抄録
A new neutron-moisture cone penetrometer has been designed and developed at the Kyoto University. It uses Cf252 as the source for fast neutrons and He3-filled proportional tube as the detector. In the present paper the principles of neutron action with the matter is briefly reviewed and some of the test results are presented. It has been shown that this newly developed Neutron-Moisture Cone Penetrometer (hereafter NM-cone penetrometer) can measure soil strength parameters such as penetration resistance (qc), friction ratio (fs), pore pressure (u) as well as natural water content (wn%) for the entire depth of the penetration. This instrument enables us to have continuous data rather than discreet data which are obtained using other types of sampling technique. It has been observed that the presence of strong neutron absorber could give erroneous results, therefore, the knowledge of the composition of the soil is necessary. One of the biggest advantages of having such a system is that it eliminates the need to procure samples which may or may not represent the actual in-situ conditions.
