• Geomechanics and Engineering
• /
• v.16 no.1
• /
• pp.97-104
• /
• 2018

The finite difference software Flac3D is used to study the influence of tunnel burial depth, tunnel diameter and lateral pressure coefficient of original rock stress on the stress and deformation of tunnel surrounding rock under sandstone condition. The results show that the maximum shear stress, the radius of the plastic zone and the maximum displacement in the surrounding rock increase with the increase of the diameter of the tunnel. When the lateral pressure coefficient is 1, it is most favorable for surrounding rock and lining structure, with the increase or decrease of lateral pressure coefficient, the maximum principal stress, surrounding displacement and plastic zone range of surrounding rock and lining show a sharp increase trend, the plastic zone on the lining increases with the increase of buried depth.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.11a
• /
• pp.194-197
• /
• 2003

The stress-strain curve of concrete confined with both lateral ties and carbon fiber sheet(CFS) is different to that of concrete confined with only lateral ties or CFS. The objective of this study is to investigate the stress-strain relation of reinforced concrete columns confined by composite material. The main variable of the specimens was the content rate of lateral ties to CFS. In the test a total 24 rectangular specimens, which are all 148$\times$148$\times$300mm size. The test results indicated that while the compressive strength of specimens confined with both lateral ties and CFS increased proportionally to the aided amount of two materials, the maximum strain of specimens depended on the larger strain of lateral ties or CFS.

• Journal of Biosystems Engineering
• /
• v.26 no.2
• /
• pp.123-130
• /
• 2001

The research described in this paper was aimed toward improving the understanding of the interaction of tire inflation pressure and the soil-tire interface stresses. A three-directional stress transducer was developed to measure stress distribution on undertread for a tractor tire. The transducer can directly measure three-directional stresses (normal stress, tangental stress and lateral stress and lateral stress) simultaneously and has both strong structure and high sensitivity, which is not changed by the abrasion of the detecting plate. Measurements of soil-undertread interface stresses were made at tire center on undertread on a 12.4-R24 radial tractor tire opeated at three combinations of a dynamic load (11.8kN) and three inflation pressures (59kPa, 108kPa and 157kPa). These measurements showed that as inflation pressure increased, the soil-undertread interface stresses increased. The results of three stresses comparisons were shown that the peak normal stresses were considerably higher than the tangential peak stresses and the peak lateral stresses.

• Journal of the Korean Geotechnical Society
• /
• v.23 no.4
• /
• pp.161-167
• /
• 2007

In this study, ultimate lateral load capacity of piles is analyzed with consideration of lateral stress effect. Based on results obtained in this study, a method for the estimation of ultimate lateral load capacity is proposed. This makes it possible to more realistically estimate the ultimate lateral load capacity under various stress states caused by in-situ soil condition and pile installation process. Calibration chamber test results with various soil conditions were used in the analysis. From the test results, it was found that effect of the lateral stress was greater than that of the vertical stress on the ultimate lateral load capacity of piles. It was also found that, as the relative density increases, displacements required to reach the ultimate state increases, showing relative displacements of around 14% and 18-25% for $D_R$ : 55% and 86%, respectively. Based on results obtained in this study, a methodology for the estimation of ultimate lateral load capacity of piles using correction factors was proposed. Results from proposed method matched well measured results.

• Journal of Korean Foot and Ankle Society
• /
• v.15 no.1
• /
• pp.22-26
• /
• 2011

Purpose: To report the effectiveness of adding distal fibular external rotation stress test on the traditional lateral stress Cotton test in evaluating distal tibiofibular syndesmotic injuries. Materials and Methods: We evaluated syndesmotic injuries with intraoperative stress test during treating ankle fractures from March 2009 to September 2010. External rotation of distal fibula using small elevator was added on traditional stress test in case of suspicious syndesmotic injury. We retrospectively reviewed and compared the results of each test in 44 cases for which we tried both tests. Results: In 9 cases of positive traditional lateral stress tests, positive results were obtained in all cases by additional external rotation tests. In 21 cases of negative traditional stress tests, additional stress tests results were also negative. But there were 10 cases of positive additional tests and 4 of negative additional tests in equivocal results cases by the traditional stress tests. Conclusion: Using additional external rotation stress test in case of equivocal test result by the traditional lateral stress Cotton test for evaluation of syndesmotic injury during operation for ankle fracture can be a supplemental method to clarify syndesmotic injury needs fixation.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.13 no.3
• /
• pp.67-80
• /
• 2009

The basic concept of seismic design is to attain the ductility required in a design earthquake. This ductility can be obtained by providing sufficient lateral confinements to the plastic hinge regions of columns. The most cost-effective design might be derived by determining the proper amount of lateral confinement using a stress-strain relationship for confined concrete. Korean bridge design code requires the same amount of lateral confinement regardless of target ductility, but Japanese design code provides the stress-strain relationship of the confined concrete to determine the amount of lateral confinement accordingly. While design based on material characteristics tends to make the design process more involved, it makes it possible to achieve cost-effectiveness, which is also compatible with the concept of performance-based design. In this study, specimens with different numbers of lateral confinements have been tested to investigate the characteristics of the stress-strain relationship. Test results were evaluated, using several empirical equations to quantify the effects.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.21 no.1
• /
• pp.59-67
• /
• 2017

Due to a lack of the hoop action of lateral reinforcements the effective confining force in rectangular sections reduces compared to circular ones. Therefore, the stress-strain model obtained from the experimental data with circular sections overestimates the lateral confinement effect in rectangular sections, which evaluates seismic safety margin of overall structural system excessively. In this study experiments with laterally-confined square sections have been performed and the characteristic values composing stress-strain model have been analyzed. With introduction of section coefficients, in addition, the new unified stress-strain model applicable to square sections as well as circular ones has been proposed.

• Journal of Korean Foot and Ankle Society
• /
• v.25 no.1
• /
• pp.1-5
• /
• 2021

Physical examination and surgical findings and symptoms are often inconsistent with magnetic resonance imaging (MRI) findings when diagnosing chronic ankle lateral ligament instability, and confirmed surgical findings are used as the gold standard in most clinical studies. Anterior drawer testing is considered unreliable because normal findings are highly variable, and its accuracy ranges from 50% to 100%. Furthermore, radiographic stress imaging, such as in anterior drawer stress view, is performed under manual stress or using a stress device, and its findings also vary widely and confuse when interpreting stress views. The average accuracy of MRI findings is around 85% (range, 66%~91.7%), and thus, cannot be used as a primary indicator for surgery. For patients with suspected lateral ankle ligament instability, based on symptoms and physical examination findings, MRI may be useful for identifying lesions in ankle joints and for differentiating them from other conditions.

• The korean journal of orthodontics
• /
• v.27 no.5 s.64
• /
• pp.697-709
• /
• 1997

This study was designed to investigate the stress intensity and distribution produced by 1mm activation of retraction archwire with $0^{\circ},\;7^{\circ},\;14^{\circ}$ torque and application of high polk J-hook headgear during retraction of four maxillary incisors using the photoelastic stress analysis. The photoelastic model was made with a PL-3 type epoxy resin which was substituted by alveolar bone portion. Each retraction archwire was fabricated from .020' X .025' stainless steel wire which had vertical loops in 7mm height and hooks for high pull J-hook headgear between central and lateral incisors. The high pull J-hook headgear was applied 35 degree backward and upward to occlusal plane with 200gm pet each side The findings of this study were as follows: 1. In case of $0^{\circ}$ torque, the stress was distributed from cervical 1/8 to apex of roots of central and lateral incisors which were the forms of arc mode. When the high pull J-hook headgear was applied, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. The stress between apecies of central and Lateral incisors was presented also. 2. In case of $7^{\circ}$ torque, the stress distributed by arc mode was presented from cervical 1/2 to apex of roots of central and lateral incisors. And the stress distributed by following the root surface was presented from alveolar crest to cervical 1/2 of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented mote apically than without headgear. The stress between apecies of central and lateral incisors was presented also. 3. In case of $14^{\circ}$ torque, the stress distributed by following the root surface was Presented from alveolar crest to apex of roots of central and lateral incisors. When the high pull J-hook headgear was applied, the stress distributed by following the root surface was presented stronger than without headgear The stress between apecies of central and lateral incisors was presented also.

• Journal of the Korean Society for Precision Engineering
• /
• v.24 no.1 s.190
• /
• pp.118-125
• /
• 2007

In this study, we analyzed the plantar shear stress and normal pressure in lateral heel diabetic foot patients during walking by using in-shoe local shear stress and plantar pressure measurement systems. The shear force transducer based on the magnetic-resistive principle, was a rigid 3-layer circular disc. Shear transducers were mounted on the locations of four metatarsal heads and heel in the insole. Twelve normal subjects and three diabetic foot patients with diabetic neuropathy in the lateral heel participated in this study. The center of pressure in lateral heel diabetic foot patients moved more medially and directed toward the first, medial to the second metatarsal heads, and the hallux during late stance, making pressure at the medial heel and the second metatarsal head significantly larger than in the normal. Shear stress at the heel changed significantly in early stance and the magnitude of shear stresses in each metatarsal head also changed. Further studies would be very helpful to design foot orthoses in patients with diabetic neuropathy or other diseases.