The Nippon Screw Weight System (NSWS) is an on-site ground survey machine that examines the

geotechnical engineering Geotechnical engineering, also known as geotechnics, is the branch of civil engineering concerned with the engineering behavior of earth materials. It uses the principles of soil mechanics and rock mechanics to solve its engineering problems. I ...

properties of

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

. The NSWS was developed to encounter weather abnormalities and natural hazards, saving human lives. Introduced in 2012 by the National Agriculture and Food Research Organization (NARO), the NSWS was designed to overcome problems with the Method for standard penetration test (SPT). NSWS was created by 耕三大北, was the member of 311 earthquake disaster committee of the Japanese Geotechnical Society. The society released a report in June, 2012 proposing to the Japanese government a use of NSWS to investigate the aftermath of the

2011 Tōhoku earthquake and tsunami On 11 March 2011, at 14:46:24 Japan Standard Time, JST (05:46:24 UTC), a 9.0–9.1 Submarine earthquake, undersea megathrust earthquake occurred in the Pacific Ocean, east of the Oshika Peninsula of the Tōhoku region. It lasted approx ...

Features

The NSWS is compact, weighs 120 kg, and has wheels, making it suitable for ground measurement in crowded

residential area A residential area is a land used in which housing predominates, as opposed to industrial and commercial areas. Housing may vary significantly between, and through, residential areas. These include single-family housing, multi-family residen ...

s. It costs much less than the conventional SPT test and triaxial compression test. NSWS can measure very soft zones, converted N-value of zero in the ground that had been considered difficult. It has 1.08 cm interval.SPT conducts the test every 50 cm, and 30 cm interval out of 50 cm is tested so the rest, 20 cm, is not measured; that means 40% of an entire hole is unknown. NSWS does not suffer from such a limitation. NSWS can penetrate the ground diagonally and can cut through soft

gravel Gravel () is a loose aggregation of rock fragments. Gravel occurs naturally on Earth as a result of sedimentation, sedimentary and erosion, erosive geological processes; it is also produced in large quantities commercially as crushed stone. Gr ...

s. NSWS has in-situ shear test capability, the result of the joint research with NARO and Okita-Ko Co., Ltd NSWS can prepare converted N-value,

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

, in-situ shear data for Stability Analysis. NSWS enables multi-point surveying due to its diagonal penetration capability and high-mobility. The multiple spots on the weak layers can be analyzed.

References

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External links

National Agriculture and Food Research Organization of Japan
Independent Administrative Agency of Japan specialized in research and development of agriculture and food.
Japanese Geotechnical Society
In situ geotechnical investigations Articles containing video clips Geotechnical engineering Land surveying systems

Features

See also

References

External links