Soil-Structure Interaction under Environmentally Induced Cyclic Loading

大多数土工结构在其使用寿命期内都会受到环境诱发的循环荷载的影响。这些循环荷载可以来自各种各样的来源，例如交通、机器、风浪、建筑或地震。重复加载的范围可以从大量的高概率周期和相对较小的振幅，到少量的低概率周期和相对较大的振幅。循环荷载通常是多轴的，其加载时间历史是不规则的，其幅值和频率随周期而变化。这种载荷会导致残余应变的积累和应力变化，从而影响结构的性能或稳定性。预测随机循环荷载对土工结构影响的模型相对粗糙，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由环境源（如风、海浪和地震）引起的随机循环荷载的不同方面，并为更好的岩土结构预测设计工具提供理解。

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.