The paper presents results of strain measurements in cohesionless sand in two different boundary value problems, namely quasi-static pull-out test of a steel wall and confined granular flow in a rectangular model silo using a non-destructive method called Particle Image Velocimetry (PIV) which is a technique for measuring surface displacements from digital images. Advantages and disadvantages of the method are outlined. 德國LaVision PIV/PLIF粒子成像測速場儀 材料應(yīng)變形變成像測量儀 便攜式應(yīng)變形變測量系統(tǒng)