绝大多数滑坡的发生都与水直接相关,滑坡土体经常处于非饱和状态,而坡体的失稳破坏大都经历了一个时间过程,即滑坡变形具有蠕变性质。因此,绝大多数滑坡的失稳过程实质为非饱和蠕变过程,数值模拟时考虑渗流耦合蠕变效应更能符合滑坡变形的真实状态。根据前期研究成果所得的非饱和土非线性蠕变模型及其三维形式,采用试验数据对模型进行验证。由于常规商业有限元软件没有提供适合特定土体的非饱和蠕变模型,编制了基于渗流及蠕变耦合计算的有限元计算程序,并利用该程序对树坪滑坡在库水位变动下的变形过程进行了数值模拟。结果表明,计算结果与实际变形的监测值趋势比较接近,说明本文所建立的蠕变模型合理,编制的程序可靠,可用于实际滑坡的长期变形计算。
Abstract
The instability of most landslides is fundamentally a non-saturated creep process as on one hand, the landslide is usually in unsaturated state because landslide is directly related to the effect of water, and on another, the landslide deformation is rheological. Taking the coupling effect of seepage and creep into consideration in numerical simulation will better reflect the mechanism of landslide deformation. First of all the nonlinear creep model of unsaturated soil and its three-dimensional form acquired in previous researches of our team are verified through experimental data. Since commercial finite element programs do not provide unsaturated creep model for specific soil mass, a finite element program is developed for seepage and creep coupling. The program is used for modeling the deformation of Shuping landslide under the effect of reservoir water level fluctuation. Results show that the calculation results are close to the actual deformation monitoring values, indicating that the creep model established in this paper is reasonable, and the program is reliable, which can be applied to the estimation of long-term deformation of landslide.
关键词
滑坡 /
长期变形 /
非饱和土 /
渗流 /
非饱和蠕变模型 /
有限元 /
树坪滑坡
Key words
landslide /
long-term deformation /
unsaturated soil /
seepage /
creep model /
finite element /
Shuping landslide
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参考文献
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基金
国家自然科学基金面上项目(41372359);三峡大学人才专项经费(8000303);中国地质调查局项目(DD20190638,DD20190716)
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