抗拔锚板群锚基础模型试验研究

抗拔锚板上拔过程是一个复杂的锚土相互作用过程,锚板周围土体在上拔过程中的变形破坏机制对于抗拔锚板基础的极限承载力研究具有重要意义。基于PIV(particle image velocimetry)无干扰测量技术对砂土中方形锚板上拔过程中变形场进行了测量分析,研究了抗拔锚板群锚基础的破坏机制。试验结果表明:锚板间距对群锚破坏面的形状有着重要影响;在临界间距内,以锚板上部1倍边长为拐点,剪切带先内倾然后外倾向上贯通到土体表面,群锚效应系数与S/B为线性关系,由此预测出群锚效应达到100%时的锚板间距;达到临界间距后,每个锚板的剪切场和单个锚板剪切场一致,试验结果可为群锚基础极限抗拔力的预测提供参考。

Model Test of Group Uplift Anchor Foundation

Uplift anchor pullout is a complicated anchor-soil interactive process. The deformation mechanism of soil around an uplifting anchor is essentially important for reliable prediction of ultimate bearing capacity. During the square anchor uplifting, the deformation fields are measured based on particle image velocity (PIV), and the deformation mechanism of uplift anchor plate is analyzed. Results show that the distance between anchors has an important impact on the shape of the rupture surface.Within the critical distance, the point at a length of double anchor side as the inflexion, the shear zones first introverts, then extroverts upward to the surface. Group anchorage effectiveness and S/B are linear relations, the distance between anchors can be predicted when group efficiency achieves 100%. After reaching the critical distance, the shear fields of each anchor is consistent with that of a single one. These results will provide reference for developing prediction of ultimate uplifting capacity.