钻孔灌注桩桩底溶洞声呐探测方法及应用研究.docx

钻孔灌注桩桩底溶洞声呐探测方法及应用研究.docx钻孔灌注桩桩底溶洞声呐探测方法及应用研究
石振明刘逶彭铭】,2,陶凤娟］.2,刘春生3.
（； ； 3•试汉长盛工程检测技术开发冇限公司湖
北 武汉430312）
摘要：在岩溶发育地区开展大型工程多采用钻孔灌注桩基础，而桩底溶洞的存在可能造成塌孔、埋钻、漏浆等事 故，给在建工程和周围建筑造成重大影响。由于钻孔灌注桩需要泥浆护壁，现行的物探方法很难在钻孔灌注桩的 泥浆内对桩底溶洞进行有效勘查。木研究结合声呐应力波传播特点，提出了一种钻孔灌注桩桩底溶洞声呐探测方 法，并研发了桩底溶洞声呐探测仪(JL-SONAR)和信号分析软件(PBCA)。JL-SONAR探测仪实现了现场声呐 信号的发射与采集，PBCA软件完成了探测数据的分析与整理。该技术充分利用了钻孔灌注桩的泥浆条件，可以在 成孔过程屮跟踪探测桩底10m内溶洞发育情况，具有成木低、速度快、精度高等优点。并通过两个具体工程案例 验证了声呐探测技术在实际丁程中的应用。木文的研究对岩溶地区尤其是液态环境卜的溶洞勘查提出了一种新的 解决方法。
关键词：岩溶；溶洞探测；声呐；反射波法；钻孔灌注桩
中图分类号： 文献标识码：A 文章编号：
STUDY ON A SONAR DETECTION TECHNOLOGY FOR KARST CAVITIES
UNDER BORED PILE AND ITS APPLICATION
SHI Zhenmingt2, LIU Liu匕 PENG Ming1'2, TAO Fengjuan1*2, LIU Chunsheng3.
(1 .Department of Geotechnical Engineering, longji University, Shanghai 200092: 2. Ministry of Education Key Laboratory of
Geotechnical and Undei^round Engineering, Tongji University, shanghai 200092 ； 3. Wuhan Conourish Engineering Exploration
Technology Development Co., Ltd., Wuhan / Hubei 430312)
Abstract： Bored piles technology is commonly adopted to cany out large-scale construction projects in the area with karst. However, those karst cavities under pile bottom may lead to hole collapsing, drill buiying, mud leakage, and some other accidents. These potential risks have significant impact on both project itself and surrounding buildings. Due to the necessary mud protection in bored pile construction, many geophysical methods at current stage are not applicable for the karst cavities detection・ This research introduces a sonar technology for the detection of karst cavities located under bored pile combining features of sonar stress wave propagation. A sonar detector (JL-SONAR) and a signal analysis software (PBCA) are developed for this purpose. JL-SONAR detector is responsible for the transmission and collection of sonar signals, and PBCA software is designed to analyze and sort the detection data. This tech no logy makes full use of drilling mud, a