Dense Gas Flow in Volcanic Ash Soil: Effect of Pore Structure on Density-Driven Flow

2008 ◽  
Vol 72 (2) ◽  
pp. 480-486 ◽  
Author(s):  
Shoichiro Hamamoto ◽  
Takeshi Tokida ◽  
Tsuyoshi Miyazaki ◽  
Masaru Mizoguchi
Keyword(s):  
Pore Structure ◽  
Gas Flow ◽  
Volcanic Ash ◽  
Dense Gas ◽  
Density Driven Flow ◽  
Volcanic Ash Soil

scholarly journals Effect of soil structure disturbance on the shear strength of black volcanic ash soil

2020 ◽  
Vol 156 ◽  
pp. 02004
Author(s):  
Okri Asfino Putra ◽  
Noriyuki Yasufuku ◽  
Ryohei Ishikura ◽  
Ahmad Rifa’i ◽  
Adel Alowaisy ◽  
...  
Keyword(s):  
Shear Strength ◽  
Pore Structure ◽  
Soil Structure ◽  
Volcanic Ash ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Degradation Index ◽  
Total Strength ◽  
Volcanic Ash Soil ◽  
Index Value

The effect of soil disturbance on the shear strength of black volcanic ash soil was investigated using a constant volume direct shear apparatus. Disturbance of soil structure was considered as the pore size distribution which obtained from the soil-water characteristic curve (SWCC). The disturbed sample was used as a representation of soil structure disturbance due to earthquake shakes. A series of cyclic tests were conducted under unsaturated and saturated samples. It was found that the undisturbed samples exhibit a unimodal pore structure, and the disturbed samples indicate to a bimodal pore structure. Since the pore structure of the disturbed sample is unstable, the degradation index value is higher than that of the undisturbed sample and increases with the increasing number of cycles. In other words, the cyclic normalized vertical stress of disturbed samples degrades faster. Furthermore, the degradation index value in the normallyconsolidated samples was found to be larger than the overconsolidated. It might be attributed to increasing of the pore water pressure during shearing. Where in the over-consolidated samples is lower than normally-consolidated. On the other hand, the normalized shear stress of unsaturated samples, it is slightly larger due to the suction forces in the total strength of soils.

scholarly journals Preparation and certification of reference materials, brown forest soil (JSAC 0401) and volcanic ash soil (JSAC 0411) for the analysis of trace metals.

2002 ◽  
Vol 51 (4) ◽  
pp. 269-279 ◽  
Author(s):  
Shin-ichi YAMASAKI ◽  
Shoji HIRAI ◽  
Masataka NISHIKAWA ◽  
Yoshinori TAKATA ◽  
Akira TSURUTA ◽  
...  
Keyword(s):  
Trace Metals ◽  
Forest Soil ◽  
Reference Materials ◽  
Volcanic Ash ◽  
Brown Forest Soil ◽  
Volcanic Ash Soil

scholarly journals Pinhole Multistep Centrifuge Outflow Method for Estimating Unsaturated Hydraulic Properties with Small Volume Soil Samples

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1169
Author(s):  
Long Thanh Bui ◽  
Yasushi Mori
Keyword(s):  
Hydraulic Properties ◽  
Volcanic Ash ◽  
Small Volume ◽  
Clayey Soil ◽  
Soil Hydraulic Properties ◽  
Retention Curve ◽  
Volcanic Ash Soil ◽  
Equilibrium Data ◽  
Soil Hydraulic ◽  
Water Holding

If soil hydraulic conductivity or water holding capacity could be measured with a small volume of samples, it would benefit international fields where researchers can only carry a limited amount of soils out of particular regions. We performed a pinhole multistep centrifuge outflow method on three types of soil, which included granite decomposed soil (Masa soil), volcanic ash soil (Andisol soil), and alluvial clayey soil (paddy soil). The experiment was conducted using 2 mL and 15 mL centrifuge tubes in which pinholes were created on the top and bottom for air intrusion and outflow, respectively. Water content was measured at 5, 15, and 30 min after applying the centrifuge to examine the equilibrium time. The results showed that pinhole drainage worked well for outflow, and 15 or 30 min was sufficient to obtain data for each step. Compared with equilibrium data, the retention curve was successfully optimized. Although the curve shape was similar, unsaturated hydraulic conductivities deviated largely, which implied that Ks caused convergence issues. When Ks was set as a measured constant, the unsaturated hydraulic properties converged well and gave excellent results. This method can provide soil hydraulic properties of regions where soil sampling is limited and lacks soil data.

scholarly journals Transfer Factors of Radioiodine from Volcanic-ash Soil (Andosol) to Crops

2003 ◽  
Vol 44 (1) ◽  
pp. 23-30 ◽  
Author(s):  
TADAAKI BAN-NAI ◽  
YASUYUKI MURAMATSU
Keyword(s):  
Volcanic Ash ◽  
Transfer Factors ◽  
Volcanic Ash Soil

Vertical bearing mechanism of pile foundation in volcanic ash soil

2015 ◽  
pp. 197-198 ◽  
Author(s):  
K. Tomisawa ◽  
T. Yamanishi ◽  
S. Nishimoto ◽  
S. Miura
Keyword(s):  
Pile Foundation ◽  
Volcanic Ash ◽  
Volcanic Ash Soil ◽  
Vertical Bearing

scholarly journals Caucasian clover performance in a year of severe drought

1998 ◽  
pp. 119-125
Author(s):  
R.N. Watson ◽  
F.J. Neville ◽  
N.L. Bell
Keyword(s):  
White Clover ◽  
Growth Rates ◽  
Volcanic Ash ◽  
Severe Drought ◽  
Summer Drought ◽  
Volcanic Ash Soil ◽  
Summer Growth

In a year of spring-summer drought on a sandy volcanic ash soil, ryegrass/caucasian clover (RG/ CC) and RG/white clover (RG/WC) pastures had similar rapid increases in pasture growth rates during September. Growth rates peaked around 25 October (65-70 kg DM/ha/day) for RG/CC and around 14 October (50-60 kg DM/ha/day) for RG/ WC. As drought intensified the declines in pasture growth rates were similar, but delayed by up to 3 weeks for RG/CC. Both pastures reached minimum summer growth rates of

scholarly journals Contribution of Micro Structure to Repeated Loading Effect on Compacted Allophaneous Volcanic Ash Soil

1987 ◽  
Vol 27 (4) ◽  
pp. 23-33 ◽  
Author(s):  
Yoshito Kitazono ◽  
Atsumi Suzuki ◽  
Mitsuhisa Kajiwara ◽  
Shojiro Aramaki
Keyword(s):  
Volcanic Ash ◽  
Repeated Loading ◽  
Micro Structure ◽  
Loading Effect ◽  
Volcanic Ash Soil
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