A,Long auger bored pileProcess characteristics
1,Long auger bored pileGenerally use superfluid concrete, superfluid concrete fluidity is good, the stone can be suspended in the concrete without sinking, will not produce segregation, easy to put into the steel cage (superfluid concrete refers to the collapse degree20~25cmConcrete);
2Pile tip without empty soil, prevent broken pile, reduced diameter, hole collapse and other common construction problems, construction quality is easy to ensure;
3, strong ability to pass through hard soil layer, high bearing capacity of single pile, high construction efficiency and simple operation;
4Low noise, no disturbing, no need for mud wall protection, no sewage, no soil extrusion, construction site civilization;
5, the comprehensive benefit is high, the project cost is low compared with other pile types;
6The design and calculation method of this construction method adopts the design method of dry borehole cast-in-place pile, and the design and calculation index of dry borehole cast-in-place pile should be adopted (the index value is larger than that of mud wall protection bored pile, and smaller than that of prefabricated pile).
Two, the scope of application
Long auger bored pileIt IS suitable for building foundation pile, FOUNDATION PIT AND deep well supporting pile, suitable for filling soil layer, silt soil layer, sandy soil layer and pebble layer, and also suitable for all kinds of soil layer with groundwater, and can be piled in soft soil layer, shifting sand layer and other adverse geological conditions. Pile diameter is generally adopted500mm～800mm.
Three, process principle
Long auger bored pileIs the use of long auger drilling to drill to the design elevation, stop drilling, at the same time through the concrete hole set on the inner pipe drill bit, pressure irrigation superfluid concrete, pressure irrigation to the design of pile top elevation, remove the drill pipe to press the reinforcement cage into the pile body.
When pressing concrete to the top of the pile, pour concrete beyond the top of the pile50cmTo ensure the strength of pile top concrete.
Four, the construction process
Flat ground→The pile location lofting→Install and adjust the drill (place the steel guard cylinder)→)Debug concrete pump and install pump pipe→Drilling emplacement→Lifting steel cage, vibration hammer→Stop drilling at design depth→Lift the drill pipe while pumping superfluid concrete→Lift the drill pipe and remove the drill pipe→Start vibrating hammer to insert steel cage to design elevation→pile→Pile head treatment→Pile top protection measures.
Five, construction matters needing attention
1High pressure pump shall not operate at negative temperature. In winter construction, heat preservation and anti-freezing measures should be taken. After construction, the water in the blades or pumps and pipes should be discharged to prevent ice.
2The prepared cement paste should be used within the initial setting time and should not be used every other day or after mixing with cement to avoid reducing the strength of the pile.
3After forming the hole, the steel cage should be lifted and the gravel should be placed for grouting. The interval should not be so long that the grouting pipe shrinks and clogs, which may reduce the section of the pile or crack it.
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