Unloading damage patterns of rock slopes in open pit mines and analyses of their mechanisms
Vol20 No.12:3648-3664
【Title】Unloading damage patterns of rock slopes in open pit mines and analyses of their mechanisms
【Author】WANG Jian-ming1; ZHOU Zi-han2*; DOU Wei3; CHEN Zhong-hui4
【Addresses】1 School of Engineering Management, Shanxi Vocational University of Engineering Science and Technology, Taiyuan 030000, China; 2 Department of Civil Engineering, Tsinghua University, Beijing 100084, China; 3 China Construction Sixth Engineering Bureau CORP., LTD, Nanjing 210000, China; 4 School of Mechanics & Civil Engineering, China University of Mining and Technology, Beijing 100083, China
【Corresponding author】ZHOU Zi-han
【Citation】Wang JM, Zhou ZH, Dou W, Chen ZH (2023) Unloading damage patterns of rock slopes in open pit mines and analyses of their mechanisms. Journal of Mountain Science 20(12). https://doi.org/10.1007/s11629-023-8344-7
【DOI】https://doi.org/10.1007/s11629-023-8344-7
【Abstract】The stability of slopes is essential for ensuring safe production in open-pit mines. Analyzing and managing the deformation and failure of the slope rock mass becomes more challenging as the slope height increases. To investigate the damage patterns of slopes with varying heights, three slope models were developed based on a rock slope in Dagushan, China. The deformation failure processes of slopes under the influence of excavation and unloading were analyzed using the base friction test method in combination with digital image technology contrasting. The results supported the following findings: (1) Unloading tensile stress caused lateral partitioning in the slope. Both the foot and top of the slope underwent initial tensile cracks. (2) The destabilization mechanism of unloading deformation in slopes of different heights involved a combination of traction at the foot of the slope or pushing at the top of the slope, followed by accelerated deformation, deceleration creep, and overall destabilization. (3) The unloading damage patterns of slopes at different heights were summarized as follows: compression tension cracking, traction, and slip damage for medium and low slopes; compression tension cracking, traction, and slip failure for the upper part of high slopes; and relaxation tension cracking, pushing, traction, and slip failure for the lower part. Moreover, the upper part of ultra-high slopes exhibited compression tension cracking, traction, and slip failure, while the middle and lower parts displayed relaxation tension cracking, pushing, traction, and slip patterns. Finally, numerical simulations were conducted to verify the results of the test analyses, which demonstrated good consistency. These research results were of great engineering value for proposing effective safety management measures for high slopes.
【Keywords】Excavation and unloading; Displacement field; Deformation mechanism; Damagepattern; Base friction test