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

Thesis (M.Eng.) - Asian Institute of Technology, 1975

Since most of the laboratory methods of K0 determination are based on no lateral yield principle, any disturbance in the sample could cause significa11.t error in the estimation of Ko. It is, therefore, important that Ko measurements be made in the field. This research is aimed at confirming the feasibility of the field and laboratory hydraulic fracturing methods for the determination of Ko for Bangkok Clay at Rangsit. Two series of field hydraulic fracturing tests (using BJERRUM and ANDERSEN' s and HILKERS ' methods) have been carried out. The results show that both methods are feasible for the determination of K0 in Weathered and Soft Bangkok Clay at Rangsit. The opening and closing of fractures and the rate of injection of water do not seem to have noticeable effect in the K0 values determined by the fracturing method. A series of laboratory hydraulic fracturing tests has been carried out, and the results confirm that the laboratory fracturing method could also be used for the determination of Ko. However, as compared to the field K0 values. the laboratory test results are found to be slightly lower. This may perhaps be due to sample disturbance.