• Journal of the Korean Wood Science and Technology
• /
• v.23 no.1
• /
• pp.21-27
• /
• 1995

고도(高度)의 엔지니어링 구조물(構造物)로 경제성이 높은 경골(輕骨) 목조(木造) 트러스에 사용될 수 있는 소나무(Pinus densiflora) 재(材)에 적용한 20게이지 아연도금강(鋼) 플레이트 접합부(接合部)의 하중(荷重)-변위(變位) 특성(特性)을 평가하기 위하여 Foschi 모형을 사용하여 모형 모수(母數)를 산출하고 실험치와 계산치를 비교 분석하였다. 접합부(接合部)의 하중(荷重)-변위(變位) 곡선(曲線)은 비선형 특성을 나타내었다. 접합부의 하중성능 및 강성(剛性)은 플레이트 및 목리에 평행한 형태에서 최대치를 나타내었고, 플레이트에 직각이고 목리(木理)에 평행한 형태로부터 플레이트에 평행이고 목리에 직각인 형태순으로 감소하다 플레이트 및 목리에 직각인 형태에 최소치를 나타내었다. 3-모수(母數) 비선형 모형으로 예측된 스테인레스강(鋼) 및 아연도금강(鋼) 플레이트 접합부의 하중-변위 특성에 대한 계산치는 실험치와 잘 일치하였다.

• The Journal of the Acoustical Society of Korea
• /
• v.16 no.4
• /
• pp.21-28
• /
• 1997

In this study, comparison between Harris-theoretical values and experimental data of load-deflection characteristics in bearing was made. The experiments are conducted under the conditions of the various radial loads and speed of shaft. In the case of non-defective ball bearing, the experimental data agreed well with the Harris-theoretical values for the small steady radial load but not for the large steady radial load. For the radial load bearing, the experimental results show that the stiffness of bearing at the single and multiple defective bearing are bigger in the radial defectiion than in the axial deflection. Load-deflection characteristics for the bearing defect part make it possible to detect the presence of a defect in bearing.

• Proceedings of the Korean Institute of Industrial Safety Conference
• /
• 1999.06a
• /
• pp.181-186
• /
• 1999

반복하중에 따른 P.C 구조물의 장착장치로 사용되는 Wedge 형상에 따른 거동특성을 파악하기 위하여 정적최대하중을 이용하여 피로시험을 수행하였다. 또한 피로시험 결과로부터 반복회수에 따른 시험 체의 균열양상, 하중-변위, 하중-변형율, 하중-중앙 최대 변위, 하중-영구 변형량, 반복횟수에 따른 S-N선도 등을 고찰하였다. (중략)

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.5
• /
• pp.487-497
• /
• 2016

If a tunnel is excavated, the released stress is redistributed in the ground around the tunnel face, which lead the stress state of the surrounding ground of the tunnel and the load acting on the tunnel support to change. If the tunnel face deforms, the ground ahead of it is relaxed, and the earth pressure acting on it decreases. And if the displacement increases so much that, the ground ahead of the tunnel face reaches in failure state. At this time, load would be transferred longitudinally in the tunnel, depending on the cover and the face deformations. The longitudinal load transfers in the tunnels induced by the tunnelling has been often studied; however, the relation between the deformation of the tunnel face and the longitudinal load transfer was rarely studied. Therefore in this study assesses the characteristics of the longitudinal load transfer as the face was failed by displacement by conducting a model test in a shallow tunnel. In other words, the longitudinal load transfer of the tunnel with the progress of the face deform was measured by conducting a model test, beginning at the state of earth pressure at rest. As results of this study, most of the longitudinal load transfers occurred drastically at the beginning of the displacement of the tunnel face, and as the displacement of the face approached the ultimate displacement, it converged to the ultimate displacement at a gentler slope. In other words, when the ground ahead of the tunnel face was still in an elastic state, the longitudinally transferred load increased sharply at the beginning stage but it tended to increase gradually if it approached to the ultimate limit. Thus, it was noted that the earth pressure in the face and the longitudinal load transfer of the tunnel had the same decreasing tendency.

• Magazine of the Korea Concrete Institute
• /
• v.9 no.1
• /
• pp.183-194
• /
• 1997

Traditional displacmir~nt measurement included an extrancous and cvrntlc. portmn due to test setup and support crushing. The magnitudc of this erroneous deformation was found to be of the same order as the actual displacement, leading to inaccurate determinations of fracture parameters. To overcome this problem, the load-CMOD relationship is a more reliable parameter for determining the fracture characteristics because it is unaffected by the specimen setup and any support crushing. An important step towards the use of load-(:MOD concept as a key fracture parameter depends on relating the CMODto the traditional load-line deflection. This investigation found that there was an unique linear relationship between the CMOD and the load-line deflection. The exact numeric value of relationship between the CMOD and the deflection. that is, the slope ofthe line, is discovered to be a material property. The relationship finds a problem with the existing IZIL,EM recommendations for. measuring the fracture energy of concrete. A proposal to correct the problem is made.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.6
• /
• pp.887-903
• /
• 2017

Lots of shallow tunnels are constructed in the mountainous areas where the stress distribution in the ground around tunnel is not simple, also the impact of stress conditions on the longitudinal load transfer characteristics is unclear. The tunnel construction methods and the ground conditions would also affect the longitudinal load transfer characteristics which would be dependant on the displacement patterns of tunnel face. Therefore, in this study, the slope of the ground surface was varied in $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and the longitudinal load transfer depended on the deformation conditions of tunnelface (that were maximum deformation on the top, constant deformation, and maximum deformation on the bottom), and the stress distribution at tunnelface. As results, when the tunnelface deformed, the earth presure on the tunnelface decreased and the load at tunnel crown increased. The load transferred on the crown was influenced by the earth presure on tunnel face. Smaller load would be transfered to the wide areas when the slope of ground surface decreased. When the slope of ground surface became larger, the longitudinal load transfer would be smaller and would be concentrated on tunnelface, In addition, the shape of the transferred load distribution in the longitudinal direction was dependant on the deformation shape of tunnelface. The deformation shape of tunnelface and stress conditions in longitudinal sections would affect the shape and the magnitude of the load transfer in the longitudinal directions.

• Proceedings of the KIEE Conference
• /
• 2008.04b
• /
• pp.16-18
• /
• 2008

연약지반에 시공된 콘크리트전주가 풍하중에 의해 받는 웅력-변형 특성을 파악하기 위해 전주 매설깊이, 버팀대의 위치 및 수량 등을 변수로 하중 파괴 시험을 실시한 결과, 전주가 깊이 묻혀질수록 재하하중에 따른 수평변위는 감소하였고 전주의 버팀대는 2개일 경우 가장 안정되는 것으로 조사되었다.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.5
• /
• pp.499-509
• /
• 2016

In recent years, the use of underground spaces becomes more frequent and the demands for urban tunnels are rapidly increasing. The urban tunnels constructed in the ground with a shallow and soft cover might be deformed in various forms on the face, which would lead, the tunnels to behavior 3-dimensionally, which may have a great impact on the longitudinal load transfer. The tunnel face might deform in various forms depending on the construction method, overburden and the heterogeneity of the ground. And accordingly, the type and size of the distribution of the load transferred to the ground adjacent to the tunnel face as well as the form of the loosened ground may appear in various ways depending on the deformation form of the tunnel face. Therefore, in this study was conducted model tests by idealizing the deformation behavior of the tunnel face, that were constant deformation, the maximum deformation on the top and the maximum deformation on the bottom. And the test results were analyzed focusing on the deformation of the face and the longitudinal load transfer at the ground above the tunnel. As results, it turned out that the size and the distribution type of the load, which was transferred to the tunnel as well as the earth pressure on the face were affected by the deformation type of the face. The largest load was transferred to the tunnel when the deformation was in a constant form. Less load was transferred when the maximum deformation on the bottom, and the least load was transferred when the maximum deformation on the top. In addition, it turned out that, if the cover became more shallow, a longitudinal load transfer in the tunnel would limited to the region close to the face; however, if the cover became higher than a certain value, the area of the load transfer would become wider.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.8
• /
• pp.57-64
• /
• 2012

The lateral behavior characteristics of concrete group pile under the lateral load were examined by the laboratory model tests in this study. Piles were socketed 1D(D : pile diameter) in the concrete block, and model tests were executed on $2{\times}3$ group piles, of which the length were 11D, 15D and 20D. All results of loading tests under each condition was presented by the lateral load-displacement curves, and the displacements in the ground under the lateral loads were measured. As a results of model tests, as the ratio of pile length/diameter(L/D) was decreased, the yielding load and the lateral displacement at that load were increased. The yielding load was evaluated as the load at lateral displacement of 15 mm. The yielding loads at the pile length of 11D, 15D and 20D were 11.7, 6.2kN and 3.4kN. The lateral displacements of pile in the ground under each condition were measured linearly and the failure occurred at the location where the piles were socketed in concrete block.

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.3
• /
• pp.29-34
• /
• 2013

In this paper, numerical analyses were conducted on piled raft foundation settlement and pile bearing characteristics in soft ground. Results obviously showed longer and larger piles developed end bearing capacity values, but also showed the load of the central pile is larger than the surrounding piles in a group formation. Additionally, after pile yielding, the load carrying capacity exists as a raft. Moreover, results showed no transverse displacement according to embedment depth for the single pile case, but larger transverse displacements for deeper embedment depths.