微型桩框架梁组合支挡结构的相似模型试验研究

Similar Model Test Study on Composite Retaining Structure of Micro Pile and Frame Beam

为探究边坡坡面多排斜向连接微型桩框架组合结构的抗滑效果和微型桩受力破坏规律,进行了相似模型试验。试验结果表明,多排斜向连接的微型桩框架梁结构可有效提高边坡的承载力,减小桩间距也能提高边坡的承载力;从坡顶到坡脚的各排微型桩破坏形式不同,抗滑段弯曲破坏依次减弱;各桩沿桩身的弯矩都呈S形分布,上半部分为正弯矩,下半部分为负弯矩,正负弯矩分界点位于滑面上方一定位置处,弯矩极大值点在滑面下方2~3倍桩径处;靠近坡顶和坡脚的微型桩所受土抗力相对较大,工程设计时应该重点关注这些微型桩的抗弯能力。

In order to explore the sliding resistance effect of the multi-row oblique connected composite structure of micro pile and frame beam on the slope surface,and the stress failure laws of micro piles,similar model tests were carried out.The test results show that the multi-row oblique connected composite structure of micro pile and frame beam can effectively improve the bearing capacity of the slope,and reducing the pile spacing can also improve the bearing capacity of the slope.The failure forms of each row of micro piles from the top to the toe of the slope are different,and the bending failure of the anti slide section is weakened in turn.The bending moment of each pile along the pile shaft is distributed in S-shape.The upper part is positive bending moment,and the lower part is negative bending moment.The dividing point between positive bending moment and negative bending moment is located at a certain position above the sliding surface,and the maximum bending moment is located at the position that 2-3 times of the pile diameter below the sliding surface.The soil resistance of micro piles near the top and toe of the slope is relatively large,so the bending resistance of these micro piles should be focused on in the engineering design.