Geomechanics and Geotechnical Engineering
CHEN SHI-HAI, ZHANG ZI-HUA, XIA XIAO
Study on unloading cracking area of deep rock tunnel excavation
Abstract: The crack problem of deep rock tunnel under unloading is one of hot issue of rock mechanics at present. Elastic dynamics, Laplace transform and convolution theorem are used to solve transient stress field of blasting unloading around rock tunnel. The crack situation and crack area of blasting transient unloading of deep rock tunnel are given combining with Hopkinson dynamic rupture theory, and the result explains that the dynamic unloading disturbance brings about the rock burst disaster more easily. The example show that the theory and methods described here can correctly reflect the dynamic process caused by excavation and effectively estimate the destroy form of the rock mass induced by excavating unloading. The research achievements are in possession of direction value to stability analysis and supporting design of deep tunnel.
Key words: deep tunnel, crack, rock, blasting, transient stress field.
