Establishing Foundation by Laying Organic Soil Layer under Han River Bank
Using 2.5m Long Wooden Piles "Modern-day H-Beams"
Amazing construction and civil engineering skills of the Baekje people have been confirmed at Pungnaptoseong in Seoul. The National Research Institute of Cultural Heritage, National Seoul Cultural Heritage Research Institute, will hold a briefing session to disclose the excavation results at the Seoseong Wall restoration site for two days starting from the 17th. Since 2017, the investigation team has been confirming the process of fortress construction and civil engineering techniques.
The area along the Han River where Pungnaptoseong is located has favorable geographical conditions with connected waterways and land routes. However, it is a back swamp area, making it vulnerable to floods and inundations. According to this investigation, the Baekje people minimized damage by utilizing natural levees (embankments formed by sand and gravel accumulating at the edges due to floods or inundations). Beneath the Han River side, they laid gravel and peat layers to establish a construction foundation. The peat layer is formed by inserting organic materials such as reeds, herbaceous plants, branches, and plant fibers as reinforcement before piling up soil. It serves to stabilize back swamp or soft ground.
The Baekje people also performed ritual acts while laying the foundation of the royal fortress. Numerous traces of jijinggu (地鎭具) used in rituals were found in the base layer of the Seoseong Wall, and animal remains were discovered as offerings (貢獻物) buried (maenap, 埋納 - the act of intentionally burying or hiding) at the Seomunji site. Jijinggu are symbolic objects enshrined to pray for safety before constructing a building, and offerings are items left to dedicate to gods or supernatural beings. A research institute official interpreted, "It was likely a ritual to pray for the successful construction of the royal fortress and to officially mark the start of large-scale construction."
The excavation also uncovered jangmokju (長木柱) longer than 2.5 meters. These are thick and long wooden pillars used to support or brace buildings, comparable to the framework of modern architecture. The research institute official said, "They probably played a role similar to H-beams (steel columns) used for structural stability."
Various panchuk (板築) structures for making panguae (板塊) were confirmed on the fortress walls with a circumference of over 3.8 km. Panchuk refers to the practice of alternately stacking soil layers of different properties with a certain thickness inside a rectangular frame (rectangular in plan view) and compacting them. The piled soil lumps are called panguae, and by continuously attaching these front, back, left, and right, the fortress wall is completed. A research institute official evaluated, "It can be regarded as a collection of Baekje Hanseong period civil engineering technology."
© The Asia Business Daily(www.asiae.co.kr). All rights reserved.
