, both sides crosses termination fore-and-aft bundle tensioning, after pressing an oar to end, can add establish network of reinforcing steel bar piece, fill with C60 concrete, wool certains the face that receive stubble first before filling a concrete and rinse clean with water.
(4) the edge crosses linear cast-in-place paragraph construction technology
The edge crosses linear cast-in-place Duan Cai to use stand way construction, mound can be used to carry stand way construction on the head when mound body is taller. Bracket is built set after ending, should undertake be pressinged beforehand, press load to be beforehand the biggest bear 1.1 times of load. The edge crosses cast-in-place paragraph should be in advocate mound edge is crossed hang the construction before irrigating an end to finish.
The edge crosses cast-in-place paragraph construction
(5) closure paragraph construction craft and technology
Closure Duan Cai uses construction of law of well glyph hanger, dangerous irrigate to closure paragraph hind, closure mouth a side hangs basket to back down, another side hangs basket reach, form closure hanger. Closure is abided by " microtherm perfusion, pull already maintain again still fight cut " principle. Choose to be in one day in air temperature undertakes concrete perfusion inside the time with little scope of change of inferior, temperature, the concrete that makes sure closure Duan Xinguan is noted is in the environment with air temperature not big change the medium, condition make known to lower levels in press press arrives to coagulate eventually, avoid concrete to suffer thereby pull craze.
Join the two sections of a bridge is crossed in paragraph construction
After join the two sections of a bridge is being crossed in
After complete bridge closure
(6) high-powered Tong Sunday run pump sends the summer construction craft and technology
Sunday run pump sends concrete construction
Watch advocate concrete of bridge box roof beam cooperates to compare
Concrete pump sends craft and technology
Concrete carries sketch map
(7) dangerous irrigate construction monitoring technology
1, monitoring of form of cantilever construction line
Because high speed railroad uses the track that do not have tiny fragments of stone, precision demand is extremely high, successive to be being crossed greatly the elevation becoming the bridge of firm compose changes with the Xu in crossing deflection demand is higher also, it is very important to because this is dangerous,irrigate construction line form and stress monitoring job. Monitoring main body is construction unit, can use the means that cooperates with the unit such as scientific research school.
(1) content of line form monitoring
1) the emulation computation of construction process;
2) the spot of elevation, deflection and central line position is measured;
3) the parameter identification of construction process;
4) of position of the elevation in construction process, central line forecast with adjust.
(2) computation of line form monitoring
Successive firm compose is finite yuan of computation model
Each are dangerous irrigate formula of computation of section construction elevation:
H applies =H to set + F5 (5.7.1-1 of ∑ of F2+f3+f4+ of ∑ F1+ ∑ )
The H in type applies: Construction of box roof beam designs elevation.
H sets: Box roof beam designs elevation into bridge hind.
∑ F1: Construction Liangduan and this follow-up construction Liang Duan is self-prossessed the deflection summation of generation.
∑ F2: Construction Liangduan and prestressing force of this follow-up construction Liang Duan are tensioning the deflection summation of generation.
F3: Hang basket self-prossessed reach its flexibility to be out of shape the deflection of generation.
F4: Change by Tong Xu, contractive, temperature, prestressing force is loose piece, the deflection of the generation such as structural system changeover.
∑ F5: By bridge floor the shop installs the deflection that 2 period constant carry and use load for a long time and arises.
(3) method of line form monitoring
1) deflection monitoring is measured the dot is decorated and monitor
Measure a dot to arrange a plan
2) the adjustment of elevation establishing a standard
The adjustment of elevation establishing a standard assures girder with wanting already each section is absolutely the precision of elevation, want to make sure the smooth-going of girder line form is a principle again. When this front mark tower above after Liang Duan is finished shows deviation, if deviation value is in ± 10mm less than, the front level that leaves one section does not need to adjust, still take design elevation for construction; If deviation value exceeds ± 10mm, should be in ever since eliminate its inside two Liang Duan. The processing technique is: error of this elevation of Liang Duan front the value returns date divide into equal parts, allocate on average from the back the standing of two Liang Duan in modular elevation.
3) the control of position of the central line in construction process
position of 0# piece center sets one center, left hind the viewpoint after pilot of every section position, use complete station appearance to undertake adjustment to position of every section pattern plate, pattern plate undertakes consolidate after exact location, undertake in termination of every pattern plate through complete station appearance section key nods lofting next, every section puts 6 reference point (5.7-3 seeing a picture) , the position that adopts reference point determines the position of a girder center line definitely, irrigate in every section after building, undertake connecting side with position of line of center of before one section, eliminate an error, ensure the accuracy of position of girder center line.
Sectional position reference point arranges central line of box roof beam graph
2, dangerous irrigate construction stress monitoring
To assure structural safety and construction safety, according to the design the requirement monitors the stress change of mound column and section of key of box roof beam, master condition of the structure getting power. Of box roof beam basically measure place to have:
(1) near ministry of root of box roof beam section;
(2) 1/4L of box roof beam is in section;
(3) closure of box roof beam paragraph department section.
Girder stress checks section to arrange a plan
Stress of box roof beam measures a dot to arrange a plan
