Dr. Luis Ribeiro e Sousa, Professor, SKL-GDUE of China University of Mining and Technology, Beijing and Tongji University, Shanghai, China

Biography: Prof. Sousa has more than 45 years of engineering experience. He has international experience on projects including dams, tunnels, and other underground structures. His technical areas of expertise include concrete dams; rock foundations and other structures; tunneling for subways, roads, railways and hydraulic projects; underground storage; mining; petroleum engineering; rock mechanics; tests; and numerical modeling. He was Professor at the University of Porto and has authored or co-authored over 20 books and hundreds of articles, presentations and reports. He was very active in a number of professional societies and served as President of the Portuguese Geotechnical Society and as Vice-President for the ISRM. He was also the Chairman of the 2007 ISRM Congress, and was President of SKEC Engineering Consulting. He is a researcher for SKL-GDUE, Beijing and was awarded by the Chinese Foreign Experts Bureau as a renowned foreign expert in several years. Now he is also Professor at Tongji University, Shanghai.

Speech Title: Advancements in SHTB Tests for Constant Resistant Large Deformation Bolts and the Use of Numerical Simulations

Abstract: In deep underground excavations, rockbursts occur in a violent manner. A comprehensive understanding of the mechanisms of the rockburst have so far left unsolved. There are several types of accidents that included rockburst. Bolts and anchors are efficient measures to control these accidents and large deformations that can occur.

The presentation of Constant Resistant Large Deformation (CRLD) bolts or anchors developed at SKL-GDUE (State Key Laboratory for Geomechanics and Deep Underground Engineering) of China University of Mining and Technology in Beijing is made. Experimental results with these bolts are analysed. A large number of tests have been conducted and developed for this bolt and test results showed that its mechanical properties are such that it can keep almost constant resistance during the elongation process. Dynamic tests are very important particularly the SHTB (Split Hopkinson Tension Bolts) tests, and devices were considered for the case of one bolt and several bolts.

Numerical simulations were performed using several types of software for the case of one bolt, which had the dual goal of verifying the experimental and numerical results. In addition, numerical predictions were used to verify the accuracy of the experimental results and to permit a deep analysis of the behavior of these bolts focusing in the development of large deformations. The numerical calculations were done by using the finite element method considering 3D models. The von Mises yield criterion was adopted and the surface contacts were set in an automatic way. The software for dynamic analysis was based in the solution of explicit equations. Several calculations were done for different velocities of a bullet and for each calculation five equal impacts were considered.

Keywords: Experimental Results, SHTB Tests, CRLD Bolts, Numerical Simulations, Large Deformations.