Research Initiation: Experimental Investigation and Constitutive Modeling of Cohesionless Soil Under Cyclic Loading

研究启动：循环荷载下无粘性土的试验研究与本构模型

• 批准号: 8809175
• 负责人: Panos Dakoulas
• 金额: --
• 依托单位: William Marsh Rice University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8809175&HistoricalAwards=false
• 关键词: Research; Initiation; Experimental; Investigation; Constitutive

Perhaps the most common problem in engineering design involving soils, is the problem of calculating the movements that result from application of general states of stress to the soils. Until the last ten to twenty years, it was feasible to calculate either the very small movements that resulted from small loads (compared to the load that causes collapse), or to calculate collapse loads and assume that movements were so large that it became unnecess- ary to calculate them. For common cases in which neither extreme was valid, it was necessary to apply "engineering judgement." With the advent of modern digital computers, researchers are engaged in a two-pronged attack on this class of problem. One mode involves attempts to measure generalized soil properties (complete state of strain in response to a generalized state of applied stress) and development of models to describe the soil response. The second mode involves development of numerical methods so the resulting soil properties can be used to predict mass movements in the field. This proposal involves the first mode. The goal of this research is to perform reliable measurements of the response of samples of clean sands to complex states of stress, and then to fit appropriate models to allow analytic description of the resulting properties. The socalled hollow-cylinder device will be used to measure properties. A variety of constitutive models will be tried. Both monotonic loading (load directly to failure) and cyclic loading (repeated application of stresses less than the failure stresses) will be used.

也许涉及土壤的工程设计中最常见的问题是计算由于对土壤施加一般应力状态而产生的运动的问题。 直到最近十到二十年，计算小载荷（与导致倒塌的载荷相比）引起的非常小的运动，或者计算倒塌载荷并假设运动太大以至于没有必要都是可行的。 ary 来计算它们。 对于一般情况，两种极端都不成立，就需要运用“工程判断”。 随着现代数字计算机的出现，研究人员对此类问题进行了双管齐下的攻击。 一种模式涉及尝试测量广义土壤特性（响应于施加应力的广义状态的完整应变状态）和开发模型来描述土壤响应。 第二种模式涉及数值方法的开发，因此所得的土壤特性可用于预测现场的质量运动。 本方案涉及第一种模式。 这项研究的目标是对干净沙子样本对复杂应力状态的响应进行可靠测量，然后拟合适当的模型以分析描述所得特性。 所谓的空心圆柱装置将用于测量特性。 将尝试各种本构模型。 将使用单调载荷（直接载荷至失效）和循环载荷（重复施加小于失效应力的应力）。