SPECIFIC RESISTIVITY MEASURING DEVICE AND TUNNEL EXCAVATING MACHINE USING THE SAME DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a natural ground measuring device which specifies the types of rocks which constitute a surrounding natural ground when excavating a mountain tunnel and execute tunnel excavation management. SOLUTION: This natural ground measuring device supplies a measuring electric current flowing by way of a natural ground between a par of voltage measurement electrodes 42a and 42b including a pair of voltage measurement electrodes 40a and 40b which come in contact with a tunnel under excavation and measures the voltage between the paired voltage measurement electrodes 40a and 40b when the measurement electric current is energized. This device measures the specific resistivity of the natural ground based on the measured voltage and the energized electric current, thereby grasping a geological status of the natural ground.