The Road Subsidence Status and Safety Improvement Plans

Abstract

Ground subsidence can result in the formation of sinkholes, potholes, settlement of structures, and road subsidence. Road subsidence is described as the sudden collapse of the road surface into subsurface cavities caused by the loss of bearing capacity in the ground, such as the dissolution of limestone by fluid flow in the surface causing the formation of voids leading to subsidence at the surface. Road subsidence occurs about 665 times annually, and this incidence has been increasing until 2013. Damaged underground facilities, management negligence, and lowering of the ground water table have been the causes of road subsidence in Seoul. Seoul metropolitan government announced special management counter plans to relieve the anxieties and make the roads safe for passing. Construction sites, such as excavation works, need to be managed properly because they have strong potential to induce road subsidence. The aim of this study was to identify the main causes of road subsidence and suggest management plans. First, life cycle cost analysis revealed the daytime construction to be more appropriate than nighttime. In addition, by analyzing the limitations of using sand as a backfill material, it is proposed to use a flowable backfill material instead of sand. Finally, to reduce the blind spots, which is a problem in surveying the road pavement conditions of local governments, the road to be managed is divided into several zones, and a specialized agency is selected for each zone and a method of surveying the blind spots through collaboration is suggested.

Strength Characteristics of Controlled Low-Strength Materials with Waste Paper Sludge Ash (WPSA) for Prevention of Sewage Pipe Damage

“…With the aging of buried pipes, incidents of ground subsidence around them have become increasingly frequent in South Korea. Underground cavities around sewage pipes in urban areas caused by aging and damage have been found to be the main cause of ground subsidence, accounting for approximately 82% of the total number of occurrences, as shown in Figure 1 [ 1 , 2 ].…”

Application of Waste Plastic Films in Road Infrastructure and Construction

“…In addition, during road excavation restoration work for the maintenance of underground buried pipes, voids can occur at the beginning of common use because of poor compaction at the bottom of buried pipes; consequently, adjacent soils move into the voids. This results in overall settlement in the backfill soil along with faulting and distresses in the pavement of the excavation recovery site (Bae et al, 2017). To improve the backfilling and fastening structure of underground buried pipes during excavation recovery construction and to improve the compaction defect, the application of WPF-RPs is proposed, which could better address the accelerated weathering issues associated with light exposure.…”

Experimental assessment of the relationship between rainfall intensity and sinkholes caused by damaged sewer pipes

“…In recent times, cases of sinkholes (or ground cave-ins) have been reported in several countries, such as the US, Japan, Italy, South Africa, China, and South Korea. Major social and economic issues have ensued owing to the resulting structural problems, such as the collapse of buildings and road erosion (Bae et al, 2016;Galloway et al, 1999;Gao et al, 2013;Guarino and Nisio, 2012;Intrieri et al, 2015;Kuwano et al, 2010a;Oosthuizen and Richardson, 2011;Yokota et al, 2012). In general, sinkholes can be classified into two types:…”

“…In Seoul, South Korea, an average of 677 sinkholes and subsidence occurred annually from 2010 to 2015, of which 81.4 % were due to damage to old sewer pipes (Bae et al, 2016). In Japan, local governments in sewage projects were surveyed to identify cases of subsidence due to damage to sewer pipes.…”