Infrastructure Safety Oriented Traffic Load Monitoring Using Multi-Sensor and Single Camera for Short and Medium Span Bridges

Abstract

A reliable and accurate monitoring of traffic load is of significance for the operational management and safety assessment of bridges. Traditional weight-in-motion techniques are capable of identifying moving vehicles with satisfactory accuracy and stability, whereas the cost and construction induced issues are inevitable. A recently proposed traffic sensing methodology, combining computer vision techniques and traditional strain based instrumentation, achieves obvious overall improvement for simple traffic scenarios with less passing vehicles, but are enfaced with obstacles in complicated traffic scenarios. Therefore, a traffic monitoring methodology is proposed in this paper with extra focus on complicated traffic scenarios. Rather than a single sensor, a network of strain sensors of a pre-installed bridge structural health monitoring system is used to collect redundant information and hence improve accuracy of identification results. Field tests were performed on a concrete box-girder bridge to investigate the reliability and accuracy of the method in practice. Key parameters such as vehicle weight, velocity, quantity, type and trajectory are effectively identified according to the test results, in spite of the presence of one-by-one and side-by-side vehicles. The proposed methodology is infrastructure safety oriented and preferable for traffic load monitoring of short and medium span bridges with respect to accuracy and cost-effectiveness.

Optimised Autocalibration Algorithm of Weigh-In-Motion Systems for Direct Mass Enforcement

“…For tracking adjustment of the calibration coefficient S, the recursive least squares (RLS) algorithm [3] was used, of which the forgetting factor is optimally derived for minimization of the weighing error (4).…”

“…One heavy vehicle with five axles and a gross vehicle weight in excess of the 40 t limit applicable in Poland does more harm through material fatigue to the road surface than 100,000 passenger cars. Heavy traffic of overloaded vehicles is the main cause of premature degradation of roads and bridges, meaning that the useful lifespan of the road surface may be as little as half as what was planned [1][2][3].…”

Detection of Moving Load on Pavement Using Piezoelectric Sensors

“…Zhao et al [12] proposed an algorithm based on a modified 2-D Moses algorithm to identify the vehicular axle weights and the identified results of the filed test showed agreement with the static method. Xia et al [13] present a traffic load identification methodology using multiple strain sensors and computer vision technology that can implement traffic information collection and load monitoring in complex traffic scenarios. González et al [14] performed an evaluation of an ANN technique applied to multiple-sensor WIM systems and the results demonstrated that the algorithm was potential in improving WIM accuracy.…”

“…There are mainly three types of sensors in the aforementioned or other researches used in WIM systems: strain sensor [8,13], piezoelectric sensor [4], and quartz sensor [18]. Among the available sensors, piezoelectric sensors have been attracting increasing interests due to their ability of self-powering and fast response to impact loadings [19][20][21][22][23], and, hence, have been widely applied in health monitoring systems for infrastructures [24][25][26][27].…”

Performance assessment of reinforced concrete columns under vehicle impact load using P‐I diagram

“…In the protective design, designers have used P-I diagrams extensively for damage assessments of structural arrangements subjected to blast loading. 39 The P-I diagram includes a series of isodamage curves. The iso-damage curve indicates the combination of the load peak and the impulse that causes a particular level of damage.…”