桩外跨孔超声波法在既有桥梁基桩检测中的应用  

Application of Cross-Hole Ultrasonic Logging in the Inspection of Existing Bridge Foundation Pile

作　　者：汤小明 曹润宇 TANG Xiaoming;CAO Runyu(Guangdong Transportation Technology Testing Co.,Ltd.,Guangzhou Guangdong 510550,China;Guangdong Nanyue Logistics Industry Co.,Ltd.,Guangzhou Guangdong 510410,China)

机构地区：[1]广东交科检测有限公司,广东广州510550 [2]广东南粤物流实业有限公司,广东广州510410

出　　处：《广东公路交通》2024年第5期72-78,共7页Guangdong Highway Communications

摘　　要：既有基桩检测是旧桥检测评估的重难点。本文介绍了桩外跨孔超声波法检测既有桥梁基桩的基本原理,针对嵌岩桩和桩底缓变型摩擦桩桩底位置不明显、容易产生误判的问题,提出了一种利用辅助线来辅助判定桩长的方法,提高了既有基桩检测的准确性。首先,依托某改扩建项目,选取部分新建基桩和旧桥基桩,开展桩外跨孔超声波法检测和钻芯法检测。其次,根据桩外跨孔超声波法实测信号结合辅助线评判既有桥梁基桩的桩长和桩身完整性。最后,将使用本文方法检测结果与取芯结果和交工检测结果作比对分析。结果表明:桩外跨孔超声波法检测结果与取芯验证结果和交工检测结果基本吻合,相比仅通过实测波列图判定桩长,结合辅助线判定桩长相对误差最大缩小了9.29个百分点,检测桩长相对误差仅为0.10%~3.29%,取得了较好的应用效果。The detection of existing foundation piles is a challenge in the inspection and evaluation of old bridges.This paper introduced the basic principles of using cross-hole ultrasonic logging method for detecting existing bridge foundation piles outside piles.Aiming at solving the problem that the unclear bottom position of rock-socketed piles and friction piles with gradual change at the pile base are not obvious for detection and prone to be misjudged,a method of using auxiliary lines to assist in measuring pile length was proposed,which improved the accuracy of existing foundation pile detection.First of all,in a reconstruction and expansion project,some new foundation piles and old bridge foundation piles were selected to use different inspection method of cross-hole ultrasonic logging method and core drilling method respectively.Secondly,based on the measured signal from the cross-hole ultrasonic logging method and the auxiliary line,the pile length and pile integrity of the existing bridge foundation pile were evaluated.Finally,the test results of this method were compared with the core drilling results and the monitoring test results from completion acceptance.The result comparison showed that the detection results of the cross-hole ultrasonic logging method were basically consistent with the core drilling verification results and the completion monitoring test results.Compared with the pile length determined only by the measured wave diagram,the relative error of the pile length determined by the auxiliary line was reduced by 9.29 percentage points at most,and the relative error of the detected pile length was only 0.10%to 3.29%,achieving good application results.

关 键 词：既有基桩检测 桩外跨孔超声波法 桩身完整性 桩长 取芯 

分 类 号：U443.15[建筑科学—桥梁与隧道工程] TU473.1[交通运输工程—道路与铁道工程]