Vertical bearing mechanism of pile foundation in volcanic ash soil

2015 ◽  
pp. 439-446
Author(s):  
K Tomisawa ◽  
T Yamanishi ◽  
S Nishimoto ◽  
S Miura
2015 ◽  
pp. 197-198 ◽  
Author(s):  
K. Tomisawa ◽  
T. Yamanishi ◽  
S. Nishimoto ◽  
S. Miura

2002 ◽  
Vol 51 (4) ◽  
pp. 269-279 ◽  
Author(s):  
Shin-ichi YAMASAKI ◽  
Shoji HIRAI ◽  
Masataka NISHIKAWA ◽  
Yoshinori TAKATA ◽  
Akira TSURUTA ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1169
Author(s):  
Long Thanh Bui ◽  
Yasushi Mori

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.


2003 ◽  
Vol 44 (1) ◽  
pp. 23-30 ◽  
Author(s):  
TADAAKI BAN-NAI ◽  
YASUYUKI MURAMATSU

Author(s):  
R.N. Watson ◽  
F.J. Neville ◽  
N.L. Bell

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


1987 ◽  
Vol 27 (4) ◽  
pp. 23-33 ◽  
Author(s):  
Yoshito Kitazono ◽  
Atsumi Suzuki ◽  
Mitsuhisa Kajiwara ◽  
Shojiro Aramaki

2020 ◽  
Vol 198 ◽  
pp. 02017
Author(s):  
Zhongju Feng ◽  
Shaofen Bai ◽  
Wu Min ◽  
Jingbin He ◽  
Zhouyi Huang ◽  
...  

In order to study the influence of steep slope-karst coupling on the vertical bearing characteristics of pile foundation, the orthogonal simulation tests of pile foundation under 4 different roof thickness and 5 different slope are carried out by using Marc finite element software, and the correction coefficient of vertical partial bearing capacity of pile foundation according to roof thickness and slope is put forward. The test results show that when the thickness of the roof is more than 3 times the pile diameter, the ultimate bearing capacity of the pile foundation tends to be stable, and the value is about 19% when the slope is 45°; the ultimate bearing capacity of the pile foundation decreases gradually with the increase of the slope, and the reduction reaches 29.83% when the slope is greater than 45°. According to the calculation results, the variation law of vertical partial bearing capacity of pile foundation is analyzed, and the calculation formula of standard value of vertical ultimate bearing capacity of pile foundation in steep slope karst area considering both roof thickness and slope is put forward, and the correction coefficients αi and β are put forward.


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