Assessment of the Performance of the Ground and Facilities at Wellington Port during Three Earthquakes

港口是重要的经济资产，其恢复能力对我们国家的安全至关重要。许多港口位于地震活跃地区，地震发生后可能会遭到破坏，失去运营准备。液化对港口影响的研究在美国至关重要，因为液化的影响，比如2016年凯库拉地震后新西兰惠灵顿港观察到的液化影响，可能会导致人员死亡，并削弱商业。由于广泛使用的液化评估程序在很大程度上是基于经验的，因此对充分记录的、有洞察力的液化案例历史进行彻底调查是至关重要的。砂砾和淤泥液化及其对港口设施的影响等问题仍有待探讨。丰富的惠灵顿港口数据集提供了一个特殊的机会，可以促进对土壤液化效应的理解，开发更强大的简化程序，并评估先进模型和模拟的能力，以识别关键港口设施的地震性能。惠灵顿港提供了对港口设施进行详细程度和复杂程度综合研究的机会，这是由于安全限制而无法在美国进行的。其液化危害和基础设施与美国相似，这意味着研究结果将直接转移到美国。经验教训将被纳入评估液化对填海土地上港口设施影响的建议中。简化的液化评估程序提供了有用的见解，但它们无法解释2016年惠灵顿港凯库拉地震中液化引起的不同程度的地面和设施损坏。这次地震的影响以及2013年库克海峡和格拉斯米尔湖地震造成的破坏较小，值得进一步研究。基于性能的地震工程需要能够辨别不同级别地震性能的分析工具。这些地震具有出色的地面运动记录，港口设施的良好记录，以及随后对土壤条件（包括液化的砾石）特征的实地调查，为进一步了解提供了绝佳的机会。记录和学习砾石液化的现场案例历史尤为重要，因为这些案例很少存在。研究目标是：a)研究含70%砾石级材料的Thorndon充填体的液化触发机制；B)调查港口粉质土场地缺乏液化表现；C)开发了一种新的估计液化后体积沉降的概率方法；D)开发并回溯分析港口设施经历不同程度液化诱发的地面破坏的历史案例；e)转移知识。这些目标是通过一项研究计划来实现的，该研究计划：(1)开发和解释港口三种土壤条件（砾石填充、粉质土壤和砂填充）的地面性能的充分记录的案例历史；(2)将港口激光雷达数据与其他案例历史数据相结合，提出了一种新的估算体积再固结地面沉降的概率方法，该方法评估了不确定性；(3)开发并回溯分析了七个有充分文献记载的港口设施性能历史案例，以评估土壤-结构-相互作用效应对码头和建筑物的重要性；(4)开展外联活动并制定指导方针。惠灵顿港出色的地基和结构性能历史案例为开发新方法提供了难得的机会，这些新方法可以捕捉到地震期间观察到的不同水平的性能。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Ports are critical economic assets and their resilience is necessary for the security of our Nation. Many ports are in seismically active areas, which could be damaged and lose operational readiness after an earthquake. Research on liquefaction effects on ports is vitally important in the U.S. where the effects of liquefaction like those observed at Wellington Port, New Zealand after the 2016 Kaikoura earthquake could kill people and cripple commerce. As widely used liquefaction evaluation procedures are largely empirically based, it is crucial that well-documented, insightful liquefaction case histories be investigated thoroughly. There remain several important issues to explore such as gravel and silt liquefaction and their effects on port facilities. The rich Wellington Port dataset provides an exceptional opportunity to advance the understanding of soil liquefaction effects, to develop more robust simplified procedures, and to evaluate the capabilities of advanced models and simulations to discern the seismic performance of critical port facilities. Wellington Port provides the opportunity for an integrated study of port facilities at a degree of detail and level of complexity that could not be performed in the U.S. due to security restrictions. The similarity of its liquefaction hazards and infrastructure with those in the U.S. means that the research findings will be directly transferable to the U.S. Lessons learned will be incorporated in recommendations for assessing the effects of liquefaction on port facilities built on reclaimed land. Simplified liquefaction evaluation procedures provide useful insights, but they cannot explain the different levels of liquefaction-induced ground and facility damage during the 2016 Kaikoura earthquake at Wellington Port. The effects of this event and the less damaging 2013 Cook Strait and Lake Grassmere earthquakes warrant further study. Performance-based earthquake engineering requires analytical tools that can discern varying levels of seismic performance. These earthquakes, with their excellent ground motion recordings, their well-documented performance of port facilities, and subsequent fieldwork to characterize the soil conditions, which includes gravel that liquefied, provide an exceptional opportunity to advance understanding. Documenting and learning from field case histories of gravel liquefaction are especially important, as few of these cases exist. The research goals are to: a) investigate liquefaction triggering of the Thorndon fill with up to 70% gravel-size material; b) investigate the lack of liquefaction manifestation at silty soil sites at the port; c) develop a new probabilistic method for estimating post-liquefaction volumetric settlement; d) develop and back-analyze case histories of port facilities undergoing different levels of liquefaction-induced ground failure; and e) transfer knowledge. These goals are realized through a research plan that: (1) develops and interprets well-documented case histories of ground performance for three soil conditions at the port: gravel fill, silty soil, and sand fill; (2) combines the Port’s lidar data with other case history data to develop a new probabilistic method for estimating volumetric reconsolidation ground settlement, which assesses uncertainty; (3) develops and back-analyzes seven well-documented case histories of port facility performance to evaluate the importance of soil-structure-interaction effects for wharves and buildings; and (4) performs outreach activities and develops guidance. The excellent case histories of ground and structural performance at Wellington Port provide an exceptional opportunity to develop new methods that capture the observed differing levels of performance during the earthquakes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.