Research On The Inner Forces Calculation Of Pile-anchor Retaining Structure And Its Applications In Foundation Pit Engineering

The pile-anchor retaining structure is a combined support structure, widely used indeep foundation excavation. The advantage of using this kind of retaining structure isthat the interaction among pile-soil-anchor can improve the working status of eachother, and thus enhance the overall stability against sliding. However, the interactionalso causes a more complex bearing mechanism of retaining structure, and bringscertain difficulties in its design and construction. Currently, researches on the bearingmechanism of pile-anchor retaining structure mainly focused on three aspects, that is,distribution pattern of internal forces of support piles, lateral earth pressure acting onsupport piles, tensile resistant properties of soil anchors. However, studies on thecommon working mechnism of pile-soil-anchor is still shallow. In addition, the designand calculation of pile-anchor retaining structures still resort to the classic staticbalance method or elastic theory method, these methods do not reflect the nonlineardeformation characteristics of soil, and can not fully reveal the pile-soil-anchorcommon working mechanism. Therefore, it is particularly necessary to carry out amore in-deep research on the bearing mechanism, design theory and constructiontechnology of pile-anchor retaining structure. To this end, this paper has done someresearch work in the following aspects:Firstly, based on existing researches, the bearing mechanism of pile-anchorretaining structure was analyzed and discussed, especially the common workingmechanism among pile, soil and anchor. The results were usefull for developing moredesirable design theory and construction technology of pile-anchor retainingstructures. Secondly, combined with the advantages of elastic theory method andco-deformation theory, this paper proposed a new method for inner force calculationof pile-anchor retaining structures, which considered the common workingmechanism of pile-soil-anchor as a main influencing factor in the accuracy of results.Then, combined with the inner force calculation method of pile-anchor retainingstructure devoleped in this paper, a set of pile-anchor retaining structure designcalculation methods was proposed, including the designing steps to be followed,designing parameters needed, et al. And then, by exploring the construction process ofthe pile-anchor retaining structure, some safety precautions that should be notedduaring the construction was pointed out, which provides an important reference for the development of a reasonable pile-anchor retaining structure construction program.In the end, the proposed method was used for the designing calculation of apile-anchor retaining structure in Changsha, and the detailed calculation process andcalculation results was given in the paper. By the engineering application example,the feasibility and rationality of the proposed method was verified.