Research On The Algorithm Of Automatic Vehicle Loading For Bridge Loading Test

In inspection of in-service bridge and before the bridge opened to traffic,the bridge needs to be load test.With the rapid development of design theory and construction technology,the bridge structure is now becoming more and more complex,many factors affect the bridge structure,so it has become increasingly difficult that Only from the theoretical analysis to determine the carrying capacity and certain mechanical properties of the bridge.Load test is the most effective method to obtain loadcapacity of existing bridges.Meanwhile,with inspection and maintenance of in-service bridges Gradually received attention,bridge load test to do more and more.However,today's automated,intelligent trend is incompatible with the current bridge load(static load)test scheme design,to determine the specific location of the test vehicle loaded still using manual spreadsheet methods,this method are generally based on the existing experience to find a general location,and then fine-tuning,and it is heavy workload and inefficiency,more importantly,unable to determine the efficiency value of the non-load section whether overload,it will bring the issue of security.In view of this situation,it has realistic significance to develop a program that can rapid and automation Arrange loading test vehicle.The main contents of this article are:1 In view of load test is still in the situation of manual computation,connecting with the existing optimization theory,to Establish an optimized design model for vehicle automatic loading of load test.In optimization,the design variables are vehicle arrangement position,vehicle direction,vehicle type and occupancy lanes,and the restriction condition are the loading efficiency of loadl and non-load section is not overload and the inter-vehicle distance not less than a certain value,and the target function is made to reducing number or costs of load test vehicle,this optimization problem is multidimensional constrained optimization problem.2 Based on the existing VEA program,the introduction of new intelligent optimization algorithm(simulated annealing and genetic algorithms),and appropriate improve those algorithm according to the fact that optimized design for vehicle automatic loading of load test is a mixed variable problem.3 Through existing project example to verify the applicability of the program.As a result,the program has a good applicability for simple beam bridges,continuous rigid-frame bridge,cable-stayed bridge and Combinatorial Bridges with Beams andArches.,it can quickly gives optimized vehicle distribution scheme.At the same time,to compare and analyse the results of different algorithms,What's more,to analyse thedifference between simulated annealing,genetic algorithms and compound form method in dealing with mixed variables problem,These example show that,VEA program can quickly give the location of the load test vehicle,and satisfy restriction condition.This program can greatly improve the computational efficiency of scheme design of static load test,it can saving time,and the result is safe and reliable,it has some practical value.