A nonlinear Hvorslev surface for highly overconsolidated soils: elastoplastic and hypoplastic implementations
A nonlinear Hvorslev surface for highly overconsolidated soils: elastoplastic and hypoplastic implementations
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DOI：
10.1007/s11440-016-0485-1
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发表时间：
2017
期刊：
影响因子：
5.7
通讯作者：
X. Shi;I. Herle;K. Bergholz
中科院分区：
文献类型：
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作者：
X. Shi;I. Herle;K. Bergholz
粘土填充物是在露天开采中生产的。粘土填充物的硬块中的应力状态明显低于原位水平。因此，它们当前的状态位于临界状态的干燥侧。线性 Hvorslev 曲面因其简单性和能够模拟干侧土壤的极限应力条件而被广泛使用。然而，它可能会高估极低应力水平下的强度。为此，在非常小的应力水平下对粉质粘土进行了一系列排水三轴试验。测试土壤的破坏点证实了临界状态干燥侧的 q 平面内的非线性关系。通过 Hvorslev 等效压力归一化后，非线性程度会增加，这可以通过 Atkinson 提出的非线性幂律准则很好地建模（Géotechnique 57(2):127–135, 2007）。基于测试数据和临界状态概念，借助等效 Hvorslev 压力提出了新的失效线。然后将非线性 Hvorslev 曲面合并到弹塑性模型和亚塑性模型中。实验数据和模拟之间的比较表明，所提出的模型可以很好地代表实验室中观察到的行为。
The clayfills are being produced in open-pit mining. The stress state in the stiff lumps of the clayfills is significantly lower than in situ level. As a result, their current states lie on the dry side of the critical state. The linear Hvorslev surface is widely used due to its simplicity and capability to model the limit stress condition of soils on the dry side. However, it may overestimate the strength at very low stress level. For this purpose, a series of drained triaxial tests were performed on a silty clay at very small stress levels. The failure points of the tested soil confirm a nonlinear relationship in–qplane on the dry side of the critical state. The degree of nonlinearity increases after being normalized by the Hvorslev equivalent pressure, which can be well modeled by a nonlinear power law criterion proposed by Atkinson (Géotechnique 57(2):127–135, 2007). Based on the test data and the critical state concept, a new failure line is proposed with help of the equivalent Hvorslev pressure. The nonlinear Hvorslev surface is then incorporated into an elastoplastic model and a hypoplastic model. Comparisons between the experimental data and simulations reveal that the proposed models can well represent the behavior observed in the laboratory.