• Journal of the Korea Safety Management & Science
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• v.14 no.1
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• pp.65-73
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• 2012

We studied the risk analysis of fire and explosion caused by gas leak in underground-parking of gas vehicle. However, an entrance regulation of gas vehicles (H2/LPG/CNG etc.) to underground garages has not been enacted in Korea. Incase, a gas explodes in an underground parking garage placed in overcrowded residential area, such as an apartment, the scale of the damage would cause tremendous disaster. Faults of vehicle parts and management problems were evaluated by using the Failure mode and effect analysis (FMEA), which is a qualitative analysis method. The range of the damaged area by the explosion and the damage scale by the explosion pressure were analyzed by using the process hazard analysis software tool (PHAST). The study is expected to facilitate enactment of the regulation for the underground parking to restrict the gas vehicle.

• Geosystem Engineering
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• v.21 no.6
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• pp.326-334
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• 2018

Underground water-sealed gas storage caverns have become the primary method for strategic storage of LPG. Previous studies of excavation blasting effects on large-scale underground water-sealed gas storage caverns are rare at home and abroad. In this paper, the blasting excavation for underground water-sealed propane storage caverns in Yantai was introduced and field tests of blasting vibration were carried out. Field test data showed that the horizontal radial velocity had a major controlling effect in the blasting vibration and frequencies would not cause the vibration velocity concentration effects. In terms of the influence of blasting vibration on adjacent caverns, the dynamic finite element model in LS-DYNA soft was established, whose reliability was verified by field test data. The numerical results indicated the near-blasting side was primary zone for the structural failure and tensile failure tended to occur in the middle of the curved wall on the near-blasting side. Meanwhile, the safety criterions for adjacent caverns based on stress wave theory and according to statistic relationship between peak effective tensile stress and peak particle velocities were obtained, respectively. Finally, with Safety Regulations for Blasting in China (GB6722-2014) taken into account, a final safety criterion was proposed.

• Journal of Digital Convergence
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• v.12 no.8
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• pp.283-288
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• 2014

The underground water quality of petroleum products storage cavern is influenced by that of dumping and landfill sites adjacent to cavern. From the chemical analysis of underground water sampled from landfill site, insignificant amounts of As, Cu and Pb were detected in a half of test samples while Cd, Hg, $Cr^{6+}$, $CN^-$, TCE, PCE and Phenol were not detected in all samples. All measurements of $COD^{Mn}$ were below $8.0mg/{\ell}$ that can be negligible for the contamination by organic matters. The total bacteria counted from 1st and 2nd microbiological analysis were $94.84{\times}10^4cells/m{\ell}$ and $146.26{\times}10^{-4}cells/m{\ell}$, respectively, and all counts of the sulfate reducing bacteria were less than $2cells/m{\ell}$. It can be suggested that the water quality adjacent to storage cavern can also be studied to improve the reliability of hydrogeologic stability of storage cavern.

• Economic and Environmental Geology
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• v.42 no.6
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• pp.599-608
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• 2009

This study was conducted to examine chemical characteristics and correlations among seepage water, subsurface waters and inland groundwater in and around a coastal underground LPG cavern using factor and cluster analyses. The study area is located in western coast of Incheon metropolitan city and is about 8 km off the coast. The LPG cavern storing propane and butane was built beneath artificially reclaimed island. Mean bathymetry is 8.5 m and maximum sea level change is 10 m. Water sampling was conducted in May and August, 2006 from 22 sampling points. Correlation analysis showed strong correlations among $Fe^{2+}$ and $Mn^{2+}$ (r=0.83~0.99), and Na and Cl (r=0.70~0.97), which indicated reductive dissolution of iron and manganese bearing minerals and seawater ingression effect, respectively. According to factor analysis, Factors 1 (May) and I (August) showed high loadings for parameters representing seawater ingression into the cavern and effect of submarine groundwater discharge, respectively while Factors 2 and IV showed high loadings for those representing oxidation condition (DO and ORP). Factors 4 and II have large positive loadings for $Fe^{2+}$ and $Mn^{2+}$. The increase of $Fe^{2+}$ and $Mn^{2+}$ was related to decomposition of organic matter and subsequent their dissolution under reduced condition. Cluster analysis showed the resulting 6 groups for May and 5 groups for August, which mainly included groups of inland groundwater, cavern seepage water, sea water and subsurface water in the LPG storage cavern. Subsurface water (Group 2 and Group III) around the underground storage cavern showed high EC and major ions contents, which represents the seawater effect. Cavern seepage water (Group 5 and Group II) showed a reduced condition (low DO and negative ORP) and higher levels of $Fe^{2+}$ and $Mn^{2+}$.

• Journal of Soil and Groundwater Environment
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• v.14 no.4
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• pp.33-44
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• 2009

Water curtain of an underground LPG storage cavern is a facility to prevent leakage of high pressure gases, for which groundwater should flow freely towards the cavern and groundwater level also must be stably maintained. In this study, in order to evaluate qualities of seepage water and surrounding groundwater of an underground LPG storage cavern in Yeosu, 4 rounds of samplings, field measurements and laboratory analyses (February, May, August, October of 2007) were conducted. According to field measurements, pH was weak acidic to neutral but it gradually increased with time. Electrical conductivity (EC) of groundwater near a salt stack showed very high values between 10.47 and 38.50 mS/cm. Dissolved oxygen (DO) showed a very wide range of 0.20~8.74 mg/L and a mean of oxidation-reduction potential (ORP) was 159 mV, which indicated an oxidized condition. Levels of $Fe^{2+}$ and $Mn^{2+}$ were mostly less than 3 mg/L. All of seepage waters showed a Na-Cl type while only groundwater near the salt stack showed a Na-Cl type with a high total dissolved solid. The other groundwaters exhibited typical $Ca-HCO_3$ types. Levels of aerobic bacteria were mostly very high (573-39,520 CFU/mL). Based on the analyses of these hydrochemistry and biological characteristics, it is concluded that there are no particular problems in groundwater and seepage water, which not causing a trouble in the cavern operation. However, both for control of bio-clogging and for sustainable operation of the water curtain system, a regular hydrochemical and microbiological monitoring is required for the seepage water and surrounding groundwater.

• The Journal of Engineering Geology
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• v.20 no.1
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• pp.1-12
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• 2010

The objective of this study was to examine the hydrogeochemical and microbiological characteristics for stable maintenance of coastal LPG storage cavern. Cavern seepage water and groundwater in the vicinity of the LPG storage cavern were sampled and analyzed (February, May, August and October 2007). Groundwater samples of propane cavern showed high pHs of 8.1~12.4 due to dissolution of cement grouting materials that had been applied during the well and cavern construction. The EC values showed distinctive seasonal variation. The negative ORP indicated reduced condition. The seepage and surrounding groundwater are classified as Na-Cl type, which represents seawater effects. All of aerobic bacteria, anaerobic bacteria, slime forming bacteria and sulfate reducing bacteria were less than 500 CFU/mL, which indicated that there was no abrupt increase of bacteria in the cavern. Therefore there exist no hydrochemical symptoms to indicate unstable conditions of the cavern operation. However, regular and continuous monitoring is essentially required.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.3
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• pp.42-50
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• 2001

In this paper, the effects of scale formation in engine water jacket upon the thermal durability of engine itself and its component parts were studied. To understand the effect of quality of water, a full load engine endurance test for 50 hours was carried out with not-treated underground water. The followings were found through the tested engine inspection after the endurance test; 1-2 mm thick scale formation in the engine water jacket, valve seat wear, piston top land scuffing, piston pin stick, and cylinder bore scuffing in siamese area. In order to understand the causes of above test results, the heat rejection rate to coolant, the metal surface temperature of combustion chamber, and the oil and exhaust gas temperatures were measured and analyzed. The scale formed in the engine water jacket played a role as thermal insulator. The scale formed in the engine reduced the heat rejection rate to coolant and it caused to increase the metal surface temperature. The reduced heat rejection rate to coolant increased the heat rejection rate to oil and exhaust gas and increased the oil and exhaust gas temperature. Also, the reasons of valve seat wear, piston top land scuffing and cylinder bore scuffing, and piston pin stick quantitatively analyzed in this paper.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.7
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• pp.897-903
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• 2010

Used gas to the vehicle fuel are the problems of the 'survival' beyond the 'quality of life' improvements and revive a new paradigm of 'sustainable development' which pursues economic development in harmony with environmental conservation. However, the fatalities caused by explosions and fires increases every year with the increase in the use of LPG; gas accidents in large-scale storage facilities also cause severe damage to property. In this study, a suitable storage tank is designed in which the surface area of the fuel exposed to flames is minimized in order to prevent explosions; thus, the occurrences of explosions in underground storage tanks can be minimized. According to the optimum design of storage tank obtained in this study, underground containment space was minimized; the minimized diameter and length of a 20-ton storage tank was 3 m and 4.83 m, respectively. Thus, safety was ensured since surface area exposed to flames decreased by 89.4%, which is less than the exposed surface area in the currently used storage tanks.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.3
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• pp.111-119
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• 1999

The purpose of this study is the simulation of discontinuous rockmass and identification of characteristics of discontinuity network as a branch of the study on characteristics of groundwater system in discontinuous rockmass for evaluation of safety on disposal site of radioactive waste. In this study the site for LPG underground storage was selected for the similarities of the conditions which were required for disposal site of radioactive waste. Through the identification of hydraulic properties. characteristics of discontinuities and selection of discontinuity model around LPG underground storage facility. the applications of discrete fracture network model were evaluated for the analysis of pathway. The orientation and spatial density of discontinuities are primarily important elements for the simulation of groundwater and solute transportation in discrete fracture network model. In this study three fracture sets identified and the spatial intensity (P$_{32}$) of discontinuities is revealed as 0.85 $m^2$/㎥. The conductive fracture intensity (P$_{32c}$) estimated for the simulation area around propane cavern (200${\times}$200${\times}$200) is 0.536 $m^2$/㎥. Truncated conductive fracture intensity (T-P$_{32c}$) is calculated as 0.26 $m^2$/㎥ by eliminating the fracture with the iowest transmissivity and based on this value the pathway from the water curtain to PC 2. PC 3 analyzed.

• 한국지구물리탐사학회:학술대회논문집
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• 1999.08a
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• pp.117-136
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• 1999

The geophysical survey at pre-investigation stage can hardly provide the detailed information on geological structure of site which has difficulty in access and thick overburden. The TSP (VSP applied in tunnel) survey at post-investigation stage can show the detailed geology ahead of tunnel and around cavern. The TSP survey was carried out at the Pyongtaek LPG storage cavern site during the cavern excavation and provided the location and orientation of the fault inferred below Namyangho. In order to confirm the result of TSP survey four boreholes were drilled in access tunnel. The fault was also detected by borehole survey and the location was coincided with the result of TSP survey. Depend on the result of TSP survey and core logging, the design such as cavern layout and length could have been changed. As another case history the TSP survey was performed at the Mumeuje road tunnel which has poor geological information due to thick overburden. The support design was also changed on the base of TSP survey.