Determination of Subsurface Conditions of Frozen Ground Layers Using Surface Waves

一种创新的地震新技术--地表谱分析 波（SASW）方法，具有定位冻结和解冻的潜力 通过对地震波的测量， 速度剖面 地震波的传播速度在 冰冻的地面比不冰冻的地面更厚。 SASW方法已经被 用于预测剪切波速度和厚度分布， 路面，土壤场地液化调查，土坝， 混凝土坝和填充物。 该方法是基于弹性波 传播理论和频谱分析方法 面波频散曲线。 该方法最令人兴奋的方面之一是它能够 探测高速层下的低速层， 在地面上进行测量。 SASW的这种能力 该方法克服了传统地震资料使用的局限性， 折射法 因此，SASW方法显示出强大的潜力， 定位冻结和未冻结的地层，即使地面 地表冻结，底层土壤解冻。 研究将 在阿拉斯加的两个地点进行， 开发测量和分析技术， 在北极地区使用SASW方法。 随着研究的深入， SASW方法探测北极其他次表层的能力 条件，如冰冻的道路，大量的冰透镜，和横向 将研究永久冻土的扩展。 的潜在利益 对冻土状况的准确了解， 承包商和公众都非常希望提高性能， 节约道路、建筑物、跑道的建设和维护， 管道设施。 自动化SASW冻结定位装置的研究与开发 土地将对建筑业产生巨大的好处， 北极地区。

An innovative new seismic technique, the Spectral Analysis of Surface Waves (SASW) method, has potential for locating frozen and unfrozen ground rapidly and accurately through measurement of the seismic wave velocity profile. The velocity of seismic waves is much faster in frozen ground than unfrozen ground. The SASW method has already been used to predict the shear wave velocity and thickness profiles for pavements, liquefaction investigations of soil sites, earth dams, concrete dams, and fills. The method is based on elastic wave propagation theory and spectral analysis methods for evaluating dispersion curves for surface waves. One of the most exciting aspects of the method is its capability to detect low velocity layers underlying higher velocity layers with measurements made on the ground surface. This capability of the SASW method overcomes the traditional limitation on the use of the seismic refraction method. Thus, the SASW method shows strong potential for locating frozen and unfrozen ground layers, even when the ground surface is frozen and the underlying soils are thawed. Research will be performed at two sites in Alaska with varying frozen and unfrozen ground conditions to develop measurement and analysis techniques for using the SASW method at Arctic sites. As the research progresses, the SASW method's capabilities for detecting other subsurface Arctic conditions such as frozen roads, massive ice lenses, and lateral propagation of permafrost will be researched. The potential benefits of accurate knowledge of frozen ground conditions to engineers, contractors and the public are tremendous for improved performance and economy of construction and maintenance of roads, buildings, runways, and pipeline facilities. Research and development of an automated SASW device to locate frozen ground would be of tremendous benefit to the construction industry in Arctic regions.