tailieunhanh - Weigh-in-Motion Measurement of Trucks on Bridges

Weigh-in-Motion Measurement of Trucks on Bridges Introduction Weigh-in-Motion Truck Weight Measurement Weigh-in-Motion Equipment • Testing Procedure • Selection of Bridges for Testing • Results of WIM Tests 55 Andrzej S. Nowak University of Michigan Fatigue Load Measurement Testing Equipment • Rainflow Method of Cycle Counting • Results of Strain Spectra Testing Sangjin Kim Kyungpook National University, Korea Dynamic Load Measurement Introduction • Measured Dynamic Load Summary Introduction Knowledge of the past and current load spectra, together with predicted future loads, is essential in the evaluation and fatigue analysis of existing bridges. Many trucks carry loads in excess of design limits. This may lead to fatigue failure | Nowak . Kim S. Weigh-in-Motion Measurement of Trucks on Bridges. Bridge Engineering Handbook. Ed. Wai-Fah Chen and Lian Duan Boca Raton CRC Press 2000 55 Weigh-in-Motion Measurement of Trucks on Bridges Introduction Andrzej S. Nowak University of Michigan Weigh-in-Motion Truck Weight Measurement Weigh-in-Motion Equipment Testing Procedure Selection of Bridges for Testing Results of WIM Tests Fatigue Load Measurement Testing Equipment Rainflow Method of Cycle Counting Results of Strain Spectra Testing Sangjin Kim Kyungpook National University Dynamic Load Measurement Introduction Measured Dynamic Load Korea Introduction Summary Knowledge of the past and current load spectra together with predicted future loads is essential in the evaluation and fatigue analysis of existing bridges. Many trucks carry loads in excess of design limits. This may lead to fatigue failure. The information concerning actual load is very important for the rating of bridges. Therefore there is a need for accurate and inexpensive methods to determine the actual loads the strength of the bridge and its remaining life. There is also a need for verification of live load used for the development of a new generation of bridge design codes 1 2 . It has been confirmed that truck loads are strongly site specific 3 4 5 . Some bridges carry heavy truck traffic volume and magnitude others carry only lighter traffic. Furthermore load effects such as bending moment shear and or stress are component specific 6 7 . This observation is important in evaluation of the fatigue damage and prediction of remaining life. This chapter presents some of the practical procedures used for field measurement of truck weights and resulting strains. Weigh-in-Motion Truck Weight Measurement Weigh-in-Motion Equipment The bridge live load is the load caused by truck traffic. In the past truck data were collected by truck surveys which had limitations. The most common survey method .