RAPID: Liquefaction and Its Effects on Buildings and Lifelines in the February 22, 2011 Christchurch, New Zealand Earthquake

RAPID：2011 年 2 月 22 日新西兰基督城地震中的液化及其对建筑物和生命线的影响

• 批准号: 1137977
• 负责人: Jonathan Bray
• 金额: $ 9.96万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1137977&HistoricalAwards=false
• 关键词: RAPID; Liquefaction; Its; Effects; Buildings

This Grant for Rapid Response Research (RAPID) award provides funding to investigate the effects of liquefaction on the built environment during the 22 February 2011, Mw=6.1 Christchurch, New Zealand, earthquake and the 4 September 2010, Mw=7.0 Darfield, New Zealand, earthquake with the goal of capturing perishable data that would lead to the development of enhanced analytical procedures for evaluating the hazard holistically. The intense ground shaking and resulting soil liquefaction from the Christchurch earthquake damaged many buildings, lifelines, and engineered systems. The Central Business District (CBD) of Christchurch is still in ruins. The 22 February event is particularly meaningful, because it occurred just 5 months after the Darfield earthquake, the epicenter of which was approximately 40 km from the CBD. Whereas the 22 February event killed almost two hundred people, the September event resulted in no deaths. Additionally, although the 4 September event caused widespread liquefaction-induced damage in the Christchurch area, it did not produce significant liquefaction-induced damage within the CBD. There is much to learn from comparing the different levels of soil liquefaction from these two earthquakes and from evaluating the differing seismic performance of buildings, lifelines, and engineered systems during these two earthquakes. It is extremely rare to have the opportunity to learn how the same ground and infrastructure responded to two significant earthquakes. The magnitude and distances of these two 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. Understanding how local geologic conditions influenced the observed damage patterns is also important. Field reconnaissance is focusing on capturing perishable data and characterizing the subsurface conditions through: (1) trenching of liquefaction features, (2) performing dynamic cone penetration tests, and (3) measuring shear wave velocities (Vs).The effects of soil liquefaction on the built environment in the Christhurch area were pervasive. The New Zealand building code is similar to that used in the U.S., and with much recent construction, there is much that can be learned that is directly applicable to seismic regions across the U.S. This study is being coordinated through the Geoengineering Extreme Events Reconnaissance (GEER) Association and in collaboration with the Univ. of Canterbury and the New Zealand government. Documenting and learning from observations after design level earthquakes 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 provide invaluable information that will serve as benchmarks to the profession's understanding of the effects of earthquakes. These earthquakes involve also 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 study combines the efforts of several leading researchers to examine the effects of liquefaction holistically. The team also includes a junior faculty member and graduate students who are in the early stages of their careers, so it will help develop their capabilities in earthquake engineering and allow them to establish research contacts in New Zealand.

该快速响应研究补助金 (RAPID) 提供资金，用于调查 2011 年 2 月 22 日新西兰克赖斯特彻奇 Mw=6.1 地震和 2010 年 9 月 4 日新西兰达菲尔德 Mw=7.0 地震期间液化对建筑环境的影响，目的是捕获易腐烂的数据，从而开发增强的分析程序来全面评估危害。 基督城地震造成的强烈地面震动和土壤液化损坏了许多建筑物、生命线和工程系统。 基督城的中央商务区（CBD）仍是一片废墟。 2 月 22 日的事件特别有意义，因为它发生在达菲尔德地震仅 5 个月后，震中距离 CBD 约 40 公里。 2 月 22 日的事件导致近 200 人死亡，而 9 月的事件则没有造成人员死亡。此外，尽管 9 月 4 日的事件在基督城地区造成了大范围的液化造成的损害，但并未在 CBD 内造成重大的液化造成的损害。 通过比较这两次地震造成的不同土壤液化程度，以及评估这两次地震期间建筑物、生命线和工程系统的不同抗震性能，可以学到很多东西。 有机会了解同一地面和基础设施如何应对两次重大地震是极其罕见的。 这两次地震的震级和距离是美国城市经常考虑的两种情况。 捕获横向扩散的细节以及液化对精心建造的结构（例如办公楼及其相互连接的埋地公用设施）的影响至关重要。 了解当地地质条件如何影响观察到的损害模式也很重要。 现场勘察的重点是通过以下方式捕获易腐烂的数据并表征地下条件：(1) 液化特征挖沟，(2) 进行动态锥入探测试，以及 (3) 测量剪切波速度 (Vs)。土壤液化对基督城地区建筑环境的影响是普遍存在的。新西兰的建筑规范与美国使用的建筑规范类似，并且随着最近的建设，有很多可以直接适用于美国地震地区的知识。这项研究是通过地球工程极端事件勘察 (GEER) 协会协调并与新西兰大学合作进行的。坎特伯雷大学和新西兰政府。 设计级地震后的观测记录和学习对于推进地震工程的实践状态非常宝贵。 调查液化的再次发生、记录液化引起的地面运动的案例以及评估液化对建筑物和生命线的影响提供了宝贵的信息，这些信息将作为专业人士了解地震影响的基准。 这些地震还涉及多种灾害影响。 两次地震期间液化造成的综合沉降使基督城的许多社区面临着包括海啸在内的河流和海洋洪水的更大威胁。 液化引起的地面运动数据的收集将成为洪水风险评估和地震脆弱性的基础。 该研究结合了几位领先研究人员的努力，从整体上研究液化的影响。 该团队还包括一名初级教员和处于职业生涯早期阶段的研究生，因此这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。