Development of experimental system controlled by electromagnetic force for the slope stability study
Grant-in-Aid for Developmental Scientific Research.
|Research Institution||Hokkaido University|
UJIHIRA Masuyuki Hokkaido Univ., Fac. of Eng., Ass. Professor, 工学部, 助教授 (90001990)
大賀 光太郎 北海道大学, 工学部, 助手 (40133706)
SAKAI Yousuke Hokkaido Univ., Fac. of Eng., Ass. Professor, 工学部, 助教授 (20002199)
根岸 正充 北海道開発局, 開発土木研究所・農業開発部, 室長
HIGUCHI Kiyoshi Hokkaido Univ., Fac. of Eng., Professor, 工学部, 教授 (20002040)
冨長 勇作 北海道大学, 工学部, 助教授 (80003200)
NAKAJIMA Iwao Hokkaido Univ., Fac. of Eng., Professor, 工学部, 教授 (50001243)
NEGISHI Masamitsu Hokkaido Development Bureau, Civil Eng. Inst., Manager
|Project Fiscal Year
1989 – 1991
Completed(Fiscal Year 1991)
|Budget Amount *help
¥12,400,000 (Direct Cost : ¥12,400,000)
Fiscal Year 1991 : ¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1990 : ¥2,700,000 (Direct Cost : ¥2,700,000)
Fiscal Year 1989 : ¥7,500,000 (Direct Cost : ¥7,500,000)
|Keywords||Slope Instability / Impact load / Experimental System for Slope Instability / Distribution of Joint Space / Distribution of the Size of Rocks / 斜面崩壊 / 落石衝撃荷重 / モデル実験システム / ジョイント間隔分布 / 落石粒度分布 / 岩盤崩壊 / 電磁制御モデル / コンピュ-タ制御 / 斜面の安定性|
In this project, experimental system for the study of slope stability in which the friction against the gravity force is given by the electromagnets has been developed. The force of electromagnets is controlled by a computer. The range of the value of friction that can be changed by the I/O expand system and computer is 0-7.6 kgf per a magnet. Number of magnets that can be controlled simultaneously by this experimental system is 144.
The results obtained from the experiments in which 72 pieces of polyethylene blocks in size of 50X50X50mm stabilized by the magnets to the slope are as follows. 1) In the case of falling along the smooth slope, the lowest end of the train begins to collapse at first then the collapse succeeds from the top of the the train. The middle portion of the train maintains the original shape for the longest interval in the process of falling. The length of the train expands gradually along the slope in the process of falling. This typical process of collapse can be
explained theoretically. 2) In the case obstacle blocks exist along the slope, lowest part of the block train is given the reaction force from the obstacle when the lowest part collides to the obstacle. This reaction force is propagated to the upside blocks falling downward, which causes the horizontal and vertical displacements and rotation of upper blocks.
The blocks fall over the obstacle intermittently or continuously. This behavior of the fallin gis as the movement of a measuring worm. These falling behaviors were made clear from analysis of the results of this experiment.
Then the measurement of impact loads in vertical and horizontal directions of rock fall was carried out. In this experiment, rock pieces of andesite were used instead of polyethylene blocks. The most interesting result obtained from this experiment is that the direction of impact load turns from outside direction to the inside direction when the slope angle increases larger than 75ﾟ.
Additionally, the study on the relation between the distribution of joint space and the distribution of the size of fallen and piled rocks, and the study on the prediction of rock fall applied by acoustic emission method were carried out in this project. Also some useful results have been obtained from these studies, which are planned to be continued. Less
Research Output (7results)