Effect of Groundwater Level Variation on Residual Settlement of Korean High-Speed Railway on Soft Ground

초록

Groundwater drawdown is one of the factors that inducoe settlement in soft ground. However, the drawdown usually does not lead to a large settlement, and thus is not considered at the design stage. A few sites along the Honam High-Speed Railway experienced relatively large residual settlements, judging from residual settlement criterion of 30 mm in Korea. This settlement occurred during the dry season in Korea; accordingly, groundwater drawdown was pointed out as a cause of the settlement. This study focuses on the effect of groundwater level variation on residual settlement by field measurement and numerical analysis. The numerical simulation produced reasonably similar settlement behavior to that of the field measurements, which proves that the numerical analysis represents field performance. The comparison of numerical analysis between the constant and variable groundwater level clearly shows the effect of groundwater variation on the settlement of soft ground. The drawdown only leads to additional residual settlements of 7.3 and 8.3 mm at the surface of the natural ground and embankment. The total residual settlement is approximately 21.9 mm; thus, more than 33% of the settlement was caused by groundwater drawdown. Therefore, the groundwater variation should be considered at the design and construction stages to reduce residual settlement in the case of strict criterion.

키워드