时 间： 2018 年5月10日 10 : 00 - 11 : 30
地 点： 南五楼 612 学术报告厅
报告人： Prof. Herbert F. Wang , 威斯康星大学麦迪逊分校
邀请人： 孙琪真 教授
报告摘要：
本报告将介绍威斯康星大学麦迪逊分校和Silixa有限公司合作开展的四次DAS现场测试：(1)结冰湖面上的90米区域；(2)加利福尼亚州加纳谷的762米区域；(3)位于NV地热站点Brady Hot Springs的地表8400米区域和360米钻孔阵列；(4)位于伊利诺斯州的地下白云石和石灰石矿区的250米阵列。威斯康星州的每个现场试验都使用有源信号源，包括锤击振动源和固定的车载40-270kN扫频源。两次现场试验都在高速公路附近完成，环境噪声主要来源于交通情况。地震检波器安装在DAS光缆附近，用于比对和补充DAS所测的数据。这项研究的主要目的是了解DAS所记录的地面运动，并利用活动源、环境或交通噪声以及地震信号对DAS应用进行原型设计。
The University of Wisconsin‐Madison and Silixa, Ltd. have conducted four DAS field trials: (1) 90‐meter layout on lake ice, (2) 762‐meter layout at Garner Valley, California, (3) 8400‐m surface and 360‐m borehole array at the Brady Hot Springs, NV geothermal site, and (4) 250‐m array in an operating, underground dolomite and limestone mine in N. Aurora, Illinois. Each of the Wisconsin field trials used active sources that ranged from a hammer source to fixed and truck‐mounted 40‐270 kN swept‐frequency sources. Two of the field trials were near highways where traffic was a source of ambient noise. Geophones were co‐located near the DAS cable to benchmark and complement the DAS response. The goals of the studies were to understand the ground motions recorded by DAS and to prototype DAS applications using active sources, ambient or traffic noise, and earthquakes.
报告人介绍：
Herb Wang是威斯康星大学麦迪逊分校的荣誉教授。本科毕业于威斯康星大学，在哈佛大学获得硕士学位并在麻省理工学院获得博士学位。在1972年至2017年期间，任威斯康星大学麦迪逊分校地球科学系教授。主要致力于地质力学方面的研究，包括岩石物理学、多孔弹性力学和地应力。曾参与了多项深地层研究项目，其中采用了光纤传感器来探测由于地球潮汐和数米范围内的负载变化引起的形变；曾参与四次分布式声波传感（DAS）现场测试，包括在NV, Brady Hot Springs进行的9公里区域测试，以此研究这种新技术如何记录地面运动。
Herb Wang is an emeritus professor at the University of Wisconsin‐Madison. He received his B.A. from the University of Wisconsin, M.A. from Harvard University and Ph.D. from MIT. He was a professor in the Department of Geoscience at the University of Wisconsin‐Madison from 1972 until 2017. His research interests in geomechanics include rock physics, poroelasticity, and in situ stress. He has participated in several deep underground research projects where fiber‐optic sensors were deployed to investigate deformation due to earth tides and load changes at the scale of several meters. He has participated in four Distributed Acoustic Sensing (DAS) field trials, including a 9‐km deployment at Brady Hot Springs, NV, to study how this new technology records ground motions.
