CONSOLIDATION OF SOFT SOILS TAKING ACCOUNT OF STRUCTURE CHANGE ON PORE PRESSURE AND SETTLEMENT

• Main Author: Suaryana, Nyoman
• Format: Theses
• Language: Indonesia
• Subjects: Teknik (Rekayasa, enjinering dan kegiatan berkaitan)
• Online Access: https://digilib.itb.ac.id/gdl/view/1186
• Institution: Institut Teknologi Bandung

Over the past few years the well-known theory of consolidation developed by Terzaghi, directly or in extended form, have been usually applied to analyse the time rate of settlement and excess pore pressure dissipation arising from loading a soft soil. In recent reviews, it has been observed that success in predicting magnitudes and rates of settlement using Terzaghi's theory for different field cases has ranged from excellent to poor. The anomalous behaviour can be explained in terms of such factors as the non linear relationship between void ratio and logarithm of effective stress , and changes in permeability and compressibility as load increases. A computer program to consider two dimensional consolidation of stratified cohesive soils under embankment loading using Terzaghi-Rendulic theory was developed previously. A new version of the program has been developed to include the effect of change in clay structure and change in permeability using non-linear theory. Three case histories were used to compare the recorded rates of settlement and excess pore pressure dissipation with those calculated using both the Terzaghi-Rendulic theory and the non-linear theory. These were the records from the trial embankments at Juru, Malaysia, Muar Flats, Malaysia, and Tickton, UK. The comparisons are presented, and good agreement between the predicted values using non linear theory and these measured was achieved for both settlement and pore pressure dissipation. Calculations using the Terzaghi- Rendulic theory were found to lead an underestimations in the rate of settlement, except for the Tickton embankment. For excess pore pressure dissipation characteristics these matched reasonably, except in the case of the Tickton embankment. It was found that changes in clay structure occur in soft soils with large organic content. These changes add to the magnitude of settlement during consolidation process. The effect of creep on excess pore pressure dissipation behaviour is influenced by the coefficient of consolidation and compression index.