• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.4
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• pp.71-80
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• 1990

Model tests for the ultimate pullout resistance of anchorages and investigation of failure behaviors in cohesionless soil have been conducted. The factors affecting the anchorage are mostly the geometry of the system, and soil properties of sands. The main conclusions of the experimental work were as follows. 1. The load - displacement relationship can be a form of parabolic curve for all plates. 2. The change in ultimate pullout resistance of anchor is mostly affected by embedment ratio and size of anchor, and influenced to a lesser degree by its shape. 3. Critical embedment ratio which is defined as the failure mode changes from shallow to deep mode is increased with increasing height of anchor. 4. For a constant anchor height, as the width of anchor increases the ultimate pullout resistance also increases. However, considering the efficiency of anchor for unit area, width of anchor does not appear to have any sigrnificant contribution on increasing anchor city. 5. Anchor capacity has a linear relation to sand density for any given section and the rate of change increases as the section increases. Critical depth determining the failure patterns of anchor is decreased with a decrease of sand density. 6. With increasing inclination angle, size of anchor, and decreasing embedment ratio, the ultimate pullout resistance of anchor under inclined loading is significantly decreased. 7. The ultimate pullout resistance of double anchor, a method of improving single of anchor capacity, is influenced by the center - to - center spacing adjacent anchors. It is also found that tandem and parallel anchor rigging arrangements decrease the anchor system capacity to less than twice the single anchor capacity due to anchor interference.

• Computational Structural Engineering
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• v.2 no.1
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• pp.65-70
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• 1989

An analytical study was conducted using the Galerkin technique to determine behaviour of thin fibrereinforced and laminated composite pipes under soil pressure. Geometric nonlinearity and material linearity have been assumed. It is assumed that vertical and lateral soil pressure are proportional to the depth and lateral displacement of the pipe respectively. It is also assumed that radial shear stress is negligible because the ratio of thickness to the radius of pipe is very small. The above results are verified by the finite element analysis.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.5
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• pp.74-84
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• 2017

Since a soldier manages a hand-held landmine detector by hands, it is necessary to develop a system that can detect the target quickly and accurately. However, the hand-held landmine detector used in Korea has a problem that it can only detect the metal mines. Therefore, it is important to solve the problem and to develop a hand-held landmine detection system suitable for the Korean environment. In this paper, we propose a hand-held landmine detection system suitable for the Korean environment using ground penetrating radar. The proposed system uses depth compensation, matched filtering, and frequency shifting filtering for preprocessing. Then, in the detection step, the system detects the target using the edge ratio. In order to evaluate the proposed system, we buried landmines in sandy loam which is most of the soil in Korea and obtained a set of ground penetrating radar data by using a hand-held landmine detector. By using the obtained data, we carried out some experiments on the size and position of the patch and the shifting frequency to find the optimal parameter values and measured the detection performance using the optimized values. Experimental results show that the proposed preprocessing algorithms are suitable for detecting all landmines at low false alarm rate and the performance of the proposed system is superior to that of previous works.