• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.133-144
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• 2009

Incheon Bridge, 18.4 km long sea-crossing bridge, will be opened to the traffic in October 2009 and this will be the new landmark of the gearing up north-east Asia as well as the largest & longest bridge of Korea. Incheon Bridge is the integrated set of several special featured bridges including a magnificent cable-stayed girder bridge which has a main span of 800 m width to cross the navigation channel in and out of the Port of Incheon. Incheon Bridge is making an epoch of long-span bridge designs thanks to the fully application of the AASHTO LRFD (load & resistance factor design) to both the superstructures and the substructures. A state-of-the-art of the geotechnologies which were applied to the Incheon Bridge construction project is introduced. The most Large-diameter drilled shafts were penetrated into the bedrock to support the colossal superstructures. The bearing capacity and deformational characteristics of the foundations were verified through the world's largest static pile load test. 8 full-scale pilot piles were tested in both offshore site and onshore area prior to the commencement of constructions. Compressible load beyond 30,000 tonf pressed a single 3 m diameter foundation pile by means of bi-directional loading method including the Osterberg cell techniques. Detailed site investigation to characterize the subsurface properties had been carried out. Geotextile tubes, tied sheet pile walls, and trestles were utilized to overcome the very large tidal difference between ebb and flow at the foreshore site. 44 circular-cell type dolphins surround the piers near the navigation channel to protect the bridge against the collision with aberrant vessels. Each dolphin structure consists of the flat sheet piled wall and infilled aggregates to absorb the collision impact. Geo-centrifugal tests were performed to evaluate the behavior of the dolphin in the seabed and to verify the numerical model for the design. Rip-rap embankments on the seabed are expected to prevent the scouring of the foundation. Prefabricated vertical drains, sand compaction piles, deep cement mixings, horizontal natural-fiber drains, and other subsidiary methods were used to improve the soft ground for the site of abutments, toll plazas, and access roads. Light-weight backfill using EPS blocks helps to reduce the earth pressure behind the abutment on the soft ground. Some kinds of reinforced earth like as MSE using geosynthetics were utilized for the ring wall of the abutment. Soil steel bridges made of corrugated steel plates and engineered backfills were constructed for the open-cut tunnel and the culvert. Diverse experiences of advanced designs and constructions from the Incheon Bridge project have been propagated by relevant engineers and it is strongly expected that significant achievements in geotechnical engineering through this project will contribute to the national development of the longspan bridge technologies remarkably.

• Korean Journal of Heritage: History & Science
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• v.49 no.3
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• pp.154-201
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• 2016

During the Incipient and Early Silla phases, which witnessed the establishment and development of the ancient Silla state, the Wolseong North Burial Ground functioned as not only the central burial ground in the Gyeongju region of the capital of Silla but also as the central burial ground of the whole Silla state. Wolseong North Burial Ground is where transformations in Silla funerary architecture first occurred. As such, an empirical study of the tombs constructed at this burial ground can be regarded as a starting point from which an understanding of the development of the tomb culture of the Silla state may be achieved. This paper therefore aims to examine the changing nature of the tomb culture of the Early Silla phase through the burial data of Wolseong North Burial Ground and the Gyeongju region. Wooden chamber tombs were constructed from the late phase of Saroguk. At Wolseong North Burial Ground, which eventually developed into the central burial ground of the Gyeongju region, wooden chamber tombs embellished with stone packing emerged during the Incipient Silla phase; wooden chamber tombs with stone mounds, on the other hand, first appeared in the Early Silla phase and eventually became established as the central tomb type. A key difference between the wooden chamber tomb embellished with stone packing and the wooden chamber tomb with stone mound is that, in the case of the latter, stones were packed not only around sides of the wooden structure that acted as the burial chamber but also on top of this structure. The addition of a high earthen mound surrounded by protective ring of stones is another distinctive feature of the latter, presenting a contrast to the low mound of the former. During the Early Silla phase, two types of wooden chamber tombs with stone mounds were constructed at Wolseong North Burial Ground: those with burial chambers located above ground and those with subterranean burial chambers. Also constructed during this phase were the wooden chamber tomb embellished with packed stones, the wooden chamber tomb embellished with packed clay, simple earth cut burials, which had been used since the Incipient Silla phase, as well as the stone-lined burials with vertical entrance which first appeared in the Early Silla phase. However, of these different types of burials, it was only the wooden chamber tomb with stone mound that was covered with a 'high mound.' Differentiation between the different tomb types can also be observed in terms of location, type of burial chamber used, construction method, and tomb size. It is therefore possible to surmise that stratification between the different tomb types, which first emerged in the Incipient Silla phase, became intensified during the Early Silla phase.