Application Of Digital Speckle Correlation Method In Simulation Of Underground Engineering

With China's rapid economic development,people's demand for energy and space continues to expand, many under construction and the new projects continued to deep,whether mining tunnels, hydroelectric development of underground caverns, energy reserves of underground gas storage Caverns,underground tunnels and traffic-building gradually to a deep direction. As the depth increases,some of the surrounding rock of deep problems that come with, therefore, must further research for underground works,and take effective measures.This digital speckle correlation method and simulation test is applied to the experimental study on the stability of underground engineering, by using digital image processing experiment data, and numerical simulation research on underground engineering floor failure process, enriching the surrounding rock stability of underground engineering study, to further improve the underground floor of theoretical study on bearing mechanism, as well as support schemes for underground engineering design provides a wealth of data. Test result analysis leads to the following conclusions:(1) By soil layer anchor pullout test, to study the feasibility of digital speckle experiments, results analysis and application of digital speckle pattern test in geotechnical engineering is feasible and effective, displacement and strain derived image with intuitive, flexible and full of features and can meet the requirements of test results.(2) Test using Visual semicircular cylinder anchor interface mechanical characteristics testing device,combining digital speckle correlation technique to experiment. By means of image processing software to analyze results, with the increasing displacement of anchorage, anchorage drive around axial displacement of soil anchor, spreading along the radial is the displacement, there was "slipping". Shear strain consists of original local,Pan-along the anchoring of the axial expansion and heterogeneous, connected to each other, and finally through, form a complete shear-slip zone.(3) Digital speckle experiments applied to stability analysis of underground engineering through test and numerical simulation for digital speckle contrast and displacement are the two images are similar,test and numerical simulation for digital speckle complement and supplement each other, complement each other, overcome the weaknesses and shortcomings of numerical simulation,numerical simulation for providing references.(4) There are two kinds of model results by comparison, drums at the end of the tunnel there are two forms,one is the overall uplift of tunnel floor,Prandtl slip line field; the other is Center plate uplift than larger on both sides of the tunnel,showing peak form, slip line field Hill.