弧形间隔排桩-桩顶拱梁空间抗滑结构理论研究

为充分利用地形、地质结构和混凝土的材料特性，优化直线排桩的不利受力状态和提高其整体稳定性，提出了弧形间隔排桩-桩顶拱梁新型空间抗滑结构，即根据滑坡地形及地质条件弧形布设抗滑桩，桩顶设置连系梁，连系梁两端设置抗力桩，形成空间结构以抵抗滑坡推力。以抗滑桩与连系梁之间的作用力为冗力，分别建立了连系梁和抗滑桩的计算模型，并对连系梁的内力和抗滑桩的位移进行了理论分析，根据连系梁与抗滑桩连接处的位移协调条件，建立了力法典型方程求解冗力。最终得出了连系梁的弯矩、剪力和轴力以及抗滑桩的位移、内力理论计算公式。通过算例分析并与悬臂桩及直线排桩-桩顶连系梁抗滑结构比较，结果表明：空间抗滑结构中弧形连系梁的内力分布更加合理，弧形连系梁对抗滑桩的位移约束效果明显。

Theoretical study of spatial anti-slide structure of arc interval row piles with coupling beam on pile top

In order to make full use of terrain, geological structure and material characteristics of concrete, and optimize unfavorable forced state of linear interval cantilever row piles and improve the global stability, a new spatial anti-slide structure of arc interval row piles with arc beam on the top of piles is proposed; that is according to the terrain and geological conditions of slope, to set piles in arc shaped with coupling beam on the top of piles and set resistance piles at the two ends of coupling beam, namely compose a new spatial anti-slide structure to resist landslide thrust. According to force method, the restraint force between the piles and the coupling beam can be regarded as the redundant force, then the calculation model of the anti-slide pile and the coupling beam are built, respectively; and to analyze theoretically the internal force of the coupling beam and the displacement of the anti-slide pile. Then according to the displacement coordination condition between anti-slide pile and coupling beam, to establish the typical equation to solve the redundant force. Finally, the theoretical calculation formula of the bending moment, shear and axial force of the coupling beam and the displacement and internal force of the anti-slide pile are obtained. By analyzing the calculation example and comparing with the cantilever row piles and the linear interval row piles with beam on the top of piles, the results show that the internal force distribution of arc coupling beams of spatial anti-slide structure is more reasonable; and the arc coupling beam can constrain displacement of piles and the effect is obvious.