Study On Parameters Of High-pressure Water Jet Impacting Concrete And Damage Prediction Model

Compared with the traditional concrete crushing technology,the high-pressure water jet concrete crushing technology has many advantages such as high efficiency,selectivity,wide adaptability,good operability,safety and environmental protection,and has great application potential in the concrete pavement renovation,bridge widening and other projects.It can be predicted that it will become one of the main ways of concrete crushing in the future.But at present,the rules and parameters of high-pressure water jet impacting concrete are not clear enough,which limits the further development of high-pressure water jet technology in the field of concrete crushing.Therefore,based on a large number of test data of high-pressure water jet impact on concrete,this paper analyzes the impact of different working conditions parameters on the crushing effect,and attempts to establish a damage prediction model of high-pressure water jet impact on concrete,in order to better optimize and evaluate the technical parameters of high-pressure water jet.The specific research contents are as follows:(1)According to the proposed evaluation index system based on the diameter of the impact hole,the expansion speed of the impact hole and the crushing volume of the concrete,the effects of abrasive flow,pump pressure,target distance and concrete strength grade on the crushing effect of the high-pressure water jet on the concrete are mainly investigated.The results show that the abrasive flow rate has a non-linear relationship with the diameter of the impact hole,the expansion speed of the impact hole and the volume of concrete crushing;the pump pressure has a positive correlation with the expansion speed of the impact hole,but has no obvious correlation with the diameter and volume of the impact hole;the target distance has a positive correlation with the diameter of the impact hole,and has a negative correlation with the expansion speed of the impact hole;the higher the strength grade of concrete,the straighter the impact hole;the smaller the diameter of the impact hole,the expansion speed of the impact hole and the volume of concrete crushing.(2)The influence of different parameters on the crushing effect of high-pressure water jet on concrete was analyzed by orthogonal test,and the sensitivity of different parameters on the crushing effect of concrete was obtained: the order of the influence on the diameter of the impact hole was: abrasive flow> target distance> concrete strength grade> pump pressure;the order of the influence on the expanding speed of the impact hole was: abrasive flow> pump pressure> concrete strength grade> target distance;the order of influence on crushing volume is: abrasive flow> target distance> concrete strength grade> pump pressure.(3)Combined with the results of orthogonal test,marginal mean test method and significance test of interaction,the interaction analysis of the impact parameters of highpressure water jet on concrete is carried out.The results show that there is an interaction between the parameters on the diameter of the impact hole,the expansion speed of the impact hole and the volume of concrete crushing.By quantifying the significance of the interaction,the interaction between different parameters and parameters is ranked according to the diameter of the impact hole,the expansion speed of the impact hole and the volume of concrete crushing.(4)Based on the breaking law of high pressure water jet and the modeling technology of neural network,the topological structure of neural network and the training algorithm of neural network are designed,and the damage prediction model of high pressure water jet impacting concrete based on BP neural network model,BP neural network model based on Drosophila optimization algorithm and BP neural network model based on particle swarm optimization algorithm is established,and the prediction is made through the test data The results show that the prediction accuracy of BP neural network model optimized by Drosophila algorithm is the best.The prediction accuracy of the diameter,expansion speed and crushing volume of the impact hole is better than that of BP neural network model and BP neural network model based on particle swarm optimization.