Full retaining cylinder undisturbed earth filling pile The construction includes preparation, positioning and laying out, drilling holes, pumping concrete, inserting reinforcement, and pulling out protective tubes.
First, construction preparation
1, must investigate the construction site and adjacent areas of underground pipelines, underground structures, adjacent dangerous houses, take corresponding reinforcement and protection measures to ensure the smooth construction.
2The whole set of construction equipment shall be inspected before the formal approach to ensure that the equipment is in good condition.
3Equipment assembly should be set up isolation area, specially-assigned command, in strict accordance with the procedure of assembly, non-installation personnel shall not be in the assembly area, in order to prevent safety accidents.
4Arrange the materials to enter the site, re-check the materials according to the requirements, and can be used only after passing the re-inspection.
5Make technical disclosure of quality and safety before starting work, and fill in Technical Disclosure Record.
Two, positioning and release
1According to the positioning axis of the building, the full-time surveyor should accurately place the pile position on the site according to the pile position plan, and use the wooden stick and white ash point as the mark of the pile position.
2Allowable error of pile position lofting:20mm.
3After the self-test of pile position lofting is correct, fill in the Application for Inspection of Construction Survey and Laying out. After Party A and the supervision unit jointly check the pile position and sign, the next process of construction will be carried out.
Three, drilling and requirements
1Check the perpendicularity of the guard cylinder:The rig is in position, the fuselage is adjusted, and the two theodolites are used to check the verticality of the guard cylinder in the vertical direction.
2Before drilling the first pile, wet the concrete pump hopper and pipeline with clean water, and then pump with mixed cement mortar(Lubrication piping), all mortar pumped out of the pipe after sealing the drill valve.
3According to the designed pile length, determine the depth of the drilling hole, and mark the corresponding position of the drilling rig prominently, as the basis for controlling the pile length in the construction process.
4After the pile machine is in place, draw a circle with the same diameter as the guard cylinder with the pile site as the center. Before drilling, the positioning of the guard cylinder coincides with that of the circle. After adjusting the verticality, the guard cylinder begins to drill, and the verticality is controlled during drilling.
5Control the verticality while drilling at the guard cylinder, and drill at the guard cylinder2-3m, the drum stops drilling, and the long auger begins to drill below the mouth of the drum500mm, the guard cylinder and auger drill synchronously to the designed elevation.
6Strictly control the drilling speed when drilling. Drilling is slow at first contact with the surface. The drilling rate should be determined according to the soil conditions:Miscellaneous fill and clay should be controlled in0.5-1.0m/min, plain fill, clay, silt, sand should be controlled in1.0-1.5m/min.
7In the process of drilling, if the drill is stuck, the rig is shaken, deviated or rhythmical sound is found, the drilling should be stopped immediately, the reason should be found, and the corresponding measures should be taken to continue the work.
8Keep the auger and casing in sync,According to the soil layer, long auger pipe can be lifted to discharge soil, and then drilling construction.
9In the construction process, the Construction Record Form of undisturbed earth taking and pressurized concrete Pile with full protective cylinder should be filled in timely and accurately.
Four, pump concrete
After the guard drum and drill bit reach the designed elevation, keep the guard drum still and lift the drill pipe200mmPump the concrete and pay attention to the following:
1Concrete pumping should be carried out continuously to avoid slow feeding on the rear platform and insufficient feeding to cause shutdown;
2Pump concrete1mAfter the height, the drill is lifted, and the concrete is pumped while the drill is lifted, and the lifting rate is controlled to match the pumping quantity.
3The exhaust valve must work normally in the process of piling to prevent pipeline blockage in the process of piling;
4In the pumping process, the concrete surface in the hopper should always be maintained no lower than400mm, prevent the inhalation of air caused by pipeline blockage;
Five, lifting steel cage
1Before hoisting the steel cage, insert the feeding bar into the steel cage with the shaped steel platform. The end of the feeding rod should be in close contact with the tip of the steel cage. The main reinforcement on the upper end of the reinforcing cage should be inserted into the steel cap on the upper end of the reinforcing bar, and the distance between the top and the cap is not less than5cm;
2, the reinforcement cage and the feeding bar should be lifted at four points, and should be lifted straight;
3After the cage is lifted off the ground, the center of gravity offset principle is used to convert the flat hanging into the vertical hanging by lifting the pulley of the wire rope on the crane trench, which is easy to enter the hole;
4Strengthen the lifting points to prevent the cage from being too heavy and deformed;
Six, insert the steel cage
1.Pile head perfusion after cleaning, should be immediately inserted into the steel cage;
2, inserted into the steel cage, should be aligned with the hole, ensure vertical and middle;
3Steel cage shall be continuously lowered, shall not stop, prohibit direct decoupling;
4When inserted into the steel cage, first rely on the dead weight of the steel cage and steel bar slowly inserted. When the self weight can not continue to insert, open the vibration device, make the steel cage sink to the design depth, cut off the connection between the vibration device and the steel cage, slow continuous vibration, pull out the steel bar.
7. Requirements for pulling out the sheath
1Pull out the guard after the reinforcement cage is inserted;
2When pulling out the guard cylinder, rotate and pull out.
Shanghai Qiangqiang Foundation Engineering Co., LTD. 's business covers foundation pit engineering, pile foundation engineering, land and waterFoundation treatment, slope treatment and other engineering fields. around"Excellent technology, reliable process, fast construction" technical requirements, is to provide customers with land, water foundation engineering technical consultation, construction services and other comprehensive solutions of the entity enterprise. Contact Number:400-100-2850