The multi-arch retaining structure composed of borehole cast-in-place piles is a type of combined section in which large diameter reinforced concrete bored piles and small diameter bored piles are arranged in the shape of an arch. In this structure the bending moment and the shearing force are converted into the axial pressure along the arch axis. It shows a reasonable bearing ability

has a better section efficiency

and performances larger strength and rigidity than the pile (wall) structure with same quality. The top is connected with reinforced concrete periphery beam

then

without anchoring and poling it can also support a deeper foundation pit than pile (wall) structure. If the excavation depth is too deep

we can lay reinforced concrete rib stiffeners in a proper distance in the direction of the depth. Briefly

this is a new type of retaining structure

and the economic benefit is notable.