‘Sinkhole risk assessment’ is mandatory for underground development

From the next year at the earliest, "preliminary safety assessment" is required for large-scale underground space development to prevent phenomenon called sinkhole (a hole caused by collapsing of the ground). "Integrated map for underground space" is to be established.

The Ministry of Land, Infrastructure and Transport announced Thursday a "ground collapse preventative measures," which includes such matters at the National Policy Adjustment meeting led by the prime minister. The ministry has formed and been operating a joint task force of the government and the private sector since a series of sinkhole phenomenon occurred this summer.

According to the measures, the government will establish "Special Act on Safety Management of Underground Space (tentative title)" next year. The special act contains provisions to introduce " preliminary safety assessment system for underground development" to assess risks that may affect the surrounding grounds and facilities before developing underground spaces. Corporation that wants to develop underground space over a certain size must receive the assessment. Otherwise, the underground construction will not be approved.

Before the preliminary safety assessment system is fully introduced, the "Construction Work Safety Management Plan," which will be established under the Construction and Technology Promotion Law, will contain the ground safety measures for excavation works. Under the law, any corporation that desires to excavate over 10 meters in depth must mandatorily submit a safety management plan.

In addition, the ministry will establish an integrated map of underground space by the year of 2017. Currently, four government ministries distribute and manage 15 types of underground usage information, which include water supply and drainage system, subway system and underground parking lots, under 11 legislations.