1. Project Overview
A storage project length 230m, width 100m, cornice 11m high, building area of 23,000 square meters, the roof slope of 3%, span of 25 meters, the main column spacing of 9 meters, the roof 0.53mm thick galvanized steel + Insulation cotton, the outer wall is 0.43mm thick color pressure plate, is a portal light steel structure, by the steel columns, beams, envelope structure, purlin, support and other components.
2 main construction points
2.1 Installation Overview
2.1.1 Due to the large area and short construction period, the project has only 40 days to install the steel structure. In order to ensure the construction progress, the entire hoisting task should be completed by means of flowing water construction through reasonable arrangement.
2.1.2 marked on the basis of the installation center line, the center line of each piece of steel up and down transversely marked with a red triangle to mark the installation and installation.
2.1.3 pairs of components to be pre-assembled on-site, erection of a simple pre-assembled platform and leveling measurement to ensure assembly quality.
2.1.4 The angle between lifting wire rope and girder can not be less than 45 degrees.
2.1.5 From the end of the wall near the cross-support hoisting, the theodolite with the crane to find the center of the beam displacement and verticality after tightening bolts, and then release the crane, the first within the open structure is completed, all the purlins, Beams and eaves Beams are installed between columns of supported supports, and the entire column is adjusted, straightened and supported before proceeding to the next step.
2.1.6 In the installation process, must be used to support the rigid rope frame, cable rope must be fixed to the correct fixtures.
2.1.7 purlin and other components of the installation, the main structure after the installation is completed, the lighter weight of the secondary structure and the main structure of the installation process is not installed in the artificial all installed in place.
2.1.8 The installation of wall purlins and other components is adjusted after the column is adjusted. The straightness of the wall purlins can be adjusted with wooden strips or rod bolts (see figure).
2.2 high-strength bolt connection
In the light steel structure of high-strength bolts from the main connection, the installation must pay attention to the following aspects:
(A) Bolts should be stored in moisture-proof, rain-proof, dust-proof and classified according to type and size.
(B) Bolts should be handled lightly to prevent impacts, damage to the package and damage to the bolts.
(C) When using the bolt, open the packing box and use it according to the quantity used on that day. The remaining bolts should be recycled on the same day and stored according to the batch number and specifications. Different batches of bolts, nuts, washers may not be mixed use.
(A) Bolt insertion shall be easy and consistent.
(B) The bolt should be free to penetrate, if not penetrate, no gas reaming, reamer and other amendments.
(C) The friction surfaces of the components shall be dry and shall not be exposed to rain.
(3) First and last twist:
(A) Initial tightening and final tightening shall be completed within 24 hours.
(B) The initial screwing value is about 50% of the final screwing.
(C) Screws shall be screwed outward in the order of their center position.
(D) mark it after it has been screwed.
2.3 column installation
Steel column installation, the first clean-up the foundation, and adjust the basis of Peugeot, and then install. Column installation levels include: basic pay-off, banding, Zhuang Zhuang, correction, fixed and so on.
2.3.1 Putting the line: Before installation, put the vertical and horizontal axial baselines of the base plane as the positioning lines for the column base. Lifting, the installation of the pillar by position, direction to the lifting position.
2.3.2 Column lifting: Before lifting the column, from the bottom of the column upward 500-1000mm Department, draw a horizontal line, in order to install fixed before and after the review plane elevation benchmark.
2.3.3 Column correction: Column calibration work generally includes the plane position, elevation and verticality of these three elements.
Column corrector with measuring tools at the same time. Placement of the steel column in place when lifting, is an alignment, generally do not need to be corrected. For the elevation of the column, sometimes lower than the installation elevation, in place, the need to use horns to adjust the exact elevation. Use theodolite to calibrate the verticality of the column.
2.4 roof beam installation
2.4.1 beam in the field to do a good job of assembling, and to do a good job of calibration; assembled, with each span as a group; hoisting before the lifting point to confirm the location of points to do a good job lifting beam protection, so paint damage, Draw the oil rope at both ends of the beam to prevent the girder from swaying in the air. When the girder is lifted, it should be lifted after being checked 50 cm above the ground.
2.4.2 When installing the axis steel beam, do a preliminary calibration before releasing the hook, align the center of the steel beam base with the positioning axis and adjust the vertical bending of the beam to check the beam for lateral bending, Do not loose, the installation of some of the purlin temporarily installed with steel beams fixed, followed by the installation of support to ensure the stability of the space between the internals. Terminate all high-strength bolts in this in-between section, and finally correct the fixed whole.
2.4.3 Steel beam lifting completed, and correct the correct position, you can carry out the sliver hanging, sliver hanging in place after the manual installation.
2.5 roof installation
2.5.1 Locking Tools: Since the roofing of the project is a lock plate, a specially designed lockstitching tool shall be adopted. After the roofing plate is laid, the manual lockstitch sewing machine shall be used to fix and establish the guide port.
2.5.2 roof installation direction: in accordance with the design requirements from the gable at the beginning of decking. Interlacing boards to achieve waterproofing requirements.
2.5.3 Special instructions Locking plate installation order: the first column from the gable along the wall to connect the strip on each purl start, before fixing to ensure that the connecting piece sliding piece in the middle of the base, from the cornice bracket to The eaves draws a reference rope along the outer corner of the gable wall and adjusts the position of the pull line by measuring the distance between the center line of the rigid frame on both sides and the pull line. The outer edge of the board connecting piece is flattened with the pull line and fastened with the purlins. Whether the first row of plate laying is square, will determine the quality of subsequent plate installation.
2.5.4 roof during the installation process must also strictly comply with the relevant provisions of the operation to avoid or reduce the pressure on the surface of the paint color plate damage.
2.5.5 In accordance with the requirements of the drawings and product specifications, the quality of the transportation and suppression of roofing panels shall be checked and accepted to ensure that the roofing panels will not undergo deformation, discoloration, paint peeling and damage during transport and storage. Meanwhile, the roof panel geometries Size, confirm that it meets the design requirements.
2.5.6 clear the roof of the grease and protective layer to prevent slipping during walking.
2.5.7 Place a bundle of roofing boards on a roof beam by crane (not to be placed on purlins), lift it manually and install it in place and fix it in time. Each bundle of roofing panels shall not exceed 10 to 15 sheets, and the uninstalled roofing sheets must be fixed when stored on the roof.
2.5.8 All areas where sealing tape is to be used must be scrubbed beforehand to improve the degree of fastening.
2.5.9 Roof installation, you must ensure that the frame is vertical and square, between the purlins with wooden stays to ensure that the purlins straight. The corresponding spare parts such as gaskets, seals, plugs, etc. should be installed in place, without omission or re-installation.
2.5.10 Installation of Roof Fasteners One of the important steps is to tighten the fasteners until the washers are firmly positioned, but not excessive.
2.5.11 roof panels should be strict, carefully, to ensure the long no deflection, bump and so on. 45o oblique angle of the corner position of the space and ensure uniform joints, lap position should be smooth and tight. Fixed bolts, rivets should be horizontal and vertical without distortion.
2.5.12 Roof panels should be installed to ensure that the main wind direction.
2.6 wall panel installation
2.6.1 Use of mobile scaffolding wallboard installation. Move to ensure its stability and on-site construction personnel safety, require the building around the formation.
2.6.2 The installation of wall panels should be strictly in accordance with the layout of the roof with reference to the installation site requirements, after the completion of the installation of the main plate, and then according to the actual situation of the scene, the installation of edge panels to ensure the quality of the wall edge.
2.6.3 pre-perforated wall panels according to wall layout and beam spacing.
2.6.4 The first plate side edge of the plate should coincide with the installation of baseline, after each row after the installation of a number of rows to check the parallelism of the inspection board and baseline, wrong hole drilling should be promptly addressed.
2.6.5 should be sewn between the wall and wall panels, all self-tapping screws should be perpendicular to the wall panels, not inclined.
2.7 gutter, down pipes and close the edge
2.7.1 Determine gutter installation and flow gradient requirements as shown.
2.7.2 Due to the influence of production and actual installation, the site needs to be partially processed and cut. For this purpose, in addition to the appearance quality requirements, it must also meet the requirements of waterproof and sealing performance, and timely conduct rainproof leak check after installation.
2.7.3 Gutter, rain pipe installation requirements to be firm, does not appear loose, fall off, deformation phenomenon.
2.7.4 Set the edge to the uniform length, the edge of the receiving area should be fixed with aluminum pull screws and waterproof plastic.
2.7.5 Roofing, self-tapping screws on the edge of the wall flat head and aluminum nail head, waterproof plastic to be waterproof.
2.7.6 all kinds of edge should be horizontal horizontal line, vertically vertical line. All corners should be clear and tidy. Make sure the edges are tidy, not grooved, creased, and the end seams and lap joints must be tightly controlled. Gable edge should be installed from the eave to the ridge.
2.8 key processes, the construction of key parts requirements
2.8.1 Tighten all the bolts after adjusting the overall structure;
2.8.2 All high strength bolts are tightened with sufficient torque;
2.8.3 all the basic bolts fully tightened;
2.8.4 The ribs of the roofing slab are parallel to the roof girder, and the sealant is properly used on the roof slamming.
2.8.5 The installation direction of the wall panels should be consistent with that in the rainy season and should be favorable for viewing.
2.8.6 Every day to remove drilling debris on the roof to prevent corrosion and scratches;
2.8.7 All panels are to be joined side by side with tight and correct seams;
2.8.8 All boards are free of mud, dust, oil, sealant or other foreign matter;
2.8.9 All plug strips are correctly constructed and folded in a straight line;
2.8.10 All the flashings are properly and surely fastened, all joints clean and tidy;
2.8.11 All gutter lap joints, gutter ends, drains impervious to water and properly tightened;
2.8.12 lighting systems, roof vents, doors and windows must be impermeable treatment;
2.8.13 roofing lap dimensions consistent, horizontal, vertical according to the installation specification requirements;
2.8.14 roof slope and water connection slope at the connection of the wall, pan water after the installation sealed.
2.9 difficult construction measures
2.9.1 roof leakage prevention measures
Install the roof panels, wall panels is the difficulty of water leakage, in order to achieve rain and snow leaking, plug, seal can not be omitted, in particular, in accordance with the instructions for installation, affixed to seal at clean, dry, temperature to meet the requirements. Get the site seal to ensure the workload of the day, the rest in the shady and dry place. After laying the seal, leave the protective paper in place and wait for the board to be installed. To pay special attention to the eye 打 打, wrong to fight, hit the office to make up promptly. Eye to be straight. Fasteners should be properly installed, do not over tighten. You can use the visual method to see whether the rubber around the pad is slightly extruded.
2.9.2 roof opening construction measures
First, install the roof opening support structure in the design position. Install the roof panel (such as the lock plate, the lock seam installation) on the roof panels cut open the mouth of the installation of the opening seat, the support floor placed in the opening below the roof panel, between the support floor and roof panels Lay continuous sealant tape. Secure with pre-drilled holes with fastening screws. Silicone destroyed around, and then clean the exposed silica gel to ensure that no water, and remove all the metal debris around. Note that the sealing tape is cut at a 45 degree angle (do not tear) at the corners, and a metal plug is installed at the high rib of each plate.
Although this project has a large construction area, short construction period, high construction quality and technical requirements, and is cross-constructed with civil works, fire protection engineering, water supply and drainage during construction, the construction methods and techniques above are strictly and strengthened Control of key processes, priorities and difficulties After the quality of the construction process, the Company successfully achieved the expected quality, safety and schedule objectives and created good economic returns. It has won praise from owners, supervisors and quality supervision units.