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

这一快速反应研究补助金(RAPID)奖提供资金，以调查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，目的是捕获易腐烂的数据，从而开发改进的分析方法，对危险进行全面评估。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级地震，包括3次ML=6.0的地震和45次ML=5.0的地震。由于距离克赖斯特彻奇很近，断层破裂深度较浅，2011年2月22日发生的Mw6.2级地震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，广泛的液化和对建筑环境的破坏。这一地震序列提供了一个相当深入地评估不同强度地震震动对各种土壤剖面响应的影响，以及液化对建筑物基础和关键生命线系统的影响的独特机会。这项研究有三个主要推动力：(1)液化的再次发生；(2)液化地区的建筑性能；以及(3)液化引起的地面破坏地区的生命线性能。在以前的一次快速努力中，这些领域的每一个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，在进行以前的调查时，又发现了一些重大的、时间紧迫的机会，以增进对岩土工程和地震生命线工程的了解。通过比较这一序列中地震引起的不同程度的土壤液化，以及评估这些地震期间建筑物、生命线和工程系统的不同抗震性能，仍然有很多值得学习的地方。有机会了解同一地面和基础设施如何应对不同程度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。捕捉横向扩散的细节和液化对建造良好的结构的影响，如办公楼及其相互连接的地下公用设施，至关重要。实地勘察的重点将是捕捉易腐烂的数据和确定选定地点的土壤剖面特征。这项研究将通过盖尔协会进行协调，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。该提案要求提供必要的资金，以便尽可能详细地仔细记录易腐烂的数据。其更广泛的影响来自于记录和学习设计级地震后的观测，这对推动地震工程的实践状态是非常宝贵的。调查液化的再次发生，记录液化引起的地面移动的案例，并评估液化对建筑物和生命线的影响，可以促进对地震影响的基本了解，并为未来的分析和设计制定基准。尤其是达菲尔德和克赖斯特彻奇地震，对美国来说代表着重要的地震情景。因此，确实有必要记录它们的岩土影响。此外，这些地震涉及多种灾害效应。这两次地震期间液化造成的联合沉降使克赖斯特彻奇的许多社区面临着更大的河流和海洋洪水的威胁，包括海啸。液化引起的地面移动数据的收集将成为洪水风险评估和地震脆弱性评估的基础。这项拟议的研究结合了几位领先研究人员的努力，从整体上检查液化的影响。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，并允许他们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.