陡倾滑面滑坡锯齿形抗滑桩力学性能研究

陡倾滑面滑坡推力竖向分力显著,基于滑坡推力水平假定与普通抗滑桩相互作用不充分这一问题,建立锯齿形抗滑桩结构。依据梯形分布滑坡推力的假设,推导了受荷段内力计算公式,采用Winkler弹性地基理论推导了锚固段内力计算公式,并开展锯齿形抗滑桩的力学性能研究。分析表明,(1)随着滑面倾角的增加,锯齿形抗滑桩的受荷段、锚固段的弯矩、剪力以及侧应力均减小,内力减小幅度随之增大;(2)滑面倾角在20°～40°时,随着滑面倾角的增加,锚固段的理论最小长度在逐渐增加,40°时锚固段的长度为4.2 m达到最大值,且该长度仅占整个桩长35%,远小于按现行规范取得的锚固段长度最大值(1/2总桩长),桩侧摩阻力就可以完全满足竖向力学平衡;(3)将锯齿形抗滑桩与普通抗滑桩内力对比,受荷段和锚固段的弯矩减小34%、剪力减小36%及桩侧应力减小幅度大于30%,力学性能良好。

Study on the mechanical performance of zigzag anti-slide pile on steep inclined slip surface landslide

The vertical component of thrust of landslide on a steep inclined sliding surface is significant.Aiming at insufficient interaction between the thrust level of a landslide and an ordinary anti-slide pile,a zigzag anti-slide pile structure is established.Based on the assumption of trapezoidal distribution of landslide thrust,the internal force calculation formula of loaded section is derived,the internal force calculation formula of anchoring section is derived by Winkler elastic foundation theory,and the mechanical properties of the zigzag anti-slide pile are studied.The analysis shows that; (1) with the increase of the inclination of the sliding surface,the bending moment,shear force and lateral stress of the loading section and anchorage section of the zigzag anti-sliding pile decrease,and the reduction range of the internal force increases; (2) when the inclination angle of the sliding surface is between 20 and 40 degrees,with the increase of the inclination angle of the sliding surface,the theoretical minimum length of the anchoring section gradually increases,at 40 degrees,the length of the anchoring section reaches the maximum value of 4.2m,which only accounts for 35% of the total length of the pile and is much smaller than the maximum length of the anchoring section (1/2 of the total pile length) obtained according to current specifications,and the friction resistance of the pile side can fully meet the vertical mechanical balance; (3) by comparing the internal forces of the zigzag anti-slide pile with an ordinary anti-slide pile,the bending moment of the loading section and anchoring section is reduced by 34%,the shear force by 36% and the pile side stress by more than 30%.