Summary of the invention
The objective of the invention is to be improved and innovate, a kind of hidden danger that can reduce in the engineering construction process is provided at the shortcoming that exists in the background technology and problem, and the job practices of the earthing jar of safety, efficient, high-quality.
Job practices of the present invention may further comprise the steps:
A, civil engineering earthing jar jar chamber:
A, the method that at first adopts backacter and artificial shoveling to combine are carried out soil excavation;
B, make ring beam then, and according to ring beam radian site prefabrication concrete block, specific as follows:
To keep mortar joint width unanimity in the building process according to the building by laying bricks or stones of ring beam radian prefabricated building block carrying out a jar interior wall, beam, pad, group block mode adopts the fissure of displacement to arrange; The building block bottom surface is counter up builds on wall; In the level of building block and perps, fill up mortar;
C, reinforced bar engineering adopt the machining welded reinforcement, on-the-spot artificial colligation;
D, template, scaffolding work, a jar chamber concrete shell roof plate template adopts the bamboo offset plate, middle part partial design camber, a jar shell soffit formwork support adopts scaffold tube;
E, then be concrete work and sand asphalt the construction;
F, do waterproofing at last, promptly finish the construction of civil engineering earthing jar jar chamber;
The installation of B, earthing tank storage jar body:
A, at first prefabricated storage tank body;
B, carry out tank bottom then and install;
C, carry out the installation of tank body again, specifically comprise:
1. rule, on margin plate, mark the installation fundamental circle line of tank shell, check circle, on the basic circle line, cushion block is installed, the basic circle line of jar Bottom Edge Board inboard spot welding between per two cushion blocks standardized of basic circle inner side;
2. the collar wallboard is installed, is enclosed the collar wallboard successively since a fixed point, with group jig is fixed between adjacent two wallboards, mortar board spot welding before coaming plate that jig uses by drawing and tank skin composing figure;
3. the tank deck top angle is installed;
4. adopt electric block to promote the upside-down installation method lift-up device; At first select the number of 10 tons of electric blocks according to the tank body size for use, evenly distribute along a jar inwall, each electric block is according to 75% jacking coefficient calculations; Select the seamless steel pipe of φ 159 * 12 to be made into column, the center adopts the seamless steel pipe of φ 219 * 12 to do central post, and its upper end links to each other by a wire rope and a jar lifting column, and the stability when increasing jar lifting is with the burn-on hanger of extension jack of column top; Make packing, prepare enough jig, pin; Make the backing plate of column then; Electric block is installed on the hoisting frame gets final product;
5. tank deck is installed; The falsework of assembling vault is set in jar, on top angle and falsework, marks the every position line of strengthening gusset, and the assembling baffle plate of burn-oning; On top angle and falsework, be assembled into a whole skeleton with prefabricated band steel, re-lay the tank deck plate, and adjust lap width, earlier the attachment weld of inboard intermittent weld of welding vault and floor, welding outside weld seam at last; The lifting of tank deck plate needs a hoist engine is installed on base plate, by the directed pulley of installing at central opening place, earthing tank top, top board prefabricated and that transport to access adit is hung on the skeleton installation successively;
6. the tank deck mast-up is installed, a cover mast-up is installed on tank deck, the lifting beam is the center of circle with the tank deck center, rotates freely, and an end of lifting beam is installed an electric block, and tank shell installs hoisted in position by this;
7. other is installed at last respectively encloses tank skin;
D, welding storage tank;
E, test at last and check, promptly finished the construction of whole earthing jar after qualified.
The technological principle of job practices of the present invention:
Adopt the construction of first civil engineering earthing jar jar chamber, outer prefabricated, the transportation of steel tank jar, earthing jar jar chamber operation room reservation operations passage is done the transportation of steel tank prefabricated component passage is installed, at the indoor technological principle that carries out the upside-down construction of steel tank of earthing jar, in the work progress of steel tank, corresponding earthing jar can carry out a jar outer protection and a backfilling working, reaches the effect of synchronous completion.
Technological process of the present invention:
Preparation of construction → location unwrapping wire → soil excavation → check of foundation subsoil → concrete bed course → tank skin foundation construction → tank skin blockwork is built by laying bricks or stones, scaffold construction → tank deck thin shell concrete construction synchronously and maintenance → jar outdoor water-proof, scaffold dismounting → jar backfilling of earthwork in jar → jar backfill sand → bitumen sand cushion → basis examination → storage tank acceptance of materials, blanking → tank skin, the prefabricated passed examination of tank deck, it is indoor by tank skin bottom plate to transport to jar, inferior bottom plate successively to the top layer wallboard place → tank bottom is anticorrosion, laying → jar back welding connects, check → collar wallboard is installed check → top angle installation → lift-up device installation → tank deck installation → circle wallboard installation second from the bottom → other circle wallboard and is installed and check foundation ring wallboard installation → dismounting lift-up device → big angle seam welding → jar end shrinkage joint welding → filling water test, foundation settlement → storage tank is anticorrosion → jar chamber passage construction → jar retaining wall and backfilling of earthwork.
Advantage of the present invention and beneficial effect:
Carry out quality procedure in the work progress of the present invention comprehensively and follow the tracks of, require the indoor steel tank construction of organizing construction, particularly large tank in strict accordance with requiring construction, do not allow to occur the quality problems phenomenon of doing over again according to construction technology process.The earthing tank field generally is that several jars are constructed simultaneously, and the scope of operation is big, and it is corresponding right every jar construction group every the jar excavation to take in work progress, set up a self-contained precasting yard, strengthen the prefabricated degree of depth, strengthened a jar outer prefabricated degree of depth, reduced a jar interior construction intensity.The construction of the earthing tank field that has is to carry out under the operation situation of original reservoir area not influencing, to the influence of original tank field more little in earthwork construction rationalization's soil excavation and cubic metre of earth stockyard and transhipment engineering quantity, employing is every the form of construction work of jar number excavation, avoid occurring a cubic metre of earth landslide, reduce the transport amount, reduce the generation probability and the running cost of security incident, come from the energy-conserving and environment-protective aspect, just increased owner's benefit, reduced the discharging of a large amount of dusts, provided cost savings.In the application of large-scale hanging device,, saved large-scale hanging device machine-team because of having taked the method for tank deck self-control arm.
The specific embodiment
A, civil engineering earthing jar jar chamber.
1, soil excavation:
Adopt backacter and artificial the shoveling to combine, for avoiding disturbance substrate soil, when excavation, reserve the earthwork of substrate absolute altitude 20-30cm during the backhoe excavation, take the labor cleaning; Foundation trench outside work face width 1800mm, excavation is put the slope by the 1:0.55 gradient, and looks the adjustment of soil property situation, if highly excessive, can take bench to fall off, and takes bank protection in case of necessity, avoids landslide; Dig out the gutter around in foundation ditch, the reasonable Arrangement sump, with φ 50 foul water pump drainings, the provisional drainage of foundation ditch combines with permanent installation as far as possible; Covered with plastic film on slight slope is avoided the rain drop erosion side slope; Check of foundation subsoil as early as possible behind the excavating foundation trench, in time construction avoids foundation trench influenced by rainwater.
2, concrete block, collar tie beam:
The method production of site prefabrication is adopted in the concrete solid block, guarantees prefabricated quality.Jar chamber enclosure wall symmetry is continuously built by laying bricks or stones, guarantees stressed even.Basis ring beam construction should be controlled absolute altitude well, guarantees the building block level.Whether correct, and check the absolute altitude horizon if at first checking axis, absolute altitude, center line size before building by laying bricks or stones, and row builds in advance.Mortar is carried out the match ratio report in advance by test room, and being ready to 6 of die trials is one group, test specimen witness sampling censorship in time.Building block horizontal joint thickness and perpends width are generally 10mm, but should be less than 8mm, also should be greater than 12mm.In operating process, conscientiously carry out self check, as have deviation, should in time correct, masonry mortar should must not use the mortar that spends the night with mixing with use, should be with building with the tongue ash being scraped to the greatest extent.It is smooth closely knit that mortar joint and block faces are wanted, and blind seam must not occur and cohere not firm phenomenon, to avoid water percolation of wall.The masonry mortar joint is should be horizontal vertically flat, and mortar is full, adopts jointing in jar, colludes horizontal joint earlier, after collude vertical seam, be beneficial to wall decoration.The pin trick is not stayed in building block, builds by laying bricks or stones every day highly to be no more than 1.5 meters.The building by laying bricks or stones of body of wall will be controlled the central point of jar chamber well, and can body is built by laying bricks or stones and adopted special hanging greatly to hang down with steel wire mid point to be drawn, and every block 1m height will once be checked, and in time rectifies a deviation.Building block construction emphasis: building block is prefabricated should be prefabricated according to the ring beam radian, guarantees mortar joint width unanimity, and group block mode is arranged in order, notes the fissure of displacement; Forbid to use the building block of fracture; Building block answers that the bottom surface is counter builds on wall up; When building by laying bricks or stones, the intensity of building block and mortar must adhere to specification; Strict control full degree of mortar at bed joint during the building block construction.Accomplish that level and perps mortar are full.
3, reinforced bar engineering:
Reinforcing bar processing concentrates in the reinforcing bar canopy to be made, and adopts machining making, on-the-spot artificial colligation.Reinforcing bar must have material to be proved, and by the national regulation requirement, under owner or management witness, by carrying out sampling test in batches.Welded reinforcement must carry out soldering test except that the raw material test, after the pass the test, can produce in batches.The strict execution checked earlier the principle of afterwards using.Serious and be infected with the dirt reinforcing bar and will clear up to corrosion, in order to avoid influence the reinforcing bar adhesion stress.
Reinforcement fabrication: according to design working drawing and reinforcing bar blanking table, check whether bar gauge, model be correct, complete and carry out blanking again after errorless, to consider reinforcing bar anchoring and lap length during blanking, and meet design working drawing and code requirement, strictness is made by the design working drawing requirement during making, unified dimensions, excessive to prevent reinforcing bar semiproduct error.Stack reinforcing bar and adopt brick the high 300mm of base, avoid directly being deposited on the earth.The crotch of reinforcing bar or bending should meet following regulation: the terminal need of I grade reinforcing steel made 1800 crotches, and its circular arc bending diameter should be less than 2.5 times of bar diameter, and straight portion length should not be less than 3 times of bar diameter.
The reinforcing bar welding: adopt flash butt welding, the contact surface that requires reinforcing bar to dock is smooth, clean, weld bond does not have slag inclusion, and misalignment of axe is in 2mm, and sampling test is qualified.
Reinforcing bar binding: the reinforcing bar of making is numbered by specification, shape lists, and in place by the position of design working drawing, require colligation firm, marshalling, end muscle gluten is well arranged, and ties up the mortar cushion block, to guarantee thickness of protection tier.Will setting-out on template during reinforcing bar binding, repave muscle then by the line colligation.During concrete pouring construction, send the special messenger to follow up to be protected and revise.The laid reinforcement binding joint should meet following requirement:
A, bar splicing place should fasten with iron wire at center and two ends;
Colligation joint location between b, each steel bar stress should stagger mutually.In 1.3 times of sections from arbitrary colligation joint center to lap length, have the steel bar stress section area of colligation joint to account for steel bar stress total cross-sectional area percentage, should meet following requirement: the tensile region must not surpass 25%; Pressure zone must not surpass 50%.Welding point must not surpass 50%;
C, make the cushion block that 50mm is square, thickness equals topping, be used for wanting pre-buried 20-22# iron wire in the cushion block of wall, post, beam steel with high-mark cement silt particle slurry;
The negative bending moment muscle of d, plate adopts ￠ 14 reinforcing bar split heads to support, in case be operated during concreting.The split heads spacing is 600 mm.
4, template, scaffolding work:
Concrete shell roof plate template adopts the bamboo offset plate, and the mid portion camber should add 1 ~ 3 ‰ arch camber by designing requirement and install, and the template piece seals with adhesive tape, guarantees tightly spillage not of piece.The interleaving agent brushing should be even, must not pollute reinforcing bar.Jar shell soffit formwork installs the employing scaffold tube, and after the steel pipe segmentation was pressed into the radian that adapts with jar inner bottom plating, 100 * 100 flitches were tightened with iron wire on the steel pipe upper berth, lay bamboo splint on the flitch.Screw arbor with nut at both-ends is adopted in the reinforcing of ring beam, guarantees that concrete does not run mould.
Establish the special messenger and see mould in concreting process, so that check the stable of template, support, pinpointing the problems in time solves.The dismounting of template should be carried out after concrete strength reaches 100 ﹪, guarantees that concrete surface and corner angle are not impaired, and symmetry is removed.Scaffold upright rod rests on the 50 mm planks, and the bottom is adopted and can be regulated the height that bearing is regulated steel pipe, puts up the bar of sweeping the floor in accordance with regulations, and the bottom vertical rod will be adopted the different steel pipe of length, avoids contact in same bar eminence, make fastener and steel pipe fastening, and contact is good.Stable for guaranteeing scaffold, scaffold upright rod spacing 0.9m, horizontal braces spacing 1.2m establishes bridging all around in length and breadth.Arc bar field lofting is adopted in the bad control of tank deck radian, presses the radian nip drum with plate bending rolls and is shaped, and jar shell top, chamber support system is as follows: set up double-pole scaffold in the outside and guarantee construction safety, make things convenient for the concrete transportation.
5, concrete work:
Stir: the raw material (cement, sand, stone) that concrete is formed all should be qualified after testing after, and prepare burden, for guaranteeing that concrete because of mechanical breakdown influence construction continuously, adopts 2 JG500 forced mixers to concentrate at the scene and stirs by on-the-spot match ratio.
The metering of composition material: the concrete mixing water adopts tap water, and water supply volume cooperates submersible pump to measure with electronic timer; Sand, stone, Admixture are all with the metering of lever electronic scale, and the usage of Admixture should strictly select for use the instructions for use of brand to add by design.In the construction, should also be noted that the variation of weather, adjust on-the-spot match ratio at any time, and hold mixing time, guarantee the stable of concrete quality according to the moisture content of sand, stone.
Shell and outer-ring beam concrete should be by the bottom to evenly symmetry cast continuously of top, must not stay constuction joint, template, reinforcing bar, reserving hole, built-in fitting etc. be should often observe when building concrete and mobile, distortion or stopping state had or not, pinpointing the problems to stop pouring immediately, and the Ying Zaiyi concrete of building is revised before condensing intact.
Concrete grade adopts the C30 waterproof concrete, and anti-penetration grade is S8.Concrete water/binder ratio must not must not adopt villaumite as antifreeze, early strong admixture greater than 0.50, should strengthen in the construction vibrating, and prevents segregation, strengthens maintenance and guarantees that concrete reaches the design strength and the impervious grade of regulation.Slump cone is got at the scene ready, is as the criterion with the slump.
Mix the UEA expansion agent in the waterproof concrete, correlation technique will be asked for an interview to product description and " Technical code for application of admixture in concrete ", and should limit the concrete expansion rate: in the water 14 days 〉=0.015%; Contract with dry rate: in the water 14 days≤0.03%, in the air 28 days≤0.03%.
Concrete cover to reinforcement thickness: shell is 30; Be respectively 40,50,40 with board wall, beam, basis that soil directly contacts; Other board walls, beam are respectively 20,30.
Maintenance: after concrete is built and finished, should should begin covering curing at high temperature season behind 6h at 12h with interior in addition covered with plastic film or gunnysack with water, concrete adopts the maintenance of natural curing method, generally is no less than 14 days.
Transportation: diesel dumper is adopted in the level transportation of concrete, and vertical transport adopts elevator and last people to expect way of combining.Adopt pumping concrete construction when shell is constructed, the nearly 200 cubes of concrete of whole shell once water shaping.
6, sand asphalt construction:
Mixing the used material of system sand asphalt must meet the requirements, and when mixing and stirring, the temperature of sand is controlled at 100 ℃-150 ℃, and the heated bitumen temperature is that 180 ℃ of-200 ℃ of strictnesses are by the match ratio uniform mixing; Temperature is not less than 140 ℃ when paving, and evenly paves and uses roller compaction, the real thickness 75mm of every lamination, and layered rolling to 50 is thick.
The bitumen sand cushion vertical construction joints staggers and retained tiltedly raft mutually, makes real with hot iron, is coated with one deck heated bitumen after the preheating when continuing construction, is connected the sand asphalt that paves then, makes real to leaving no trace with hot iron.Horizontal construction joint is coated with one deck heated bitumen earlier and repaves sand asphalt.Has pressed last one deck heated bitumen shop, plates with hot iron.
The sand asphalt that has pressed the shop will be in conjunction with firm, closely knit, smooth with basic unit, and not handy pitch is done the surface and handled, and crackle must not be arranged, play phenomenons such as drum, delamination.
Sand asphalt proportioning: pitch: French chalk: medium coarse sand: fine sand=7.7:6:70:24
The medium coarse sand bed course requires even compacting, and layering is spread out and put on.Every layer of ramming at least three times, cutting ring sampling coefficient of consolidation 〉=0.96 is carried out the construction of last layer more in accordance with regulations.
7, waterproofing and jar outdoor cubic metre of earth of earthing backfill:
The waterproof operating procedure: base treatment, 20 thick 1:2.5 cement mortar screeding layers, 3mmSBS modified asphalt waterproof coiled material two roads, paving SBS coiled material during construction of waterproof layer adopts during paving to begin paving from bottom to top, and adopts hot melt to carry out paving.The lap width of each layer coiled material all should satisfy the related specifications requirement.After inspecting for acceptance and finish, every layer of waterproof carry out the outdoor earthing backfill of jar synchronously, banket to per 300 millimeters compactings and reach 94% coefficient of consolidation, sync check, the adjacent tank chamber intersects carries out synchronously, the in layer staggered backfill of inspecting for acceptance, carry out the construction and the waterproof of access adit passage simultaneously, until the tank deck shell.Tank deck shell waterproof adopts the construction of roofing coating waterproofing, action is 20 thick 1:2.5 cement mortar screeding layers, be coated with base treatment agent outward and be coated with SBS modified waterproof asphalt material two roads together again, carry out earthing after inspecting for acceptance again, thickness of earth covering 20 millimeter, adopt the vibratory plate compactor compacting, do not allow machinery to enter in the tank deck shell scope, so far whole jar of outdoor earthing finished.
The installation of B, earthing tank storage jar body.
Adopt the electric block upside-down construction.In precasting yard, blanking, roll bending by tank bottom, wallboard material cutting plan carry out jar are transported to the erecting bed then and install.Prefabricated end back is equipped with flat car with 16 tons of mobile cranes prefabricated component is transported to the job site, cooperates the lifting assembly welding by prypole, electric block.Deepen the prefabricated degree of depth in the construction as far as possible, reduce on-the-spot installation workload, increase work efficiency.
1, the storage tank body is prefabricated:
General requirement: all prefabricated units all should take to prevent the measure of being out of shape when keeping, transportation and on-the-spot the stacking.The prefabricated work of earthing storage tank is consistent by the prefabricated and conventional storage tank prefabrication system of material cutting plan after examining.
 2, tank bottom is installed:
With reference center's point is that the center is marked 0 °～180 ° respectively, and 90 °～270 ° cross reference lines mark middle plate and two side plate installation site lines respectively again according to composing figure, lay prefabricated steel plate.All weld seams of the intact back of jar back welding carry out 100% vacuum leak test inspection, and the test negative pressure value is not less than 53Kpa, not leak to qualified.
3, tank body is installed:
A) mark the installation fundamental circle line of tank shell on margin plate, basic circle inside radius design formulas is: Rb=(Ri+na/2 π)/cos θ;
Rb in the formula-foundation ring wallboard is installed inside radius (mm);
Ri-storage tank inside radius (mm);
The upright seam of n-wallboard quantity;
The upright seam of a-every amount of contraction (mm), hand welding gets 2;
θ-basic gradient angle (°);
B) check circle standardized of the inboard 50mm of basic circle position, the inspection diameter is D=2R-100mm;
C) on the basic circle line, install 14 cushion blocks, each cushion block is about 150mm, and the distance between per two cushion blocks is about 500mm, also marks the basic circle line on each cushion block, at δ=6mm of the inboard spot welding of each cushion block basic circle line, the block of 70 * 50mm.The inboard spot welding δ=8mm of the basic circle line of jar Bottom Edge Board between per two cushion blocks, 100 * 80mm baffle plate.
The installation of collar wallboard:
Enclose the collar wallboard by drawing and tank skin composing figure successively since a fixed point, with group jig is fixed between adjacent two wallboards, to jig, the mortar board that jig uses point before coaming plate welds the per pass longitudinal joint with 2 groups.
The tank deck top angle is installed:
Prefabricated tank deck top angle segmentation is installed on the first lap tank skin, notes top angle and the radian that engages tank skin during installation, radian requires same tank skin.
Lift-up device is installed: adopt electric block to promote upside-down construction.
A, select the number of 10 tons of electric blocks for use according to the tank body size, evenly distribute along a jar inwall, each electric block is according to 75% jacking coefficient calculations, design formulas: cucurbit number=jacking position weight T/(cucurbit tonnage 10T * jacking coefficient).5000 cubes of earthing jar jar body jacking position weight are 105 tons, cucurbit number=105T/(10T * 75%)=14, consider to distribute symmetrically and evenly, adopt 16 10 tons electric block can satisfy the jacking requirement.10000 cubes of earthing tank jacking position weight are 170 tons, the jacking coefficient according to 75%, cucurbit number=170T/(10T * 75%)=23, considering distributes symmetrically and evenly adopts 24 10 tons electric block can satisfy the jacking requirement.
B, check that by platform electric block should not have heavy wear, Plant in good condition.
The seamless steel pipe of c, selection φ 159 * 12 is made into column.The center adopts the seamless steel pipe of φ 219 * 12 to do central post, and its upper end links to each other with a jar lifting column by wire rope, the stability when the increase jar promotes.The column top burn-on hang the hanger of jack.
D, making packing are prepared enough jig, pin, and packing adopts [25 making.Locate apart from about feather edge 300mm at tank shell, packing is installed, packing expands real (circle is established 4 jack and is advisable) with 20t or 32t jackscrew, and each is connected the both sides of packing jack joint with tank skin with gantry jig, and beats reality with pin and tank skin.Packing and tank skin gantry jig and pin, connections such as anti-skidding baffle plate.The installation application level pipe levelling of packing, the deflection of tank body when preventing to promote.Gantry jig should respectively be provided with one in the both sides of distance column center 750mm, other is provided with one every 2000mm.
The backing plate of e, making column, the backing plate specification is 800 * 800 * 12mm.
F, 10 tons of electric blocks are installed on the hoisting frame.
The normal lifting of g, tank body: suitable for reading at the outer ring wallboard at first every 1200mm spot welding one postive stop baffle.Carry out the lifting of tank skin by the special messenger commander, accomplish the consistent all directions hoisting velocity unanimity that guarantees of step as far as possible.After putting in place, lifting carries out counterpart by riveter.---shrinkage joint---girth weld---the weld seam falling packing that cools completely is reserved in welding, and tank skin is looked for circle for spot welding circumferential weld then.
Tank deck is installed:
The installation of vault plate, should be undertaken by follow procedure:
A, owing to be subjected to the influence in space, the installation of vault plate can't carry out sheet to assemble, can only be on top angle and falsework on-the-spot overall package;
B, in jar, be provided with the assembling vault falsework, spring of arch should exceed 50-80mm than design load;
C, on top angle and falsework, should mark the every position line of strengthening gusset, and the assembling baffle plate of burn-oning;
D, with prefabricated-80 band steels on top angle and falsework, be assembled into a whole skeleton, re-lay the tank deck plate, and adjustment lap width, the lap width allowable variation is ± 5mm that the attachment weld of inboard intermittent weld of welding vault and floor welds the outside weld seam at last earlier.The lifting of tank deck plate: the hoist engine of a 2T is installed on base plate,, top board prefabricated and that transport to access adit is hung on the skeleton installation successively by the directed pulley of installing at central opening place, earthing tank top.
The tank deck mast-up is installed:
One cover mast-up is installed on tank deck, and the lifting beam is the center of circle with the tank deck center, rotates freely.One end of lifting beam is installed 10 tons of electric blocks, and tank shell installs hoisted in position by this.
Other respectively encloses the installation of tank skin:
(a) next circle of gusset (the 3rd joint) wallboard outside the tank body of having constructed, the longitudinal joint outside weld bond of assembly welding except that shrinkage joint is with promoting first and second good joint tank body of assembly welding, with the 3rd joint plate assembly welding shrinkage joint and circumferential weld;
(b) each operating procedure of repetition (a) is until the last lap wallboard;
(c) the last lap wallboard is constructed to finish and should be removed 14 cushion blocks;
(d) all need check upper and lower girth and verticality after every circle wallboard assembles;
(e) before each circle tank skin promotes, should the crator polishing of medial and lateral is clean.
4, welding in storage tank:
The general employing of steel tank welding manual electric arc welding, the J422 welding rod is selected in selecting for use according to material and drawing standard of welding rod for use.Carbon steel welding in storage tank construction Deformation is a ubiquitous problem, must be to welding sequence, and strict control such as welding current.
The tank bottom welding:
The welding principle of tank bottom is the short seam of weldering earlier, the elongated seam of back weldering.Short weld seam weld again to be decided long spot welds solid welding, is to control welding deformation, and long weld seam spot welding must one be fixed every a spot welding.Welding sequence is outside by the jar center, and backstep is adopted in the welding of elongated seam, and section length is 1000mm.
Tank body all installs, and checks overall verticality, and the big angle seam of qualified back spot welding requires to take the anti-deformation measure before the weldering, and four anti-deformation braces of every wallboard weldering require the welder to be evenly distributed during welding.Adopt backstep sequence, section length is about 1000mm.
Jar end shrinkage joint first floor adopts segmentation to regress and welds, and room for manoeuvre length is 500-600mm, and jar end shrinkage joint must weld the back welding in whole fillet welds and base plate center weld seam.
The tank shell welding:
Manual electric arc welding is adopted in the welding of tank shell, and total welding sequence is: weld the upright seam of two adjacent rings wallboard earlier, back welding circumferential weld therebetween.
Upside-down construction, the wallboard verticality must be adjusted and measure to the top first floor wallboard of installing earlier, levelness and circularity, each layer wallboard installed and met the drawing dimensional requirement after guaranteeing.When circumferential weld welds, for the circumferential weld upper can body weight that reduces welding weight to circumferential weld, prevent that the fusion weld metal zone from producing big internal stress and distortion, should take following measure: it is stressed to allow cucurbit have slightly with the cucurbit lifting, make the upper can body weight carry to lower floor's wallboard like this, rather than all be pressed on the circumferential weld by limiting plate.It is under pressure and produce welding line angular distortion, i.e. deformation of unevenness to do when guaranteeing the circumferential weld welding not reason like this.Should evenly distribute along circumference by several welders during the upright seam welding of tank skin, simultaneously, welding in the same way.Welding sequence is to weld collar extension earlier, mouth in the weldering of back.Should divide three sections backstep weldings during the back cover welding.
The tank skin circumferential weld is evenly distributed along circumference by several welders, simultaneously, welding in the same way, and arcing point and receive acnode and should stagger more than the 50mm.Weld collar extension earlier, mouth in the weldering of back.Answering backstep, room for manoeuvre length during the back cover welding is 800mm.
Packing must could be removed after the weld seam welding finishes and cools off fully, could effectively prevent welding deformation.
The vault welding:
The welding of vault plate, should press the follow procedure welding:
Behind the vault tacking, be interrupted welding vault weld joint on inner side earlier, the outer side weld of back weldering vault; To prevent welding deformation.
T connector between warp-wise rib and the latitudinal ribs adopts two-sided full-fillet weld;
The slit of vault outer radial adopts space symmetrical welding method, and by the outside backstep in center; Room for manoeuvre length is 1000mm.
The opening-nozzle welding:
During the opening-nozzle welding, interlayer temperature be should control,, laggard promoting the circulation of qi tightness test and dye penetrant inspection welded with the control welding deformation.Opening diameter such as manhole and loophole is bigger also needs to strengthen with gusset.
5, test and check:
The test of the test of steel tank and check and above-ground storage tank and check is identically carried out corresponding design specifications and is carried out.
Embodiment of the present invention only is the description that preferred implementation of the present invention is carried out; be not that design of the present invention and scope are limited; under the prerequisite that does not break away from design philosophy of the present invention; engineers and technicians make technical scheme of the present invention in this area various modification and improvement all should fall into protection scope of the present invention.