Q1: Low construction efficiency
Mainly due to the excessive time taken to lift and lower the drill tools and the low efficiency of the Kelly bar in transmitting drilling pressure.
A1:
- (1) Increase the length of the drill tools to increase the amount of drilling debris per drilling;
- (2) The drill bucket has a vent hole to increase the drilling speed;
- (3) If it does not enter the rock, try to use a Friction Kelly Bar to save the unlocking time.
Q2: The failure rate of the drill rod increases sharply.
After the KELLY BAR is lengthened, the slenderness ratio of the KELLY BAR is particularly unreasonable. During construction, it has to withstand greater torque and pressure, especially the machine lock. The KELLY bar has to be unlocked frequently, so the failure rate of the Kelly bar will increase sharply.
A3:
- (1) The work site should be as flat and solid as possible to reduce the swing of the drilling rig;
- (2) Frequently correct the leveling system to make the Kelly bar work vertically;
- (3) It is strictly forbidden to lift the drill rig during pressure drilling;
Q3: Pile hole deviation
The main reasons are the uneven hardness of the stratum, the low Kelly Bar material low to reduce overall stiffness, and the drill bucket swing after the drill bucket is lengthened.
A3:
(1) Increase the height of the drill tool;
(2) Choose a good kelly bar to use
