Foundation Soil Response to Wind Turbine Generator Loading

风力发电机（WTG）的结构通常由一个大的八角形（在底部）混凝土和钢筋支撑，以支持倾覆、旋转刚度和承载能力稳定性要求。系统的倾覆稳定性和最大承载压力随风速和风向的变化而变化。高偏心荷载条件（即倾覆力矩与竖向重力荷载之比较大）导致压力分布不均匀，假定在系统偏心距基础中心偏移的椭圆形有效面积上土压力分布均匀。然而，这种假定的分布在机械上是不正确的。目前的WTG基础理论依赖于弹性半空间模型，而弹性半空间模型是为其他目的而开发的，在WTG基础系统中几乎没有物理证据支持该模型。正因为如此，动态剪切模量值和压力分布假设的现场验证与建立机械正确的WTG基础响应以及动态应力-应变关系与深度相关性（与刚度和沉降分析相关）非常相关。威斯康星大学麦迪逊分校正在与哈特兰社区学院（伊利诺斯州）合作，对即将投入使用的WTG基础进行仪器检测，重点是评估动力和基础土壤对运行中的风作用的反应。监测将测量动力参数（大小和周期），监测基础土壤响应，并分析和制定机械验证的动态基础响应建议。拟议的研究计划的结果将通过外展和教学活动在多个教育环境中加以利用。该项目将为本科生和研究生提供参与可再生能源系统建设、分析和运行的机会。实验结果和分析将被纳入PI？5 .全国认可并参加了风能继续工程教育短期课程，包括风力发电机基础和塔系统设计以及风能民用电厂平衡设计。此外，研究结果将直接用于该项目在威斯康星大学麦迪逊工程学院开设的首个此类学分设计课程CEE639，风能场地设计与施工。

A wind turbine generator (WTG) structure is typically supported on a large octagonal (at the base) mass of concrete and steel rebar reinforcement that supports overturning, rotational stiffness, and bearing capacity stability requirements. The overturning stability and maximum bearing pressure of the system vary as a function of wind speed and direction. The highly eccentric loading conditions (i.e., large ratio of overturning moments to vertical gravity loads) lead to an uneven pressure distribution that is assumed as a uniform soil pressure distribution over an oval-shaped effective area offset from the center of the foundation by the system eccentricity. However, this assumed distribution is mechanically incorrect. Current WTG foundation theory relies on elastic halfspace models that have been developed for other purposes, with little physical evidence to support the model in a WTG foundation system. Because of this, field verification of dynamic shear modulus values and pressure distribution assumptions is very relevant to establishing mechanistically correct WTG foundation responses, along with dynamic stress-strain relationships versus depth correlations (relevant for stiffness and settlement analyses).The University of Wisconsin-Madison is working with Heartland Community College (Illinois) on instrumenting a WTG foundation that will shortly be put into service, with emphasis on evaluating the dynamic forces and the foundation soil response to in-service wind action. The monitoring will measure dynamic force parameters (magnitudes and periods), monitor foundation soil responses, and analyze and develop recommendations for a mechanically validated, dynamic foundation response. The results of the proposed research program will be leveraged across multiple educational environments through outreach and teaching activities. The project will provide an opportunity to engage undergraduate and graduate students with the construction, analysis, and operation of a renewable energy system. Experimental results and analyses will be incorporated into the PI?s nationally recognized and attended continuing engineering education short courses in wind energy including Wind Turbine Foundation and Tower System Design and Wind Energy Civil Balance-of-Plant Design. In addition, results will be directly used in the PI's first of its kind, for-credit design course in the UW-Madison College of Engineering - CEE639, Wind Energy Site Design and Construction.