考虑岩石蠕变与损伤的直立层状边坡倾倒模型

倾倒破坏是直立层状岩质边坡失稳破坏的模式之一,目前仅研究了岩石分别为线弹性体、损伤体或蠕变体时在自重作用下边坡倾倒临界高度的计算方法,而实际工程中,岩体则往往同时具有损伤及蠕变特性。为此,针对软岩中同时存在的损伤与蠕变特性,在经典欧拉压杆模型的基础上分别假定岩石为Maxwell蠕变体、基于Weibull分布的统计损伤体及损伤与蠕变共存的复合体等三种模型,获得了相应的边坡倾倒临界高度计算方法,并讨论了相关参数对计算结果的影响。研究结果表明,在直立层状边坡倾倒计算中,应同时考虑细观损伤与蠕变对计算结果的影响,当考虑岩石蠕变性时,边坡倾倒临界高度随时间增加近似呈指数规律下降。

Toppling Model of Vertical Slabbed Rock Slope by Considering Rock Creep and Damage

Toppling failure is one of the main instability modes of the vertical slabbed rock slope. However, the current calculation methods of the slope toppling critical height is based on the assumptions that the rock is a linear elastic body, a damage body or a creep body, respectively. However, the rock mass in engineering practices often has the damage and creep properties, and therefore the existing studies cannot meet the practical engineering needs. In this paper, considering the soft rock having both damage and creep properties, the corresponding calculation methods of the slope toppling critical height are obtained based on the classical Euler compression rod model when the rock is assumed as the Maxwell creep body, the Weibull statistical damage body and the combined body with damage and creep properties, respectively. In addition, the effect of the relevant parameters on the calculation results is discussed. The calculation results show that the effect of the mesoscopic damage should be considered in toppling calculation of the vertical slabbed rock slope. When the rock creep property is taken into account, the slope toppling critical height decreases generally following an exponential law with the elapsed time.