|Table of Contents|

Test method of clip bite force(PDF)

《交通运输工程学报》[ISSN:1671-1637/CN:61-1369/U]

Issue:
2019年03期
Page:
27-35
Research Field:
道路与铁道工程
Publishing date:

Info

Title:
Test method of clip bite force
Author(s):
ZHANG Feng;  LIU Jia-qi;  GAO Lei;  LIU Guan-zhi
(Geotechnical and Structural Engineering Research Center, Shandong University, Jinan 250061, Shandong, China)
Keywords:
bridge engineering;  prestressed steel strand;  lift-off method;  bite force
PACS:
U446.3
DOI:
-
Abstract:
To study the relationship between the mutation segment of tension test curve and the clip bite force when using the lift-off method to test the force of prestressed steel strand, the high-frequency acquisition technique in the resistive pressure sensor was used to test the prestressed steel strand forces of a prestressed concrete beam under and outside the anchorage when the clip disengages. A total of 20 samples were tested. The clip bite force test scheme was designed. A total of 326 samples were tested and the statistical analysis was performed. The calculation formula for the clip bite force considering the tension was established. Through the verification test of 37 samples, the test accuracy of bite force correction results was studied. 257 samples were tested in the actual project, and the test results were compared with the proposed calculated formula results. Research result shows that the clip will break away from the original bite mark when the steel strand extends more than 4.5 mm. However, when the clip disengages during the actual test, the tension will be stopped in time, so the lift-off test will not change the effective prestress of prestressed steel strand under the anchorage and affect the project quality. When installing the clip, if the clip does not completely fit the taper hole of socket, the clip will have a large elastic pressing force in the lateral direction to form an additional friction force. The friction force will completely disappear when the clip is separated from the socket. The change of tension outside the anchorage is not obvious at this moment, so the slope of descending segment of tension test curve obtained by the lift-off method has a dispersion after the peak tension, and it is related to the clip installation precision. The bite force of socket in the lift-off test consists of the transient internal force redistributions under and outside the anchorage. The proposed calculation formula for clip bite force can eliminate the test error caused by the bite force between the clip and the socket, and improve the test accuracy by 6.78%. The test bite force in the actual project is larger than the mutation segment of tension test curve obtained by the lift-off method. Therefore, when using the lift-off method to test the prestressed steel strand, the effective prestress under the anchorage is the difference between the peak value of tension test curve obtained by the lift-off method and the bite force. 1 tab, 18 figs, 32 refs.

References:

[1] BAANT Z P, YU Q, LI G H. Excessive long-time deflections of prestressed box girders. Ⅰ: record-span bridge in Palau and other paradigms[J]. Journal of Structural Engineering, 2012, 138(6): 676-686.
[2] ROBERTSON I N. Prediction of vertical deflections for a
long-span prestressed concrete bridge structure[J]. Engineering Structures, 2005, 27(12): 1820-1827.
[3] TAKÁCS P F. Deformations in concrete cantilever bridges: observations and theoretical modeling[D]. Trondheim: The Norwegian University of Science and Technology, 2002.
[4] 付 丹.预应力锚索工作应力的检测方法研究[D].北京:清华大学,2010.
FU Dan. Working stress tests of prestressed tendons in ground anchorage[D]. Beijing: Tsinghua University, 2010.(in Chinese)
[5] 付 丹,郭红仙,程晓辉,等.预应力锚索工作应力的检测方法——拉脱法的检测机制和试验研究[J].岩土力学,2012,33(8):2247-2252.
FU Dan, GUO Hong-xian, CHENG Xiao-hui, et al. Working stress measurement of prestressed anchor cables: detection mechanism and experimental study of lift-off test[J]. Rock and Soil Mechanics, 2012, 33(8): 2247-2252.(in Chinese)
[6] 詹桂超,刘冠之.基于拉脱法的预应力钢绞线张拉力测试分析[J].公路与汽运,2016(3):191-193.
ZHAN Gui-chao, LIU Guan-zhi. Test and analysis on prestressed steel strand tension test based on lift-off method[J]. Highways and Automotive Applications, 2016(3): 191-193.(in Chinese)
[7] 赵 煜,洪路加,周勇军.基于钢束应力测试的预应力混凝土箱梁承载力评估方法[J].长安大学学报(自然科学版),2019,39(1):61-69.
ZHAO Yu, HONG Lu-jia, ZHOU Yong-jun. Bearing capacity assessment method for PC box girder by testing stress of tendon[J] Journal of Chang'an University(Natural Science Edition), 2019, 39(1): 61-69.(in Chinese)
[8] 李瑞鸽.全预应力梁预应力损失的动力检测研究[D].武汉:华中科技大学,2005.
LI Rui-ge. Prestress loss of full prestressed concrete beams by dynamic technology[D]. Wuhan: Huazhong University of Science and Technology, 2015.(in Chinese)
[9] 艾辉林,陈朝慰,戴文达.预应力梁锚下有效预应力的快速检测方法研究[J].世界桥梁,2015,43(4):42-46.
AI Hui-lin, CHEN Chao-wei, DAI Wen-da. Study of rapid inspection method for under-anchorage effective prestress in prestressed beams[J]. World Bridges, 2015, 43(4): 42-46.(in Chinese)
[10] 喻国强.预应力混凝土桥梁有效预应力测试技术应用[D].西安:长安大学,2013.
YU Guo-qiang. The application of prestressed concrete bridge effective prestressed testing technology[J]. Xi'an: Chang'an University, 2013.(in Chinese)
[11] 杨国立,李瑞鸽.预应力混凝土梁中预应力损失检测方法的发展与展望[J].四川建筑科学研究,2008,34(4):113-116.
YANG Guo-li, LI Rui-ge. Development and prospect of prestress loss detection in prestressed concrete beams[J]. Sichuan Building Science, 2008, 34(4): 113-116.(in Chinese)
[12] 郭 琦.复杂预应力体系梁式结构有效预应力预测理论与方法研究[D].西安:长安大学,2008.
GUO Qi. Theory and method of effective prestress prediction of beam prestressed composite prestressed system[D]. Xi'an: Chang'an University, 2008.(in Chinese)
[13] XU Jiang, WU Xin-jun, SUN Peng-fei. Detecting broken-wire flaws at multiple locations in the same wire of prestressing strands using guided waves[J]. Ultrasonics, 2013, 53(1): 150-156.
[14] CHEN R H L, WISSAWAPAISAL K. An ultrasonic method
for measuring tensile forces in a seven-wire prestressing strand[J]. AIP Conference Proceedings, 2002, 615(1): 1295-1302.
[15] 张奔牛,袁 灿,陈卓敏,等.基于LC振荡的钢绞线应力测量研究[J].重庆交通大学学报(自然科学版),2017,36(3):8-12.
ZHANG Ben-niu, YUAN Can, CHEN Zhuo-min, et al. Stress measurement of steel strands based on LC oscillation[J]. Journal of Chongqing Jiaotong University(Natural Science), 2017, 36(3): 8-12.(in Chinese)
[16] 贾巧燕.基于应力释放法的在役混凝土结构现存预应力确定研究[D].武汉:武汉理工大学,2008.
JIA Qiao-yan. Study on the extant pre-stressed force of the concrete structure in service based on the stress release method[D]. Wuhan: Wuhan University of Technology, 2008.(in Chinese)
[17] 欧进萍,周 智,王 勃.FRP-OFBG智能复合筋及其在加筋混凝土梁中的应用[J].高技术通讯,2005,15(4):23-28.
OU Jin-ping, ZHOU Zhi, WANG Bo. Smart FRP-OFBG bars and their application in reinforced concrete beams[J]. Chinese High Technology Letters, 2005, 15(4): 23-28.(in Chinese)
[18] 周 智,武湛君,赵雪峰,等.混凝土结构的光纤光栅智能监测技术[J].功能材料,2003,34(3):344-348.
ZHOU Zhi, WU Zhan-jun, ZHAO Xue-feng, et al. Smart monitoring technique of concrete structures based on optical fiber Bragg grating sensors[J]. Journal of Functional Materials, 2003, 34(3): 344-348.(in Chinese)
[19] 贺拴海,赵祥模,马 建,等.公路桥梁检测及评价技术综述[J].中国公路学报,2017,30(11):63-80.
HE Shuan-hai, ZHAO Xiang-mo, MA Jian, et al. Review of highway bridge inspection and condition assessment[J]. China Journal of Highway and Transport, 2017, 30(11): 63-80.(in Chinese)
[20] 钟正强,戴 典,袁建伟.基于虎克定理的预应力检测系统开发及应用[J].中南大学学报(自然科学版),2018,49(3):725-731.
ZHONG Zheng-qiang, DAI Dian, YUAN Jian-wei. Development and application of prestress testing system based on Hooke theorem[J]. Journal of Central South University(Science and Technology), 2018, 49(3): 725-731.(in Chinese)
[21] 董 雁,刘佳琪,张 峰.锚下有效预应力检测仪器研发及工程应用[J].中外公路,2017,37(5):117-120.
DONG Yan, LIU Jia-qi, ZHANG Feng. Instrument development and engineering application of effective prestressing test under anchor[J]. Journal of China and Foreign Highway, 2017, 37(5): 117-120.(in Chinese)
[22] 罗 斌,唐树名,程晓辉,等.锚下预应力反拉检测技术[J].公路交通技术,2012(1):12-14,22.
LUO Bin, TANG Shu-ming, CHENG Xiao-hui, et al. Techniques of reverse drawing detection for prestress under anchor[J]. Technology of Highway and Transport, 2012(1): 12-14, 22.(in Chinese)
[23] 夏 静,袁建伟.反拉法锚下有效预应力检测方法研究[J].公路与汽运,2016(6):210-212.
XIA Jing, YUAN Jian-wei.Research on detection method of effective prestress under anchor by lift-off method[J]. Highways and Automotive Applications, 2016(6): 210-212.(in Chinese)
[24] 成剑波,姚 晨,张 峰.反拉法检测预应力钢绞线工作应力的模型试验研究[J].公路与汽运,2015(3):181-184.
CHENG Jian-bo, YAO Chen, ZHANG Feng. Experimental study of lift-off method for detecting service stress of prestressed strand[J]. Highways and Automotive Applications, 2015(3): 181-184.(in Chinese)
[25] 任传亭,刘伟超,凌天清,等.有效预应力不均匀度初探[J].公路交通技术,2015(6):63-67,72.
REN Chuan-ting, LIU Wei-chao, LING Tian-qing, et al. Primary investigation for unevenness of effective prestress[J]. Technology of Highway and Transport, 2015(6): 63-67, 72.(in Chinese)
[26] 吴玉财,张国炳,李 芬.预应力锚索拉拔力检测技术研究[J].交通科技,2006(5):36-37,59.
WU Yu-cai, ZHANG Guo-bing, LI Fen. Prestressing steel wire drawing force testing technology[J]. Transportation Science and Technology, 2006(5): 36-37, 59.(in Chinese)
[27] 韩 侃,李登科,吴冠仲.预应力锚索锚固力拉拔试验分析[J].岩土工程学报,2011,33(增1):385-387.
HAN Kan, LI Deng-ke, WU Guan-zhong. Pull-out tests on anchoring force of prestressed anchor cables[J]. Chinese Journal of Geotechnical Engineering, 2011, 33(S1): 385-387.(in Chinese)
[28] 张 峰,高 磊,徐向锋,等.施工期钢绞线锚下有效预应力测试技术[J].东北大学学报(自然科学版),2017,38(8):1201-1205.
ZHANG Feng, GAO Lei, XU Xiang-feng, et al. Testing technology of under-anchorage effective prestress of steel strand in construction period[J]. Journal of Northeastern University(Natural Science), 2017, 38(8): 1201-1205.(in Chinese)
[29] 张 峰,高 磊,韩福洲.预应力钢绞线夹片式锚具咬合力试验[J].应用基础与工程科学学报,2017,25(6):1273-1281.
ZHAGN Feng, GAO Lei, HAN Fu-zhou. Experiment on bite force of prestressed steel wire clip-type anchors[J]. Journal of Basic Science and Engineering, 2017, 25(6): 1273-1281.(in Chinese)
[30] 孔庆华,王四玲,谢 强.夹片式单孔预应力锚具的结构分析[J].精密制造与自动化,2005(3):10-11.
KONG Qing-hua, WANG Si-ling, XIE Qiang. Structure analysis of wedge type single hole prestressed anchor[J]. Grinder and Grinding, 2005(3): 10-11.(in Chinese)
[31] 冯天鹏,王 栋,韩福洲,等.预应力孔道摩阻系数测试新技术[J].施工技术,2017,46(9):39-42.
FENG Tian-peng, WANG Dong, HAN Fu-zhou, et al. New testing technology for friction coefficient of prestressed duct[J]. Construction Technology, 2017, 46(9): 39-42.(in Chinese)
[32] 时南翔.预应力锚固系统的检测与监控[J].重庆建筑大学学报,2002,24(2):43-46.
SHI Nan-xiang. Inspection and monitoring of prestressed anchoring system[J]. Journal of Chongqing Jianzhu University, 2002, 24(2): 43-46.(in Chinese)

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Last Update: 2019-06-27