Geotechnical, hydrogeological and engineering parameters, these three factors are constantly changing, resulting in the complexity of rotary excavation construction, therefore, the analysis of three basic elements is the rotary excavation method of the benchmark, to ensure the stability of rotary excavation construction, safety and income.
The construction budget, construction scheme, model configuration, construction technology, operation control and construction management of rotary excavation are all carried out around these three elements.
The pile length affects host configuration, drill pipe type and specifications, pile diameter impact machine, the types of drill pipe, drill the configuration and the way of pore forming, and then affects the construction technology of hydrological geology and mud quality, different soil types and intensity affect host the type, the types of drill pipe, drill configuration, construction technology and operation control, etc.
No matter before undertaking the project, the construction preparation stage or the construction process, we need to fully understand and comprehensively consider the three elements, in order to ensure the safety of rotary digging construction, hole quality, cost reduction, and profit.
The diversity of geology, the strength range from very soft to hard, and different geological structures and states, affect rotary digging types, drill pipe types and specifications, drill tool types, drill tool diameters, drill tooth types and models,
Type and model of guide teeth, construction technology, hole forming method, operation control, hole forming quality, construction accident, construction cost, construction efficiency and profit.
The underground initial water level, rich condition and confined water affect the construction technology of rotary drilling rig, mud quality, the length of guard/casing, the way of setting guard drum, the type of drilling tool, the quality of hole formation and construction accidents.
Pile diameter: with the increase of pile diameter, the diameter of drill tool increases, the number of drill teeth increases, and the ground pressure of drill teeth decreases, which reduces the cutting/crushing ability of drill teeth; With the increase of pile diameter, the radius of drill tool increases, the resistance arm lengthens, the torque load of power head increases and the speed decreases.
Therefore, with the increase of pile diameter, the drilling ability and efficiency will decrease. At the same time, the matching rig size also increased; In addition, it may be necessary to divide the holes.
Pile length: with the extension of pile length, larger specifications of drill pipe are needed to meet the drilling depth, so larger main engine, higher mast and larger power head are needed to install drill pipe; If the rock and soil strength is low, the friction rod can be selected to lift the drilling depth; If the geological strength is high, only the machine lock rod can be selected to lift the grounding pressure value of drill teeth to improve the shear crushing ability. Therefore, pile length affects the main engine model, drill pipe type and specification.
Special pile foundation: rotary digging and expanding pile, bite pile and inclined pile construction. Process, auxiliary equipment installation, radius or height promotion, construction cooperation, etc., will affect the construction cost and construction efficiency.