Study on the calculation method for stability against overturning of portal water injection sheet piles

摘要

Portal water injection sheet piles, with the advantages of low cost, rapid construction and low routine maintenance work, have been widely used in oil field works for disaster prevention and hydraulic structures. Stability against overturning of the sheet piles is the main factor determining their embedded depth, which in turn, determines construction cost and the overall stability and safety of the portal structure. However, there is no perfect method for calculating the stability against overturning for portal water injection sheet piles at present. Using an analytical model of a double-row pile, commonly used for studying forced principle, this paper presents a new sliding failure model, which regards the portal structure and the earth between the double-row piles as integral. It emphasizes the overall stability of sheet piles and earth, and the variation of the earth shear failure plane with the embedded depth of sheet piles. The principle of the process is introduced in detail and a simplified method is established. An example is given to demonstrate the conclusion, and the result when compared with that derived from finite-element method shows the new calculation model is feasible.