预应力梁板中塑料波纹管注浆饱满度探地雷达检测

Ground penetrating radar detecting saturation of plastic corrugated pipe grouting in prestressed deck

为了探讨预应力梁板中塑料波纹管注浆饱满度,本文以探地雷达理论为基础,运用时域有限差分法,建立塑料波纹管中空洞在不同位置模型,进行探地雷达二维正演模拟,模拟结果表明运用2.6G天线可以检测到钢绞线底部和上部的空洞;将该型号天线应用于某大桥预应力梁板检测中,对典型雷达图像进行打钻验证,与检测结果相符.综合模拟和现场探测结果表明,探地雷达法使用2.6G天线检测预应力梁板中塑料波纹管注浆饱满度是可行的.

The paper was aimed at researching saturation of grouting plastic corrugated pipe in prestressed deck.On the basis of ground penetrating radar（GPR）theory four different models were designed：the first had no void in plastic corrugated pipe;the second had a void above the strands in the plastic corrugated pipe;the third had a void under the strands;the last had voids above and below the strands.They were done2D-forward simulation.The results of 2D-forward simulation show GPR could detect void under and below strands by the 2.6GHz antenna;we could judge the position of voids from the simulating results.GPR with the 2.6GHz antenna was applied in some bridge to detect the quality of grouting plastic corrugated pipe in prestressed deck,two typical decks which had voids were detect.One deck had two voids,the other had three voids,but we could not judge the position of voids from the detecting results,for the positions of grouting plastic and the strands were not regular.We bored on the three typical voids,it was consistent with detecting and boring results.Model and field detecting results show：it is feasible to detect saturation of grouting plastic corrugated pipe in prestressed deck by GPR using 2.6GHz antenna.