Geotechnical Engineering Commons^™

Simulation Of Seepage And Heat Transfer In 3d Fractured Rock Mass Based On Fracture Continuum Method, Dong-Dong Liu, Li-Xin Wei, Guo-Yuan Xu, Yan-Yong Xiang

Rock and Soil Mechanics

The main challenge of simulating the processes of seepage and heat transfer in fractured rock mass is the heterogeneity of rock mass at various scales. In order to balance the efficiency and accuracy of numerical simulation, the two-dimensional fracture continuum method is extended to a three-dimensional one. Based on the depth-first search algorithm, the effective fractures contributing to the permeability of rock blocks are collected. The block permeability tensor is obtained by considering the contribution of effective fractures and rock matrix. The finite element software COMSOL Multiphysics is integrated with Matlab to generate a three-dimensional fracture continuum model that contains …

Improvement Of Rainfall Boundary Treatment Based On The Diffusion Wave Approximation Equation, Xu Wang, Mei Dong, Meng-Yue Kong, Yun-Peng Deng, Ri-Qing Xu, Xiao-Nan Gong

Rock and Soil Mechanics

During the simulation of rainwater infiltration, the conventional rainfall boundary cannot accurately reflect the influence of the variation of ponding water depth on the calculation of actual rainwater infiltration rate. To address this issue, the conventional rainfall boundary is improved by incorporating the diffusion wave approximation equation, allowing for the coupling of ponding water depth variations with actual infiltration rate during heavy rainfall events. Additionally, the accuracy of the improved boundary is validated through two classical experimental cases. The improved boundary is subsequently applied to the simulation of an actual engineering scenario. The findings indicate that the improved rainfall boundary …

Numerical Analysis Of The Impact Of Internal Erosion On Underground Structures: Application To Tunnel Leakage, Ying-Jing Liu, Jie Yang, Zhen-Yu Yin

Rock and Soil Mechanics

No abstract provided.

Experimental Investigation On Dynamic Properties Of Soft Clay Under Coupled Cyclic-Seepage Loads, Hua-Yang Lei, Ying-Gang Xu, Jiang-Yan Miao, Xu Liu

Rock and Soil Mechanics

In this paper, a series of triaxial tests under coupled cyclic-seepage loads were carried out for saturated soft clay in Tianjin. The results show that the development of cumulative plastic strain is characterized by three stages: initial instantaneous growth, decelerated increase and stable / linear development, and seepage can enlarge the dynamic deformation up to 1-2 times of that compared to cyclic load only. Larger seepage force induces greater cumulative plastic deformation. The lower frequency or greater cyclic stress amplitude induces larger strain. The prediction model of cumulative plastic deformation of soft clay is established under the condition of dynamic- …

Analytical Solution Of Startup Critical Hydraulic Gradient Of Fine Particles Migration In Sandy Soil, Ming-Nian Wang, Yong-Tao Jiang, Li Yu, Yu-Cang Dong, Ru-Yu Duan

Rock and Soil Mechanics

Suffusion will occur in the internally unstable sandy soil because of the groundwater seepage. Soil failure caused by the suffusion has adverse effects on the building structures or foundations. In this paper, a model that can calculate the force acted on fine particles in seepage field was established by considering the effective stress of soil and the stress reduction of fine particles. According to the equilibrium state of ultimate stress, the formula for calculating the startup critical hydraulic gradient of fine particles migration in sandy soil during the suffusion process was obtained. A DEM-CFD coupled method and the existing experimental …

Stability Analysis Of Slope Based On Green-Ampt Model Under Heavy Rainfall, Yong-Hua Su, Cheng-Cheng Li

Rock and Soil Mechanics

The method of rainfall infiltration analysis directly affects the prediction and prevention of rainfall-induced landslides. Green-Ampt (GA) model, which has clear physical meaning and few parameters, has been paid more and more attention in the analysis of rainfall-induced landslides. However, this method ignores the existence of the unsaturated layer of the wetting layer and the seepage of the saturated layer, which affects the calculation accuracy. In view of the above deficiencies, the LSGA model is established based on the stratified hypothesis and the saturated layer seepage, and the expression of slope stability coefficient is established. All results show that LSGA …

Model Experiment And Calculation Analysis Of Excavation-Seepage Stability For Shallow Shield Tunneling In Sandy Ground, Bo Mi, Yan-Yong Xiang

Rock and Soil Mechanics

Regarding the influence of seepage on face support pressure and ground collapse mode in shallow shield tunnel excavation, an experimental system composed of a shallow shield tunnel excavation-seepage model and a setup of measurement and data acquisition is designed and established, with consideration of pore water pressure in the excavation chamber and face plate opening ratio. The saturated soil pressures and pore water pressures at the face and settlements of surrounding strata are measured under various steady-state seepage conditions, as the soil input into the excavation chamber is gradually increased. Correspondingly, numerical simulations and limit equilibrium calculations are carried out. …

Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton

Theses and Dissertations--Civil Engineering

Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. …

Seepage And Stability Of A Dam In An Artesian Setting, Sean A. Parks

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Willow Creek Dam is located in a unique region on the boundary of a confined aquifer, where artesian conditions exist. Recently, groundwater levels have exceeded the elevation of the downstream berm well above anticipated piezometric elevations. It was presumed from limited evidence that these high piezometric levels resulted from pressure in the aquifer rather than from seepage out of the reservoir. The purpose of this investigation was to determine the relative contributions of the reservoir and the regional groundwater to observed piezometric levels and how these levels affect seepage exit gradients and slope stability of the dam.

Comparing the head …

Coalbed Methane Development In Wyoming’S Powder River Basin, Diana Hulme

Coalbed Methane Development in the Intermountain West (April 4-5)

21 pages (includes color illustrations and maps).

Contains endnotes.