Abstract:In view of the relatively few researches and practices on the safety monitoring of small and medium span bridges at home and abroad, the influence of the ratio of live load on the selection of bridge safety monitoring and evaluation methods was analyzed and selected accordingly, and the early warning threshold value based on the structure response characteristics of small and medium bridges was set. The formula of data validity coefficient for dynamic acquisition of small and medium bridges was derived. Taking Luojiaba Bridge as an example, its monitoring data was analyzed. The results show that the small and medium bridges should use the live load response monitoring value to evaluate the safety status during the operation period. According to the setting of the early warning threshold value based on the structure response characteristics of small and medium bridges, the influence of calibration coefficient and data validity coefficient should be considered on the basis of the finite element theoretical calculation value. The applied bridge γ=0.81, the strain index Z1=43 με, Z2=57 με, the deflection index Z1=6.32 mm, Z2=8.42 mm. According to accidental achievement of the first and second warning conditions of strain and deflection index, it is judged that the proposed bridge is in the first level (yellow) early warning state, and there is no safety problem. Therefore, it is necessary to pay attention to the overload vehicles crossing the bridge.
吴海军1,袁光杰1,2,王涛1,3,屈浩然4,李明珊2. 基于中小跨梁桥结构响应特点的阈值设定及应用[J]. 重庆交通大学学报(自然科学版), 2020, 39(09): 54-58.
WU Haijun1, YUAN Guangjie1,2, WANG Tao1,3,QU Haoran4, LI Mingshan2. Threshold Setting and Application Based on Structural Response
Characteristics of Small and Medium Span Beam Bridges. Journal of Chongqing Jiaotong University(Natural Science), 2020, 39(09): 54-58.
[1] 王庆珍.重庆中小桥梁结构监测的特点及实践探索[J].中国公路,2018(21):60-63.
WANG Qingzhen. Characteristics and practice exploration of structure monitoring for small and medium-sized bridge in Chongqing[J].China Highway,2018(21):60-63.
[2] 陶祥林,雷震.中小桥梁健康监测系统研究现状与发展对策[J].交通标准化,2010(20):138-140.
TAO Xianglin, LEI Zhen. Research status and development strategy of health monitoring system of small and medium-sized bridges [J]. Traffic Standardization,2010 (20):138-140.
[3] 刘纲. 基于长期静态监测数据的大型桥梁安全状态评估方法研究[D]. 重庆:重庆大学,2010.
LIU Gang. Condition Assessment Research to Large-span Bridges Based on Long-term Static Monitoring Data [D]. Chongqing:Chongqing University, 2010.
[4] 吴海军,韦跃,黄友帮,等.基于监测数据的连续刚构桥梁“零活载点”识别方法[J] .重庆交通大学学报(自然科学版),2013,32(增刊1):884-887.
WU Haijun, WEI Yue, HUANG Youbang, et al. Null live load point identification method of continuous rigid frame bridges based on monitoring data [J]. Journal of Chongqing Jiaotong University (Natural Science), 2013, 32 (Sup 1): 884-887.
[5] 屈浩然.中小跨混凝土梁桥运营期安全监测参数与评估方法研究[D].重庆:重庆交通大学,2018.
QU Haoran. Research on Safety Monitoring Parameters and Evaluation Methods for Medium and Small Span Concrete Girder Bridges During Operation Period[D]. Chongqing: Chongqing Jiaotong University, 2018.
[6] 吴海军,李俊,黄友帮,等.大跨径连续刚构桥在活载单项作用下的预警级别[J].重庆交通大学学报(自然科学版),2014,33(5):29-31+115.
WU Haijun, LI Jun, HUANG Youbang, et al. Warning level of large-span continuous rigid frame bridge in single live load [J]. Journal of Chongqing Jiaotong University (Natural Science Edition), 2014, 33(5): 29-31+115.
[7] 王丹阳. 桥梁安全监测预警阈值一般设置方法[J].福建质量管理,2018(4):189-189.
WANG Danyang. General setting method for bridge safety monitoring early warning threshold [J]. Fujian Quality Management, 2018(4); 189-189.
[8] 韦跃. 基于长期监测数据的混凝土梁桥健康状态评判方法研究[D]. 重庆:重庆交通大学,2014.
WEI Yue. Assessment Method Research to Concrete Beam Bridges Health Conditions Based on Long-term Monitoring Data [D]. Chongqing :Chongqing Jiaotong University, 2014.
[9] 高翔宇. 芜湖长江公路二桥健康监测系统设计与预警阈值研究[D]. 合肥:合肥工业大学,2016.
GAO Xiangyu. Health Monitoring System Design and Warning Threshold Study of the Second Wuhu Yangtze River Highway Bridge [D]. Hefei :Hefei University of Technology, 2016.
[10] 郭毅霖,田蕊,何玉珊,等.桥梁结构工程健康监测安全预警系统[J].建筑技术,2012,43(2):125-127.
GUO Yilin, TIAN Rui, HE Yushan, et al. Health monitoring and safety early warning system of bridge structure engineering [J]. Architecture Technology,2012,43 (2):125-127.