| With the development and utilization of underground space at home and abroad,a large number of underground works have sprung up,such projects are faced with complex engineering geological conditions with the increase of depth.Anchor is used to reinforce surrounding rock in underground engineering,creep of anchored rock mass increases with time during construction and service period,which seriously affects the safety and stability of engineering.This paper based on the technology of 3D strain flower,firstly,similar materials are used to make rock mass test blocks,uniaxial compression creep test for test blocks.The variation characteristics of strain in parallel loading direction and vertical loading direction are obtained through data analysis of 3D strain flower and through matrix calculation,it is deduced that the spatial location of strain maximum at every time point is related to the internal friction angle.Secondly,uniaxial tensile creep tests of sample were carried out by using the loading system that we invented,two groups of 3D strain flowers were preembedded in the sample,comparison and analysis of data collected from two groups of strain flowers,the results show that internal strain of anchored rock mass is related to anchoring depth and anchor distance.Through comparison,the most stable position and the most active position in the creep process of anchored rock mass are obtained.Finally,by comparing and analyzing the measured data,the creep characteristics of the internal strain of rock mass under the direction of parallel loading and vertical loading are summarized.The analysis shows that the strain at the deep anchor position changes synchronously in the direction of parallel loading,and the vertical load direction is far away from the anchor strain,which is less affected by external force.The research results provide corresponding data support and theoretical guidance for rock mass anchorage in actual engineering. |
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