A method for estimating the overall load response of long-span bridges under the action of stochastic traffic flow

Abstract

The invention discloses a method for estimating the overall load response of long-span bridges under the action of stochastic traffic flow, which comprises the following steps: S1, collecting the traffic flow Q of a road surface and the proportion P of a freight car to obtain the traffic speed V; S2, collecting the traffic flow Q of the road surface and the proportion P of the freight car; S2, calculating the traffic density K according to the collected traffic flow Q, the freight car proportion P and the traffic speed V according to the function relationship Q=f (K) between the traffic flow Qand the traffic density K determined by the flow-density-speed model; 3, calculating the car density K1 and the freight car density K2 according to the traffic density K and the freight car proportion P; S4, calculating the car load concentration degree q1 according to the car density K1; S5, calculating the load concentration degree q2 of the freight car according to the freight car density K2;S6, calculating the uniformly distributed load set q of the bridge accord to the load set degree q1 of the car and the load set degree q2 of the freight car. Comparing the deck uniform load concentration q with the design load concentration qk of the vehicle load model, this method provides a method to estimate the overall load response of long-span bridges quickly by traffic flow macroscopic parameters.

Description

Technical field [0001] The invention relates to the interdisciplinary field of traffic engineering and bridge engineering, in particular to a method for quickly estimating the overall load response of a long-span bridge under the action of random traffic flow. Background technique [0002] As the main variable function of bridge operation, vehicle load has been a research hotspot in the field of bridge engineering in the past decade. In the context of the explosive growth of my country’s transportation industry and more and more bridges entering the middle and late stages of operation and use, improving the understanding of the actual operating vehicle load level of bridges is significant for ensuring the safety of bridge structures and optimizing management and maintenance resources. Engineering significance. [0003] At present, China’s assessment of the vehicle load and response of bridge operating vehicles is mainly based on the "Highway and Bridge Carrying Capacity Inspection ...

AI Technical Summary

Problems solved by technology

[0005] (1) The weighing method at the toll station is economical, easy to operate, and highly accurate, but the load data obtained is static and has no lane sequence, which cannot truly restore the operation of the fleet;

[0006] (2) The dynamic weighing technology can obtain various information of the fleet load sequence without interfering with traffic conditions, but the obtained results are cross-sectional test results, which can be used for small and medium-span bridges, but it is difficult to directly use for long-span bridges, which requires the help of microscopic traffic flow The simulation method considers microscopic behaviors such as vehicle acceleration, deceleration, and lane change, but the calculation cost of microscopic simulation is very high, and the test technology has high economic cost and the life of the sensor is difficult to guarantee;

[0007] (3) The bridge dynamic weighing technology calculates the vehicle load information through the bridge response under vehicle traffic, which is mainly used for small and medium-span bridges. It is difficult to accurately calculate complex traffic behaviors such as multi-lane multi-vehicle traffic, and cannot be directly used for large-span bridges Analysis of the load effect of the diameter bridge;

[0008] (4) High-definition camera recognition technology can obtain the microcosmic driving behavior of the fleet on long-span bridges, but lacks load information and needs to be combined with dynamic weighing technology to carry out vehicle load correlation. This method has high analysis accuracy but high computational cost;

[0009] (5) The health monitoring system can directly test the load response status of the bridge for structural performance evaluation, but the test structure response is easily disturbed by environmental noise and cannot accurately analyze the real bridge response, and the health monitoring system is mainly used in major bridge projects

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