【摘要】 锚板上拔过程中板周土体变形破坏机理的研究对锚板极限承载力的可靠预测至关重要。通过室内模型试验,采用数字图像关联技术对锚板上拔过程中锚板周围土体的变形场进行了研究。分析结果表明:在锚板上拔过程中锚板周围土体伴随着剪胀现象,其应力水平、峰值摩擦角和剪胀角控制着破坏面的形状,进而影响着锚板的极限承载力。在此基础上,建立了锚板承载力计算模型。通过引入Bolton理论所建立的剪胀角、相对密实度和应力水平之间的关系,得到了锚板极限承载力的理论计算公式。该理论公式考虑了埋深率、剪切摩擦角、剪胀和应力水平等影响因素,可对不同密实度砂土中锚板的极限承载力进行预测。理论公式与其他学者的试验结果对比表明该理论模型计算结果与其他学者的试验结果有较好的一致性,验证了该理论模型的合理性。更多还原

【Abstract】 The deformation mechanism of sand around plate anchors during uplifting is essentially important for the reliable prediction of their ultimate bearing capacity in sand.First,a series of model tests are conducted.The digital image correlation method is used to measure the sand deformation fields during uplifting of anchors.The deformation fields show that a pair of shear zones accompanied by dilatancy are formed.The stress level,friction angle and dilatancy angle control the shape of the failure surface,thus affecting the bearing capacity of the plate anchors in sand.A prediction model for uplift force is developed based on the sand deformation mechanism around an uplifting plate anchor.The relationship among the dilatancy angle,the relative density and stress level established by Bolton is introduced to develop the theoretical formula.The comparison between the theoretical and test results is conducted.The theoretical results show good agreement with the test results.更多还原