Assessment of Geosynthetic Materials for Tunnel Drains: Laboratory Tests and Image Analyses

• Published in: KSCE journal of civil engineering Vol. 28; no. 11; pp. 4844 - 4852
• Main Authors: Jo, Youngseok, Cha, Wonjun, Yoo, Wan-Kyu, Kim, Bumjoo
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Civil Engineers 01.11.2024; Springer Nature B.V; 대한토목학회
• Subjects: Calcium; Calcium carbonate; Calcium carbonates; Calcium imaging; Carbonates; Chemical agents; Civil Engineering; Confining; Design analysis; Design factors; Discharge; Discharge capacity; Drainage; Drainage systems; Drains; Engineering; Environmental engineering; Geocomposites; Geosynthetics; Geotechnical Engineering; Geotechnical Engineering & Applied Earth Sciences; Geotechnical fabrics; Groundwater; Harmonica music; Hydrostatic pressure; Image analysis; Image processing; Imaging techniques; Industrial Pollution Prevention; Investigations; Laboratories; Laboratory tests; Liquids; Microscopy; Polymers; Pore water pressure; Pressure; Scanning electron microscopy; Scanning microscopy; Scientific imaging; Spectrometry; Tunnel linings; Tunnels; Water pressure; X-ray spectroscopy; 토목공학; Discharge capacity; Secondary scanning microscopy (SEM); Energy-dispersive X-ray spectrometry (EDS); Calcium carbonate (CaCO; Geosynthetic materials; Laboratory test; ); Tunnel drainage systems
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-024-1690-3

Tunnel drainage systems are crucial design factors in tunnels because the accumulation of groundwater at the back of linings can affect tunnel safety. Geotextiles are used to facilitate the dissipation of pore-water pressure. However, chemical agents in the water can lead to clogging as tunnels age. In this study, laboratory tests and image analysis, namely Secondary Scanning Microscopy (SEM) and Energy-dispersive X-ray Spectrometry (EDS), were conducted to assess the drain performance of five geosynthetic materials: four geocomposites and one three-layered Non-Woven Needle-Punched (NWNP) geotextile. Calcium carbonate (CaCO 3 ) in liquids affects the discharge capacity of drains, and this capacity decreases with increasing confining pressure. NWNP geotextile is the most vulnerable to confining pressure as it lacks a core. The reason behind the significant decrease in the discharge capacity of NWNP geotextile is clarified based on the SEM analysis. EDS analysis investigated the major composition of the clogged materials, revealing that the primary components are carbon, oxygen, and calcium. Advanced imaging techniques can be utilized to gain a deeper understanding of the underlying mechanisms. The results of this study can aid in the design and maintenance of engineering systems, especially tunnel drainage systems, that incorporate geosynthetic materials.