Abstract We quantitatively study magnetic anomalies of reinforcement rods in bored in-situ concrete piles for the first time and summarized their magnetic anomaly character. Key factors such as measuring borehole orientation, borehole-reinforcement distance, and multiple-section reinforcement rods are discussed which contributes valid and quantitative reference for using the magnetic method to detect reinforcement rods. Through tests with model piles, we confirm the accuracy of theoretical computations and then utilize the law discovered in theoretical computations to explain the characteristics of the actual testing curves. The results show that the Za curves of the reinforcement rod reflect important factors regarding the reinforcement rods, such as rod length, change of reinforcement ratio, length of overlap, and etc. This research perfects the magnetic method for detecting reinforcement rods in bored in-situ concrete piles and the method has great importance for preventing building contractor fraud.
The work is supported by Transportation Research Project of Jiangsu Province (05Y015), China.
Cite this article:
SUN Bin,DONG Ping,WANG Chong et al. Quantitative analysis of magnetic anomaly of reinforcements in bored in-situ concrete piles[J]. APPLIED GEOPHYSICS, 2009, 6(3): 275-286.
[1]
Changchun College of Geology, 1979, Magnetic prospecting: Geology Publishing House, China.
[2]
Chengdu College of Geology, 1976, Magnetic prospecting: Geology Publishing House, China.
[3]
Dong, P., Fan, J. L., Liu, C. H., Chen, G. W., Wang, L. S., Sun, B., and Pu, X. X., 2007, Magnetic anomaly characteristics out of reinforcement cage in cast-in-situ pile: Progress in Geophysics(in Chinese), 22(5), 1660 - 1665.
[4]
Dong, P., Fan, J. L., Wang, L. S., Pan, W. Y., and Yang, Y. W., 2008a, Magnetic anomaly characteristics inside the reinforcement cage of the cast-in-situ pile: Geophysical and Geochemical Exploration (in Chinese), 32(1), 101 - 104.
[5]
Dong, P., Fan, J. L., Chen, Z. Z, Wang, L. S, Gao, X. N., and Qin, R., 2008b, Applying mise-a-la-masse method to determine the length of reinforcement in bored in-situ concrete piles: Journal of Environmental and Engineering Geophysics, 13(2), 51 - 56.
[6]
Fan, J. L., Dong, P., Ye, J. Y., Li, M., and Zhu, G. W., 2008, Method for reinforcement cage length detection in the core drilling hole: Geophysical and Geochemical Exploration (in Chinese), 32, 335 - 337.
[7]
Li, X., and Jin, G., 1996, The experiment of detection flaws in length of reinforcement cage in pile foundation using transient electromagnetic method: Geophysical and Geochemical Exploration (in Chinese), 3, 1 - 7.
[8]
Liu, J. D., Fan, X. P., and Xu, H. G., 2008, Electricity method for checking the length of reinforcing cage in piles: Chinese Journal of Geotechnical Engineering (in Chinese), 32(2), 288 - 291.
[9]
Shi, L.K., Sun, Y.F., and Sun, M.X., 2000, Application of geophysical radar in checking on the quality of piles: Journal of North China Institute of Water Conservancy and Hydroelectric Power (in Chinese), 21(4): 45 - 47
[10]
The China People’s Republic of Industry Standards, 2003, Technical code for testing of building foundation piles: JGJ 106 - 2003, The China People’s Republic of Industry Standards, People’s Republic of China Ministry of Construction.
[11]
Wan, M., and Ye, Z., 1999, Non-destructive testing of the length of reinforcement cage in cast-in-situ bored pile: Geophysical and Geochemical Exploration (in Chinese), 23(2), 146 - 149.
[12]
Wang, J.R., Lv, J.D., 2003, Technical application of applying ground penetrating radar to the detection of obstruction: Geology and Prospecting (in Chinese), 39(3), 84 - 86.
[13]
Xu, X.Y., and Ren, X.J., 2003, Application of geological radar technique in the bottom detection of manual earth-boring piles: Geotechnical Engineering World (in Chinese), 5(9), 54 - 55.
[14]
Zeng Zhaofa, Wu Fengshou, Huang Ling, Liu Fengshan, and Sun Jiguang, 2009, The adaptive chirplet transform and its application in GPR target detection: Applied Geophysics, 6(2). 192 - 200.
2009, Vol. 6 
