Detailed Characterization of Rock Mass Quality and Slope Stability Analysis for Open-Pit Mines

doi:10.12068/j.issn.1005-3026.2025.20230272

Abstract

Abstract:

Rock masses are often simplified as homogeneous materials when evaluating rock mass quality and analyzing slope stability. However， natural rock masses actually exhibit heterogeneous characteristics. To address this issue， a detailed characterization of rock mass quality and a modeling method for mechanical parameters considering heterogeneitying are proposed. Taking the Wulagen lead-zinc mine as an example， the process of the detailed modeling method for rock mass mechanical parameters is elaborated in detail. Based on the established detailed mechanical parameter model， a stability analysis of the southern slope was conducted using both homogeneous and heterogeneous rock mass mechanical parameters. The results indicate that the calculations using heterogeneous mechanical parameters can more accurately reflect the true stability conditions of open-pit slopes. The detailed block model established in this study can identify weak and unstable areas in open-pit slopes， providing a scientific and effective solution for rock mass quality evaluation， stability analysis， and support design.

Key words: open-pit mine, rock mass quality, detailed modeling, block model, slope stability analysis

CLC Number:

TD 854

Dong-dong SUN, Tian-hong YANG, Fei-yue LIU, Yang LIU. Detailed Characterization of Rock Mass Quality and Slope Stability Analysis for Open-Pit Mines[J]. Journal of Northeastern University(Natural Science), 2025, 46(4): 97-105.

Figures/Tables 20

Fig.1 Fnal boundary pit morphology of the Wulagen lead-zinc mine

Fig.2 Photographs of the Wulagen lead-zinc open-pit mine and southern slope landslide area

Fig.3 Flow diagram of detailed modeling and numerical simulation

Fig.4 Automatic identification of RQD in core photos

Fig.5 Modeling area

Fig.6 Block model of RQD

Fig.7 Block model profile of RQD

Fig.8 SZK3602 borehole core photos

Fig.9 Rock layer distribution

Table 1 RMR grading system evaluation factor

岩性	A1	A3	A4	A5	B
含砾砂岩	2	15	17	7	-5
中风化砂岩	4	15	18	4	-5
含矿砂岩	2	15	20	4	-5
微风化砂岩	7	15	20	10	-5
微风化泥岩	4	15	20	10	-10
灰岩	7	10	18	10	-5
中风化石膏	7	15	18	10	-5
砾岩	4	15	20	7	-10
长石砂岩	2	15	18	7	-10

Fig.10 Block model of RMR

Fig.11 Block model of GSI

Table 2 H-B index values of mi𝑖

岩性	m_i
含砾砂岩	20
中风化砂岩	17
含矿砂岩	19
微风化砂岩	20
微风化泥岩	8
灰岩	9
中风化石膏	14
砾岩	12
长石砂岩	13

Fig.12 Block model of mechanical parameters

Fig.13 Calculation profile

Table 3 Mechanical parameter values

岩性	黏聚力	内摩擦角	容重
岩性	kPa	（°）	kN·m^-3
微风化泥岩	674	32.00	25.69
长石砂岩	355	31.43	23.26
含砾砂岩	304	31.28	25.09
砾岩	433	37.91	26.74
中风化石膏	477	36.50	29.39

Table 4 Design safety factors for slope

边坡工程安全等级	自重+地下水+爆破振动力
Ⅰ	1.23~1.18
Ⅱ	1.18~1.13
Ⅲ	1.13~1.08

Fig.14 Slope stability analysis results of the

Fig.15 Slope stability analysis results of the

Fig.16 Distribution of mechanical parameters on

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