Physical simulation experiments offer a powerful method to explore influence of plastic flow, material failure and hybrid monitoring in a high and steep slope of open-pit mines composed with discontinuous rocks. We adopted an experimental setup using a stiff modular applied static loading to fulfill visual excavation to the slope at random depth. Before constructing 3D model, searching of scientific model materials had been done. The simulation experiments were instrumented with acoustic emission (AE) censors, and monitored by crack optical acquirement (COA), ground penetrating radar (GPR), and close-field photogrammetry (CFP) being unequivocal mechanisms of rock destabilization in the high and steep slope. The Shuichang iron mine in Hebei province of China was taken as a prototype for large 3D physical simulation experiments. The high and steep slope mainly concluded a steep slope whose angle ranged from 30 to 47 degrees, an ore body with 80 degrees, and maximum width and height of the model were both 800 meters as well as other geological structures under in-situ complicated stress. For the complex situation of study area, model experiments show that slope was excavated with multi stage-parameter real monitoring under constant boundary conditions. It also showed inner correlation between model's destabilization resulted from slope excavation and diverse monitoring information was clearly gotten. Although the model with large scale did not include the whole complexity found in the actual open-pit mines or even in the experimental scaled models, it was also a useful tool to study the mechanism of high and steep slope destabilization both qualitatively and quantitatively.

General Introduction

Copious of approaches, like engineering geology analysis, limit equilibrium method, limit analysis method and numerical simulation experiment are offered for analyses of a high and steep slope stability of openpit mines [1,2]. Compared with approaches above, physical simulation as one of most useful research approaches in rock mechanics has oceans of unique advantages for slope stability [3–8], particularly building up a Large-three-dimensional physical simulation experiment would obtain deformation and fracture characteristics of rock masses in slope accurately which was prerequisite to foretell dynamic destabilization and design rock excavation in steep slope scientifically.

It should be necessary to enrich accuracy of simulation experiment with having a better understanding of mechanical properties of model materials and achieving quantifications for proportion here [9]. We have gotten distinctly about basic information from No.9 to No.33 exploration line, where boundary line of openpit mines has been already moved 1400 meters towards thewest and level of open-pit fell dramatically to-440 meters which has been plotted to -350 meters. Moreover, geometric similar scale has been 1:400 being small scale model, so the simulation experiment was difficult to achieve. Various kinds of model materials developed by research institutes home and abroad in succession have possessed different mechanical properties and achieved success in actual application, as lead oxide adopted for modeling basic indigents of rock masses has been invented by Bergamo institute in Italy [10]. Besides, NIOS, IBSCM and MIB were invented separately by Qiangyong Zhang [11,12], Zhongkui Li [13] and Boli Han [14]. Surely all of them had similar properties in contrast with prototypes.

This content is only available via PDF.
You can access this article if you purchase or spend a download.