• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.4-23
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• 2013

Songsalli Ancient Tombs of Gongju consists of seven tombs. King Muryeong's tomb, the seventh tomb, is a brick chamber tomb discovered during the drainage works for the fifth and the sixth tombs in 1971. The excavation at the time focused on topographic surveys of the tomb entrance and the inside of the burial chamber as well as collection of the remains. The burial mount survey confirmed the status of some stone slab remaining and lime-mixed soil layers, but the survey did not examine the exterior structure of the whole tomb as the mounds were removed even more deeply. The excavation revealed damages to the bricks and mural damages due to moisture and fungus in the sixth and the seventh tombs. Between 1996 and 1997, Gongju National University conducted a comprehensive detailed survey of Songsalli Ancient Tombs including a geophysical survey, with an aim to identify the root causes of such degradation. Based on the results, repair took place in 1999 and the fifth, sixth and seventh tombs were placed under permanent conservation to conserve the cultural assets. General public is currently denied access. The purpose of this study was to conduct a three-dimensional resistivity and GPR surveys on the ground surface of the fifth, sixth and seventh tombs of Songsalli Ancient Tombs in order to understand the underground status after repair. The study also aimed to understand the thickness of all the tomb walls and exterior structure based on GPR inside King Muryeong's tomb. The exploration on the ground surface found that the three tombs and soil adjacent to the tombs had resistivity as low as 5 to $90{\Omega}m$, which confirmed that the soil water content was still as high as that prior to the repair work. Additionally, GPR found that the wall construction of the burial chamber of King Muryeong's tomb was approximately 70cm in thickness, while the structure was of 2B with two bricks, about 35cm in length, put together longitudinally(2B brick masonry). The pathway to the burial chamber was of the 2B structure just like that of the burial chamber walls, while its thickness was 80cm with an eyebrow-type arch connected to it. Also, the ceiling exterior appears to have an arch structure, identical to the shape inside.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.167-175
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• 2019

To effectively deal with the fire in tunnel which is mostly the vehicle fire, it's more important to suppress the fire at early stage. In urban tunnel, however, accessibility to the scene of fire by the fire fighter is very limited due to severe traffic congestion which causes the difficulty with firefighting activity in timely manner and such a problem would be further worsened in underground road (double-deck tunnel) which has been increasingly extended and deepened. In preparation for the disaster in Korea, the range of life safety facilities for installation is defined based on category of the extension and fire protection referring to risk hazard index which is determined depending on tunnel length and conditions, and particularly to directly deal with the tunnel fire, fire extinguisher, indoor hydrant and sprinkler are designated as the mandatory facilities depending on category. But such fire extinguishing installations are found inappropriate functionally and technically and thus the measure to improve the system needs to be taken. Particularly in a double-deck tunnel which accommodates the traffic in both directions within a single tunnel of which section is divided by intermediate slab, the facility or the system which functions more rapidly and effectively is more than important. This study, thus, is intended to supplement the problems with existing tunnel life safety system (fire extinguishing) and develop the remote-controlled automatic fire extinguishing system which is optimized for a double-deck tunnel. Consequently, the system considering low floor height and extended length as well as indoor hydrant for a wide range of use have been developed together with the performance verification and the process for commercialization before applying to the tunnel is underway now.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.307-324
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• 2020

Major and trace elements, and Sr, Nd, isotopic composition analysis have been carried out on the Miocene basalt (Huangsongpu basalt, 20 Ma) 25 km to northeast from the Mt. Baekdu. The basalt has Na2O+K2O=3.5~4.7 wt.%, and MgO=9.9~11.1 wt.%, containing Mg-rich olivine (Mg#=75~86), clinopyroxene (Mg#=72~85) and Ca-rich plagioclase micro-phenocrysts. These data suggest that the basalt belongs to the alkaline magma series with a primitive nature, crystallized at a near-liquidus. The basalt is also characterized by high Cr (394~479 ppm) and Ni (389~519 ppm) contents, Nb-Ta enrichment anomalies and OIB-like trace elements patterns, displaying identical signatures to those of typical intraplate magmas. The rare earth element (REE) patterns of the basalt and high (Gd/Yb)sample/(Gd/Yb)PM ratio (=2.8~3.5) suggest the parental magma was derived from relatively low-degree (3~5%) partial melting of garnet peridotite. The 143Nd/144Nd and 87Sr/86Sr composition of the basalt are higher than those of BSE. The high 87Sr/86Sr (= ~0.7058) ratio of the basalt indicates a contribution of recycled ancient oceanic crust or continental crust on the Pacific slab suggesting that the Huangsongpu basalt was generated from metasomatized mantle.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5A
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• pp.557-564
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• 2009

In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast overpressure is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, information and test results related to the blast experiment of internal and external have been limited due to military and national security reasons. Therefore, in this paper, to evaluate blast effect on reinforced have concrete structure and its protective performance, blast tests are carried out with $1.0m{\times}1.0m{\times}150mm$ reinforce concrete slab structure at the Agency for Defence Development. The standoff blast distance is 1.5 m and the preliminary tests consists with TNT 9 lbs and TNT 35 lbs and the main tests used ANFO 35 lbs. It is the first ever blast experiment for nonmilitary purposes domestically. In this paper, based on the basic experiment procedure and measurement details for acquiring structural behavior data, the blast experimental measurement system and procedure are established details. The procedure of blast experiments are based on the established measurement system which consists of sensor, signal conditioner, DAQ system, software. It can be used as basic research references for related research areas, which include protective design and effective behavior measurements of structure under blast loading.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.152-161
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• 2023

In general, large-capacity hydrogen storage vessels, typically in the form of vertical cylindrical vessels, are constructed using steel materials. These vessels are anchored to foundation slabs that are specially designed to suit the environmental conditions. This anchoring method involves pre-installed anchors on top of the concrete foundation slab. However, it's important to note that such a design can result in concentrated stresses at the anchoring points when external forces, such as seismic events, are at play. This may lead to potential structural damage due to anchor and concrete damage. For this reason, in this study, it selected an vertical hydrogen storage vessel based on site observations and created a 3D finite element model. Artificial seismic motions made following the procedures specified in ICC-ES AC 156, as well as domestic recorded earthquakes with a magnitude greater than 5.0, were applied to analyze the structural behavior and performance of the target structures. Conducting experiments on a structure built to actual scale would be ideal, but due to practical constraints, it proved challenging to execute. Therefore, it opted for an analytical approach to assess the safety of the target structure. Regarding the structural response characteristics, the acceleration induced by seismic motion was observed to amplify by approximately ten times compared to the input seismic motions. Additionally, there was a tendency for a decrease in amplification as the response acceleration was transmitted to the point where the centre of gravity is located. For the vulnerable components, specifically the sub-system (support columns and anchorages), the stress levels were found to satisfy the allowable stress criteria. However, the concrete's tensile strength exhibited only about a 5% margin of safety compared to the allowable stress. This indicates the need for mitigation strategies in addressing these concerns. Based on the research findings presented in this paper, it is anticipated that predictable load information for the design of storage vessels required for future shaking table tests will be provided.

• Korean Journal of Heritage: History & Science
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• v.42 no.4
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• pp.20-49
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• 2009

This paper explores the Korean royal tombs steles such as monumental steles and tombstone marks (神道碑, 表石) that are broadly fallen into the following three periods ; the 15~16th centuries, 17th~18th centuries, and 19th century. As a result, the royal tombs steles were built, unlike the private custom, on the heirs to the King's intentions. During the 15~17th centuries the construction and reconstruction of the monumental steles took place. In the late Joseon period, monumental steles had been replaced with a number of tombstone marks were built to appeal to the king's calligraphy carved on stone for the first time. During the Great Empire Han(大韓帝國) when the Joseon state was upgraded the empire, Emperors Gojong and Sunjong devoted to honor ancestors by rebuilding royal tombstone mark. Based on these periodical trends, it would not be exaggerated that the history of establishing the royal tombs steles formed in late Joseon. The type of royal tombs monuments originated from those of the Three Kingdoms era, a shapeless form, the new stele type of the Tang Dynasty (唐碑) has influenced on the building of monuments of the Unified Silla and Buddhist honorable monuments (塔碑) of the Goryeo Dynasty. From the 15th century, successive kings have wished to express the predecessors's achievements, nevertheless, the officials opposed it because the affairs of the King legacy (國史) were all recorded, so there is no need to establish the tombs steles. Although its lack of quantity, each Heonneung and Jereung monumental steles rebuilt in 1695 and 1744 respectively, is valuable to show the royal sculpture of the late Joseon period. Since the 15th century, the construction of the royal tombs monumental steles has been interrupted, the tombstone marks (boulders) with simpler format began to be erected within the tomb precincts. The Yeoneung tombstone mark(寧陵表石), built in 1682, shows the first magnificent scale and delicate sculpture technique. Many tombstone marks were erected since the 1740s on a large scale, largely caused by King Yeongjo's announce to the honorific business for the predecessors. Thanks to King Yeongjo's such appealing effort, over 20 pieces of tombstone marks were established during his reign. The fact that his handwritten calligraphic works first carved on tombstones was a remarkable phenomenon had never been appeared before. Since the 18th century, a double-slab high above the roof(加?石) and rectangular basement of the stele have been accepted as a typical format of the tombstone marks. In front of the stele, generally seal script calligraphic works after a Tang dynasty calligrapher Li Yangbing(李陽氷)'s brushwork were engraved. In 1897 when King Gojong declared the Empire, these tombstone marks were once again produced in large amounts. Because he tried to find the legitimacy of the Empire in the history of the Joseon dynasty and its four founding fathers in creating the monuments both of the front and back sides by carving his in-person-calligraphy as a ruler representing his symbolic authority. The tombstone marks made during this period, show an abstract sculpture features with the awkward techniques, and long and slim strokes. As mentioned above, the construction of monumental steles and tombstone marks is a historical and remarkable phenonenon to reveal the royal funeral custom, sculpture techniques, and successive kings' efforts to honor the royal predecessors.