Failure Modes and Influence of Interlaminar Fracture Zone Connectivity on Slope Stability of Bedding Rock Slope in Ya’an, West Sichuan

doi:10.19657/j.geoscience.1000-8527.2021.011

Abstract

Abstract:

Bedding rock slope is a common slope type in sedimentary rock areas, and is a slope-type that is focused on by various engineering construction. Taking a typical bedding rock slope in Ya’an area of west Sichuan as an example, the deformation and failure modes of the slope are summarized by field investigation, UAV mapping, drilling, geophysical exploration, stability calculation and other technical methods. The relation between the connectivity of interlaminar fracture zone and slope stability under different conditions is analyzed and calculated. The results show that: the interlaminar fracture zone has an important influence/control on slope stability. When the connectivity of the interlaminar fracture zone in the shallow part of the slope is less than 86%, the slope stability is consistent with the current investigation results. This provides a new idea to analyze the extension length or connectivity of interlaminar fracture zone of layered rock bodies. The research results have important engineering significance for infrastructure planning and construction, as well as for disaster prevention and mitigation in west Sichuan.

Key words: bedding rock slope, failure mode, interlaminar fracture zone, stability analysis

CLC Number:

P642

ZHOU Hongfu, RAN Tao, CHEN Bo, GAO Shu, WU Wenxian. Failure Modes and Influence of Interlaminar Fracture Zone Connectivity on Slope Stability of Bedding Rock Slope in Ya’an, West Sichuan[J]. Geoscience, 2021, 35(01): 137-144.

Figures/Tables 8

Fig.1 Characteristics of Leba slope in Ya’an, Sichuan

Fig.2 Failure modes of slope rock body in district I

Fig.3 Failure modes of slope rock body in district Ⅱ

Fig.4 Landslide profile and Quaterary sediment accumulation in district II

Fig.5 Photos of ZK02 cores and interlaminar fracture zone

Fig.6 Engineering geological section ((a)L3;(b)L4) and sketch map(c) of potential sliding surface of the Leba slope

Table 1 Calculation parameters of slope stability

名称	天然密度/ (g·cm^-3)	饱和密度/ (g·cm^-3)	天然黏聚力/kPa	饱和黏聚力/kPa	天然内摩擦角/(°)	饱和内摩擦角/(°)
强风化岩体	2.4	2.45	160	110	27	21
弱风化岩体	2.5	2.55	450	300	31	25
微风化岩体	2.6	2.65	700	500	36	33
强风化岩体中的层间破碎带	1.8	1.85	12	7	22	15
弱风化岩体中的层间破碎带	1.9	1.95	20	13	24	18
断层破碎带	2.0	2.05	40	25	23	17

Fig.7 Correlations between potential landslide stability and interlaminar fracture zone connectivity

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