| 引用本文: | 连继峰,罗强,张文生,谢宏伟,魏明,熊勇.路堤边坡膨胀土强度非线性应力阈值与浅层稳定性[J].哈尔滨工业大学学报,2021,53(3):142.DOI:10.11918/201908149 |
| LIAN Jifeng,LUO Qiang,ZHANG Wensheng,XIE Hongwei,WEI Ming,XIONG Yong.Nonlinear stress threshold for expansive soil strength and shallow stability of embankment slope[J].Journal of Harbin Institute of Technology,2021,53(3):142.DOI:10.11918/201908149 |
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| 路堤边坡膨胀土强度非线性应力阈值与浅层稳定性 |
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连继峰1,罗强2,张文生2,谢宏伟2,魏明2,熊勇3
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(1.西南科技大学 土木工程与建筑学院,四川 绵阳 621010;2.西南交通大学 土木工程学院,成都 610031; 3.水利部岩土力学与工程重点实验室(长江科学院),武汉 430010)
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| 摘要: |
| 为探究膨胀土边坡浅层土体低应力下强度非线性特征及失稳模式对稳定性的影响,针对重塑膨胀土饱和慢剪试验中低应力区段强度非线性变化规律,采用统计原理的Chauvenet准则,确定了低应力下强度非线性与常规应力下线性变化的应力阈值,明确了雨水入渗导致膨胀土边坡浅层溜坍土体的强度处于低应力非线性区段；基于“顺坡曲面”失稳破坏模式,建立了膨胀土路堤边坡浅层稳定分析方法,可以反映雨水渗流作用及低应力下膨胀土强度非线性特征. 研究结果表明:处于低应力下的膨胀土路堤边坡浅层饱和土体具有小黏聚力、大内摩擦角的力学特性是强降雨诱发溜坍破坏的强度条件；采用低应力下强度非线性幂函数模型的“顺坡曲面”组合失稳模式,能更准确描述膨胀土边坡的浅层稳定性,所得安全系数明显低于常规应力下库伦线性模型的圆弧滑面破坏模式. |
| 关键词: 路堤边坡 膨胀土 浅层稳定性 强度非线性 应力阈值 |
| DOI：10.11918/201908149 |
| 分类号:TU43 |
| 文献标识码:A |
| 基金项目:西南科技大学科研基金(17zx7152)； 国家自然科学基金面上项目(51878560)； 国家自然科学青年基金(51709016) |
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| Nonlinear stress threshold for expansive soil strength and shallow stability of embankment slope |
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LIAN Jifeng1,LUO Qiang2,ZHANG Wensheng2,XIE Hongwei2,WEI Ming2,XIONG Yong3
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(1. School of Civil Engineering and Architecture, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China; 2.School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China;3. Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources (Changjiang River Scientific Research Institute), Wuhan 430010, China)
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| Abstract: |
| Strength nonlinearity and failure modes are considered to have impact on the stability of shallow expansive soil slopes at low stresses. Based on the nonlinear characteristics of shear strength of saturated remolded expansive soil in low stress section obtained from slow shear test, the stress threshold for linear development at normal stresses and nonlinear variation at low stresses was determined by adopting the Chauvenet criterion. It was clarified that rain infiltration was the main reason that the strength of shallow sliding bodies of expansive soil slope was in the nonlinear section at low stresses. On the basis of the failure mode of “parallel slope-curve”, a stability analysis method was established to investigate the nonlinear strength characteristics of expansive soil in shallow embankment slopes at low stresses under seepage force. Results show that the mechanical properties of small cohesion and large internal friction angle of saturated expansive soil in embankment slopes at low stresses were the strength conditions of the sliding failure induced by heavy rainfall. The composite failure mode of “parallel slope-curve” based on the strength nonlinear power function model at low stresses could describe the shallow stability of expansive soil slopes more accurately, and the obtained safety factor was obviously lower than that of the circular failure mode based on the Coulomb model at normal stresses. |
| Key words: embankment slope expansive soil shallow stability nonlinearity of shear strength stress threshold |
