Strength evolution prediction of concrete structures during long-term service life based on GA-BP neural network
In order to study the strength evolution law and prediction model of existing concrete structures during long-term service,the actual projects such as Tangbao Railway and Xihu Railway were taken as the research background,and the in-service bridges and culverts with service time of 2,16,25,30,40,52,66,88,95 and 100 a were taken as the research objects.Based on the concrete rebound method,the concrete strength test of the in-service bridge and culvert was carried out,and the dynamic development process of the strength of the existing bridge and culvert concrete during the ultra-long service period was analyzed.At the same time,based on the concrete strength data measured by the test and the concrete strength data of 230 sets of in-service bridges and culverts(service time 2-88 a)collected under similar conditions,a GA-BP neural network concrete strength prediction model was constructed.In addition,in order to improve the applicability of the model,a general matrix formula and a simplified formula were established based on the high-precision GA-BP neural network strength prediction model.Based on the concrete strength prediction model constructed in this paper,the strength evolution law of concrete structures during the long service period in such areas(the areas that have been investigated in the experiment)was analyzed.The results show that compared with the existing concrete strength prediction model,the GA-BP neural network concrete strength prediction model constructed in this paper can effectively predict the concrete strength under different service times,and the average absolute percentage error of the prediction data is 8.76% ,and the coefficient of determination is 0.83.The simplified formula(C25)in this paper has high accuracy,the average absolute percentage error is 6.6% .Therefore,in order to facilitate the simplified calculation,the simplified formula(C25)is recommended as the concrete strength prediction formula during the ultra-long service period.The concrete strength during the 100 a service period goes through two time stages,namely,the period of slow rise of concrete strength(1-49 a)and the period of rapid decline of concrete strength(49-100 a).With the increase of the service time of concrete structures,the deterioration rate of concrete structures increases,resulting in the concrete strength of concrete structures cannot meet the service requirements of concrete structures in the long-term service process.
concretelong service periodGA-BP neural networkevolution lawstrength prediction model
万方数据
维普
