Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The Journal of Engineering Geology
Journal Basic Information
Journal DOI :
The Korea Society of Engineering Gelolgy
Editor in Chief :
Volume & Issues
Volume 8, Issue 3 - Dec 1998
Volume 8, Issue 2 - Aug 1998
Volume 8, Issue 1 - Apr 1998
Selecting the target year
A Statistical Analysis of the Seismicity of the Yangsan Fault System
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 99~114
The Yangsan fault system of Kyungsang Basin in the southeastern part of Korean peninsula is one of the most important structures in the peninsula. A number of strong earthquakes occurred in the vicinity of the fault. It was suggested that this fault can be divided into three segments: northern, central and southern ones. Earthquake data around the Yangsan fault were classified into two groups as incomplete and complete ones; the former is the data before the Choseon Dynasty and the latter is those since the dynasty. The maximum likelihood method was applied to compute seismicity parameters such as earthquake occurrence rates, b-values of frequency-magnitude relation and maximum possible magnitudes for each segment and the entire fault. These parameters show considerably different values from segment to segment. The b-value for the entire fault turned out to be 0.85 and maximum possible magnitudes for the northern, central and southern segments are 5.2, 6.8 and 6.0, respectively. The mean return periods for the maximum possible magnitudes for each segments are greater than 1000 years. In addition, according to the analysis of the frequency-magnitude relation, the occurrence pattern of earthquakes around the Yangsan fault show more similarity to the characteristic earthquake model than the Gutenberg-Richter model. The data for each segments are, however, too scarce to obtain any physically meaningful results.
Landslide Types and Susceptibilities Related to Geomorphic Characteristics - Yeonchon-Chulwon Area -
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 115~130
An analysis on landslide types and susceptibilities associated with geomorphic characteristics has been conducted with 916 landslide inventories in Yeonchon-Chulwon District, where two day's heavy rainfall was concentrated on July, 1996. The precipitation during the 2 days, which is equivalent to 0.372 of event cofficient, can cause large landslides based on Olivier's equation. Sliding materials are dominantly composed of debris mixed with rock fragments and soil derived from colluvium and residual soils. 66% of the landslides are belong to debris flow md 23% are due to sediments flow, in accordance with the classification of sliding materials. Most of landslides(> 90%) are small and shallow, less than l00m in length and about 1m in depth, and classified as transitional type. Granite is more susceptible as much as 4.7 times than metamorphic rocks and 2.7 times than volcanic rocks, probably due to higher weathering grade of granite. The highest landslide frequency is concentrated on the areas between 200 and 300m in height and on the slopes between
in dgree. More than 50% of landslides occurred under these geomorphic conditions. Consequently, colluviums and residual soils distributed on the gentle slopes are most susceptible to the landslides of the area.
A Study of Joint System for Groundwater Pathway
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 131~143
The study area, Beulgok-myon Nonsan-goon Chungcheongnan-do is consist of Changri slate(Och, okcheon system), lithic tuff(Kslt, kyoungsang system), granite (Kqb, kyoungsang system) and quartz porphyry(Kgf, kyoungsang system). More than 3000 joints were measured and classified by direction. Main dipdirection/dips of Kqb are 228~257/73~88, 010~150/70~85, Och are 134~164/40~90, 214~249/55~89, Kslt are 291~332/75~82, 235~241/73~71. But Kgf are not appeared distinct directions of joint. In field, p-wave velocities(Vp) are measured on the bed rock. Vp of Kgf are
, Kqb are
, Kslt are
and Och are
. Also P-wave velocities on specimen are measured. It is slightely higher than it's measured on the bed rock. For engineering properties of rock, we measured Poisson's ratio, rigidity, Young's modulus and bulk modulus by dynamic method.
A Probabilistic Evaluation of Design Earthquakes for Nuclear Power Plant Sites in Korea
Myunghyun Noh ;
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 145~152
A new probabilistic method was applied to evaluate the design earthquakes for the nuclear power plant sites in Korea. The new method is different from the current ones in that it can determine the controlling earthquakes (or modal earthquakes) through the so-called seismic hazard deaggregation. It turned out that the seismic hazard is greatly dependent on the attenuation formulas applied and its standard deviation is very large. This implies that intensive efforts should be made to characterize attenuation formulas and seismic sources in Korea. At the target probability of exceedance of
, the design earthquakes of four nuclear power plant sites are estimated to be 13 to 26km in epicentral distance from the sites and 5.7 to 6.1 in magnitude. Comparison of the design earthquakes by deterministic method with controlling earthquakes by probabilistic method shows that they are consistent at three sites of the four but relatively less consistent at one site. Two contrasting sites among four were chosen to compare the site-dependent variation of response spectra, i.e., site-specific response spectra. The result shows that the site-specific response spectrum of one site is higher by a factor of 1.5 than that of the other. Finally, the comparison of uniform hazard spectrum and site-specific response spectrum at one of the two sites shows that the both spectra are consistent with each other.
Stability Analysis of Existing Tunnel in Stratified Sedimentary Rocks Subjected to Bridge Pier Load
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 153~161
An anisotropic characteristics of stratified sedimentary rocks should be considered in the design of tunnel. The second line of Taegu subway is under construction through the sedimentary rocks which is stratified by alternation of shale and sandstone, and Tongsoe over bridge road is planned to be constructed along the subway line. Thus the subway twin tunnels will be subjected by the bridge load of 76.2 MN per pier that will be placed in between the twin tunnels of the subway line. A numerical analysis is carried out for the stability of the twin tunnel, and the result shows that the maximum principal stress of surrounding ground is increased by 5∼6 MPa and the additional displacement of concrete lining is reached up to 8∼10mm due to the external bridge load. For the safety operation of the subway, reinforcement of the tunnel structure is highly recommended.
Lithology Determination by Log Analysis from a Borehole-PABH1 in the Pungam Sedimentary Basin
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 163~173
Suite of log analysis techniques consisting of geophysical well log, geological core log, and physical core log have been made to understand the well log responses and to determine the lithology of a test borehole-PABH1 located in Pungam sedimentary basin, Sosok, Hongchon-gun, Kangwon Province. Geological core logging has been precisely made over the cores taken between 64 and 124 meters, and 11 groups of rock types were deduced. Using the core samples divided by 11 groups, geophysical property measurements consisting of resistivity, natural gamma and density were made. Each rock group in the area is shown to have its characteristic physical response from geophysical well log and geophysical core logs. The outstanding physical responses particularly shown from siltstone, coarse sandstone to conglomerate, and granitic gneiss in the area were effectively used as keybeds in correlating the geophysical well logs to the result of geological core logs.
Formation Processes of Fault Gouges and their K-Ar Ages along the Dongnae Fault
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 175~188
This paper describes the internal structures and K-Ar ages of fault gouges collected from the Dongnae fault zone. This fault zone is internally zoned and occurs in the multiple fault cores. A fault core consists of thin gouge and narrow cataclastic zones that are bounded by a much thicker damage zone. Intensity of deformation and alteration increases from damage zone through cataclastic zone to gouge zone. It is thought that cataclasis of brittle deformation was the dominant strain-accomodation mechanism in the early stage of deformation to form the gouge zone and that crushed materials in the regions of maximum localization of fault slip subsequently moved by cataclastic flow. Deformation mechanism drastically changed from brittle processes to fluid-assisted flow along the gouge zone as the high porosity and permeability of pulverzied materials during faulting facilitated the influx of the hydrothermal fluids. Subsequently, the fluids reacted with gouge materials to form clay minerals. Fracturing and alteration could have repeatedly taken place in the gouge zone by elevated fluid pressures generated from the reduction of pore volume due to the formation of clay minerals and precipitation of other materials. XRD analysis revealed that the most common clay minerals of the gouge zones are illite and smectite with minor zeolite and kaolinite. Most of illites are composed of 1Md polytype, indicating the products of hydrothermal alteration. The major activities of the Dongnae fault can be divided into two periods based upon K-Ar age data of the fault gouges : 51.4∼57.5Ma and 40.3∼43.6Ma. Judging from the enviromental condition of clay mineral formation, it is inferred that the hydrothermal alteration of older period occured at higher temperature than that of younger period.
Development of Packer-Dilatometer Method
Kern Shin Yoon ;
The Journal of Engineering Geology, volume 8, issue 2, 1998, Pages 189~203
Packer-dilatometer techniques, which are borehole-dilatometer techniques using commercial rubber packer, were developed to measure the deformability of rocks. Packer-dilatometers for 0.5 inch, AX, BX, NX and HX size boreholes were developed and were used for rock deformability measurements in the field. In the packer-dilatometer method, the packer pressurizes the borehole-wall and the borehole deformation is determined by the amount of fluid injected into the packer. A detailed description of the theoretical development of quantitative interpretation of the packer-dilatometer method; apparatus, setup and procedures for the determining of calibration constants; contact pressure determination and field tests using the packer-dilatometer are provided.