Flow soil stability calculation method for composite soil layer

Abstract

The invention discloses a flow soil stability calculation method for a composite soil layer. The method comprises the following steps: determining the total number of soil layers in a seepage direction through field exploration and a design file; obtaining a total water head difference delta h of the soil body and basic physical parameters of each soil layer through an indoor test, an in-situ test and a design file; calculating a water head difference between upper and lower interfaces of each soil layer based on the Darcy law and the physical parameters of each soil layer; carrying out stress analysis on the soil skeleton of the ith layer, and establishing a mechanical equilibrium formula by considering gravity, buoyancy, seepage force, constraint force of the soil skeleton of the upper-layer soil body and residual seepage force of the lower-layer soil body; the seepage force is increased, and a soil seepage stability coefficient is introduced; and enabling the residual seepage force of the last layer of soil body to be equal to zero, and solving to obtain a seepage stability coefficient. Compared with an existing method, the method has the advantages that interaction of soil skeletons of the upper and lower soil layers is considered, calculation is convenient, and the seepage stability of the multi-layer soil body can be calculated.

Description

technical field

[0001] The invention relates to a calculation method for flow soil stability of a composite soil layer, belonging to the technical field of seepage stability calculation of a soil layer. Background technique

[0002] During the construction of buildings and water conservancy projects, the seepage stability of foundation pits and dams has a crucial impact on project safety. Engineering excavation, earth-rock dam water storage, rainfall, artificial precipitation and other engineering and natural activities often cause changes in the formation flow field, which in turn causes changes in seepage force, and the size and direction of seepage force directly affect the stability of the soil layer. The buoyant weight, permeability coefficient, void ratio, and soil particle specific gravity are all important indicators that affect the seepage stability of the soil layer. As the main form of seepage damage, flowing soil usually occurs suddenly, which is very harmful to...

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