• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 추계 학술발표회 3차
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• pp.104-110
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• 2010

In this study, a series of two-dimensional model test and numerical analysis was carried out to investigate the pile movement due to tunnelling in soft ground. The model test consists of 21 cases according to locations of the pile tip over the centre position of model tunnel. To identify both the pile and ground movements a close-range photogrammetric technique was adopted in the model test. The results from the model test were compared to the two-dimensional finite element analysis using the CRISP program. It was found that the rotation point on the pile was significantly affected by factors such as the offset distance from the model tunnel and the volume loss that occurred during the tunnelling operation.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.224-231
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• 2005

The ground excavation causes the deformation of the ground where the neighborhood structure is located. The ground deformation result in the vertical settlement of the neighborhood structure as well as the horizontal displacement of the temporary earth retaining structures. The decreased volume of the soil due to the ground settlement is defined as 'the ground loss quantity' or 'the ground loss'. When excavation is performed nearby existing structures, retaining walls should be designed and constructed to minimize the ground loss. Among various methods for reducing the ground loss, this study introduces the pre-loading method which has been recently developed. The reduction effect of the ground loss by pre-loading has been found to be larger as using a wall with relatively smaller rigidity.

• Geomechanics and Engineering
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• 제34권4호
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• pp.397-408
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• 2023

Pipe pile walls are commonly used as retaining structures for excavation projects, particularly in densely populated coastal cities such as Hong Kong. Pipe pile walls are preferred in reclaimed land due to their cost-effectiveness and convenience for installation. However, the pre-bored piling techniques used to install pipe piles can cause significant ground disturbance, posing risks to nearby sensitive structures. This study reports a well-documented case history in a reclamation site, and it was found that pipe piling could induce ground settlement of up to 100 mm. Statutory design submissions in Hong Kong typically specify a ground settlement alarm level of 10 mm, which is significantly lower than the actual settlement observed in this study. In addition, lateral soil movement of approximately 70 mm was detected in the marine deposit. The lateral soil displacement in the marine deposit was found to be up to 3.4 and 3.1 times that of sand fill and CDG, respectively, mainly due to the relatively low stiffness of the marine deposit. Based on the monitoring data and site-investigation data, a 3D numerical analysis was established to back-analyze soil movements due to the installation of the pipe pile wall. The comparison between measured and computed results indicates that the equivalent ground loss ratio is 20%, 40%, and 20% for the fill, marine deposit and CDG, respectively. The maximum ground settlement increases with an increase in the ground loss ratio of the marine deposit, whereas the associated influence radius remains stationary at 1.2 times the pipe pile wall depth (H). The maximum ground settlement increases rapidly when the thickness of marine deposit is less than 0.32H, particularly for the ground loss ratio of larger than 40%. This study provides new insights into the pipe piling construction in reclamation sites.

• 한국언론정보학보
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• 제71권
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• pp.52-74
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• 2015

한국전쟁 이후에 발생했던 수많은 사건들 가운데 '$5{\cdot}18$' 만큼 사회적 기억의 편차가 컸던 경우는 드물 것이다. $5{\cdot}18$은 다른 민주화운동 관련 사건들에 비해 의미의 변용이 다양하게 이루어졌다는 점에서도 특별하다. 그래서 이 글은 먼저 기념사업을 중심으로 $5{\cdot}18$의 의미가 변용되었던 배경과 논리를 파악하고, 이것이 $5{\cdot}18$기념사업의 관점과 형태에 어떠한 영향을 미쳤는가를 고찰한다. $5{\cdot}18$기념사업에 관한 인식과 형태는 2000년을 전후하여 크게 달라졌다. 이전 시기의 기념사업은 사회 운동 논리가 제도화의 논리로 일정하게 수렴되는 양상을 보였다. 이 시기에는 민주성지와 성역화의 담론이 중심을 이루었고, 기억투쟁의 성격을 띠었다. 반면 이후의 시기에는 $5{\cdot}18$의 의미가 문화도시와 인권도시를 조성하는 역사적 자원으로 해석되었다. 이러한 변화 과정에서 $5{\cdot}18$의 의미는 때로는 지역 발전 담론으로 전유되었고, 때로는 도시차별화 전략의 소재로 채택되었다. 이에 맞추어 기념사업이 추진되었던 형태도 기억투쟁형에서 유산산업형으로 달라졌다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.299-306
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• 2001

Crushed Stone Pile(CSP) is one of the ground improvement methods available to loose sand and clayey ground by forming compacted CSP in the weak soil layer. The effects of this method are enhancement of ground bearing capacity, reduction of settlement and prevention of lateral ground movement in cohesive layer, reduction of liquefaction potential in sandy ground. This study performs model tests in 1.0m${\times}$1.0m${\times}$1.0m and 1.5m${\times}$1.5m${\times}$l.2m model tank to observe bearing capacity of CSP treated ground. The area replacement ratio of CSP composite ground varies 20%, 30% and 40% with square grid pattern. After the composite ground was consolidated under pressure of 0.5kg/$\textrm{cm}^2$ and 1.0kg/$\textrm{cm}^2$, load tests were carried out. The results show that ultimate bearing capacity increases with area replacement ratio and the preconsolidation pressure of ground.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1473-1478
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• 2010

For the cassion type of breakwater under the condition of large wave loads, stability about lateral movement of breakwater was investigated by performing centrifuge model experiments. Prototype of breakwater was modelled by scaling down to centrifuge model and the soft ground reinforced with grouting was also reconstructed in the centrifuge model experiments. Sandy ground beneath breakwater was prepared with a soil sampled in field so that identical value of internal friction angle could be obtained. Centrifuge model experiments were carried out to reconstruct the construction sequence in field. Lateral static wave load was applied to the model caisson after the final stage of construction sequence was rebuilt and the measured lateral movement of caisson was compared with allowable value by the code to assess the stability about lateral movement of the breakwater.

• 한국운동역학회지
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• 제21권3호
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• pp.327-334
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• 2011

The objective of this study was to develop a scientific approach for investigating Korean dance in detail, and to examine the intense expressions and various movements, which are based on Danjeon breathing. For the purpose, we analyzed the movement changes and distribution of forces resulting from the switch in movement between exhalation and inhalation while bending, which is the most basic movement in Korean dance. The following conclusions were drawn from this study. In Korean dance, bending with breathing involves less back-and-forth-movement and more up-and-down movement, as compared to bending without breathing; this indicates greater body stability and a wider range of movements while bending with breathing. In addition, less time is required for bending with breathing at the point of switching from exhalation to inhalation, and it involves less movement of the supporting leg; thus, vending with breathing involves faster switching from bending movements to extending movements. While bending, the raised leg goes through a less smooth curve while breathing, which indicates stronger movement of the toes. Bending with breathing requires a greater braking force than bending without breathing, and the vertical force, generated by switching from exhalation to inhalation, is transferred to extending movements using the ground load. The results of this study can be potentially employed to investigate the expressions used in Korean dance on th basis of its principle of forces. Korean dance has evolved into various creative forms, and basic analytical studies of these diverse forms and related breathing methods re required in the future.

• PNF and Movement
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• 제8권2호
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• pp.9-15
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• 2010

Purpose : This study aimed to investigate the effect of differing ground contact conditions on the eletromyographic(EMG) activity in rectus femoris, biceps femoris, tibialis anterior, gastrocnemius medialis during step-up activity in patients with hemiparesis. Methods : 10 hemiparetic patients performed step-up activity on three different ground contact conditions: entire ground contact, 2/3 ground contact, 1/3 groud contact. Result : The EMG activities of gastrocnemius medialis significantly changed on 1/3 ground contact(p<.05). However, no significant changed rectus femoris, biceps femoris, tibialis anterior between three differing ground contact conditions (p>.05). Conclusion : This study provides that EMG activities of gastrocnemius medialis significantly changed on different ground contacts. Therefore, this method can be used to strengthen the gastrocnemius medialis.

• 대한토목학회논문집
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• 제29권4C호
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• pp.153-162
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• 2009

본 논문은 지반굴착으로 인해 발생된 인접지반에서의 진행성 지반변위가 구조물에 미치는 영향을 구조물 및 지반의 특성을 달리하면서 지반-구조물 상호작용이 고려된 상태에서 조사한 것이다. 지반굴착에 의해 발생된 진행성 지반변위에 노출된 4층 및 2층의 블록식구조물이 서로 다른 조건의 지반위에 위치할 때 발생되는 구조물 거동이 수치해석을 통해 조사된다. 수치해석을 위한 구조물은 소요전단 및 인장강도 이상의 응력이 발생할 때 구조물에 크랙이 발생될 수 있도록 모델링되었다. 굴착유발 진행성 지반변위에 노출된 4층 및 2층의 블록식구조물의 거동은 지반변위의 진행단계에 따라 조사되며, 이로부터 얻어진 거동특성은 구조물이 지반굴착의 최종단계에서 일어나는 지반변위에 일시에 노출될 때 발생하는 구조물의 거동특성과도 비교된다. 서로 다른 구조물 특성 및 지반조건을 가진 구조물이 진행성 지반변위 및 최종 지반변위에 노출될 때 발생하는 거동비교는 구조물에 발생한 크랙의 분포정도 및 변형크기를 고려하면서 조사되며, 이러한 비교로부터 얻어진 결과는 지반굴착으로 인해 유발되는 인접구조물의 손상을 제어하고 최소화하는데 필요한 정보를 제공한다.

• 한국정밀공학회지
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• 제4권2호
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• pp.36-46
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• 1987

An optical technique using laser for non-contact measurement of surface roughness and form accuracy of ground surfaces is presented. It is found that, when a ground surface is illuminated by a beam of laser light, the roughness height and slope distribution has significant influence on the pattern of reflection and it maintains an unique Gaussian distribution relationship with the surface roughness. The principle idea of the optical measurement system is therefore monitor the radiation, and then calibrate it in process against surface roughness by means of necessary digital data processing. On the other hand, measuring the form accuracy of a ground surface is accomplished by using a triangular method, which is based on observing the movement of an image of a spot of light projected onto the surface. The image is focused, through a series of lenses for magnification, on a photodetector array lf line configur- ation. Then the relative movement of image and consequently the form accuracy of the surface can be obtained through appropriate calibration procedures. Experimental test showed that the optical roughness measurement technique suggested in this work is very efficient for most industrial applications being capable of monitoring the roughness heights ranging 0.1 to 0.6 .$\mu$m CLA values. And form accuracy can be measured in process with a resolution of 10 .$\mu$m.