露天煤矿含水边坡稳定性弹塑性有限元计算方法
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摘要
为了确定能使边坡保持稳定的边坡含水率,主要考虑了含水率对边坡强度参数的影响。把边坡岩土体看作是理想弹塑性的Drucker-Prager材料,边坡的破坏准则以计算的收敛性为依据,边坡的稳定性用强度折减提取的稳定系数来衡量。采用大变形理想弹塑性有限元法计算了不同含水率的边坡体分别对应的稳定系数。结果表明,边坡塑性区从坡脚萌生,随着重力加载进行,塑性区从坡脚以带状向坡顶方向扩展,最终形成滑坡体的滑面;含水率提高使边坡岩土体的强度参数降低,进而降低了边坡的稳定性,边坡的稳定系数在一定含水率水平以下才有意义;理想弹塑性有限元结合强度折减法和计算收敛性判据可以很好地给出一定边坡稳定系数的含水率。
In order to determine the slope water content that cannot make slope instability,the effect of water content on the strength parameters of slope is studied. The slope rock mass is considered as ideal elastic plastic Drucker-Prager material,the convergence of calculation is taken as failure criterion of slope to as the basis,the stability factor of slope by strength reduction is taken as measure to the slope stability. Stability factors of slope corresponding to different water contents were calculated using large deformation elastic-plastic finite element method. The results showed that,the plastic zone initiates from the toe of the slope,with the gravity loading,the plastic zone expand from the foot to the top of the slope with the strip shape,eventually forming sliding surface of landslide; water content increase induces the strength parameters of rock and soil slope decrease,thereby reducing the stability of the slope,stability factor of slope is significant in a certain condition of water content; ideal elastic plastic stability FEM combining strength reduction method and convergence criterion can give the water content for certain slope stability factor.
In order to determine the slope water content that cannot make slope instability,the effect of water content on the strength parameters of slope is studied. The slope rock mass is considered as ideal elastic plastic Drucker-Prager material,the convergence of calculation is taken as failure criterion of slope to as the basis,the stability factor of slope by strength reduction is taken as measure to the slope stability. Stability factors of slope corresponding to different water contents were calculated using large deformation elastic-plastic finite element method. The results showed that,the plastic zone initiates from the toe of the slope,with the gravity loading,the plastic zone expand from the foot to the top of the slope with the strip shape,eventually forming sliding surface of landslide; water content increase induces the strength parameters of rock and soil slope decrease,thereby reducing the stability of the slope,stability factor of slope is significant in a certain condition of water content; ideal elastic plastic stability FEM combining strength reduction method and convergence criterion can give the water content for certain slope stability factor.
引文
[1]白建光,周天平,梁鸿.配合比及含水率对三合土抗剪强度指标的影响研究[J].内蒙古农业大学学报(自然科学版),2013(4):119-122.
[2]蔡正银,吴志强,黄英豪.含水率和含盐量对冻土无侧限抗压强度影响的试验研究[J].岩土工程学报,2014(9):1-7.
[3]傅蜀燕,袁坤,彭胜利.含水率对高液限细粒土砾与粉质黏土抗剪强度影响比较研究[J].水利科技与经济,2014(2):10-12.
[4]张磊,陈正汉,苗强强.含水率对含黏砂土孔压、强度和变形的影响[J].后勤工程学院学报,2012(5):10-15.
[5]叱干晓敏.考虑含水率变化对黄土结构强度影响的边坡稳定性分析[J].水利与建筑工程学报,2013(5):169-172.
[6]郭亚兵.含水量对黄土边坡稳定性的影响[J].天水师范学院学报,2015,35(2):78-80.
[7]杨晓杰,张寿涛.含水率对软岩边坡稳定性的影响分析[J].煤炭技术,2015,34(5):216-218.
[8]李硕琦,张雅慧,胡斌,等.含水率和干湿循环对人工填土边坡稳定性的影响[J].水电能源科学,2014,32(8):65-67.
[9]申春妮,方祥位,王和文,等.吸力、含水率和干密度对重塑非饱和土抗剪强度影响研究[J].岩土力学,2009(5):1347-1351.
[10]赵尚毅,郑颖人,张玉芳.极限分析有限元法讲座—Ⅱ有限元强度折减法中边坡失稳的判据探讨[J].岩土力学,2005(2):332-336.
[2]蔡正银,吴志强,黄英豪.含水率和含盐量对冻土无侧限抗压强度影响的试验研究[J].岩土工程学报,2014(9):1-7.
[3]傅蜀燕,袁坤,彭胜利.含水率对高液限细粒土砾与粉质黏土抗剪强度影响比较研究[J].水利科技与经济,2014(2):10-12.
[4]张磊,陈正汉,苗强强.含水率对含黏砂土孔压、强度和变形的影响[J].后勤工程学院学报,2012(5):10-15.
[5]叱干晓敏.考虑含水率变化对黄土结构强度影响的边坡稳定性分析[J].水利与建筑工程学报,2013(5):169-172.
[6]郭亚兵.含水量对黄土边坡稳定性的影响[J].天水师范学院学报,2015,35(2):78-80.
[7]杨晓杰,张寿涛.含水率对软岩边坡稳定性的影响分析[J].煤炭技术,2015,34(5):216-218.
[8]李硕琦,张雅慧,胡斌,等.含水率和干湿循环对人工填土边坡稳定性的影响[J].水电能源科学,2014,32(8):65-67.
[9]申春妮,方祥位,王和文,等.吸力、含水率和干密度对重塑非饱和土抗剪强度影响研究[J].岩土力学,2009(5):1347-1351.
[10]赵尚毅,郑颖人,张玉芳.极限分析有限元法讲座—Ⅱ有限元强度折减法中边坡失稳的判据探讨[J].岩土力学,2005(2):332-336.