Temperature dependent viscous behavior on natural clay and the extension of a elasto-thermo-viscoplastic constitutive model

天然粘土在一维固结过程中的性状强烈地受。应变速率以及温度。前期固结压力是应变速率和温度的函数。根据天然粘土的试验结果，讨论了天然粘土骨架的粘性特性和渗透特性。此外，一个弹-热-粘塑性本构模型被开发，以再现天然粘土在不同应变率和温度下的一维行为。采用有效应力有限元法对固结试验结果进行了分析。1）对于所有试验，竖向有效应力与竖向应变之间的关系是唯一的。2）通过扩展阿达奇本构模型，建立了弹-热-粘塑性本构模型。3）在固结试验中，竖向有效应力与竖向应变之间的关系是唯一的。 ...更多信息 d Oka的模型，以再现天然粘土在不同应变速率和温度下的行为。引入的粘塑性参数至少作为第一近似，仅通过前期固结压力的温度依赖性而依赖于温度。粘塑性本构模型较好地再现了Berthierville粘土在不同应变速率和温度下的一维粘性行为，并讨论了屈服特性的重要性和微观结构的影响大坂上更新统海相粘土的应力-应变特性进行了研究。为了获得高质量的粘土样品，采用块体取样技术对更新统海相粘土进行了取样。采用块体取样技术获得的粘土样品的质量高于采用管式取样技术获得的更新世粘土样品。本研究得出以下结论：1.大坂更新世海相粘土的屈服性质是各向异性的。2.更新世海相粘土具有明显的键合结构，比扰动和重塑样品具有更高的脆性、抗压强度和刚度。少

The behavior of natural clays during one dimensional consolidation is strongly influenced by. strain rate as well as temperature. The preconsolidation pressure is a function of both strain rate and temperature. The viscous behavior of the natural clay skeleton as well as the characteristics of the permeability are discussed, based on the experimental results obtained on natural clay. Also, an elasto-thermo-viscoplastic constitutive model is developed to reproduce the one dimensional behavior of natural clays at different strain rates and temperatures. An effective stress based finite element method is applied to the experimental results of consolidation.1) For all the tests performed, the relationship between the vertical effective stress normalized with respect to the preconsolidation pressure corresponding to the strain rate and temperature at that time, and the vertical strain is unique.2) An elasto-thermo-viscoplastic constitutive model has been developed by extending the Adachi an … More d Oka's model to reproduce the behavior of natural clays at different strain rates and temperatures. The viseoplastic parameter introduced is found to depend at least as a first approximation on the temperature only through the temperature dependence of the preconsolidation pressure.3) It is found that the proposed elasto-thermo-viscoplastic constitutive model satisfactorily reproduce the one dimensional viscous behavior of the natural Berthierville clay at different strain rates and temperatures.An importance of yielding characteristic and an effect of the microstructure on stress-strain characteristics of Osaka Upper-Most Pleistocene marine clay are also studied. To get high quality clay samples, Pleistocene marine clays were sampled by block-sampling technique. Clay samples undertaken by the block-sampling technique are found to have higher quality than Pleistocene clay samples obtained by the tube : >sampling technique. The following conclusions are obtained from the present study : 1. Yielding properties of Osaka Pleistocene marine clays from the two sites are anisotropic. 2. The Pleistocene marine clay has a linkage structure with significant bonding, which induces more brittle behavior, higher compressive strength and higher stiffness than the disturbed and reconstituted samples. Less