• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.670-675
• /
• 2006

The purpose of this study is the infiltration characteristics of soil cut-slope by the repetition & concentration rainfall. The maximum rainfall concentrate from June until September which is a rainy season in our country Stability analysis of soil cut-slopes has been conducted by limit equilibrium method on Seep/w and finite element method on Slope/w.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.676-680
• /
• 2006

Many collapse of road cut slope consisted of representative granite of korea peninsula is happened by weathering progress. Chose hangye pass consisted of korea peninsula's representative granite style for this study. Purpose of this study is that consider suitable reinforcement of cut slope consisted of granite by analyzing characteristic of hangye pass vicinity road cut slope.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.735-738
• /
• 2005

The purpose of this study is the infiltration characteristics of soil cut-slope by rainfall. Stability analysis of soil cut-slopes has been conducted by limit equilibrium method on Seep/w and finite element method on Slope/w. Result is same as following. First. the hour when seepage line and groundwater in contact is proportionate from rainfall rate condition and upper natural slope gradient condition which is identical. Second, when seepage line and groundwater is contact, seepage line moves gradually at soil cut-slope surface. Finally, seepage line is formed similarly with soil cut-slope gradient. Third, when rainfall is ended, from the recording upper natural slope where the hour will pass it is stabilized

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.745-750
• /
• 2005

The demand of tunnels has been increased for the linear improvement of general national highway, and road construction and/or enlargement in Korea. Also, the collapses of tunnel portal slope have been increased in recent due to heavy rain caused by global warming. Therefore, it has been risen the requirement of system for the stability of tunnel portal slope in Korea as well as all over the world. The objective of this research is to develop an effective maintenance system for supervising the tunnel portal slope. This paper is a basic proposal to execute a survey on the current status and state of the tunnel portal slopes that were already installed along general national highways.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2005.03a
• /
• pp.423-430
• /
• 2005

Fire accidents in underground space may bring much loss of lives as well as properties and result in catastrophic disasters. This study aimed to manufacture the high-temperature furnace capable of simulating fire scenarios (RABT and RWS) and carry out the preliminary fire tests to evaluate fire-induced damage in underground structures. Specimens used in the fire tests were the concrete segments generally used in shield TBM tunnels. The simulated fire scenario was set to the RABT curve that is the most representative fire scenario in underground space. From the fire tests, the spalling was estimated to reach approximately 20cm from the surface exposed to fire. In addition, from the observation of core specimens obtained after fire tests, the deteriorated zone of unspalled specimens amounted to approximately 10cm from the surface of spalling.

• Structural Engineering and Mechanics
• /
• v.54 no.2
• /
• pp.363-378
• /
• 2015

Estimation of geotechnical properties is an essential but challenging task since they are major components governing the safety and reliability of the entire structural system. However, due to time and budget constraints, reliable geotechnical properties estimation using traditional site characterization approach is difficult. In view of this, an alternative efficient and cost effective approach to address the overall uncertainty is necessary to facilitate an economical, safe and reliable geotechnical design. In this paper a probabilistic approach is proposed for real-time updating by incorporating new geotechnical information from the underlying project site. The updated model obtained from the proposed method is advantageous because it incorporates information from both existing database and the site of concern. An application using real data from a site in Hong Kong will be presented to demonstrate the proposed method.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.03a
• /
• pp.233-244
• /
• 2009

A new bridge scour countermeasure using geobags and recycled aggregates which is more stable and economical than existing methods is proposed, and its stability was verified through material tests. PP short staple nonwoven geotextile and PET long staple nonwoven geotextile produced in Korea were selected, and a series of strength tests and a test of hydraulic characteristics were conducted to determine a suitable geotextile for geobags. A series of leaching test was also conducted to assess the potential environmental risk of recycled concrete produced in Korea when it is utilized as a material for protecting bridge piers against scour.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.243-246
• /
• 2009

Localized rainfall due to abnormal climate has caused extensive damages killing several tens to hundreds of people for yearly basis. The typhoon 'Lusa' of year 2002 has resulted 5,400 billion won of property damage and the damages for roads were approximated to be 2,860 billion won at 12,377 locations holding 53% damage of total. The recent typhoon, 'Aewinia' of yeat 2006 caused the 1,400 billion-won property damage including sweeping and flooding of 127 roads and 65 rivers, respectively. There are needs to minimize the damages for important structures for repeated heavy rainfalls every year and, especially, because debris flow might be a main cause of road damage, the design criteria and guideline for roads are required to be improved. Therefore, this paper presented design method of debris-flow control structure for road protection.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2009.09a
• /
• pp.1271-1274
• /
• 2009

One of the landslide, Debris flow means flow mixed of rocks, gravels, sand and soil with water. Debris flow occurred in summer by passed the rainy season and typhoon. Especially, Localized heavy rain derived from abnormal weather caused debris flow independent of season. It is increase to collapse of house, bridge, roads by debris flow but countermeasure studies about occurrence cause, movement pattern, damage scale about debris flow are insufficient. This study performed debris flow model experiment using dry material and calculated shock force predicted debris flow occurrence.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.199-210
• /
• 2008

Acoustic emission(AE)/Microseimsic(MS) activities are low-energy seismic events associated with a sudden inelastic deformation such as the sudden movement of existing fractures, the generation of new fractures or the propagation of fractures. These events rapidly increase before major failure and happen within a given rock volume and radiate detectable seismic waves. The main difference between AE and MS signals is that the seismic motion frequencies of AE signals are higher than those of MS signals. As the failure of geotechnical structures usually happens as a high velocity and small displacement, it is not easy to determine the precursor and initiation stress level of failure in displacement detection method. To overcome this problem, AE/MS techniques for detection of structure failure and damage have recently adopt in civil engineering. In this study, AE/MS monitoring system, which consist of sensor, data acquisition and operation program, is constructed with domestic technology. To verify and optimize the developed system, we are now carrying out the field application at an underground research laboratory and the developed AE/MS monitoring will be used in detecting of seismic events with various scales.