Abstract: 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.

Key words: arc interval row piles, coupling beam, new spatial structure, internal force distribution, displacement constraint