Soil-Structure Interaction under Environmentally Induced Cyclic Loading

大多数岩土工程结构在其寿命期内将承受环境引起的循环荷载。这些循环荷载可能来自各种来源，例如交通、机器、风和波浪、建筑或地震。重复加载的范围可以从大量具有相对较小振幅的高概率循环到少量具有相对较大振幅的低概率循环。循环载荷通常是多轴的，并且具有不规则的载荷-时间历史，在不同的循环之间具有振幅和频率变化。这种载荷会导致残余应变和应力变化的积累，从而影响结构的性能或稳定性。用于预测随机循环荷载对岩土结构影响的模型相对粗糙，并且通常基于有限的现场和比例模型研究。因此，需要更多的研究来解决不同方面的随机循环荷载引起的环境源（如风，海浪和地震），并提供更好的预测设计工具的岩土结构的理解。 本项目的目的是调查两种岩土结构的土壤-结构行为：即基础和管道，在随机变幅循环条件下承受垂直、水平和弯矩荷载的复杂组合时。将验证和校准循环预测模型，以预测这些岩土结构的行为，并得到现场测试、比例物理模型测试和计算机分析数据的支持。在这些预测方法的发展中，将使用典型随机环境过程的适当载荷和响应时间历程。了解这些岩土系统在循环环境荷载作用下的行为和优化分析方法，将有助于改进其行为的设计和预测。在资助期间，从研究中获得的数据和知识将被建筑、地球科学、能源和近海工业的工程师利用。拟议的基础设施将能够创建：（i）结构和岩土工程过程的知识，（ii）现场规模行为的数据库，（iii）设计和施工信息，以及（iv）用于数值和分析方法验证的数据。受这项工作影响的主要应用领域将是风能、石油和天然气行业。

The majority of geotechnical structures will be subjected to environmentally induced cyclic loads during their life-spans. These cyclic loads can be from a variety of sources, e.g. traffic, machines, wind and waves, construction or earthquakes. Repeated loading can range from a large number of high-probability cycles with relatively small amplitude, to a small number of low-probability cycles with relatively large amplitude. The cyclic loading will commonly be multi-axial and have a loading-time history that is irregular, with amplitude and frequency changes from cycle to cycle. This loading can lead to the accumulation of residual strains and stress changes that affect the performance or stability of the structure. Models for predicting the effects of random cyclic loading on geotechnical structures are relatively crude and are generally based on limited field and scaled model studies. Hence, more research is needed to address different aspects of random cyclic loads induced from environmental sources (e.g. wind, sea-waves and earthquakes) and provide understanding for better predictive design tools for geotechnical structures. The aim of this project will be the investigation of the soil-structure behavior of two types of geotechnical structure: namely, foundations and pipelines, when subjected to complex combinations of vertical, horizontal and moment loads under random variable amplitude cyclic conditions. Cyclic predictive models will be validated and calibrated for predicting the behavior of these geotechnical structures, supported by data from field testing, scaled physical model testing and computer analysis. Appropriate loading and response time-histories for typical random environmental processes will be used in the development of these predictive methods. Understanding of the behavior of these geotechnical systems under cyclic environmental loading and optimization of analytical methods will provide improvements in design and prediction of their behavior. Over the funding period, data and knowledge accrued from the research will be utilized by engineers working in construction, geosciences, energy and the offshore industry. The proposed infrastructure will enable the creation of: (i) knowledge of structures and geotechnical processes, (ii) databases of field-scale behavior, (iii) design and construction information and (iv) data for numerical and analytical method validation. The primary sectors of application impacted by this work will be the wind energy, and oil and gas industries.