Research on Dynamic Failure of Bedrock-Overburden Layered Accumulation Slope Considering Influence of Soil Layer Dip
-
摘要:
为研究土层倾角对边坡动力失稳的影响,基于振动台模型试验,研究不同土层倾角的层状堆积体基覆型边坡在地震作用下的失稳特征和动力响应规律. 通过改变基覆界面倾角,设计表面为直线形、凹形、凸形的3类边坡,在此基础上开展边坡振动台模型试验,得到3种变倾角边坡的失稳模式;并通过考虑边坡破坏的加速度放大效应,结合土体应力状态与摩尔-库仑强度理论,探究边坡动力响应机理及边坡失稳临界条件. 试验结果表明:凹形边坡在破坏时破坏特征集中在上部土层,凸形边坡集中在下部土层,直线形边坡则是出现上部土层拉裂、下部土层剪切滑移的破坏模式;相同震级下,凹形边坡加速度放大系数最小,直线形边坡、凹形边坡与凸形边坡的加速度放大效应分别集中在坡顶、坡肩与坡顶后缘位置;随着变倾角系数的增大,边坡失稳临界加速度相应增大. 研究结果可为层状堆积体基覆型边坡工程的抗震设计、稳定性评价和防灾减灾提供科学依据.
-
关键词:
- 层状堆积体基覆型边坡 /
- 土层倾角 /
- 模型试验 /
- 失稳特征 /
- 动力响应
Abstract:To investigate the influence of soil layer dip on the dynamic failure of slopes, the failure characteristics and dynamic response laws of bedrock-overburden layered accumulation slopes with different soil layer dips under seismic action were studied based on shaking table model tests. By varying the bedrock-overburden interface dip, three types of slopes with linear, concave, and convex surfaces were designed. Shaking table model tests were subsequently conducted on these slopes, yielding the failure modes of the three types of slopes with various dips. By taking into account the acceleration amplification effect of slope failure, the soil stress state, and the Mohr-Coulomb strength theory, the dynamic response mechanism of slopes and the critical conditions for slope failure were explored. The test results show that the failure characteristics of the concave slope are concentrated in the upper soil layer during the slope failure process, while those of the convex slope are concentrated in the lower soil layer. By contrast, the linear slope exhibits a failure mode characterized by tensile cracking in the upper soil layer and shear sliding in the lower soil layer. Under the same seismic magnitude, the concave slope exhibits the smallest acceleration amplification coefficient, and the acceleration amplification effects of the linear slope, concave slope, and convex slope are concentrated at the slope crest, slope shoulder, and the rear edge of the slope crest, respectively. With the increase in the various dip coefficients, the critical acceleration for slope failure increases accordingly. The research results can provide a scientific basis for the anti-seismic design, stability evaluation, and disaster prevention and mitigation of engineering projects involving bedrock-overburden layered accumulation slopes.
-
表 1 边坡模型试验参数及相似关系
Table 1. Similarity relationship of physical quantities in slope model test
物理量 量纲 相似律 物理量试验取值(实际值) 边坡高度H1 L CH=25 0.6 m 黏土土体重度γ1 ML−2T−2 ${C_{{\gamma _1}}} $=1 13 kN/m3 砂土土体重度γ2 ML−2T−2 ${C_{{\gamma _2}}} $=1 16 kN/m3 重力加速度g LT−2 Cg=1 9.8 m/s2 坡顶宽度L L CL=25 0.3 m 黏土层厚度d1 L ${C_{{d _1}}} $=25 0.2 m 砂土层厚度d2 L ${C_{{d _2}}} $=25 0.2 m 上覆土层倾角β1 1 30°/45° 下覆土层倾角β2 1 30°/45° 基覆界面倾角θ1 1 52° 基覆界面倾角θ2 1 10° 黏土黏聚力c1 ML−1T−2 Cc=CγCH=25 23.2 kPa 砂土黏聚力c2 ML−1T−2 Cc=CγCH=25 5.4 kPa 黏土内摩擦角φ1 1 22° 砂土内摩擦角φ2 1 38° 黏土压缩模量Es1 ML−1T−2 CEs=CγCH=25 18.6 MPa 砂土压缩模量Es2 ML−1T−2 CEs=CγCH=25 38.2 MPa 黏土泊松比μ1 1 0.4 砂土泊松比μ2 1 0.3 基覆界面与黏土的摩擦系数 1 0.3 基覆界面与砂土的摩擦系数 1 0.7 黏土与砂土的摩擦系数 1 0.45 黏土含水率ω1 1 10% 砂土含水率ω2 1 5% 地震荷载峰值加速度a LT−2 Ca=Cg=1 0.1~0.5 g 地震荷载主频f T−1 Cf=CH−0.5Cg0.5=0.2 10 Hz 地震持续时间t T Ct=CH0.5Cg−0.5=5 20 s 表 2 试验工况设计表
Table 2. Design of test working conditions
工况编号 土层分布 黏土层厚度/cm 砂土层厚度/cm 上覆土层倾角/(°) 下覆土层倾角/(°) 地震波类型 地震波频率/Hz 1 黏土-砂土 35 35 45 45 正弦波 10 2 黏土-砂土 35 35 45 30 正弦波 10 3 黏土-砂土 35 35 30 45 正弦波 10 4 砂土-黏土 35 35 45 45 正弦波 10 表 3 数值模拟材料参数
Table 3. Material parameters in numerical simulation
类型 土体重度/(kN·m−3) 弹性模量/MPa 泊松比 黏聚力/kPa 内摩擦角/(°) 频率/Hz 黏土 砂土 黏土 砂土 黏土 砂土 黏土 砂土 黏土 砂土 非完全满足相似律的0.6 m边坡 13 16 8.68 28.38 0.4 0.3 13 16 8.68 28.38 0.4 原型15 m边坡 13 16 8.68 28.38 0.4 0.3 13 16 8.68 28.38 0.4 完全满足相似律的0.6 m边坡 13 16 0.35 1.14 0.4 0.3 13 16 0.35 1.14 0.4 注:压缩模量Es与弹性模量E换算公式E$ =E_s\left(1-\dfrac{2 \mu^2}{1-\mu}\right) $,µ为泊松比. 表 4 地震作用下变倾角边坡失稳模式
Table 4. Slope failure modes with various dips under seismic action
工况 变倾角形式及土层分布 失稳模式示意 失稳加速度 失稳模式 1 直线形
(黏土-砂土)
0.3g 上部黏土拉裂-下部砂土局部滑移破坏 2 凹形
(黏土-砂土)
0.4g 上部黏土溃滑破坏(下部砂土稳定) 3 凸形
(黏土-砂土)
0.25g 下部砂土浅层剪切破坏(上部黏土稳定) 4 直线形
(砂土-黏土)
0.3g 上部砂土局部剪切滑移破坏 注:黑色虚线为原始边坡轮廓线,黑色实线为破坏后边坡轮廓线,红色实线为边坡破坏线. -
[1] 黄雨, 张云秋, 邱振东, 等. 强震作用下青藏高原地区断裂控制型边坡动力响应规律与变形破坏机制研究[J]. 中国科学: 技术科学, 2025, 55(5): 927-942.HUANG Yu, ZHANG Yunqiu, QIU Zhendong, et al. Dynamic response and deformation failure mechanism of fault-controlled slope in Qinghai-Xizang Plateau under strong earthquake action[J]. Scientia Sinica (Technologica), 2025, 55(5): 927-942. [2] 冯海洲, 蒋关鲁, 郭玉丰, 等. 降雨后地震作用下基覆型边坡动力响应特性的振动台试验研究[J]. 中国铁道科学, 2023, 44(3): 1-12.FENG Haizhou, JIANG Guanlu, GUO Yufeng, et al. Shaking table test on dynamic response characteristics of bedrock and overburden layer slope under earthquake after rainfall[J]. China Railway Science, 2023, 44(3): 1-12. [3] 何梓雷, 蒋关鲁, 冯海洲, 等. 基于变形的降雨后地震基覆型边坡劣化特性与机制研究[J]. 岩土力学, 2024, 45(6): 1789-1802.HE Zilei, JIANG Guanlu, FENG Haizhou, et al. Investigation of deterioration characteristics and mechanisms of bedrock and overburden layer slope under seismic conditions after rainfall based on deformation[J]. Rock and Soil Mechanics, 2024, 45(6): 1789-1802. [4] 唐红波, 王立纬, 蒋文鹏, 等. 库水位变化与地震作用下堆积体边坡动力稳定性研究[J]. 土工基础, 2024, 38(3): 496-502.TANG Hongbo, WANG Liwei, JIANG Wenpeng, et al. Study on dynamic stability of a colluvial slope under reservoir pooling water level varation and earthquake[J]. Soil Engineering and Foundation, 2024, 38(3): 496-502. [5] 仝霄金, 唐建政, 付艳青, 等. 双向地震作用下崩塌堆积体边坡动力模糊可靠性分析[J]. 地震工程学报, 2024, 46(2): 343-348. doi: 10.20000/j.1000-0844.20220617003TONG Xiaojin, TANG Jianzheng, FU Yanqing, et al. Dynamic fuzzy reliability analysis of collapse accumulation slopes under bidirectional earthquakes[J]. China Earthquake Engineering Journal, 2024, 46(2): 343-348. doi: 10.20000/j.1000-0844.20220617003 [6] 陈磊, 张强, 贾朝军, 等. 强降雨对库岸堆积体边坡稳定性影响的离心模型试验和数值模拟研究[J]. 岩土力学, 2024, 45(5): 1423-1434. doi: 10.16285/j.rsm.2023.0917CHEN Lei, ZHANG Qiang, JIA Chaojun, et al. Centrifugal modeling and numerical simulation on stability of reservoir bank accumulation slope caused by heavy rainfall[J]. Rock and Soil Mechanics, 2024, 45(5): 1423-1434. doi: 10.16285/j.rsm.2023.0917 [7] 丁秀美. 西南地区复杂环境下典型堆积(填)体斜坡变形及稳定性研究[D]. 成都: 成都理工大学, 2005. [8] 潘毅, 范元青, 任宇, 杨兵, 侯江荣, 熊耀清. 芦山6.1级地震山区典型震害调查与分析. 土木工程学报. 2023, 56(12): 35-47.PAN Yi, FAN Yuanqing, REN Yu, YANG Bing, HOU Jiangrong, XIONG Yaoming. Typical seismic damage investigation and analysis in mountainous areas of the Lushan m6.1 earthquake. Chinese Journal of Civil Engineering. 2023, 56(12): 35-47. [9] 许强, 裴向军, 黄润秋, 等. 汶川地震大型滑坡研究[M]. 北京: 科学出版社, 2009. [10] YANG X L, DONG J Y, LIU H D, et al. Seismic dynamic response characteristics and failure mechanisms of an accumulation body slope[J]. Natural Hazards, 2024, 120(9): 8239-8261. doi: 10.1007/s11069-024-06451-1 [11] YANG B, HOU J R, ZHENG X S, et al. On stability of a slope with bedrock using the upper bound limit analysis[C]//Engineering Geology for a Habitable Earth: IAEG XIV Congress 2023 Proceedings, Chengdu, China. Singapore: Springer, 2024: 1-24. [12] 任华江, 郭涛, 潘远阳, 等. 基于振动台试验的库岸堆积体斜坡动力响应与变形破坏模式研究[J/OL]. 西南交通大学学报, 1-11[2025-12-08]. https://link.cnki.net/urlid/51.1277.U.20250711.1912.008. [13] Hou J, Zhang M X, Chen Q, et al. Failure-mode analysis of loose deposit slope in Ya'an-Kangding Expressway under seismic loading using particle flow code[J]. Granular Matter, 2019, 21(1): 1-12. [14] IGWE O. The influence of bedrock geology and slip surface characteristics on failure mode and mobility: a comparative study of instability patterns in Nigeria[J]. Arabian Journal of Geosciences, 2015, 8(11): 9831-9844. doi: 10.1007/s12517-015-1918-0 [15] 梁敬轩, 胡卸文, 叶正晖, 等. 大型堆积体边坡基-覆界面及坡面动态响应特性试验研究[J]. 岩土力学, 2017, 38(8): 2249-2260. doi: 10.16285/j.rsm.2017.08.013LIANG Jingxuan, HU Xiewen, YE Zhenghui, et al. Dynamic response characteristics of slope surface and rock-soil boundary in deposit slope[J]. Rock and Soil Mechanics, 2017, 38(8): 2249-2260. doi: 10.16285/j.rsm.2017.08.013 [16] 杨兵, 周子鸿, 陶龙, 等. 降雨作用下基覆型边坡失稳特征及承载力试验研究[J]. 西南交通大学学报, 2022, 57(4): 910-918.YANG Bing, ZHOU Zihong, TAO Long, et al. Experimental study on instability characteristic and bearing capacity of slope with bedrock under rainfall[J]. Journal of Southwest Jiaotong University, 2022, 57(4): 910-918. [17] YANG B, HOU J R, ZHOU Z H, et al. Influence of different soil properties on the failure behavior of deposit slope under earthquake after rainfall[J]. Journal of Mountain Science, 2023, 20(1): 65-77. doi: 10.1007/s11629-021-7243-z [18] YANG B, YANG F, ZHENG X S, et al. Dynamic failure of deposit slope with different characteristic of soil–bedrock interface[J]. Natural Hazards, 2025, 121(11): 13217-13236. doi: 10.1007/s11069-025-07321-0 [19] 郑开欢, 罗周全, 罗成彦, 等. 持续暴雨作用下排土场层状碎石土边坡稳定性[J]. 工程科学学报, 2016, 38(9): 1204-1211. doi: 10.13374/j.issn2095-9389.2016.09.002ZHENG Kaihuan, LUO Zhouquan, LUO Chengyan, et al. Layered gravel soil slope stability of a waste dump considering long-term hard rain[J]. Chinese Journal of Engineering, 2016, 38(9): 1204-1211. doi: 10.13374/j.issn2095-9389.2016.09.002 [20] 韩同春, 苏钰钦, 张宇. 双层结构边坡降雨入渗与坡面径流耦合分析[J]. 工程科学与技术, 2020, 52(6): 145-152. doi: 10.15961/j.jsuese.202000179HAN Tongchun, SU Yuqin, ZHANG Yu. Coupling analysis of rainfall infiltration and slope runoff in two-layered slope[J]. Advanced Engineering Sciences, 2020, 52(6): 145-152. doi: 10.15961/j.jsuese.202000179 [21] 宋健, 陆朱汐, 谢华威, 等. 地震作用下分层土边坡多滑面变形破坏的数值模拟研究[J]. 地震工程学报, 2023, 45(2): 296-305.SONG Jian, LU Zhuxi, XIE Huawei, et al. Numerical study of the deformation and failure of layered soil slopes with multiple sliding surfaces under earthquakes[J]. China Earthquake Engineering Journal, 2023, 45(2): 296-305. [22] 文钊, 刘汉香, 李欣, 等. 基于振动台试验的水平层状边坡共振响应分析[J]. 地震工程与工程振动, 2024, 44(3): 116-126. doi: 10.13197/j.eeed.2024.0311WEN Zhao, LIU Hanxiang, LI Xin, et al. Resonance response analysis of horizontal layered slope based on shaking table tests[J]. Earthquake Engineering and Engineering Dynamics, 2024, 44(3): 116-126. doi: 10.13197/j.eeed.2024.0311 [23] 位伟, 段绍辉, 姜清辉, 等. 反倾边坡影响倾倒稳定的几种因素探讨[J]. 岩土力学, 2008, 29(增1): 431-434. doi: 10.3969/j.issn.1000-7598.2008.z1.087WEI Wei, DUAN Shaohui, JIANG Qinghui, et al. Discussion on several factors affecting dumping stability of reverse slope[J]. Rock and Soil Mechanics, 2008, 29(S1): 431-434. doi: 10.3969/j.issn.1000-7598.2008.z1.087 [24] 陈致润. 地震降雨作用下分段式堆积体基覆型边坡失稳特征及规律研究[D]. 成都: 西南交通大学, 2023. [25] 杨翔. 基覆型边坡破坏模式及动力响应研究[D]. 成都: 西南交通大学, 2019. [26] 杨兵. 土木工程相似理论与模型试验[M]. 北京: 科学出版社, 2021. -
下载: