The Seoul Metropolitan Government conducted an exploratory mission to locate any sinkholes in a 30km-wide area around Seoul Nat’l Univ. of Education Station, Yeouido Station, and Jongno 3 (sam) ga Station. To carry out the investigation, cutting-edge exploration devices provided by Geo Search, Japan’s largest geographic research services provider, were mobilized from December 1 to 5.
The relevant areas are near subway transfer stations that are frequented by Seoul citizens, with many antiquated sewage ways and underground facilities. The Seoul Metropolitan Government will respond quickly to the discovery of any sinkholes in order to prevent the collapse of roads while introducing state-of-the-art exploration devices and expanding exploration activities to those offered by private agencies.
For this exploration, one vehicle-based Ground-Penetrating Radar (GPR) system and one sinkhole exploration endoscope, both owned by Geo Search, were used. The exploration will be divided into two parts: a basic sinkhole exploration and an in-depth investigation by endoscope. After exploring the sinkholes through the use of a vehicle-based GPR system, if an area suspicious of having a sinkhole is found, a hole will be drilled and an in-depth investigation carried out.
The vehicle-based GPR system, which is used for exploration, can explore a width of 2.4m at a time; therefore, in comparison to regular GPR, which must be operated manually by several people, it can explore a much wider area in the same amount of time. The endoscope is a cutting-edge device that can observe underground images and create color films.
Located in Tokyo, Japan, Geo Search has 100 GPR systems and 40 endoscopes with many years of related experience and technology. Prior to this exploration, Geo Search signed “an agreement on conducting sinkhole exploration activities for free” on November 19; thus, the equipment that was used during the exploration were offered to the Seoul Government at no cost.