The photogrammetry combining conventional triaxial testing with digital measurement technology can measure the lo-cal deformation of soil samples.However,the measurement accuracy is relatively low due to the refraction influence.In order to re-duce refractive error,the photogrammetry was used to conduct triaxial test on saturated sandy soil samples and some corrective methods were adopted.We took photos of soil samples by continuous surround shooting.The coordinates could be extracted by im-porting the obtained photos into the PhotoModeler Scanner.A 3D refraction correction model using ray tracing technology was es-tablished,and refraction error correction coefficients were obtained by a large amount of data analysis.The test results showed that the correction coefficient at the axial height direction was1.006 and the average of relative error after correction was 0.185%.The correction coefficient at radius direction was1.361 and the average of relative error after correction was0.451%.Both meet the accuracy requirement.For the saturated sandy soil in this test,the correction coefficient can reduce the influence of refraction and improve the measurement accuracy.
关键词
摄影测量/误差修正/修正系数/精度/三轴试验
Key words
photogrammetry/error correction/correction coefficient/accuracy/triaxial test
维普
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