| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability when investigating soil properties of a front natural ground using a hydraulic hammer.SOLUTION: In an investigation method for a front natural ground, the natural ground 25 is bored by a hydraulic hammer 22, water supply pressure to the hydraulic hammer is measured by a water pressure gage 28 of a high pressure pump 27 connected to the hydraulic hammer to obtain the water supply pressure P (101), time fluctuation of the circumferential direction strain in a high pressure hose 29 is measured by a strain gage 19 stuck to the high pressure hose (102), a striking number of the hydraulic hammer 22 is identified by a processing unit 31 on the basis of fluctuation characteristic in the measured time fluctuation of the circumferential direction strain to obtain the striking number N (103), an energy index value M is calculated based on the formula (1) using the water supply pressure P and the striking number N (104), and soil properties of the front natural ground is estimated based on the energy index value M (105).SELECTED DRAWING: Figure 1 |
