Testing and Modeling of Saturated Interfaces in Soil- Structure Problems

在地质力学问题中，如结构-地基、结构-岩石地基系统中，接触面和节理的特性对其在静、动荷载作用下的响应起着至关重要的作用。 虽然实验室测试和建模的界面响应，主要是在干燥条件下，已经在过去进行的，孔隙水压力在界面上的土壤结构响应的影响的重要问题还没有得到充分的研究。 饱和界面的响应显着影响孔隙压力的发展和由此产生的影响的变形，故障和承载能力的结构基础系统是重要的安全和经济的设计。 这项研究将使用一个新开发的剪切试验装置，允许静态和动态加载和孔隙水压力的因素，如粗糙度，正应力，密度，简单和直接剪切条件和大尺寸的标本。 由于砂和混凝土之间的界面可以提供一个一般的条件，一系列的准静态和循环试验的干燥和饱和渥太华砂混凝土界面将进行。 研究的另一个主要目标是开发统一的扰动状态概念（DSC），允许弹性和塑性变形，硬化，软化和降解，以及液化模型，如果在测试结果中显示。 该模型将根据测试数据进行校准，并根据独立测试进行验证。 优化过程将允许系统简化和减少参数，以实现实际的分析和设计。 最后，将制定模型应用指南，包括通过非线性有限元程序。

The behavior at interfaces and joints in geomechanical problems such as structure-soil foundation, and structure-rock foundation systems plays a vital role in their response under static and dynamic loads. Although laboratory testing and modeling for the interface response, mostly under dry conditions, have been performed in the past, the important issue of the effect of pore water pressures at interfaces on the soil-structure response has not been fully investigated before. The response of saturated interfaces is influenced significantly by the pore pressure development and its resulting effect on deformations, failure, and load carrying capacities of the structure-foundation systems is important for safe and economical design. This research will use a newly developed shear test device that allows static and dynamic loading and pore water pressures with inclusion of factors such as roughness, normal stress, density, simple and direct shear conditions and large-sized specimens. As interfaces between sand and concrete can provide a general condition, a series of quasistatic and cyclic tests on dry and saturated Ottawa sand-concrete interfaces will be performed. Another main objective of the research is to develop the unified disturbed state concept (DSC) which allows elastic and plastic deformations, hardening, softening and degradation, and modeling of liquefaction if indicated in the test results. The model will be calibrated based on the test data, and validated with respect to independent tests. An optimization procedure will permit systematic simplification and reduction in parameters, toward practical analysis and design. Finally, guidelines for application of the model, including through nonlinear finite element procedures, will be developed.