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(1 唐山工業(yè)職業(yè)技術(shù)學(xué)院建筑工程學(xué)院, 唐山 063299; 2 東北林業(yè)大學(xué)土木工程學(xué)院,哈爾濱 150040)
摘要: 針對建筑結(jié)構(gòu)中后張法預(yù)應(yīng)力孔道的灌漿缺陷,采用沖擊回波法對灌漿缺陷的識別進(jìn)行研究. 采用ANSYS / LS-DYNA 軟件建立了 5 種不同灌漿情況的有限元模型,同時建立了 3 組現(xiàn)場試驗(yàn)?zāi)Ｐ?采用沖擊回波法進(jìn)行了檢測,得到了不同灌漿情況模型的頻譜響應(yīng). 通過對比理論計(jì)算頻率與現(xiàn)場實(shí)測頻率,研究了缺陷程度、預(yù)應(yīng)力孔道材料、缺陷橫截面周長對厚度主頻和關(guān)鍵頻率的影響,分析了不同因素對檢測結(jié)果產(chǎn)生的誤差;根據(jù)缺陷橫截面半周長與名義厚度比值和板厚偏移率的關(guān)系推導(dǎo)了計(jì)算缺陷橫截面周長的公式. 結(jié)果表明:越靠近厚度主頻,缺陷和鋼絞線響應(yīng)關(guān)鍵頻率計(jì)算值與實(shí)測值的誤差越小,越遠(yuǎn)離厚度主頻其誤差越大;一般密度的鋼筋和箍筋對檢測結(jié)果無影響;計(jì)算與實(shí)測的關(guān)鍵頻率均隨缺陷程度的增大而降低,且與厚度主頻的變化趨勢一致;塑料孔道模型的厚度主頻和關(guān)鍵頻率較金屬孔道普遍向低頻漂移,但各關(guān)鍵頻率的影響系數(shù)和厚度主頻的影響系數(shù)保持一致,可以據(jù)此估算出缺陷程度;缺陷尺寸越大,檢測構(gòu)件厚度越小,誤差越小.
關(guān)鍵詞: 沖擊回波法; 預(yù)應(yīng)力孔道; 灌漿缺陷; 有限元模擬; 頻譜響應(yīng); 缺陷橫截面周長
中圖分類號:TU378 文獻(xiàn)標(biāo)志碼:A 文章編號:1002-848X(2023)10-0097-08
DOI:10. 19701 / j. jzjg. 20210467
Research on identification of grouting defect size based on impact-echo method
YANG Hailin1, ZHANG Hongxiang2
(1 School of Civil Engineering, Tangshan Polytechnic College, Tangshan 063299, China; 2 School of Civil Engineering,Northeast Forestry University, Harbin 150040, China)
Abstract: Aiming at the grouting defects of post tensioned prestressed duct in building structure,the impact-echo methodwas adopted to identify the grouting defects. ANSYS / LS-DYNA software was used to establish finite element models for fivedifferent grouting situations, field test models of 3 groups were established for impact-echo testing, the spectral responses ofthe models under different grouting conditions were obtained. By comparing the theoretical calculation frequency with theon-site measurement frequency, the effects of defect degree, prestressed duct material and defect cross-sectioncircumference on the thickness frequency and characteristic frequency were studied, the error caused by different factors onthe inspection results was analyzed. Based on the relationship between the ratio of the half circumference of the defectcross-section to the nominal thickness and the plate thickness deviation rate, the formula for calculating the defect crosssection circumference was derived. The results show that the closer to the thickness frequency, the smaller the errorbetween the calculated value and the measured value of characteristic frequencies of the response to defects and steelstrands,the farther to the thickness frequency, the error becomes larger. The general density of reinforcement and stirruphas no influence on the test results; The calculated and measured characteristic frequencies decrease with the increase ofdefect degree, and the variation trend is consistent with the thickness frequency. The thickness frequency and characteristicfrequency of the plastic duct model generally drift to low frequency compared with the metal duct model. However, theinfluence coefficient of each characteristic frequencies are consistent with the thickness frequency, and the degree of defectscan still be estimated. The larger the defect size is,the smaller the thickness is, the smaller the error is.
Keywords:impact-echo method; prestressed duct; grouting defect; finite element analysis; spectrum response; defectcross-section circumference
∗唐山市科學(xué)技術(shù)研究與發(fā)展計(jì)劃(第三批)項(xiàng)目(20150221C).
第一作者:楊海林,碩士,講師,主要從事橋梁工程防災(zāi)減災(zāi)研究,Email:yanghailin1987@ 163. com.
[引用本文] 楊海林,張宏祥. 沖擊回波法識別孔道灌漿缺陷尺寸的研究[ J]. 建筑結(jié)構(gòu),2023,53(10):97-104.YANG Hailin,ZHANG Hongxiang. Research on identification of grouting defect size based on impact-echo method [ J].Building Structure,2023,53(10):97-104.
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