| The transiting test is a new method that uses the relative wind field generated by the moving vehicle to investigate the structural wind effect.It has the advantages of convenience and cost saving and can be applied to wind engineering research in the fields of bridge,building,wind turbines,and automobiles.However,the transiting test needs to be carried out under actual road conditions.The test model is directly exposed to the external environment,so the test results will be interfered by vehicles on the test road.Therefore,investigating the influence of vehicle interference behavior on transiting test is of great significance to improve the accuracy of transiting test and promote its development.In this paper,the CAARC standard high-rise building model was used as the experimental object.The changes of the wind pressure coefficient under different conditions were analyzed from the two aspects of overtaking behavior interference and following driving interference.The influences of three levels of interference vehicles,namely,small,medium and large,on the transiting test method for measuring building wind pressure coefficients were investigated,and suggestions for avoiding vehicle interference were put forward.Firstly,the influence of the interference behavior of small vehicle on the transiting test method for measuring building wind pressure coefficients was investigated.In the experiment,a small interference vehicle was set up to drive under specific conditions.The influence law of relative vehicle speed,test vehicle speed and driving lane when the test vehicle was overtaken was studied.Then,the interferences of test vehicle actively overtaking and the wake interference of following driving were studied.The results show that overtaking interference only occurs when the test vehicle is overtaken by small vehicle in adjacent lanes.The mean wind pressure coefficient during overtaking interference period is higher than that during non-interference period.The higher the relative speed and the lower the test speed during overtaking,the greater the influence on the transiting test.More than 26 s of data calculation time can eliminate the overtaking interference of small vehicle.When no overtaking occurs,only the wake of small vehicle in the same lane will affect the test results.And the transiting test results will no longer be affected by the wake of small vehicle when the vehicle spacing exceeds 24 m.Secondly,the influence of the interference behavior of medium vehicle on the transiting test method for measuring building wind pressure coefficients was investigated.In the experiment,a medium vehicle was set up to drive under specific conditions.The overtaking behavior interference including test vehicle being overtaken,test vehicle actively overtaking and different driving lanes and the wake interference of following driving were studied.The results show that overtaking interference only occurs when overtaking in adjacent lanes.When the test vehicle is overtaken by a medium vehicle,the wind pressure coefficients are significantly convex,and the average values are greater.The wind pressure coefficients fluctuate only slightly when the test vehicle actively overtakes a medium vehicle,and this interference can be ignored.More than 40 s of data calculation time can eliminate the overtaking interference caused by medium vehicle.For the behavior of following driving,the wake of medium vehicle significantly interferes with the transiting test results,and this interference disappears after the vehicle spacing exceeds 42 m.Finally,the influence of the interference behavior of large vehicle on the transiting test method for measuring building wind pressure coefficients was analyzed.In the experiment,a large vehicle was set up to drive under specific conditions.The overtaking behavior interference including test vehicle being overtaken and actively overtaking and the wake interference of following driving were studied.The results show that the time history of wind pressure coefficient will have obvious up and down fluctuations during the overtaking interference period instead of a single convex phenomenon.The mean wind pressure coefficients of the measuring points in the negative pressure area are lower during the overtaking interference period.The features of overtaking interference are obvious,easy to distinguish,and the interference lasts for a long time.In contrast,the interference is greater when the test vehicle is overtaken.For the behavior of following driving,the wake of the large vehicle will have a huge interference to the transiting test results.To avoid the wake interference,the vehicle spacing must be more than 70 m.When the transiting test is carried out on the expressway,the interferences caused by small,medium and large interference vehicles to the transiting test method for measuring building wind pressure coefficients increase sequentially.More than 40 s of data calculation time can eliminate the overtaking interferences caused by the small and medium vehicles.It is recommended that the overtaking interference of the large vehicle be eliminated by eliminating data.In order to avoid the wake interference,it is necessary to ensure a vehicle spacing of more than 70 m during the transiting test. |
