Comprehensive analysis method for validating geostress measurement data

Owing to the current measurement technical level of geostress and complexity of geological conditions for actual rock mass, validity of measured results might be suspected;and the quality and precision of measured data of geostress as basic information will directly affect the reliability of quantitative model of geostress field. A comprehensive analysis method has been put forward to study the reliability and validity of measured data of geostress. The method combines with macrotectonic geological background in project area, geostress measurement data interpretation, mechanical qualitative analysis of rock mass failure phenomenon. Firstly, influences of comprehensive geological tectonic background and local geomorphology have been considered to form overall impression and macroscopical judgment of geostress field in project area. Then, full-space stereoprojection method and typical plane stress projection method have been used to quantitatively study the characteristics of stress tensor of geostress measuring point acquired through measurements. Comparative study will be conducted on the result mentioned above and the mechanical qualitative analysis results of certain rock mass failure phenomenon at exploration adit. So, measured data, which are assumed to be representative and reliable and can reflect geostress field in project area, are selected for the regression analysis of initial geostress field. By using this method, the distribution characteristics of geostress field at dam site of a large hydropower station, located in deeply incised river valley area of Southwest China, has been analyzed. The stress concentration position predicted by the established numerical quantitative model of initial geostress field and actual stress-induced failure parts have good consistency.