scholarly journals The Unsaturated Hydromechanical Coupling Model of Rock Slope Considering Rainfall Infiltration Using DDA

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Xianshan Liu ◽  
Ming Xu
Keyword(s):  
Water Flow ◽  
Rock Slope ◽  
Rainfall Intensity ◽  
Water Pressure ◽  
Great Influence ◽  
Coupling Model ◽  
Rainfall Infiltration ◽  
Discontinuous Deformation Analysis ◽  
Reservoir Rock ◽  
Hydromechanical Coupling

Water flow and hydromechanical coupling process in fractured rocks is more different from that in general porous media because of heterogeneous spatial fractures and possible fracture-dominated flow; a saturated-unsaturated hydromechanical coupling model using a discontinuous deformation analysis (DDA) similar to FEM and DEM was employed to analyze water movement in saturated-unsaturated deformed rocks, in which the Van-Genuchten model differently treated the rock and fractures permeable properties to describe the constitutive relationships. The calibrating results for the dam foundation indicated the validation and feasibility of the proposed model and are also in good agreement with the calculations based on DEM still demonstrating its superiority. And then, the rainfall infiltration in a reservoir rock slope was detailedly investigated to describe the water pressure on the fault surface and inside the rocks, displacement, and stress distribution under hydromechanical coupling conditions and uncoupling conditions. It was observed that greater rainfall intensity and longer rainfall time resulted in lower stability of the rock slope, and larger difference was very obvious between the hydromechanical coupling condition and uncoupling condition, demonstrating that rainfall intensity, rainfall time, and hydromechanical coupling effect had great influence on the saturated-unsaturated water flow behavior and mechanical response of the fractured rock slopes.

Research of Slope Stability Analysis Considering Rainfall Infiltration

2012 ◽  
Vol 204-208 ◽  
pp. 487-491
Author(s):  
Jian Hua Liu ◽  
Zhi Min Chen ◽  
Wei He
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Rock Slope ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Rainfall Infiltration ◽  
Safety Coefficient ◽  
Rainfall Duration ◽  
Unsaturated Seepage

Based on the saturated-unsaturated seepage theory and considering soil-hydraulic permeability coefficient characteristic curves of rock slope, the variation of suction in unsaturated region and transient saturated zone formation of rock slope were analyzed. Combined with engineering example, the strength reduction methods were adopted to analyzing the rock slope stability influence factors considering unsaturated seepage with different rainfall intensity and duration. The results show that the flow domain owing to rainfall infiltration mainly appears surface layer region of slope. The rainfall infiltration caused the groundwater level rise, the rising of transient pore water pressure and the fall of suction in unsaturated region caused the slope stability decrease. The rainfall intensity and duration have obvious influence on slope stability, and in the same rainfall duration condition, the safety coefficient of slope decreases with the accretion of rainfall intensity. With the rainfall duration increasing, the water in soil has more deep infiltration, the water content and pore water pressure was higher in the same high position, the decreasing of suction caused the safety coefficient of slope has more reduce.

scholarly journals Seepage Analysis on the Surface Layer of Multistage Filled Slope with Rainfall Infiltration

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Bingxiang Yuan ◽  
Zengrui Cai ◽  
Mengmeng Lu ◽  
Jianbing Lv ◽  
Zhilei Su ◽  
...  
Keyword(s):  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Rainfall Infiltration ◽  
Feature Points ◽  
Saturation State ◽  
Seepage Analysis ◽  
Safety Coefficient ◽  
Infiltration Model ◽  
Saturation Region

Based on the theory of rainfall infiltration, the surface infiltration model of multilevel filled slope was established by using the SEEP/W module of GeoStudio. The changes of the volumetric water content (VWC) and pore water pressure (PWP) in the surface of the slope during the rainfall infiltration were analyzed, and the influence of the change of the rainfall conditions on the VWC and PWP was considered. The analysis showed that VWC and PWP increased when the rain fell, and the growth rate of the higher feature point was higher. The affected area was concentrated on the upper part of the surface about 0.75 m. With the increasing of rainfall intensity, the slope surface getting to transient saturation state was quick, and the time of the PWP increasing to 0 among the feature points of same elevation was shortened. Meanwhile, the PWP presented a positive value, and as the infiltration depth increased, the transient saturation region expanded. The safety coefficient of the multistage filled slope was continuously reduced; after the stop of rainfall, the VWC and the PWP decreased, and the decline rate of the higher feature points was higher. In addition, the PWP of the lower part increased, and the safety factor of the slope presented a trend of rebound.

Analysis of Seepage Field and Stability of Clinosol Slope under Rainfall Infiltration

2013 ◽  
Vol 353-356 ◽  
pp. 307-311 ◽  
Author(s):  
Xi Yi Yang ◽  
Fang Guo
Keyword(s):  
Moisture Content ◽  
Pore Water ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Rainfall Infiltration ◽  
Seepage Field ◽  
Volumetric Moisture Content ◽  
Initial Stage

In order to research on slope seepage field and slop stability under rainfall infiltration, this paper combines finite element with limit equilibrium theory to study. The results show that under rainfall, pore water pressure of the slope crest and slope toe in slope wash is greatly influenced by rainfall; Change in the volume moisture content is more sensitive than pore water pressure, volumetric moisture content of each location is increasing quickly at the initial stage of rain, volumetric moisture content in the lower locations is the first to reach saturated due to the continued supply and gravity of the rain; The slope stability reduces with rainfall infiltration, the greater the rainfall intensity, the more obvious decline the slope safety factor.

Response of Soil Suction to Heavy Rainfalls in a Tailings Dam

2011 ◽  
Vol 250-253 ◽  
pp. 1681-1685 ◽  
Author(s):  
Rui Chen ◽  
Ben Zhuo Zhang ◽  
Wei Dong Lei ◽  
Wen Bin Luo
Keyword(s):  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shallow Landslide ◽  
Rainfall Infiltration ◽  
Tailings Dam ◽  
Wetting Front ◽  
Tailings Dams ◽  
The Impact ◽  
Heavy Rainfalls

Rainfall is a significant factor leading to failure of tailings dams. The impact of rainfall on the instability of dams is mainly reflected in the variation of negative pore-water pressure (i.e. matric suction) during rainfall infiltration. However, there is a lack of study on the effects of rainfall on suction in tailings dams. In this study, the response of suction to artificial heavy rainfalls in a tailings dam was investigated. The effects of rainfall intensity and surface vegetation conditions on the response of suction were studied. It is found that suctions at a certain depth in the tailing dam were kept constant until the wetting front reached this depth. Once suctions were altered, the values dropped rapidly. The magnitude of suction change generally decreased with depth. Rainfall infiltration mainly occurred above the depth of 40 to 80 cm when subjected to rainstorm and heavy rainstorms. Larger rainfall intensity leads to shorter response time and to larger depth affected by rainfall, implying that the tailings dam is more susceptible to shallow landslide failure under larger rainfall intensity. The existing vegetation increases infiltrability significantly and then produces an adverse effect on the stability of the tailings dam. On the other hand, it is observed that the presence of vegetation greatly prevented surface erodibility and then decreases the possibility of debris flow.

scholarly journals Rainfall Infiltration Process of a Rock Slope with Considering the Heterogeneity of Saturated Hydraulic Conductivity

2022 ◽  
Vol 9 ◽  
Author(s):  
Qingqing Zhang ◽  
Laigui Wang ◽  
Huabin Zhang
Keyword(s):  
Hydraulic Conductivity ◽  
Safety Factor ◽  
Rock Slope ◽  
Rainfall Intensity ◽  
Saturated Hydraulic Conductivity ◽  
Rainfall Infiltration ◽  
Infiltration Depth ◽  
Infiltration Process ◽  
Rainfall Duration ◽  
Unsaturated Seepage

In order to analyze the effects of rainfall events on the stability of an open-pit rock slope, with considering the spatial variability of saturated hydraulic conductivity, based on the unsaturated seepage theory and the random filed theory, modified functions of the unit saturation, the hydraulic conductivity (k), and the shear strength parameters are established for unsaturated slope, by using FISH and the non-intrusive stochastic method. A saturated-unsaturated seepage random field model is proposed. And then the impacts of the rainfall intensity, the rainfall duration, and the spatial variability of saturated hydraulic conductivity (ks) on the infiltration process and stability of the unsaturated rock slope are analyzed. The results show that the proposed model can estimate rainfall infiltration of rock slope accurately. Rainfall mainly affects the seepage field in the shallow layer of the slope, where a transient saturated zone can be formed. With the development of the rainfall duration, the weight of the rock mass increased, the matric suction reduced, the negative pore pressure, the degree of saturation, and the infiltration depth of the rock slope increased, and the water in the slope root connects with the initial water table gradually, the unsaturated zone shrinks, which causes the safety factor of the model decreases, but the trend of change slows down gradually. As the rainfall intensity strengthened, the infiltration depth increased and the safety factor of the slope reduced, while the changing rate increases first and then decreases. Increasing the correlation length of k can reduces the infiltration depth and safety factor of the slope. Increasing the variation coefficient of k will increase the infiltration depth, while the safety factor of the slope decreases. The infiltration depth and safety factor of the slope are most affected by rainfall duration, but its sensitivity to the variability coefficient of k will be strengthened when the rainfall intensity exceeds the infiltration capacity. This conclusion can provide reference significance for the risk estimation of slope geological hazards, which are induced by the rainfall infiltration.

scholarly journals A Coupled Thermal-Hydraulic-Mechanical Nonlinear Model for Fault Water Inrush

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 120 ◽  
Author(s):  
Weitao Liu ◽  
Jiyuan Zhao ◽  
Ruiai Nie ◽  
Yuben Liu ◽  
Yanhui Du
Keyword(s):  
Numerical Simulation ◽  
Fault Zone ◽  
Water Flow ◽  
Water Inrush ◽  
Great Influence ◽  
Simulation Method ◽  
Coupling Model ◽  
Flow Equation ◽  
Nonlinear Flow ◽  
Flow Process

A coupled thermal-nonlinear hydraulic-mechanical (THM) model for fault water inrush was carried out in this paper to study the water-rock-temperature interactions and predict the fault water inrush. First, the governing equations of the coupled THM model were established by coupling the particle transport equation, nonlinear flow equation, mechanical equation, and the heat transfer equation. Second, by setting different boundary conditions, the mechanical model, nonlinear hydraulic-mechanical (HM) coupling model, and the thermal-nonlinear hydraulic-mechanical (THM) coupling model were established, respectively. Finally, a numerical simulation of these models was established by using COMSOL Multiphysics. Results indicate that the nonlinear water flow equation could describe the nonlinear water flow process in the fractured zone of the fault. The mining stress and the water velocity had a great influence on the temperature of the fault zone. The temperature change of the fault zone can reflect the change of the seepage field in the fault and confined aquifer. This coupled THM model can provide a numerical simulation method to describe the coupled process of complex geological systems, which can be used to predict the fault water inrush induced by coal mining activities.

A novel fluid–solid coupling model for the oil–water flow in the natural fractured reservoirs

2021 ◽  
Vol 33 (3) ◽  
pp. 036601
Author(s):  
Dongxu Zhang ◽  
Liehui Zhang ◽  
Huiying Tang ◽  
Shuwu Yuan ◽  
Hui Wang ◽  
...  
Keyword(s):  
Water Flow ◽  
Fractured Reservoirs ◽  
Coupling Model ◽  
Oil Water

scholarly journals Numerical simulation of three-dimensional velocity fields in pressurized and non-pressurized Nye channels

2003 ◽  
Vol 37 ◽  
pp. 281-285 ◽  
Author(s):  
Paul D. Bates ◽  
Martin J. Siegert ◽  
Victoria Lee ◽  
Bryn P. Hubbard ◽  
Peter W. Nienow
Keyword(s):  
Water Flow ◽  
Water Pressure ◽  
Three Dimensional ◽  
Experimental Manipulation ◽  
Navier Stokes ◽  
Ice Dynamics ◽  
Theoretical Understanding ◽  
Water Flow Velocity ◽  
Hydraulic Behaviour ◽  
Strong Control

AbstractChannels incised into bedrock, or Nye channels, often form an important component of subglacial drainage at temperate glaciers, and their structure exerts control over patterns and rates of (a) channel erosion, (b) water flow-velocity and (c) water pressure. The latter, in turn, exerts a strong control over basal traction and, thus, ice dynamics. In order to investigate these controls, it is necessary to quantify detailed flow processes in subglacial Nye channels. However, it is effectively impossible to acquire such measurements from fully pressurized, subglacial channels. To solve this problem, we here apply a three-dimensional, finite-volume solution of the Reynolds averaged Navier– Stokes (RANS) equations with a one-equation mixing-length turbulence closure to simulate flow in a 3 m long section of an active Nye channel located in the immediate foreground of Glacier de Tsanfleuron, Switzerland. Numerical model output permits high-resolution visualization of water flow through the channel reach, and enables evaluation of the experimental manipulation of the pressure field adopted across the overlying ice lid. This yields an increased theoretical understanding of the hydraulic behaviour of Nye channels, and, in the future, of their effect on glacier drainage, geomorphology and ice dynamics.

Developing an in situ, hydromechanical coupling, true triaxial rock compression tester and investigating the deformation patterns of reservoir bank slopes

2021 ◽  
pp. qjegh2021-043
Author(s):  
Lei Fan ◽  
Meiwan Yu ◽  
Aiqing Wu ◽  
Yihu Zhang
Keyword(s):  
Coupling Effect ◽  
Water Pressure ◽  
Pressure Coefficient ◽  
Hydromechanical Coupling ◽  
Rock Interaction ◽  
True Triaxial ◽  
Rock Structure ◽  
Deformation Patterns

Interactions between water and rocks are the main factors affecting the deformation of rock masses on sloped banks by reservoir impoundment. The technology used in laboratory tests of water-rock interaction mechanisms cannot simulate the coupling of water, the rock structure and the initial stress environment. In this work, we develop an in situ hydromechanical true triaxial rock compression tester and apply it to investigate the coupling response of reservoir bank rocks to changing groundwater levels. The tester is composed of a sealed chamber, loader, reactor, and device for measuring deformation, which are all capable of withstanding high water pressures, and a high-precision servo controller. The maximum axial load, lateral load and water pressure are 12 000 kN, 3 000 kN and 3 MPa, respectively. The dimensions of the test specimens are 310 mm×310 mm×620 mm. The test specimens are grey-black basalts with well-developed cracks from the Xiluodu reservoir area. The results show that increasing water pressure promotes axial compression and lateral expansion, while decreasing water pressure causes axial expansion and lateral compression. A water pressure coefficient, K, is introduced as a measure of the hydromechanical coupling effect (expansion or compression) with changing groundwater level. A mechanical tester can be used to perform accurate field tests of the response of wet rocks to hydromechanical coupling. The test results provide new information about the deformation patterns of rock slopes in areas surrounding high dams and reservoirs.Thematic collection: This article is part of the Role of water in destabilizing slopes collection available at: https://www.lyellcollection.org/cc/Role-of-water-in-destabilizing-slopes

scholarly journals ANALISIS BANJIR KELURAHAN TANJUNG DUREN SELATAN

2020 ◽  
Vol 3 (3) ◽  
pp. 569
Author(s):  
Natanael Tadeus Sutanto ◽  
Wati Asriningsih Pranoto
Keyword(s):  
Water Resources ◽  
Natural Disasters ◽  
Water Flow ◽  
Channel Capacity ◽  
Rainfall Intensity ◽  
Chi Square ◽  
Channel Condition ◽  
Direct Measurements ◽  
Kolmogorov Smirnov ◽  
City Water

Flood is one of the natural disasters that occur due to various factors and causes many losses. Tanjung Duren Selatan village was recorded as having floods in January 2020. This research aims to determine the causes of the flood in the area as well as the solution. The data obtained were taken from BMKG, West Jakarta City Water Resources Department, and direct measurements in the review area. This research analyzed rainfall, channel capacity, channel condition dan topography in Tanjung Duren Selatan village. Rainfall is tested for data compatibility using Chi-Square and Kolmogorov-Smirnov methods. Rainfall intensity is calculated using the Mononobe formula. The capacity of the existing channels is analyzed using Manning formula that will be compared with the planned discharge calculated using Rasional method. The analysis included secondary channels and tertiary channels, based on the calculation of 8 of the 48 channels reviewed that were unable to accommodate the planned discharge. After the analysis, it can be concluded that the flooding in Tanjung Duren Selatan village was caused by the lack of existing channel capacity, contours, and rubbish that blocked the water flow. Floods that occurred on January 1, 2020 due to rainfall that occurred exceeded the planned rainfall.ABSTRAKBanjir merupakan salah satu bencana alam yang terjadi akibat berbagai faktor dan menimbulkan banyak kerugian. Di Kelurahan Tanjung Duren Selatan tercatat mengalami banjir pada bulan Januari 2020. Penelitian ini bertujuan untuk mengetahui faktor penyebab terjadinya banjir pada daerah tersebut serta solusinya. Data-data yang didapat diambil dari BMKG, Suku Dinas Sumber Daya Air Kota Jakarta Barat, serta pengukuran langsung di daerah tinjauan. Pada penelitian ini dianalisis curah hujan, kapasitas saluran, kondisi saluran, serta topografi di Kelurahan Tanjung Duren Selatan. Curah hujan di uji kecocokan datanya menggunakan metode Chi-Square dan Kolmogorov-Smirnov. Intensitas curah hujan di hitung menggunakan rumus Mononobe. Kapasitas saluran eksisting di analisis menggunakan rumus Manning yang akan dibandingkan dengan debit rencana yang dihitung menggunakan metode Rasional. Analisis yang dilakukan mencakup saluran sekunder dan saluran tersier, berdasarkan perhitungan 8 dari 48 saluran yang ditinjau tidak mampu menampung debit rencana. Setelah analisis dilakukan dapat disimpulkan bahwa banjir di Kelurahan Tanjung Duren Selatan disebabkan oleh kurangnya kapasitas saluran eksisting, kontur, serta sampah yang menghalangi aliran air. Banjir yang terjadi pada tanggal 1 Januari 2020 dikarenakan curah hujan yang terjadi melebihi curah hujan rencana.

Sign in / Sign up

Export Citation Format

Share Document