基于PIV技术的锚板抗拉破坏模式识别

Identification of failure modes for uplift anchor plates based on PIV technology

利用自行开发的力、位移和图像同步数据采集系统对锚板上拔过程中的力、位移和图像进行同步采集,基于PIV(particle image velocity)无干扰测量技术对初始点和峰值点的图像进行分析,根据分析得到的锚板峰值点处的变形场对砂土中锚板的抗拉破坏模式进行了识别.结果表明:在峰值点处,锚板上部土体中间部分位移大、两边位移小,位移场呈倒梯形状分布;剪切应变场沿锚板两侧出现对称的剪切带,剪切带倾斜向上并延伸到地面,剪切带内出现剪胀现象.

By use of the self-developed data acquisition system,the force,displacement and images of anchor plates during uplift were synchronously collected.The images at the initial and peak points were analyzed based on the non-intrusive measuring technology of particle image velocimetry（PIV）.According to the deformation fields obtained at the peak point,the failure modes of the uplift anchor plates in sand were identified.The results show that at the peak point,the displacement of the soil at the upper part of the anchor plates is large in the center and small at the both sides,and an inverted trapezoid of the displacement fields is observed.Two symmetrical shear bands are formed along the two sides of the anchor plates.They are obliquely upward and extend to the ground surface.The shear dilation is also observed in the shear bands.