The Study Of Root Anchor Foundation Non-linear Analysis

Root-open caisson foundation is an innovation of traditional pile-open caisson foundation. It works through driving the root keys into open caissons to strengthen the baring capacities, also improve the vertical and horizontal pulling resistance ability, while keeping the frictions between open caissons and surrounding earth unvariable. Group-well anchor foundation is consisted with wells of root-open caissons, and in contemporary time, the study of it is still somewhat limited, thus, the research of it is of grave importance.In this study, we utilized the limitedly-differentiated analysing software Flac3D to make geofeas numerical simulations of Root-open caisson foundation to find out its mechanics properties, site-varifing mechanisms and the effects of root keys.Firstly, Flac3D software was used to re-develop the Duncan-Chang model, and simple arithmetic examples were performed to test its correctness.Secondly, numerical calculation was carried out by using the re-developed Duncan-Chang model, and from which we can found that the traditional open caisson anchors embraced in thick earth covers would siginificantly revoled when undergoing certain horizontal pressures. This indicated that the horizontal-pulling resistance ability was mainly generated by the front passive earth pressure.Thirdly, re-developed Duncan-Chang model was also used to make numerical simulation of group-well anchor foundations, and the results demonstrated that in terms of veitical-pulling resistance ability, the new one was slightly better than the traditional one; in the meanwhile, the new open caisson anchors also revolved, and this also testified that the horizontal-pulling resistance ability mainly came from the front passive earth pressure.Finally, the horizontal and vertical baring capacities of open caissons were studied when steal root keys were set up on the well walls. From the results we can figure out that the baring capacities of the open caissons possessing root keys were obviously higher than their counterparts; the improving efficiency was different between the vertical and horizontal, and with the horizontal better than the vertical; adding the length, the number and the layer of root keys, the lineardisplacements all decreased.