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.