6 From the view point of grain size distribution, criteria of the grain size were introduced based onthe effective size D10, which is derived from the grain size accumulation curve and representspermeability. For materials other than coals, they can be regarded as non-liquefaction materials in casethat D10 is bigger than 1 mm. Here, D10 is the value under the condition that the maximum grain size ofthe material is not more than 9.5 mm. If the solid density of a material is smaller than 2,000 kg/m3criterion of grain size distribution for coals should be applied.
For coals, they can be regarded as non-liquefaction materials in case that D10 is bigger than 2 mmunder the condition that the maximum grain size is not more than 19. 0 mm
Liquefaction potential test
7 The sample is made saturated in a vessel and the moisture is naturally drained from the saturatedsample for a while through a small hole on the bottom. In case that the degree of saturation of the sampleafte drainage is less than 70%. the material is regarded as not liable to liquefy. The principle of thisjudgement is based on that of Proctor/Fagerberg method presented in D.1.3 of the BC Code.
Action requested of the Sub-Committee
8 The Sub-Committee is invited to take action as it deems appropriate, especially:
.1 take note the results of the research;
.2 endorse the draft MSC Circular; and
.3 invite the Committee to endorse the draft as an MSC Circular.
