Before construction, check the raw materials, mechanical equipment and spray process, mainly in the following aspects:

1 Quality certificate and re-inspection report of raw materials (including cement, admixture, accelerator, suspending agent and other admixtures), identification results of mixing water;

2 Whether the slurry mix ratio is suitable for the actual soil quality conditions;

3 Whether the mechanical equipment is normal, before the construction, high-pressure rotary jet equipment, geological drilling machine, high-pressure mud pump, water pump, etc. should be tested, and the drill pipe (especially multiple drill pipe), drill bit and deflector should be unobstructed;

4 Check whether the spraying process is suitable for geological conditions. Before the construction, it should be tested by the process. The test spray should be sprayed at the original pile position. The number of test spray holes should not be less than 2 holes. If necessary, adjust the injection process parameters.

5 Before the construction, the underground obstacles should be uniformly checked to ensure that the drilling and injection meet the design requirements.

6 Check the accuracy and sensitivity of the pile position, pressure gauge and flow meter before construction.