CAREER: A Framework for Integrated Computational and Physical Simulation of Dynamic Soil-Pile Interaction

职业：动态土桩相互作用的综合计算和物理模拟框架

基本信息

批准号：
1351828
负责人：
Jeramy Ashlock
金额：
$ 40万
依托单位：
Iowa State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-03-01 至 2019-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1351828&HistoricalAwards=false
关键词：
CAREER Framework Integrated Computational Physical

项目摘要

The goal of this Faculty Early Career Development (CAREER) Program award is to develop an integrated research and education program aimed at advancing fundamental knowledge on dynamic pile-soil interaction for pile groups. To this end, integrated full-scale physical and computational studies will be carried out in the quasi-elastodynamic and nonlinear ranges. Advancements in physical simulation methods developed for single piles in the PI's recent NEES Payload project will be extended to pile groups. Specifically, coupled vertical-horizontal-rocking tests with broadband excitation and random-vibration signal processing techniques will be used to efficiently characterize the dynamic response of soil pile-group interaction in the frequency domain. Concurrently, three-dimensional inhomogeneous disturbed-zone computational models developed for single piles in the PI's previous centrifuge studies will be extended to the more complex and practically significant, yet less well-understood, case of pile groups. The sensitivity of the theoretical pile response will be determined through parametric studies of the model parameters, including (1) modulus and damping profiles in the disturbed zones around the piles, (2) modulus and damping profiles in the far-field, (3) size and shape of the disturbed zone, and (4) pile-soil contact conditions. Upon characterizing their relative contributions to the overall elastodynamic response, these parameters will then be calibrated to the observed experimental responses in a system-identification optimization approach, to produce calibrated computational disturbed-zone models of the observed soil pile-group interaction. The research will be transformative in its use of unique multi-modal and random-vibration experimental testing techniques developed in previous centrifuge projects and a full-scale NEES project; the 3D modeling of dynamic soil-structure interaction (SSI) by advanced BEM and FEM programs with capabilities for multiple, multi-layered domains to capture both near-field and far-field soil response through the use of disturbed-zone continuum models; and by examining the link between the elastodynamically calibrated disturbed-zone models for small strains, and their performance as initial models in nonlinear time-domain analyses for large strains. In accord with the purpose of the CAREER program, this award will enable the PI to develop a research program that will build a firm foundation for a lifetime of leadership in integrating education and research. The CAREER research project will be unified with a comprehensive education, outreach and training (EOT) program aimed at strengthening the analytical and teaching skills of graduate and undergraduate students, while reaching out to K-12 students to introduce them to topics of geotechnical engineering. To maximize the impact of the EOT program, the activities will be planned in consultation with established university outreach and diversity programs with proven records of inspiring K-12 students towards STEM fields and increasing participation of underrepresented minorities in engineering. The EOT activities include development of teaching modules for dissemination via NSF's TeachEngineering web site, outreach lectures on geotechnical and earthquake engineering for an annual science festival and K-12 classrooms, NSF field days through which students will learn about the project and observe tests, and involvement of local middle school students in summer research. The project also includes a formal assessment plan to ensure the success of the EOT activities through collaboration with an evaluator from the ISU Research Institute for Studies in Education.

这个教师早期职业发展（职业）计划奖的目标是制定一项综合研究和教育计划，旨在促进有关桩组动态桩土互动的基本知识。为此，将在准弹性动力和非线性范围内进行综合的全尺度物理和计算研究。 PI最近的NEES有效载荷项目中为单个桩开发的物理模拟方法的进步将扩展到桩组。具体而言，具有宽带激发和随机振动信号处理技术的耦合垂直 - 旋转岩石测试将用于有效地表征频域中土壤桩组相互作用的动态响应。同时，在PI先前的离心机研究中为单个桩开发的三维不均匀的不均匀区域计算模型将扩展到更复杂，实际上是显着但较少且较不熟悉的桩组的情况。理论桩响应的敏感性将通过对模型参数的参数研究来确定，包括（1）桩周围受干扰区域中的模量和阻尼轮廓，（2）模量和远场中的模量和阻尼轮廓，（3）受干扰区域的大小和形状，以及（4）堆积的土壤接触条件。在表征其对整体弹性动力响应的相对贡献后，这些参数将在系统识别优化方法中校准，以产生观察到的土壤桩组相互作用的校准计算干扰区模型。这项研究将在使用独特的多模式和随机振动实验测试技术方面具有变革性，并在先前的离心机项目和全尺度NEES项目中开发了。高级BEM和FEM程序对动态土壤结构相互作用（SSI）的3D建模具有多个多层多层域，可通过使用干扰区的连续模型来捕获近场和远场土壤响应；并检查小应变的弹性动力学校准的干扰区模型与它们作为大型菌株的非线性时间域分析中的初始模型之间的连接。根据职业计划的目的，该奖项将使PI能够制定一项研究计划，该计划将为整合教育和研究的领导能力奠定坚定的基础。职业研究项目将通过全面的教育，推广和培训（EOT）计划统一，旨在增强研究生和本科生的分析和教学技能，同时与K-12学生接触，以将其介绍给岩土技术工程主题。为了最大程度地提高EOT计划的影响，将与既定的大学推广和多样性计划进行协商计划，并以可靠的记录启发K-12学生进入STEM领域，并增加代表性不足的少数群体在工程方面的参与。 EOT活动包括通过NSF的Teachengeering网站开发用于传播的教学模块，为年度科学节和K-12教室的岩土技术和地震工程讲座，NSF实地日期，学生将学习该项目并观察该项目的测试，并参与当地中学生的夏季研究。该项目还包括一个正式的评估计划，以通过与ISU教育研究所的评估者合作来确保EOT活动的成功。