A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1990

The available information on basic and engineering properties of t h e Hanoi sub soils were collected from past research reports at Union of Survey Construction Companies, Ministry of construction, S . R. Vietnam. The seven sub layer model for soil stratigraphy of Hanoi formation is classified and used in this study. A preliminary study on the geotechnical characteristics of t h e Red River De l ta within Hanoi City is made by computing and analyzing the means , standard deviations and ranges of basic an d engineering properties with depth from laboratory and in-sit u tests. The PI - LL relationships for each layer are presented by t h e regression lines. It is found t h at there are two sets of parallel line , which are almost parallel to each other by the equations: PI = 0.46 LL - 3.50 PI = 0.47 LL - 3.80 and , PI = 0.29 LL + 0.6 0 PI = 0 .29 LL + 0 .70 for weathered silty clay , soft silty c l ay , organic clay and stiff silty clay , respectively. Furthermore , the relationships between compressibility and basic properties were first performed. A series of regression equations between them were worked out. The probability distribution of Cc and CR in weathered silty clay and stiff silty clay layer was found to follow the log-normal distribution s , while in soft silty clay and organic c l ay it was found to follow the normal distributions , except CR in soft silty clay was found to follow both normal and log-normal distributions. The empirical distributions were checked us i ng the Chi-square goodness-of-fit tests at 5% level of significance. These results can be applied to obtain the relevant characteristics of the properties. All the statistical results and regression analysis are applicable in preliminary design and planning but should not be applied in detail design with out verification.