Performance Evaluation of Geosynthetics Pocket filled with Expansive Material by Field Test

Daeyoung Lee

Korea Institue of Civil Engineering & Building Technology, Department of Infrastructure Safety Research, Korea (dylee@kict.re.kr)

In this study, field test for evaluating the applicability of road cavity-filling method to prevent subsidence due to cavity under the road was conducted. To simulate the cavity occurred under the road, ice was used and surface layer was paved with asphalt. GPR investigation was performed before and after filling the cavity so as to identify the cavitation and ground behaviour and the effect of filling material was verified through the partial excavation. Cavity-filling was completed by filling it with the sand and compaction and the sand containing the geosynthetics pocket filled with expansive material. After applying the filling material, it’s monitored by endoscope that geosynthetics pocket filled with expansive material began swelling, making sand layer dense. When filling with the sand according to traditional method, soil compaction was impossible and filling performance was not satisfactory, but geosynthetics pocket filled with expansive material proved to have enhanced the compaction effects. Through the excavation survey of the road cavity filled with sand and expansive material, it was confirmed that the backfill method using the geosynthetic pocket filled with expansive material is effective for road cavity restoration.