Interpretation of Construction Technology in Construction Engineering 1 Range Artificial Bored Pile This technical standard is applicable to the engineering of artificial bored piles with clay, silty clay, sand and stone clay in industrial and civil buildings and low groundwater level. 2 Construction preparation 2.1 Material and main machinery: 2.1.1 Cement: No. 325-425 ordinary Portland cement or slag Portland cement should be used. 2.1.2 Sand: Medium or coarse sand, mud content is not more than 5%. 2.1.3 Stone: Pebble or gravel with particle size of 0.5-3.2 cm; stone with particle size of less than 5 cm and mud content of less than 2% can also be used in pile concrete. 2.1.4 Water: Use tap water or clean water without harmful substances. 2.1.5 Additional early strength agent should be selected through test, and fly ash admixture should be determined according to the regulations of laboratory. 2.1.6 Reinforcement: The grade and diameter of reinforcing bar must meet the design requirements, with factory certificate and re-examination report. 2.1.7 Generally, it should be equipped with three wooden hitches, hoisting units or electric hoists, trolleys or dumpers, pickaxes, shovels, shovels, brazes, wire drops, fixed pulleys, guide pulleys, concrete mixers, buckets, chutes, conduits, vibrating rods, brazing, coarse linen ropes, steel wire ropes, safety movable cover plates, waterproof lamps (low pressure 36V, 100W), welding machines, ventilation and oxygen supply equipment, lift water.Pumps, wooden rollers, movable ladders, safety hats, seat belts, etc. 2.1.8 Template: Composite steel die, arc tool steel die four pieces (or eight pieces) assembly.Fixtures, hooks and accessories.Wood boards, wooden square, channel steel No. 8 or No. 12, etc. 2.2 Operating conditions: 2.2.1 In order to excavate pile holes manually, a feasible construction plan should be worked out according to the soil characteristics and groundwater distribution in this area, and the calculation and design of shaft lining support should be carried out. 2.2.2 Three links and one leveling should be completed before excavation.Obstacles such as cables, pipelines, old buildings and equipment foundations on the ground and underground have been removed and disposed of.Temporary facilities such as lighting, power, ventilation and safety facilities are ready. 2.2.3 Familiar with the construction drawings and the underground soil and hydrogeological data of the site, so as to have a good idea. 2.2.4 According to the plan of the foundation, the axis of the pile position and the locating point are set, and the grey line is scattered around the pile hole.Determine the elevation level.After the wiring process is completed, the pre-inspection formalities shall be handled. 2.2.5 According to the design requirements, steel cages are made in segments. 2.2.6 Before full excavation, two test pile holes should be excavated selectively to analyze the soil quality and hydrology, so as to modify the original construction plan. 2.2.7 In the area with high groundwater level, the groundwater level should be lowered to about 0.5m below the pile level. 2.2.8 The safety of manual hole digging operation is very important. Before excavation, the construction personnel should make a comprehensive safety technical statement. Before operation, the hangers should be inspected and tested safely and reliably to ensure the construction safety. 3 Operation process 3.1 Technological process: 3.2 Setting Pile Position and Elevation by Placing Line: On the basis of three links and one level of the site, according to the data of the building survey control network and the layout plan of the foundation, the grid control network of the pile axis and the allowable elevation datum points are determined.Determine the center of the pile, take the midpoint as the center of the circle, and take the radius of the pile body and the thickness of the retaining wall as the radius to draw the circumference of the upper part (i.e. the first step).Lime line is used as dimension line of pile hole excavation.After the hole location line has been fixed, it must be checked by the relevant departments and excavated after the pre-inspection procedures have been completed. 3.3 Excavation of the first section of pile hole earthwork: Excavation of pile hole should be carried out layer by layer from top to bottom, first excavating the middle part of