Simplified method for calculating inflow into a deep excavation with consideration of the effects of cutoff walls

Luo, Guanyong; Qiu, J. S.; Hong, Chen; Pan, Hong

doi:10.1007/s10040-018-1808-0

Cited by 2 publications

(2 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Zhu et al [18] obtained the discharge by solving the seepage field on the inside of the cut-off wall by solving the resistance coefficient. Luo et al [27] proposed a new computational model to simplify the calculation of water inflow in pits with impermeable walls based on the concept of segmental resistance coefficients under the assumption of two-dimensional seepage in the profile, and gave the formula of segmental resistance coefficients. This is highly accurate and can be used for both watered and unwatered, confined and unconfined, and single-layer and double-layer systems.…”

Section: Introductionmentioning

confidence: 99%

Simplified Calculation Method for Active Anti-Floating of Elliptical Basements by Relief Wells

Luo,

Yang,

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

Currently, there are two main types of anti-floating methods for underground structures; one is the passive anti-floating method represented by anti-draft piles, the other is the active anti-floating method which focuses on interceptor-discharge pressure-reducing (IDPR). In the design of an IDPR anti-floating system, the relief well system situated within the cut-off wall serves as the primary drainage channel. The determination of the seepage field distribution within the multi-well system is vital for the overall design. For the seepage field analysis of the IDPR anti-floating multi-well system, currently numerical analysis is usually used, and there is a lack of simplified analysis methods. The simplified analysis methods already available are based on the uniform distribution of wells in circular pits, while the conversion of non-circular pits into circular pits produce large errors, which are not conducive to promoting the use of the method. To address this, we propose a simplified calculation approach suitable for multi-well systems (arbitrary layout) within elliptical pits. The analytical solution of non-uniformly distributed wells in circular pits is deduced through the principle of superposition. Then, the ellipse is mapped into a circle by using conformal mapping. The resistance coefficient method is adopted, and the internal and external seepage fields are connected in series to obtain the total flow rate, as well as the distribution of the seepage field. This is based on the consideration of the permeability of the waterproof curtains and the bypassing seepage. According to the verification of the calculation example, the results of the simplified algorithm are similar to the results of the finite element method, which proves the accuracy of the method; at the same time, when applied to the actual engineering, the obtained calculation results coincide with the measured data, which proves the practicability and reliability of the method. The simplified method can provide an effective way to design an IDPR anti-floating system.

show abstract

Section: Introductionmentioning

confidence: 99%

Simplified Calculation Method for Active Anti-Floating of Elliptical Basements by Relief Wells

Luo,

Yang,

et al. 2023

Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Although the wall is permeable, its permeability is generally much smaller than the aquifer permeability, and thus the seepage mainly occurs under the wall (see Figure 1a). Many studies have been conducted for this seepage analysis, such as fundamental analytical solutions for the seepage beneath a dam with a partially penetrating cut-off wall [23][24][25][26] and analysis of inflow into a deep foundation pit considering the effect of such type of wall [27].…”

Section: Introductionmentioning

confidence: 99%

Analytical Method for Groundwater Seepage through and Beneath a Fully Penetrating Cut-off Wall Considering Effects of Wall Permeability and Thickness

Mei

Hong

Luo

et al. 2022

Water

View full text Add to dashboard Cite

A fully penetrating cut-off wall is a vertical seepage barrier that fully penetrates an aquifer and is embedded in an underlying aquitard to a certain depth. Groundwater seepage with this type of wall occurs through three paths: leakage through the body of the wall in the aquifer, leakage through the body of the wall embedded in the aquitard, and seepage under the wall. Seepage through the first path can be simply treated as one-dimensional flow. However, due to the mutual influence of seepage through the latter two paths, the seepage problem is complicated and still needs to be studied. An analytical method is proposed to solve this problem in this study. Mathematic expressions for flow rate and head value are obtained by superposition of drawdowns of two exact models, namely, the model with only leakage through the wall body and the model with only seepage under the wall, respectively. Exact solutions are quoted or derived for the exact models, but they involve Legendre’s elliptic integrals of the first and third kinds. To facilitate an engineering application, approximate models of the exact models are introduced and their solutions are applied to the analytical formulas. The accuracy and applicability of the proposed method are verified compared with the numerical method. The proposed method provides a simple but effective method for quickly estimating the quantity of seepage in the aquitard (including leakage through the wall body and seepage under the wall) when simultaneously considering the effects of wall permeability and thickness.

show abstract

Simplified method for calculating inflow into a deep excavation with consideration of the effects of cutoff walls

Cited by 2 publications

References 20 publications

Simplified Calculation Method for Active Anti-Floating of Elliptical Basements by Relief Wells

Simplified Calculation Method for Active Anti-Floating of Elliptical Basements by Relief Wells

Analytical Method for Groundwater Seepage through and Beneath a Fully Penetrating Cut-off Wall Considering Effects of Wall Permeability and Thickness

Contact Info

Product

Resources

About