Research On Security Detection Method Of Piled Wharf Structure With The Digital Speckle Principle

The article is based on the chongqing traffic science and technology project "after the three gorges reservoir water level difference overhead upright deep water wharf foundation design, construction and key structural nondestructive testing technology research", through the high pile wharf, component and structure of the overall model test carried out based on the principle of digital speckle piled wharf structure security detection method research.First of all, according to the basic principle of digital speckle correlation method, combination of piled wharf components and structure of the overall model test and the precision and computing cycles, with thick search method, the gradient search method, sub-pixel displacement calculation method of gray level interpolation method as a basic algorithm speckle program, combined with the Beijing institute of technology university Dr. Ma developed image processing program, eventually as high pile wharf component and structure of whole model test measurement procedures. Secondly, using the speckle measurement procedures separately rigid body translation test, single component force test and overall model test of piled wharf structure based on the collection of speckle image measurement analysis, it is concluded that the rigid body, single component and high pile wharf structure as a whole in the process of deformation and strain or displacement value, then with the traditional test strain gauge or displacement meter, comparing the measured data to determine the accuracy of the speckle measurement program to 0.01 pixels, and the maximum error of measurement results is not more than 13%, to ensure the validity of the measurement procedures in engineering survey deformation and accuracy. Then by abaqus numerical simulation method and digital speckle measurement method, with concrete specimen, artifacts and piled wharf pile foundation test of main stress components in the whole model of target area as the object, the two method calculated the displacement and strain contour cloud image contrast each other, found that the deformation trend generally consistent, and the deformation value of maximum error less than 11.7%, thus further validation of digital image on the basis of the principle of digital speckle measurement technology can be used for piled wharf test model of deformation of the main bearing member in detection.Due to the results of Digital Speckle Measurement fit well with abaqus calculated,he displacement contour image and the maximum displacement deformation value fro m dscm uesd the most unfavorable combination of loads by abaqus simulated provide th e basis for security assessment of the pile wharf.From then on, it can be used to assess t he structure security that compared the displacement contour image and deformation val ue from dscm with theoretical calculation.