Study on dynamic response of moisture content and stability evolution under rainfall infiltration using SEEP/W-SLOPE/W coupling

doi:10.16265/j.cnki.issn1003-3033.2025.S2.0026

Abstract

Abstract:

To investigate the dynamic response characteristics of volumetric water content and the stability of dump slopes under heavy rainfall conditions, a typical rainfall-induced landslide in a dump was studied. Based on unsaturated seepage theory and the finite element numerical simulation method, the influence of rainfall infiltration on slope stability was analyzed. The research results indicate that the dynamic variation of volumetric water content within the dump slope is significantly correlated with the duration of rainfall, and the distribution of saturated and unsaturated zones exhibits dynamic response characteristics as water content changes. In the initial stage of rainfall, the local water content in the surface layer of the slope increases rapidly, with transient saturated zones forming first at the toe and the rear edge of the slope crest. As rainfall continues, the infiltration range and depth of water gradually expand, and the volumetric water content of the slope shows an increasing trend from top to bottom. This leads to a rise in the groundwater level. After rainfall ceases, water is gradually discharged through dual mechanisms of vertical infiltration and horizontal migration, causing a progressive decrease in internal water content. Under heavy rainfall conditions, the stability of the dump slope significantly deteriorates with increasing rainfall intensity, and the time required for the safety factor to decline shortens progressively, the range of the safety factor reduction increases from 12.69% to 20.36%, while the required time decreased from 72 h to 36 h, indicating a time-dependent cumulative effect of rainfall intensity on slope stability. By analyzing the slope radar monitoring data of surface displacement during rainfall, the study demonstrates the significant impact of rainfall infiltration on slope stability.

Key words: waste dump slope, rainfall infiltration, volumetric water content, safety factor, slope stability

CLC Number:

X936

HUI Yubo, YU Zhengxing, WANG Nuo, LI Xiteng. Study on dynamic response of moisture content and stability evolution under rainfall infiltration using SEEP/W-SLOPE/W coupling[J]. China Safety Science Journal, 2025, 35(S2): 223-230.

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岩土层名称及层号	渗透系数K/ (cm·s^-1)	γ		抗剪强度				含水率/ %
		天然/ (kN·m^-3)	饱和/ (kN·m^-3)	天然		饱和
		天然/ (kN·m^-3)	饱和/ (kN·m^-3)	c/kPa	φ/(°)	c/kPa	φ/(°)
①粉砂	4.1×10^-3	15.1	18.5	1	26	0^*	23^*	6.9
②碎石	5.5×10^-2*	20.0^*	25.0	10^*	35^*	0^*	30^*	6.5^*
③黄土	4.4×10^-4	16.5	19.4	10	26	4	13	7.6
④强风化灰岩	3.4×10^-5*	20.9	22.1	80	35	50	30	5.7
⑤中等风化灰岩	4.0×10^-6*	23.4	—	1 000	44	—	—	—