Seepage calculation of foundation with suspended curtain based on improved resistance coefficient method

Abstract

The combination of the curtain and pit dewatering is the main trend of groundwater control in the deep foundation pit project.Due to the complexity and scale effect of the seepage field around the deep foundation pit, there is still no mature and accurate analytical calculation method for dewatering design.Based on the comparison of the characteristics of the seepage field between the suspended curtain and the gate dam, a new subsection mode of seepage section of suspended curtain foundation pit under confined aquifer is proposed.Modified from the improved resistance coefficient method of the gate dam, a new formula for calculating equivalent resistance coefficient of "horizontal confluence section"within special zone of foundation pit is derived, which is extended to the anisotropic condition of aquifer and can be used in the quantitative calculation of the water outflow and drawdown in the suspended curtain foundation pit.Finally, the accuracy of the method is verified by numerical simulation combined with a typical foundation pit case.The studies show that, after reasonable segmentation, equivalence and correction, the relative error between the improved resistance coefficient method and the numerical modeling can be controlled within 5%, with high accuracy.Besides, it has the advantages of flexible segmentation and simple calculation, and can be applied to the calculation of foundation pit dewatering design under different site conditions.

Keywords

• deep foundation pit engineering
• improved resistance coefficient method
• groundwater control
• suspended curtain
• foundation water outflow
• drawdown