(1) set-up, installation rig drilling platform, remove the drill to pile frame with a steel pillow and make stable base, rig substructure with inverted chain block cross symmetric tensioning, ensure do not produce displacement and subsidence in the drilling and operation, and drill pipe to the vertical drilling, drill bit, drill pipe and drill diameter center on a plumb line, its biggest deviation shall not be greater than the mm, to ensure the hole location is correct, drilling straight. Rig chassis tuning into level state and stable, boot try to drill. Careful bit alignment design center, cover the sealing plate, try revolutions, monitoring the perpendicularity of the drill pipe, make the rig lifting pulley, wheel center, and at the top of the pile hole center on the same vertical line. Drill stand temporarily removed, it shall make good marks, to ensure the accurate position of reduction, para again when necessary. Rig put the position to combine force bearing platform, reasonable decorate, drilling in order to unified arrangement, to avoid interference. In the rock formation in a such as gravel soils, appropriate USES cross bit, appropriate is used in clayey soil and sand soil type pipe drilling tool. 2 pile the percussion drill borehole drilling (1) column. Drilling hole into the bottom mouth period, when the cylinder is to protect a small flaky clip clay mixture (Ratio is about:)With a small stroke, should pay attention to keep the heavy hammer guiding role in the construction, ensure the hole perpendicularity. Drilling to continuous, often should also drilling mud sampling test, the timely adjustment is not in conformity with the requirements. The aim to make it liners to silt layer formed between the coordinately, solid transition section, enter the pebble layer in large proportion (γ=. )High quality mud and a small amount of cement. With a heavy hammer guide impact drill, the pebble bed hard wall of hole formation, prevent the hole collapse phenomenon, until the design elevation. (2) the method of impact pore-forming, small opening stroke, should be adopted to make it solid, straight into a hole and coordinately, can play a guiding role, and prevent the collapse of orifice. Overall height and depth over drilling bit after stroke, can the normal impact. Drift, pebble bed hard rock, large stroke, should be adopted in loose formation should be adopted, small stroke. (3) impact drilling, in order to prevent the impact vibration collapse adjacent distributed wall or affect the solidification of adjacent holes has been pouring concrete, concrete pouring should stay adjacent hole, and to achieve. MPa compressive strength of the rear can spud. (4) when drilling should be spare bit, use rotation, abrasion than bit diameter. Cm, should be replaced timely repair. (5) or soft soil layer when drilling in sand soil, slumping hole easily. Appropriate chooses flat drill cone penetration, control, light pressure, low block slow, large pump capacity, thick mud drilling. 6 mud complement and purification: prior to the start of the modulation should be a sufficient number of mud, in the process of drilling, such as mud loss, loss, should be added. And should be in accordance with the stipulations of the mud to check on time check mud index, changes in soil should increase inspections, and adjust the mud target. Drilling m or 7 each stratum changes, should make drill slag samples in the mud tank, find out the soil and record, in a timely manner to eliminate drilling slag and displacement mud, often make drill cone drilling fresh formation. At the same time pay attention to the change of the soil, rock, soil change all should make slag samples, determine soil and recorded in the record to the geological profile check it.
