Development and engineering application of three-dimensional disturbed stress measurement system for deep hard rock engineering based on fiber bragg grating
The evolution characteristics and laws of surrounding rock disturbance stresses in deep tunnels are the most important factors for engineering stability and disaster analysis.At present,the research on the disturbance stress characteristics of hard surrounding rock is limited to analytical and numerical simulation,and there is a lack of reliable in-situ testing technology and equipment.In view of the complex geological environment of deep hard rock tunnel engineering,the disturbance stress comprehensive sensing technology based on fiber bragg grating and hollow inclusion was developed on the basis of the systematic analysis of the measurement principle and theory of the disturbance stress,and a multi-point three-dimensional disturbance stress testing system was developed.The seal oil pressure calibration device was designed to carry out the overall calibration of the sensor,and the indoor concrete model test was designed to verify the accuracy and reliability of the stress testing system.Based on the China Jinping Underground Laboratory phase Ⅱ project,the in-situ test of the corresponding disturbance stress was carried out.The three-dimensional disturbance stress distribution and evolution characteristics during the excavation of deep hard rock tunnels were obtained for the first time,the evolution characteristics and laws of the magnitude and direction of the disturbance stress and their relationships with construction activities were systematically analyzed,and the applicability and reliability of the fiber bragg grating hollow inclusion stress testing system were further verified.The research provides a scientific method and technical support for deep hard rock engineering disturbance stress test and evolution characteristics research.
underground engineeringdeep hard rocktunnelthree-dimensional disturbance stress measurementfiber bragg gratingin-situ test
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