Evaluation of the Degree of Consolidation of Coastal Reclaimed Lands Based on Settlement Data and CPTu

Abstract

Reclamation works in coastal area has started to be done a lot in Indonesia due to the increasing of land requirements caused by population growth. There are some important geotechnical problem in reclamation works to be concerned such as the density of compacted fill material related to the liquefaction potential due to the earthquake, the slope stability of fill works along the construction period, and one of the main issue is the degree of consolidation of the very soft sub soil. This paper is focused to address the evaluation of the degree of consolidation of coastal reclaimed land based on the settlement monitoring and CPTu (piezocone) data using various method of interpretation. Method of interpretation used for settlement data is from the generally used method such as hyperbolic extrapolation method, Asaoka’s method, and 1/T vs settlement method for settlement data. And the relatively new interpretation method of degree of consolidation of the underconsolidating soil based on the CPTu data such as Bq vs U method (Setionegoro, 2013 and Rahardjo et al., 2016) and effective stress approach from the measured qc (Santoso and Rahardjo, 2014). The results of the study show that interpretation of the degree of consolidation using CPTu data is consistent to the settlement measurement except that the method ignore secondary compression.