考虑内部摩擦变形耗能的预应力锚索边坡极限分析

发布时间：2018-03-06 11:27

本文选题：预应力锚索边坡　切入点：稳定性　出处：《岩土工程学报》2017年02期 　论文类型：期刊论文

【摘要】：根据变形协调原则,认为对数螺旋线滑面滑坡体在下滑过程中并非完全不变形而是根据滑面形状自适应变形从而产生能量耗散。为量化该过程中的能量耗散,根据协调速度场的关系提出了2种多块体划分法来计算该变形摩擦耗能功率,并结合极限分析上限法和强度折减法推导了预应力锚索加固边坡的安全系数计算式。通过算例分析表明,虽然2种多块体划分方法获得的边坡安全系数随着划分块体接触面数量的增加变化规律不同,但最终都趋于稳定收敛,且收敛值十分接近,并从具体划分原理角度解释了2种不同变化趋势的原因。典型边坡算例的不同分析方法安全系数结果比较表明,滑坡体内部变形摩擦耗能有助于提高边坡的抗滑作用,安全系数较不考虑时有所增大。分析总结了预应力锚索边坡随锚索预应力、锚索倾角、锚索位置高度变化条件下有无考虑滑坡体内部变形摩擦耗能的边坡安全系数变化规律。该方法弥补了以往上限法中忽略该项摩擦耗能的不足,可为预应力锚索加固边坡的稳定性分析提供参考。
[Abstract]:According to the principle of deformation coordination, it is considered that the logarithmic spiral slide body is not completely non-deformed, but adaptively deforms according to the shape of the sliding surface to generate energy dissipation, in order to quantify the energy dissipation in the process. According to the relation of coordinated velocity field, two kinds of multi-block partition methods are proposed to calculate the energy dissipation power of the deformation friction. Combined with the upper limit method of limit analysis and the strength reduction method, the formula for calculating the safety factor of the slope strengthened by prestressed anchor cable is derived. Although the slope safety coefficient obtained by the two multi-block partitioning methods varies with the increase of the number of contact surfaces, both of them tend to converge stably and converge, and the convergent values are very close to each other. From the angle of concrete division principle, the causes of two different variation trends are explained. The comparison of the safety coefficient of different analysis methods of typical slope examples shows that friction energy dissipation of internal deformation of landslide body is helpful to improve the anti-slide effect of slope. When the safety factor is not considered, the slope of prestressed anchor cable is analyzed and summarized. Under the condition of the change of anchor cable position height, there is a slope safety coefficient variation law considering the friction energy dissipation of the internal deformation of the landslide body. This method makes up for the deficiency of the former upper bound method which neglects the friction energy dissipation. It can provide a reference for the stability analysis of the slope strengthened by prestressed Anchorage cable.
【作者单位】：武汉理工大学土木工程与建筑学院;
【基金】：国家自然科学基金面上项目(51374163)
【分类号】：TU43

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