| 摘要 |
PROBLEM TO BE SOLVED: To provide a measuring method for the amount of earth excavated and removed with an improved accuracy by eliminating the measuring error caused by pulsation of a force feed pump. and a control method for the amount of earth excavated and removed for which the excavation is controlled by using the amount of dry sand actually excavated. SOLUTION: Piping 3 attached with a force feed pump equipped with an electromagnetic flowmeter 4 for feeding excavated earth under pressure from a shield chamber 2 to the external is to be a type outputting voltage signals in a form of pulse every time when a certain amount of sediment to be force fed flows through the piping 3 equipped with the force feed pump. Thus, the electromagnetic flowmeter 4 is not affected by the pulsation of the force feed pump 31, and thus its voltage signal is output accurately in conformity with the amount of sediment to be force fed. As a result, a calculator 6 for calculating the amount of excavated earth in the sediment to be force fed by using an output from the electromagnetic flowmeter 4 and an output from aγ-ray densitometer 5 is able to accurately calculate the amount of earth excavated and thus it is able to coincide the amount of excavated earth removed from the piping 3 having the force feed pump more accurate with the amount of earth excavated by the shield chamber 2 compared with the conventional one.
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