The operation of drill jumbo tunneling for driving rock in rock strata.
Before the 17th century, rock roadway was mainly excavated by hand. Subsequently, the tunneling speed was improved by using artificial drilling, black powder blasting, manual rock loading and wooden shed support. In the late 19th century, hand-held rock drills, mining explosives and blasting accessories appeared in Europe. The method of drilling and blasting has developed into the main mean of modern rock tunneling.
In modern times, tunneling method of combining the mechanical breaking of rock with combined road header for simultaneous operation of mucking has been adopted, and the driving speed has been greatly improved. Rock tunnel driving operation modes:
① Parallel operation of tunneling and support;
② Single operation of tunneling and support. Generally, the rock roadway driving adopts once-tunneling technique, namely tunneling, supporting and ditch are completed in one time. When possible, the track laying works shall also be completed at the same time.
The main operation of drill jumbo tunneling
is drilling, blasting and rock loading transportation. When the rock stratum is not stable enough, support is needed. The commonly used rock drills for rock drilling and blasting are hand-held rock drills
, air-leg rock drills and guide rock drills. There are three kinds of power: pneumatic, electric and hydraulic.
At present, rock drill jumbo is widely used in various countries. The latest jumbo has the functions of full hydraulic program control, automatic hole location, automatic advancing and retreating. According to the section size and rock hardness of the rock roadway, several blast holes are arranged on the working face. Generally, shallow holes are used, which have developed into deep holes with hole depth greater than 3.5 m now. The smooth blasting is widely used to reduce the damage to the surrounding rock so that the surrounding of the roadway can be smooth. After blasting, local fan and air duct shall be used for ventilation to remove smoke.