<p>Effective stress is a crucial parameter in governing the strength and deformation behavior of soil. This study introduces an effective stress decoupling algorithm based on seepage lines and formulates a simplified computational framework applicable to both saturated and unsaturated soils. The framework is capable of directly solving the unified effective stress equation based on field measurements or results from saturated flow analysis, thereby determining the effective stress field of the soil layer. The specific steps include: estimating the pore pressure distribution based on the groundwater table, calculating the seepage force induced by the hydraulic gradient, applying the seepage force as an external load to the computational element, and employing the finite element method to solve for the effective stress field of the soil. Through comparative analysis in dam engineering, the results of effective stress calculations obtained using the decoupling algorithm are compared with those from the fluid-structure interaction method (FSIM), thereby verifying the reliability of the proposed method. As demonstrated through the example of tailings pond engineering, effective stress solutions were obtained for both the existing dam with a known seepage line and the final piled-up dam, which was determined through saturated seepage analysis, thereby showcasing the practical application of the simplified framework in real-world engineering. The proposed method is highly efficient and particularly suitable for conditions where the phreatic line is gentle(inclination angle ≤ 20°). Under these conditions, the calculation error for pore water pressure can be controlled within 10%. It is capable of directly computing the effective stress field of geotechnical structures based on measured or numerically simulated seepage lines, thereby providing a practical tool for subsequent deformation and stability analysis.</p>