RAPID: Liquefaction and its Effects on Buildings and Lifelines in the 2010-2011 Canterbury, New Zealand Earthquake Sequence

该快速反应研究（Rapid）赠款为2010-2011年新西兰坎特伯雷地震序列中的液化及其对建筑物和生命线的影响提供资金，目的是获取易损数据，从而开发增强的分析程序，以全面评估危害。2010-2011年新西兰坎特伯雷地震序列始于2010年9月4日发生在克赖斯特彻奇以西的Mw7.0级达菲尔德地震，包括3次ML =6.0级和45次ML =5.0级地震。2011年2月22日克赖斯特彻奇发生的里氏6.2级地震由于距离克赖斯特彻奇很近且断层破裂深度浅，是该序列中最具破坏性的事件，造成近200人死亡，数千人受伤，并造成广泛的液化和对建筑环境的破坏。这个地震序列提供了一个独特的机会，可以相当深入地评估不同强度的地震震动对各种土壤剖面的反应的影响，以及液化对建筑物基础和关键生命线系统的影响。本研究有三个重点：(1)液化的再发生；(2)液化地区的建筑性能；(3)液化诱发地面破坏区域的生命线性能。在以往的快速发展项目中，在这些领域都取得了重大成就。然而，正如研究中经常出现的情况一样，在进行先前的调查时，发现了额外的重要的、时间紧迫的机会，以提高岩土工程和生命线地震工程的知识。通过比较这一系列地震引起的不同程度的土壤液化，以及评估建筑物、生命线和工程系统在这些事件中的不同抗震性能，还有很多东西需要学习。有机会了解相同的地面和基础设施如何应对具有不同震动强度的多次地震是极其罕见的。此外，达菲尔德和克赖斯特彻奇地震的震级和距离是美国城市经常考虑的两种情况。获取横向扩散的细节和液化对良好建筑（如办公楼及其相互连接的地下公用设施）的影响是至关重要的。实地侦察将集中于收集易腐烂的数据，并在选定地点描绘土壤概况。这项研究将通过GEER协会协调，并与坎特伯雷大学（即Misko Cubrinovski教授，Brendon Bradley教授和Mark Quigley教授）和新西兰政府合作进行。这项建议要求提供必要的资金，以便尽可能详细地仔细记录易变质的数据。这种更广泛的影响源于记录和从设计级地震后的观察中学习，这对于推进地震工程的实践状态是非常宝贵的。调查再次发生的液化，记录液化引起的地面运动的案例，评估液化对建筑物和生命线的影响，促进了对地震影响的基本理解，并为未来的分析和设计制定了基准。特别是达菲尔德和克赖斯特彻奇地震，代表了美国重要的地震情景，因此，确实需要记录它们的地质技术影响。此外，这些地震涉及多重灾害影响。两次地震期间液化造成的沉降使基督城的许多社区面临河流和海洋洪水的威胁，包括海啸。液化引起的地面运动数据的收集将构成洪水风险评估和地震脆弱性的基础。提议的研究结合了几位主要研究人员的努力，全面检查液化的影响。该团队还包括研究生；这项研究将有助于发展他们在地震工程方面的能力，并使他们能够在新西兰建立研究联系。该奖项由国际科学与工程办公室，东亚和太平洋项目共同资助。

This Grant for Rapid Response Research (RAPID) award provides funding to investigate liquefaction and its effects on buildings and lifelines in the 2010-2011 Canterbury, New Zealand earthquake sequence with the goal of capturing perishable data that would lead to the development of enhanced analytical procedures for evaluating the hazard holistically. The 2010-2011 Canterbury, New Zealand earthquake sequence started with the Mw7.0, 4 September 2010 Darfield earthquake that occurred to the west of Christchurch and included 3 events having ML =6.0 and 45 events having ML =5.0. Because of its close proximity to Christchurch and shallow depth of fault rupture, the Mw6.2, 22 February 2011 Christchurch earthquake was the most devastating event in the sequence, resulting in nearly 200 deaths and thousands of injuries, with widespread liquefaction and damage to the built environment. This earthquake sequence provides a unique opportunity to evaluate in considerable depth the effects of earthquake shaking of different intensities on the response of various soil profiles, and the effects of liquefaction on building foundations and critical lifeline systems. This research has three main thrusts: (1) re-occurrence of liquefaction; (2) building performance in areas of liquefaction; and (3) lifeline performance in areas of liquefaction-induced ground failure. Significant accomplishments were made in each of these areas in a previous RAPID effort. However, as is often the case in research, in performing the previous investigations additional significant, time-critical opportunities to advance the knowledge of geotechnical and lifeline earthquake engineering were identified. There is still much to learn from comparing the different levels of soil liquefaction caused by the earthquakes in this sequence and from evaluating the differing seismic performance of buildings, lifelines, and engineered systems during these events. It is extremely rare to have the opportunity to learn how the same ground and infrastructure responded to multiple earthquakes having different levels of shaking intensities. Furthermore, the magnitude and distances of the Darfield and Christchurch earthquakes are two of the scenarios often considered in US cities. Capturing details of lateral spreads and the impacts of liquefaction on well-built structures, such as office buildings and their interconnecting buried utilities, are critically important. Field reconnaissance will be focused on capturing perishable data and characterizing the soil profiles at select sites. This study will be coordinated through the GEER Association and performed in collaboration with the University of Canterbury (i.e., Professors Misko Cubrinovski, Brendon Bradley, and Mark Quigley) and the New Zealand government. This proposal requests the funding necessary for carefully documenting the perishable data in as much detail as possible. The broader impacts of this stem from documenting and learning from observations after design level earthquakes, which are invaluable to advancing the state-of-practice in earthquake engineering. Surveying the re-occurrence of liquefaction, documenting cases of liquefaction-induced ground movements, and evaluating the effects of liquefaction on buildings and lifelines advances fundamental understanding of earthquake effects and develops benchmarks for future analysis and design. The Darfield and Christchurch earthquakes, in particular, represent important earthquake scenarios for the U.S. Thus, there is a real need to document their geotechnical effects. Moreover, these earthquakes involve multi-hazard effects. The combined settlement caused by liquefaction during both earthquakes has exposed many Christchurch neighborhoods to increased threats from river and ocean flooding, including tsunami. Collection of data on liquefaction-induced ground movement will form the basis for flood risk assessment as well as earthquake vulnerability. The proposed study combines the efforts of several leading researchers to examine the effects of liquefaction holistically. The team also includes graduate students; this research will help develop their capabilities in earthquake engineering and allow them to establish research contacts in New Zealand. This award is co-funded by the Office of International Science and Engineering, East Asia and Pacific Program.