Seoul, South Korea – In response to a series of recent ground subsidence incidents near large-scale excavation sites, including a sinkhole in Myeongil-dong, Gangdong-gu, and a ground collapse at the Shinansan Line construction site in Gwangmyeong, Gyeonggi Province, the Seoul Metropolitan Government (SMG) has announced a set of enhanced special measures to bolster ground subsidence safety management. A key component of this initiative involves the prioritized implementation of Ground Penetrating Radar (GPR) surveys at and around major underground excavation sites.

The SMG will initially conduct intensive GPR surveys across 18.5 kilometers of three urban railway construction sections within the city and adjacent roads. To facilitate this, the city has mobilized its available workforce of 41 personnel and 15 survey equipment units, commencing the GPR investigations at the end of last month.

The three urban railway construction sites under focused inspection are: the 4.1-kilometer section of the Seoul Metropolitan Subway Line 9 Phase 4 construction (sections 1-3), the 13.4-kilometer section of the Dongbuk Line urban railway private investment project construction (sections 1-4), and the 1.0-kilometer section of the Yeongdongdaero underground space complex development project.

Furthermore, the SMG will also extend its scrutiny to metropolitan railway construction sections within Seoul, even if the ordering party is not the city government. These include the 12.1-kilometer Seoul section of the Shinansan Line (Seoksu Station to Yeouido Station) and the 18.7-kilometer Seoul section of the Great Train eXpress (GTX-A) (Suseo Station to Seoul Station). Notably, GPR surveys on the Seoul section of the Shinansan Line commenced earlier this month.

The city also plans to complete the investigation and analysis of GPR surveys on 50 priority inspection areas, spanning 45 kilometers, which were selected by eight autonomous districts at the end of last year, by the end of this month. For the 17 autonomous districts that did not submit priority areas last year, the SMG will conduct a renewed demand survey, collect data, and implement additional investigations.

To enhance the efficiency of GPR surveys, the SMG will prioritize GPR investigations in sections identified as requiring inspection on the newly created priority maintenance zone map. This strategic approach aims to further strengthen activities aimed at preventing ground subsidence.

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In a pioneering move nationwide, the SMG will pilot the installation and operation of a "ground subsidence monitoring network" that utilizes in-ground sensors to measure ground changes in real time. Additionally, the city plans to deploy advanced technology-based measurement equipment around construction sites to continuously monitor ground variations.

The findings of the enhanced GPR surveys and details regarding the adoption of new technologies will be made publicly available on the "Seoul Safety Nuri" website. This initiative aims to alleviate public anxiety and address any concerns related to safety.

Han Byung-yong, Head of the Disaster and Safety Management Office, stated, "In response to the recent series of ground subsidence incidents, the Seoul Metropolitan Government is reinforcing GPR surveys to reassure citizens and verify the safety of our roads. We are committed to preventing similar incidents in the future by not only enhancing GPR surveys but also by introducing real-time ground change measurement equipment and implementing even stronger safety management measures."

Additional Information Supplementing the Article:

What is Ground Penetrating Radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This non-destructive 1  technique utilizes electromagnetic radiation in the microwave frequency band (typically from 10 MHz to 2.6 GHz) and detects the reflected signals from subsurface structures. GPR can be used to detect voids, cracks, buried utilities, soil layering, and other anomalies beneath the ground surface, making it a valuable tool for assessing ground stability and identifying potential risks of subsidence.  

Significance of Recent Ground Subsidence Incidents: The sinkhole in Gangdong-gu and the ground collapse at the Shinansan Line construction site raised significant public concern about the safety of infrastructure and the potential for further incidents, especially in densely populated urban areas with extensive underground development. These incidents underscored the need for proactive and comprehensive ground safety management measures.
Details of the Urban and Metropolitan Railway Projects:Seoul Metropolitan Subway Line 9 Phase 4: This extension project aims to extend Line 9 further east, improving connectivity in southeastern Seoul.
Dongbuk Line Urban Railway: This privately funded project will create a new north-south light rail line in northeastern Seoul, enhancing public transportation access in underserved areas.
Yeongdongdaero Underground Space Complex Development: This ambitious project involves the creation of a large-scale underground complex beneath Yeongdongdaero, featuring transportation hubs, commercial facilities, and public spaces.
Shinansan Line: This new commuter rail line will connect southwestern Seoul with Ansan, significantly improving travel times for commuters in the region.
GTX-A: This high-speed commuter rail line will connect Suseo in southeastern Seoul with Goyang and Unjeong to the northwest, drastically reducing travel times within the greater Seoul metropolitan area.
"Seoul Safety Nuri" Website: This online platform serves as a central hub for safety-related information in Seoul, providing the public with access to data, reports, and updates on various safety initiatives and measures implemented by the city government. The inclusion of GPR survey results and new technology information on this platform demonstrates the SMG's commitment to transparency and public reassurance.
The Importance of Real-time Monitoring: Implementing real-time ground change monitoring systems represents a significant advancement in proactive safety management. By continuously tracking subtle ground movements, the city can identify potential risks early and intervene before major incidents occur, enhancing the safety and reliability of infrastructure.
By implementing these enhanced measures, the Seoul Metropolitan Government aims to create a safer urban environment and mitigate the risks associated with large-scale underground construction. The proactive use of GPR technology and the adoption of real-time monitoring systems demonstrate a commitment to leveraging advanced technologies for public safety.