Crosshole permeability testing method in bedrock

Equipment for the crosshole permeability test was developed, and the large-scale permeability test and the sinusoidal pressure test performed in low permeability deep bedrock and other area. The results were summarized as follows: 1) Large-scale permeability tests are useful testing methods to evaluate the average permeability of a relatively large rock mass. 2) The results of sinusoidal pressure tests in low permeability deep bedrock show that the bedrock storage properties are strongly influenced by the joint system, as demonstrated by the fact that the direction of the response of sinusoidal pressure tests coincides with the dominant direction of joints. The sinusoidal pressure tests are also useful to calculate the hydraulic diffusivity and specific storage coefficient and to investigate the hydraulic characteristics related to the joint system in bedrock. 3) A method for calculating the coefficient of permeability using the sinusoidal pressure test was proposed. The in-situ application achieved favorable results showing the effectiveness of this method.