付録1 ニッケル鉱荷崩れ危険性評価試験法マニュアル
Test procedure for evaluating danger of sliding failure of nickel ore
1 Scope
When nickel ore contains much moisture, its shear strength becomes low and piles of nickel ore formed in cargo holds of bulk carriers may slide. To prevent sliding failure, nickel ore containing much moisture should not be accepted for shipment. The shear strength of nickel ore can be evaluated by this test procedure in view of the danger of sliding failure.
If a shipper or a master of the ship have doubts that the sliding failure of nickel ore may take place during the voyage, it is recommended to apply this test procedure to the cargo, prior to shipment.
For the evaluation, it is assumed that the cargo pile is trimmed as level as practicable. The assumed width and height of remaining slopes of the cargo pile after trimming at each side are 7 m and 4 m, respectively. The assumed rolling condition is static heel at 30 degrees.
This test procedure should not be applied to solid bulk cargoes other than nickel ore.
2 Terminology
For the purpose of explanation of the test procedure, the following terms are used with the following meanings:
.1 Original sample means a sample of nickel ore without sieving;
.2 Sieved sample means a sample obtained by sieving of which the maximum diameter is 19 mm;
.3 Sample means original sample and sieved sample;
.4 Specimen means a sieved sample filled and tamped in the mould and leveled off along the brim of the mould without collar;
.5 Sieve is the sieve described in paragraph 3.2;
.6 Mould is the mould described in paragraph 3.3;
.7 Collar is the removable extension piece of the mould;
.8 Cylinder is the cylindrical part of the mould other than the collar;
.9 Bottom plate is the bottom plate of the mould;
.10 Compaction hammer is the tool for compaction descried in paragraph 3.4;
.11 Hammer is the part of compaction hammer;
.12 Straight edge is a flat bar for leveling off the sample piled up above the brim of the mould in order to control the volume of specimen;
.13 Sample removing apparatus is the apparatus for removing the sieved sample in the mould descried in paragraph 3.5;
.14 Cone-penetrometer is the apparatus descried in paragraph 3.6;
.15 Cone is the part of the cone-penetrometer;
.16 Penetration depth is the depth from the brim of the mould without collar to the tip of the cone, during penetration of the cone into the specimen;
.17 Cone penetration test is the test described in paragraph 4.5.2;
.18 Cone penetrating force is the force required to penetrate the cone into the specimen during the cone penetration test;
.19 Maximum cone penetrating force is the maximum value of cone penetrating force obtained by single cone penetration test; and
.20 Representative cone penetrating force means the lowest value of the three figures of the maximum cone penetrating force, which are obtained through cone penetration tests of three times for a sieved sample.
