Transient analyses of hydraulic head in the fault slip experiments in fracture zones of Shionohira and Kuruma Faults

Wakahama, Hiroshi*; Nojo, Haruka*; Aoki, Kazuhiro; Imai, Hirotaro; Guglielmi, Y.*; Cook, P.*; Soom, F.*

Oyo Chishitsu, 64(5), p.236 - 254, 2023/12

Upon the Hamadori earthquake (Mw 6.7) of 11 April 2011, coseismic surface deformation of 14 km running NNW to SSE in southeast Fukushima Prefecture occurred and was newly named the Shionohira Fault. However, no surface deformation was observed along the Kuruma Fault which is a southern extension of the Shionohira Fault. Fault injection tests using SIMFIP method at the Shionohira site on the former active segment and the Minakamikita site on the latter inactive segment were conducted to evaluate the activity of the two faults. Based on hydraulic responses to water injection into the fault rupture zone in the monitoring boreholes at the two sites, hydraulic properties of the area across the fault zone were estimated using the GRF model (Barker, 1988). The results obtained on hydraulic conductivity, specific storage and flow dimension were consistent with those in the domestic and international literature. The hydraulic conductivity and specific storage were larger in Shionohira than in Minakamikita. The flow dimension of Shionohira was three-dimensional, while that of Minakamikita was found to be a two-dimensional fractional flow. In addition, it is understood that the volumetric expansion occurs in the former site in the triaxial direction and the latter in the uniaxial with the comparison between the uniaxial expansion coefficient calculated from the results of SIMFIP displacement measurements and the specific storage in the hydraulic analysis. The difference in the hydraulic parameters between the two sites corresponded to the difference in the spatial development of fractures considered to be the "water passway," indicating the possibility of a correlation between the parameters and the different possible causes for fault activity at the two sites.

Magnetic and dielectric study of BiCuO

Yoshii, Kenji; Fukuda, Tatsuo; Akahama, Hiroshi*; Kano, Jun*; Kambe, Takashi*; Ikeda, Naoshi*

Physica C, 471(21-22), p.766 - 769, 2011/11

https://doi.org/10.1016/j.physc.2011.05.049

We have investigated the magnetic and dielectric properties of BiCuO, which has the same chemical formula as that of the parent materials of high-Tc superconductors, RCuO (R: rare earths). Magnetic measurements showed that this oxide exhibits an antiferromagnetic transition at around 40 K, owing to the localized Cu spins. Dielectric constants were found to be about 100 at room temperature, which are smaller than those of RCuO (about 10000 at room temperature). The imaginary part of dielectric response showed the activation energy of about 0.1 eV, suggesting that the dielectric response is brought about by a transfer of Cu-3d electrons.

Installation of the Groundwater Monitoring System to Borehole DH-2

Wakahama, Hiroshi*; Nakata, Mitsuhiko*; Hiroki, Minenari*; Futakuchi, Katsuhito*; Okada, Akio*

JNC TJ7440 2003-004, 128 Pages, 2003/03

JNC-TJ7440-2003-004.pdf:15.57MB

This report describes the results of installation of the long-term groundwater monitoring system into borehole DH-2 as a part of the Regional Hydrogeological Study and Mizunami Underground Research Laboratory Project. DH-2 was driglled with 100mm diameter through Toki-granite to the depth of 501meter below the ground level, in which 5inch-steel-casing pipe was inserted to the depth of 171m. The monitoring system was composed of concentrically arranged seven open PVC(polyvinyl chloride)-stand-pipes("Piezo-pipes"), housed within outer 4inch PVC-casings, followed by 3inch PVC-casings, packers and several stainless steel units. In the system, seven monitoring zones were isolated by expandable rubber type packers inflating with water. From the view point of quality assessment, leak-off tests were conducted for all of 7 packers before the shipment and the installation at the site. In terms of individual casing joints, air-tight inspections were carried out ...

Measurement of free surface fluctuations of IFMIF liquid metal lithium flow; Experimental study on influence of standing wave from sidewalls

Ko, Kazuhira*; Kanemura, Takuji*; Kondo, Hiroo*; Takahama, Hiroto*; Yamaoka, Nobuo*; Miyamoto, Seiji*; Ida, Mizuho; Nakamura, Hiroo; Matsushita, Izuru*; Muroga, Takeo*; et al.

no journal, , 

no abstracts in English

Development, improvement and performance test of the groundwater monitoring system

Nanjo, Isao; Mizuno, Takashi; Murakami, Hiroaki; Amano, Yuki; Hosoya, Shinichi*; Wakahama, Hiroshi*; Yamashita, Riyo*

no journal, , 

This study aimed to develop a hydrochemical monitoring system for in-situ groundwater. JAEA has developed the hydrochemical monitoring system which is available at underground facility focused on low-permeable sedimentary rocks. After performance test, it can be demonstrated that the monitoring system is workable completely at 350m depth research gallery.

Hydraulic monitoring results during SIMFIP injection experiments through Shionohira fault zones in Fukushima Prefecture, Japan

Aoki, Kazuhiro; Wakahama, Hiroshi*; Nojo, Haruka*; Iwasaki, Etsuo*; Kametaka, Masao*; Tanaka, Yukumo; Yoshida, Takumi; Seshimo, Kazuyoshi

no journal, , 

no abstracts in English