A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering of the Asian Institute of Technology, Bangkok, Thailand

Thesis (M.Eng.) - Asian Institute of Technology, 1977

The geotechnical properties of deep Bangkok subsoils between 60 and 88 m have been investigated from a borehole at AIT campus, Rangsit. The laboratory testing program comprised lever-arm oedometer tests with small load increment ratios and one-day load increment duration, unconfined compression and unconsolidated undrained compression tests on clay samples and direct shear tests on sand samples. Some of the physical, chemical and mineralogical properties were also determined. The results showed that the hard Bangkok clays have low water con tents (average about 20.3%) which are usually lower than the plastic limit; low compressibility's (average Cc-value about 0.104); high undrained strength (more than 40 t/m2) and low pore water salinity. Montmorillonite was found to be a major component of the clay size fraction. The sand layers encountered in the borehole were all very dense. The material was fine to coarse with an angle of shearing resistance of about 36° in the loose state and about 42° in the dense state.