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

Thesis (M. Sc.) - Asian Institute of Technology, 1982

A case history of the foundation grouting practice at Khao Laem dam site, Thailand is presented with critical review of the adopted methods and procedures. The foundation conditions being very complex due to the presence of solution cavities even at deeper depths, it was found that the reduction in rock mass permeability was not achieved uniformly in zones where the cavities are prevalent. To open up fractures to provide communications to the cavities it has been suggested that the grout pressure could be increased from the present value of 0.3 - 0.5 Kg/cm2 per m depth to 0.7-1.0 Kg/cm2 per m depth to the packer with careful monitoring of any possible upheaval in the surrounding rock. Further, comparison was made between the interpretation of water pressure test according to HOULSBY (1976) and that according to GUERRA et al.(1968), It was found that the two interpretations coincide only in limited number of cases. Cases, defined as pertaining to a particular type of flow by one interpretation, consist of different types of flow according to another interpretation showing incongruency in the two interpretations. Houlsby's interpretation generally gives higher number of cases of laminar flow whereas, the interpretation based on GUERRA et al.(1968) gives higher instances of turbulent flow and is unsuitable for use in lower ranges of rock mass permeability. Turbulent flow, as interpreted by HOULSBY(1976) includes much of the cases of flow which are interpreted as something in between laminar and turbulent.