主动源与被动源面波联合勘探在过江通道的应用

Combined Exploration of Active and Passive Surface Waves in River Crossing Channel

摘要: 在工程建设中，不良地质条件会带来各种安全问题，使得施工难以顺利完成，同时也会造成经济利益和人民生命财产的损失。为详细查明工程场地的地下各类地质情况，划分地层及基岩的完整性评价，预测可能出现的地质问题和提出应对不良地质条件下的施工建议，本文采用瞬态瑞雷波法与微动法进行工区勘查，根据面波的频散特性得到地下结构的横波速度剖面，以较好地达到查明地下地质情况的目的。本文以江苏省南京市某过江隧道地基勘查为例，采用瞬态瑞雷波法与微动法联合的方式进行勘查，研究其探测效果。结果表明：利用面波法提取的特征频率和频散特性，可以有效地获得地下介质的横波速度图像，该方法对于地层划分、圈定软弱层具有明显效果，能将低速异常区域能较好地识别出来，结合钻孔资料可以较好地进行地下地质解释。

Abstract: In engineering construction, adverse geological conditions can bring various security issue, making it difficult to complete the construction successfully, and also causing the loss of economic interests and people’s lives and properties. By using this method, we can identify the various of subsurface geological conditions at the project site in detail, divide the stratigraphy, evaluate bedrock integrity, predict possible geological problems and propose recommendations for construction under adverse geological conditions. In this paper, the transient Rayleigh wave method and the micro-motion survey method are used to explore the work area, and the S-wave velocity profile of the subsurface structure is obtained according to the dispersion characteristics of the surface wave, in order to achieve the purpose of identifying the subsurface geological conditions well. In this paper, we take the soil investigation of a river crossing tunnel as an example in Nanjing, Jiangsu Province, and combine the transient Rayleigh wave method and micro-motion survey method to analysis its detection effect. The results show that the characteristic frequency and dispersion characteristics extracted by the surface wave method. The method can effectively obtain S-wave velocity profile of the subsurface medium, and it has obvious effects on stratigraphic delineation and trapping of soft layers. It can identify the low-velocity anomalous areas, which can survey subsurface geologic well combined with the drill hole information.