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，它们的弹性对我们国家的安全是必要的。许多港口位于地震活跃地区，地震后可能会遭到破坏并失去运营准备。 液化对港口影响的研究在美国至关重要，2016年凯库拉地震后在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价程序主要是基于经验的，这是至关重要的，充分记录，深刻的液化案例历史进行彻底调查。仍有几个重要问题有待探讨，如砾石和淤泥液化及其对港口设施的影响。丰富的惠灵顿港口数据集提供了一个难得的机会，以促进土壤液化效应的理解，开发更强大的简化程序，并评估先进的模型和模拟的能力，以辨别关键港口设施的抗震性能。惠灵顿港提供了对港口设施进行综合研究的机会，其详细程度和复杂程度在美国由于安全限制而无法进行。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。吸取的经验教训将纳入评估液化对填海土地上建造的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期间不同程度的液化引起的地面和设施损坏。这一事件的影响以及2013年破坏性较小的库克海峡和格拉斯米尔湖地震值得进一步研究。基于性能的地震工程需要能够识别不同抗震性能水平的分析工具。这些地震，其出色的地面运动记录，其良好的记录性能的港口设施，以及随后的实地考察，以表征土壤条件，其中包括砾石液化，提供了一个特殊的机会，以促进了解。记录和学习砾石液化的现场案例历史尤其重要，因为这些案例很少存在。研究目标是：a）调查含有高达70%砾石尺寸材料的Thorndon填充物的液化触发; B）调查港口粉质土场地液化表现的缺乏; c）开发一种新的概率方法来估算液化后的体积沉降; d）开发和反向分析经历不同水平的液化引起的地面破坏的港口设施的案例历史;以及e）传递知识。这些目标是通过一项研究计划实现的：（1）开发和解释港口三种土壤条件下的地面性能的有据可查的案例历史：砾石填充，粉土和砂填充;（2）将港口的激光雷达数据与其他案例历史数据相结合，开发一种新的概率方法，用于估计体积再固结地面沉降，评估不确定性;（3）开发和反向分析七个有据可查的港口设施性能案例历史，以评估码头和建筑物的土壤-结构相互作用效应的重要性;（4）开展推广活动并制定指导。惠灵顿港地基和结构性能的优秀案例历史为开发新方法提供了一个难得的机会，这些方法可以捕捉地震期间观察到的不同性能水平。该奖项反映了NSF的法定使命，并被认为值得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来支持。

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.