孔内超声波成像技术在地质勘察中的应用

Application of borehole ultrasonic imaging technology in geo-engineering investigation

某长江隧道地质条件以板岩为主,受构造影响,岩层极为破碎,且上覆较厚的覆盖层,基岩露头条件差,钻探采芯率难于保证,辅以孔内超声波成像技术则能清晰反映地下深部工程岩体各种结构面的构造特征,并且计算出岩层每组结构面的特征参数,既有利于了解和分析地下岩体的状况(岩体完整性),也是建立长江穿越地下地质模型的基础,同时这些原始数据和参数为进一步研究地下深部工程地质环境提供了良好的第一手资料,保证了勘察质量。本文介绍了ABI40钻孔超声波成像综合测试系统在长江盾构隧道勘察中的成功应用,并结合该实例,对ABI40钻孔超声波成像综合测试系统在分析破碎岩体、软弱结构面产状以及探测结果的分析对比等方面进行了探讨。

The geological condition of certain Yangtze river tunnel is mainly slates,which are affected by structures. The rock layers are easily broken with thick overburden layers so that the exposure of bedrock condition is bad and the recovery of core drilling can't be guaranteed. However,with the assistance of the borehole ultrasonic imaging technology,it can clearly reflect the structural characteristics of various structural planes for deep engineering rock mass and calculate the characteristic parameters for each set of structural plane of the rock,which not only benefit in understanding and analyzing the status of the underground rock mass( its integrity),but also is fundamental to establish the underground geological model of the Yangtze river crossing. Meanwhile,these original data and parameters provide the well firsthand information for the further researching of underground deep engineering geological environment,ensuring the quality of the survey. The application of ABI40 borehole ultrasonic imaging technology in a Yangtze river tunnel crossing survey is introduced. Based on the example,analyzing the broken rock mass,the attitude of the weak structure plane and the exploration results with the said technology are carried out.