The Gongsanseong Fortress in Gongju, Republic of Korea, is one of the most essential remains for historical research of Baekje Kingdom, and reinforces on the fortress wall has continuously been implemented since the sixth century to present. Through visual inspections of the fortress ramparts, sections in which structural deformations have occurred, and then they were classified by morphological characteristics based on lithofacies that compose the ramparts, shape of each rock, and construction method. Also, automatic sensors that can measure behavior changes of the ramparts, and the surrounding environment were installed to monitor microscale movements of the ramparts and changes in the surrounding microclimate. As a result, damages were shown intensively on the ramparts that retain specific morphological characteristics, and it has been discovered that, even for the ramparts located in an identical environment, morphological characteristics affect damages and structural deformations of the ramparts because of behavior changes for minutes. Such changes in behavior can be classified based on reversibility and predictability, and different management schemes must be applied based on behavior change patterns. If we continuously operate and develop this monitoring system, it is expected to be meaningfully utilized in efficient maintenance of the cultural heritage of the ramparts.

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Physicochemical characteristics and evaluation were studied by subdividing the concretes, bricks and earth pipes on the site of the Japanese Ministry of General Affairs in Joseon Dynasty, known as modern architecture, into three periods. Concretes showed similar specific gravity and absorption ratio, and large amounts of aggregates, quartz, feldspar, calcite and portlandite were detected. Porosity of the 1907 bricks were higher than those of 1910 and 1950 bricks. All earthen pipe is similar, but the earlier one was found to be more dense. Bricks and earthen pipes are dark red to brown in color within many cracks and pores, but the matrix of the earthen pipe is relatively homogeneous. Quartz, feldspar and hematite are detected in bricks, and mullite is confirmed with quartz and feldspar in earthen pipes, so it is interpreted that the materials have a firing temperature about 1,000 to 1,100 o C. Concretes showed similar CaO content, but brick and earthen pipe had low SiO 2 and high Al 2 O 3 in the 1907 specimen. However, the materials have high genetic homogeneity based on similar geochemical behaviors. Ultrasonic velocity and rebound hardness of the concrete foundation differed due to the residual state, but indicated relatively weak physical properties. Converting the unconfined compressive strength, the 1st extended area had the highest mean values of 45.30 and 46.33 kgf/cm 2 , and the 2nd extended area showed the lowest mean values (20.05 and 24.76 kgf/cm 2 ). In particular, the low CaO content and absorption ratio, the higher ultrasonic velocity and rebound hardness. It seems that the concrete used in the constructions of the Japanese Ministry of General Affairs in Joseon Dynasty had similar mixing characteristics and relatively constant specifications for each year. It is interpreted that the bricks and earthen pipes were through a similar manufacturing process using almost the same raw materials.

The Iksan Ssangneung (twin tombs), a pair of tombs comprising the Daewangneung (large royal tomb) and the Sowangneung (small royal tomb), were constructed in the typical style of stone tunnel and chamber tombs in the Baekje Kingdom during the Sabi period (538 to 660 AD) of ancient Korea. Soil layers exposed during excavation of Sowangneung in a trench east of the tomb are: the bottommost layer, the ground level layer, the Panchuk (rammed earth) layer of the Baekje, the layer created by a grave robbery, and soil recovered during the Japanese colonial period. Soil samples were obtained by segmenting an easy stratigraphic horizon into sub categorized soil layers, and their material properties were analyzed; they are composed mainly of sandy loam based on the particle size distributions. In the site foundation, loamy sand is packed in the bottommost layer, and sandy loam with high sand and silty sand fills most of the overlying layer. The central and topmost portion of the Baekje layer is composed of loam with high clay content. All soil layers show geochemical behaviors similar to those of the bottommost layer. X-ray diffraction analysis verified kaolinite in all layers, also observed in soil layers displaying high crystallinity. Kaolinite and halloysite were identified by scanning electron microscopy. Thus, we conclude that the Baekje layer of the Sowangneung is composed of sandy loam containing kaolin procured from near the site. An impermeable middle to upper layer was created using viscous loam. The top of the tomb was closed tightly.

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