Collaborative Research: Shear Wave Velocity Profiling by SASW Method at Selected Strong-Motion Stations, Liquefaction Sites, and Sites of Building Damage: 1999 Turkey Earthquakes

合作研究：在选定的强震站、液化地点和建筑损坏地点采用 SASW 方法进行剪切波速度剖面分析：1999 年土耳其地震

• 批准号: 0085257
• 负责人: James Bay
• 金额: $ 3.87万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0085257&HistoricalAwards=false
• 关键词: Collaborative; Research; Shear; Wave; Velocity

CMS-0085257BayThe 1999 Kocaeli and Duzce earthquakes in Turkey have generated important information and data at: (l) stations where strong ground motions were recorded, (2) sites where significant soil liquefaction occurred, and (3) localized areas with widely varying building damage. One key variable in investigating the earthquake response at these three types of sites is the shear stiffness profile of the foundation soils. A joint study will be conducted by researchers at Utah State University (USU) and the University of Texas at Austin (UTA) to characterize selected sites in each category using seismic measurements made in the field. A total of about 20 sites will be investigated. The seismic measurements will be used to develop small-strain shear modulus profiles, some one-dimensional and some two-dimensional, over critical depths at the sites. Profiling depths will range from 9 to 60 m, with liquefaction sites generally requiring the shallowest profiles and strong motion recording stations requiring the deepest profiles.To perform the seismic measurements, a non-intrusive seismic testing technique involving Rayleigh-type surface waves will be used. This technique is called spectral-analysis-of-surface-waves (SASW) testing. The technique is non-intrusive because both the source and receivers are placed on the ground surface. Measurement of surface wave dispersion (i.e. surface waves of differing wavelengths travelling at different velocities) is performed in the field and forward modeling is used in the laboratory to evaluate the shear wave velocity profile at the site. Researchers at UTA have been successfully using SASW testing at geotechnical sites on land for the past 18 years. During the 1990's, UTA researchers completed numerous investigations in California at liquefaction sites, solid-waste landfills, and strong motion stations shaken by the 1989 Loma Prieta and 1994 Northridge earthquakes. In Turkey, this previous experience will be used to optimize profiling at the selected sites. For instance, a bulldozer, which will be rented locally near the strong-motion sites, will be used as a source for deep profiling. A drop-weight source, which can be readily fabricated in Turkey, will be used in profiling the shallower depths.The proposed project is critical because it provides extensive shear wave velocity characterization of important sites shaken by the Kocaeli and Duzce earthquakes. SASW testing is the most cost-effective method for evaluating shear wave velocity profiles. The shear wave velocity data obtained from this study will be shared with the earthquake engineering and seismological communities and will prove invaluable to future research projects.

1999年土耳其科贾埃利和杜兹切地震在以下方面产生了重要的信息和数据：（1）记录了强烈地面运动的台站，（2）发生严重土壤液化的地点，以及（3）建筑物损坏程度差异很大的局部地区。 研究这三种场地地震反应的一个关键变量是地基土的剪切刚度剖面。 犹他州州立大学（USU）和德克萨斯大学奥斯汀分校（UTA）的研究人员将进行一项联合研究，利用实地进行的地震测量来确定每一类中选定地点的特征。 总共将调查约20个地点。 地震测量将用于绘制各场址临界深度的小应变剪切模量剖面图，有些是一维的，有些是二维的。 剖面深度将从9米到60米不等，液化地点一般需要最浅的剖面，而强震记录站则需要最深的剖面。 这种技术被称为表面波频谱分析（SASW）测试。 该技术是非侵入性的，因为源和接收器都放置在地面上。 在现场测量表面波色散（即以不同速度传播的不同波长的表面波），并在实验室中使用正演模型来评估现场的剪切波速度剖面。 在过去的18年里，UTA的研究人员一直在陆地上的岩土工程现场成功地使用SASW测试。 在20世纪90年代，UTA的研究人员在加州完成了大量的调查，在液化现场，固体废物填埋场，并在1989年洛马普列塔和1994年北岭地震震动强震站。 在土耳其，这一以往的经验将用于优化选定地点的特征分析。 例如，将在强震现场附近当地租用一台推土机，作为深度剖面测量的来源。 将使用一个在土耳其很容易制造的落锤源来描绘较浅的深度，拟议的项目是至关重要的，因为它提供了科贾埃利和杜兹切地震所震动的重要地点的广泛的剪切波速度特征。 SASW测试是评估剪切波速度剖面的最具成本效益的方法。 从这项研究中获得的剪切波速度数据将与地震工程和地震学社区共享，并将证明对未来的研究项目是非常宝贵的。