| "Recently, Japan has felt the need to reduce the cost of dam foundation grouting. We have endeavored to establish an effective and economical dam foundation grouting. In this paper, we will introduce an investigation into cost reduction in water pressure tests, which are performed to evaluate rock permeability and thus determine grouting specifications. The water pressure test, in its conventional form, is conducted in increasing and decreasing pressure steps, i.e. with a stepwise pressurization. A new form for a water pressure test, which is conducted without pressure steps, i.e. a monotonous pressurization, has been proposed. We will introduce case histories of water pressure tests with monotonous pressurization in order to verify the accuracy and cost performance thereof. In addition, we will perform a saturated-unsaturated seepage analysis to simulate water pressure tests with monotonous pressurization in an unsaturated area above the groundwater table. Based on the results of case histories and numerical simulation, we will summarize our remarks on the performance and evaluation results of water pressure tests with monotonous pressurization." |
