... and their connectivity. As a result, there is a large effort in continuously developing better understanding and improved techniques of analysis and interpretation. acoustic event velocity model Kaiser effect Visualization hydraulic fracturing pressurization acoustic emission event stress concentration...

... ABSTRACT: This paper introduces the development of a new device, Kaiser in-situ stress system. This device is designed to measure in-situ stresses via detected acoustic emissions caused by the Kaiser effect in rocks. With the assumption that the orientation of one of the three principal...

... of using the Kaiser effect to determine the in situ horizontal stresses from a rock core. 1 INTRODUCTION Rocks exhibit stress memory. This was demonstrated already 50 years ago, when Joseph Kaiser (Kaiser, 1953) discovered that acoustic emissions (AE) in cyclic uniaxial loading occurred only after...

... on the Kaiser effect and incomplete erasion phenomena of AE activity. The preparation of rock sample, experimental procedures and data processing method are also introduced. In addition, the effetcs of rock types, experimental parameters and the core preservation time on test results are also investigated...

... of the cracking process in the material. Laboratory experiments [2] have demonstrated that AE was absent in rock until the load exceeded the previous maximum load that had been imposed to rock before. This is the socalled Kaiser effect. In the tests, rock specimens were uniaxially loaded and unloaded repeatedly...

...% of failure strength. They found a decreasing decay rate for AE activity with increasing stress level. However, they showed that during transient creep, AE rate obeyed Reservoir Characterization hydraulic fracturing correlation mechanism AE event acoustic emission localization Kaiser effect...

... ABSTRACT INTRODUCTION Although discovered more than 40 years ago, [ 1], there has been little or no development of a theory of the Kaiser effect, particularly for rocks. The purpose of this paper is to supply a theoretical framework for thinking about the Kaiser effect under general stress...

... of Kaiser Effect as a reliable and economical stress measurement method, a comprehensive investigation has been undertaken into various aspect of this subject. This paper presents the results of the first stage of a comparative study to determine existing stresses in a rock mass by testing specimens...

... of AE will increase with increasing loads. Mogi (1962) gave an AE signature pattern, which has corresponding relations with the physical model of fracturing processes by Bieniawski (1967). The Kaiser effect is an AE phenomenon briefly defined as the absence of detectable acoustic emissions until...

... to obtain initial ground pressure in bedrock by utilizing the Kaiser effect of AE. There is already a case reported in which initial geostress was estimated by utilizing the Kaiser effect (Hayashi). In order to estimate initial geostress by utilizing the Kaiser effect, it is necessary to solve the following...