考虑基岩蠕变特性的重力坝深层抗滑稳定性分析
|
摘要
对于坝址岩性软弱的重力坝,其基岩的蠕变特性导致地基应力随时间不断调整,目前采用的弹塑性计算无法得到坝体的长期深层抗滑稳定性。通过典型算例,分别采用基于Cvisc模型的考虑蠕变的强度折减法以及常规的弹塑性强度折减法进行深层抗滑稳定计算,并对结果进行比较。结果表明,考虑基岩的蠕变特性时,重力坝的深层抗滑稳定安全系数偏小,而坝体失稳时的特征点位移值偏大。当重力坝的基岩较软,蠕变特性较明显时,必须充分考虑基岩的蠕变特性对坝体深层抗滑稳定性的影响。
For gravity dams with weak foundation, the creep behavior of the bedrock causes the stress of the foundation to adjust with time. The present elastic-plastic calculation cannot obtain the long-term deep sliding stability of the dam. In this paper, the creep-considered strength reduction method based on Cvisc model and the conventional elastic-plastic strength reduction method are used to calculate the deep anti-sliding stability through typical examples, and the results are compared. The results show that the safety factor of deep anti-sliding stability of gravity dam is smaller and the displacement of characteristic points is larger when the creep characteristics of bedrock are considered. When the foundation rock of gravity dam is weak and the creep characteristics are obvious, the influence of the creep characteristics of the foundation rock on the deep sliding stability of the dam must be fully considered.
For gravity dams with weak foundation, the creep behavior of the bedrock causes the stress of the foundation to adjust with time. The present elastic-plastic calculation cannot obtain the long-term deep sliding stability of the dam. In this paper, the creep-considered strength reduction method based on Cvisc model and the conventional elastic-plastic strength reduction method are used to calculate the deep anti-sliding stability through typical examples, and the results are compared. The results show that the safety factor of deep anti-sliding stability of gravity dam is smaller and the displacement of characteristic points is larger when the creep characteristics of bedrock are considered. When the foundation rock of gravity dam is weak and the creep characteristics are obvious, the influence of the creep characteristics of the foundation rock on the deep sliding stability of the dam must be fully considered.
引文
[1] 于沭,陈祖煜,王玉杰,等.用强度折减方法分析重力坝深层抗滑稳定性[J].水文地质工程地质,2009,36(3):64-70.
[2] 俞祥荣,张社荣,孟亚运,等.柬埔寨甘再重力坝深层抗滑稳定分析[J].水利水电技术,2014,45(8):62-65,69.
[3] 张尧,熊良宵.岩石流变力学的研究现状及其发展方向[J].地质力学学报,2008,14(3):274-285.
[4] 陈卫兵,郑颖人,冯夏庭,等.考虑岩土体流变特性的强度折减法研究[J].岩土力学,2008,(1):101-105.
[5] 马冲,胡斌,詹红兵,等.基于蠕变强度折减法的滑坡稳定性分析[J].金属矿山,2014,(11):50-53.
[6] 刘东燕,谢林杰,庹晓峰,等.不同围压作用下砂岩蠕变特性及非线性黏弹塑性模型研究[J].岩石力学与工程学报,2017,36(S2):3 705-3 712.
[7] 李男,徐辉,简文星.砂质泥岩的剪切蠕变特性和本构模型探究[J].铁道建筑,2011,(2):82-85.
[8] 徐辉,胡斌,唐辉明,等.饱水砂岩的剪切流变特性试验及模型研究[J].岩石力学与工程学报,2010,29(S1):2 775-2 781.
[2] 俞祥荣,张社荣,孟亚运,等.柬埔寨甘再重力坝深层抗滑稳定分析[J].水利水电技术,2014,45(8):62-65,69.
[3] 张尧,熊良宵.岩石流变力学的研究现状及其发展方向[J].地质力学学报,2008,14(3):274-285.
[4] 陈卫兵,郑颖人,冯夏庭,等.考虑岩土体流变特性的强度折减法研究[J].岩土力学,2008,(1):101-105.
[5] 马冲,胡斌,詹红兵,等.基于蠕变强度折减法的滑坡稳定性分析[J].金属矿山,2014,(11):50-53.
[6] 刘东燕,谢林杰,庹晓峰,等.不同围压作用下砂岩蠕变特性及非线性黏弹塑性模型研究[J].岩石力学与工程学报,2017,36(S2):3 705-3 712.
[7] 李男,徐辉,简文星.砂质泥岩的剪切蠕变特性和本构模型探究[J].铁道建筑,2011,(2):82-85.
[8] 徐辉,胡斌,唐辉明,等.饱水砂岩的剪切流变特性试验及模型研究[J].岩石力学与工程学报,2010,29(S1):2 775-2 781.