Challenges and Innovations in Geomechanics - Proceedings of the 16th International Conference of IACMAG - Volume 3
Challenges and Innovations in Geomechanics - Proceedings of the 16th International Conference of IACMAG - Volume 3
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地质力学的挑战与创新 - 第 16 届 IACMAG 国际会议论文集 - 第 3 卷
DOI：
10.1007/978-3-031-12851-6_24
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Ciantia M
中科院分区：
文献类型：
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作者：
Ciantia M
在这项工作中，复杂的耦合变形和流动过程中发生在周围的土壤中的CPTu流量计在结构性天然粘土的测试过程中，通过土工颗粒有限元法（GPFEM）代码进行了研究。采用的GPFEM实现采用了一个完全耦合的流体力学配方，正则化的基础上，混合低阶线性应变三角形。为了捕捉天然结构性粘土的力学响应的相关特征，土的行为是使用有限变形，非关联的弹塑性模型，这类岩土材料，简称FD_米兰模型。该模型的制定是基于乘法分解的变形梯度和通过的弹性响应的基础上存在一个合适的自由能函数。两个键合相关的内部变量，量化的结构上的屈服轨迹的影响，被纳入提供一个宏观描述的机械破坏效应。为了处理应变局部化现象，该模型配备了一个非局部版本的硬化定律。数值模型已被证明能够捕捉破坏与锥尖周围的塑性变形;孔隙水压力的空间和时间的演变，作为锥尖的进步;预测的超孔隙水压力的土壤渗透性的影响，和土壤粘结锥尖阻力的预测值的影响。
In this work, the complex coupled deformation and flow processes occurring in the soil around a CPTu penetrometer during a test in structured natural clays are investigated by means of the Geotechnical Particle Finite Element Method (GPFEM) code. The GPFEM implementation adopted incorporates a fully coupled hydro-mechanical formulation, based on regularized, mixed low-order linear strain triangles. To capture the relevant features of the mechanical response of natural structured clays, the soil behaviour is described using a finite deformation, non-associative elastic-plastic model for this class of geomaterials, referred asFD_Milanmodel. The model formulation is based on a multiplicative decomposition of the deformation gradient and on the adoption of an elastic response based on the existence of a suitable free energy function. Two bonding-related internal variables, quantifying the effects of structure on the yield locus, are incorporated to provide a macroscopic description of mechanical destructuration effects. To deal with strain localization phenomena, the model is equipped with a non-local version of the hardening laws. The numerical model has demonstrated capable of capturing the destructuration associated with plastic deformations around the cone tip; the space and time evolution of pore water pressure as the cone tip advances; the effect of soil permeability on predicted excess pore water pressures, and the effect of soil bonding on predicted values of cone tip resistance.