Several details that must be paid attention to when crossing horizontal directional drilling!

(1) Analyze the self stability of the stratum crossed to prevent the ground collapse caused by hole forming and diversion.

(2) Analyze the compactness of formation soil and select appropriate mud. Pressure to prevent slurry from polluting the environment.

(3) Mud production, utilization, recycling and waste mud treatment should avoid polluting the environment, and the discharged wastewater and waste circles must meet the national pollutant discharge standards. When directional drilling crosses the embankments of important rivers, we must prevent the adverse effects of slurry leakage on the embankments. In the construction, we should not only pay attention to the slurry ratio and pressure, but also carry out a detailed survey of the geological conditions under the embankments and take geological improvement measures before drilling, which is also conducive to the approval of the design and construction scheme of the crossing by the water conservancy department of the government.

(4) In areas with large changes in rock strata, different drilling speeds should be adopted for different soft and hard strata to prevent borehole lifting and sinking and form staggered holes.

(5) The specific gravity, viscosity and displacement of mud should be reasonably configured according to different geological conditions and the size of rock cuttings drilled.

(6) Before pulling back, pressure test and anti-corrosion leak detection should be completed for the crossing pipe section, and diameter measurement should be done to prevent the pipe and anti-corrosion coating from failing to meet the standard after smelling and dragging, and the radial buckling instability caused by the excessive ovality of the pipe.

(7) After the completion of pulling back, both ends of the pipe section shall be sealed and backfilled and compacted to prevent piping in case of flood, which will affect the safety of the embankments on both banks.