scholarly journals Seepage Failure Mechanism of the Gouhou Rockfill Dam During Reservoir Water Infiltration

2006 ◽  
Vol 46 (5) ◽  
pp. 557-568 ◽  
Author(s):  
L.M. Zhang ◽  
Qun Chen
Keyword(s):  
Failure Mechanism ◽  
Water Infiltration ◽  
Reservoir Water ◽  
Seepage Failure ◽  
Rockfill Dam

Three-dimensional analysis of water infiltration into the Gouhou rockfill dam using saturated–unsaturated seepage theory

2006 ◽  
Vol 43 (5) ◽  
pp. 449-461 ◽  
Author(s):  
Qun Chen ◽  
L M Zhang
Keyword(s):  
Three Dimensional ◽  
Water Infiltration ◽  
Internal Erosion ◽  
Seepage Water ◽  
Two Dimensional ◽  
Material Anisotropy ◽  
Seepage Failure ◽  
Rockfill Dam ◽  
Seepage Theory ◽  
Unsaturated Seepage

The Gouhou Dam was a concrete-faced rockfill dam built in a steep canyon that collapsed in 1993 due to internal erosion during the initial reservoir filling. In this paper, the process of water infiltration into the originally unsaturated rockfill dam is studied using three-dimensional saturated–unsaturated seepage theory. The three-dimensional characteristics of seepage through the dam bounded by steep abutments, the effect of material anisotropy, and the effect of rockfill stratifications are studied. The three-dimensional results are compared with those from two-dimensional analyses. The three-dimensional simulations show that seepage water flows faster and the hydraulic gradients are greater near the abutment boundary in the dam. As such, the evolution of the seepage failure in the three-dimensional cases is faster than that in the two-dimensional analyses, and the two-dimensional analyses will underestimate the risk of seepage failure, particularly near the abutment boundary. If the materials in the dam were uniform, the reservoir water would infiltrate into the dam along a downward flow path towards the riverbed, and not exit from the surface on the downstream slope. Increasing the horizontal coefficient of permeability of the rockfill increases the infiltration velocity, but the material anisotropy does not appreciably change the infiltration pattern. Stratifications in the rockfill, however, cause the seepage water to advance more quickly in the horizontal direction along the interface between the sandwich layer and the rockfill, thus increasing the possibility of seepage failure.Key words: seepage, seepage failure, rockfill dam, unsaturated soils, wetting front, numerical analysis.

scholarly journals Shear Stress Analysis and Crack Prevention Measures for a Concrete-Face Rockfill Dam, Advanced Construction of a First-Stage Face Slab, and a First-Stage Face Slab in Advanced Reservoir Water Storage

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Kongzhong Hu ◽  
Jiankang Chen ◽  
Dong Wang
Keyword(s):  
Shear Stress ◽  
Internal Stress ◽  
Water Storage ◽  
Water Levels ◽  
Power Station ◽  
Reservoir Water ◽  
Second Stage ◽  
Rockfill Dam ◽  
Concrete Face ◽  
Concrete Face Rockfill Dam

Due to the demand in flood season for power generation, the first-stage face slab of a high concrete-face rockfill dam often must be constructed ahead of schedule, and advanced water storage is needed for the reservoir. Since the dam-body filling has not yet been completed at this point, the internal stress of the first-stage face slab is more complicated than that of normal construction. Taking Buxi Power Station as an example, the first-stage face slab temporary construction seam showed large areas of shear stress damage during the rise in reservoir water levels during the second segment of the second construction stage. The concrete-face slab showed large-piece brittle bulging, and the steel rebar was exposed and developed contortional deformation. Based on the monitoring data for Buxi Power Station along with the first-stage fracture characteristics of Shuibuya concrete face, this paper applied a numerical analysis to conduct research on the causes of fracture mechanics. The results indicate that the cracks occurred on the face slab during the second segment of second-stage water storage primarily due to the advanced concrete pouring of the first-stage face slab; during the first stage of reservoir water storage, the internal stress of the first-stage face slab was not reduced or eliminated prior to second-stage face slab pouring. Thus, with the rise in the reservoir water level, the shear stress increased continuously, eventually leading to partial large-scale shear stress failure of the first-stage face slab. The research results provide important references for the design and construction of concrete-face rockfill dams.

scholarly journals STRATEGI PENGELOLAAN HUTAN KOTA WADUK SUNTER UTARA DALAM RANGKA MEMPERTAHANKAN FUNGSI WADUK SEBAGAI RESAPAN AIR

2017 ◽  
Vol 6 (1) ◽  
pp. 51
Author(s):  
Sri Rahayu Maykewati
Keyword(s):  
Forest Management ◽  
Swot Analysis ◽  
Urban Forest ◽  
Group Discussion ◽  
Stakeholder Analysis ◽  
Water Infiltration ◽  
Reservoir Water ◽  
The North ◽  
Future Expectation ◽  
Internal And External Factors

Forest of North Sunter Reservoir is one of the urban forest that has been determined by Decree of Jakarta Governor No.317 Year 1999 about Sunter North Road Forest Size Establishment +2,2 ha as jungle city forest in North Jakarta Municipality. This study aims to find out how the strategy of Forest Management of North Sunter Reservoir City that can be applied, how the role of stakeholders in management, internal and external factors what, what solution has been done and how the success and what the future expectation. The method used is descriptive qualitative approach. Data collection techniques and procedures used are: (1) Observation; (2) Interviews; (3) Documents; (4) FGD (Focus Group Discussion). The analysis was conducted using environmental analysis, stakeholder analysis, SWOT analysis (Strength Weakness Opportunity Treath) and QSPM (Quantitative Strategic Planning Matrix) analysis.The North Sunter City Forest Management Strategy can be implemented with the collaboration of relevant stakeholders, it is expected to increase the benefit value of its strengths and opportunities, and can minimize the value of weaknesses and threats, so that the North Sunter Reservoir Forest can function optimally and can maintain the function of the reservoir water infiltration.

scholarly journals Fluctuation Effect of Reservoir Water Level on the Seepage of Earth-Fill Dam

2021 ◽  
Vol 9 (6) ◽  
pp. 11-19
Author(s):  
R. Asmaranto ◽  
D. Sisinggih ◽  
R.N.A Rastanto
Keyword(s):  
Water Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Levels ◽  
Water Infiltration ◽  
Seepage Discharge ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Critical Discharge ◽  
Earth Fill

Lots of dam failures are the result of uncontrolled seepage. The collapse of the Situ Gintung Dam in Tangerang, Banten-Indonesia in 2009 due to heavy rains caused the dam structure to collapse. This is due to increased pore water pressure in the landfill. To anticipate collapse due to uncontrolled seepage, it is necessary to monitor it based on the behavior of changes in rainfall and reservoir water levels. Seepage within the dam body is often monitored using instrumentation tools such as standpipe piezometer (standpipe piezometer) or electric piezometer. But often the piezometer cannot work properly because it is clogged, so it cannot monitor the condition of the seepage. Other instrumentations such as V-Notch are also used to measure seepage discharge. This study aims to determine the behavior of changes in the reservoir water level caused by changes in rainfall and its effect on body seepage of the earth-fill Type dam. By knowing the phenomenon of the behavior of the relationship between reservoir water infiltration and rainfall, it will obtain information on rainfall that endangers the dam which will affect the downstream. In this study, a case study of the Selorejo Dam was taken which has a large enough reservoir capacity of about 31 million m3 which is included in the Brantas River Basin. The results showed that 5 piezometers devices were damaged (SL 1, SL 2, SL 4, SL 6, and SL 7) where they could not read the phreatic water level properly, and 2 piezometers were less sensitive to reading fluctuations in reservoir water levels. namely SL 10 and SL 11 which showed R2 values of 29.78% and 39.4%, respectively. While the maximum seepage discharge is recorded at 1474 liters/minute, this is still below the critical discharge of 1630 liters/minute allowed for this dam, but this needs to be a concern, especially the discharge from toe drain from the left side seepage and C-area which is the leakage from the left support pedestal also contributes a larger discharge than other observation points.

Mechanisms of massive failure for flowthrough rockfill embankments

1995 ◽  
Vol 32 (6) ◽  
pp. 927-938 ◽  
Author(s):  
Vinod K. Garga ◽  
David Hansen ◽  
D. Ronald Townsend
Keyword(s):  
Key Words ◽  
Failure Mechanism ◽  
Slope Failure ◽  
Darcy Flow ◽  
Experimental Measurements ◽  
Embankment Slope ◽  
Rockfill Dam ◽  
Downstream Slope ◽  
The Stability ◽  
Rotational Failure

A modified wedge method for the analysis of the stability of a downstream slope of a flowthrough rockfill dam is presented. The results from this wedge analysis are compared with results from a conventional Bishop method of analysis, and both are compared with experimental measurements of the forces at incipient failure from model tests performed on simple granular embankments in hydraulic flumes. The proposed wedge method, based on a nonrotational failure mechanism, compared more favourably with experimental observations than did the Bishop method of analysis, based on a rotational failure mechanism. It is also concluded that the Bishop method is very conservative for the analysis of such rockfill slopes. Key words : rockfill embankment, slope failure, bursting forces, model slopes, non-Darcy flow.

scholarly journals Hubungan antara Elevasi Muka Air Waduk dan Panjang Lintasan Rembesan Terhadap Debit Rembesan pada Bendungan Urugan Batu Inti Tegak

2019 ◽  
Vol 10 (2) ◽  
Author(s):  
Siswanto Siswanto ◽  
Suprapto Suprapto ◽  
Sri Sangkawati Sachro
Keyword(s):  
Permeability Coefficient ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
The Core ◽  
Basic Model ◽  
Rockfill Dam ◽  
Drainage Design ◽  
Homogeneous Soil ◽  
The Relationship ◽  
Core Rockfill Dam

Rockfill dams have better stability than homogeneous soil dams. It allows to design the dam more slim with a higher slope. The disadvantage of rockfill dam is in the core zone as an impermeable zone. Zoned vertical core rockfill dam is a combination of various material properties. Geometry and drainage design will affect the seepage and phreatic line properties that occur. Numerical modeling and calculations are used to calculate the seepage profile more accurately. The combination of the parameters of the permeability coefficient (K), reservoir water level (Δh) and the length of the seepage path (L) can be used to determine the relationship between parameters with the same unit. 2D modeling take into account saturated/unsaturated conditions with steady state on each parameter. This study uses the Jatibarang-Indonesia dam as a basic model. The seepage profile at condition K1 (k = 1x10-5cm/sec) is q/k = -0.0018 (h2/L)2 + 1.3496h2/L + 53.241 and the seepage profile K2 (k=1x10-7cm/s) is q/k = -0.1521 (h2/L)2 + 90.402h2/L + 5480.2. This equations can be used to estimate seepage that occurs in a dam of other rock fill zoned vertical core dam based on the permeability coefficient value (K) more practically for all values of Δh and L reviewed.Keywords: Seepage, Rockfill Dam, Permeability, FEM, Numerical Analysis

scholarly journals Failure Mechanism of the Qianjiangping Slope in Three Gorges Reservoir Area, China

Geofluids ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Zhenhua Zhang ◽  
Mingming Qian ◽  
Song Wei ◽  
Juxiang Chen
Keyword(s):  
Failure Mechanism ◽  
Three Gorges Reservoir ◽  
Slope Failure ◽  
Combined Effect ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Reservoir Water ◽  
Reservoir Impoundment ◽  
Study Results ◽  
Influence Degree

The Qianjiangping landslide is the first large-scale rock slide in Three Gorges Reservoir (TGR) Area, China, after the impoundment of the TGR. Previous studies on the slope showed that most researchers agreed that reservoir impoundment and rainfall were the two main triggering factors of the slope failure. However, there were different views about the influence degrees of the two factors on the slope failure. In order to clarify the influence degrees of each of three conditions (reservoir impoundment, rainfall, and combined effect of reservoir impoundment and rainfall) on the failure of the Qianjiangping slope and reveal the failure mechanism of the slope, underground water tables and stresses in the slope were calculated under the three conditions, respectively, based on fluid-solid coupling theory using the Abaqus software in this paper; then, the failure approach index (FAI) was adopted to analyze the failure characteristics of the slope under each of the three conditions. Research results show that the influence degree of rainfall is greater than that of reservoir impoundment on the slope failure, and the influence degree of the combined effect of reservoir impoundment and rainfall is greater than that of rainfall; the sliding surface runs through only in the condition of the combined effect of reservoir impoundment and rainfall. Study results suggest that with the reservoir water level rising, the toe of the slope was gradually submerged in reservoir water and the strength of rock mass submerged by reservoir water decreased due to water-rock interaction; furthermore, the heavy rainfall was rapidly injected into the slope through the interlayer staggered zone and slope surface, the groundwater table in the middle part of the slope rose rapidly, the sliding force of the slope increased, and the stress concentration appeared at the lower part of the slope; finally, the rock bridges submerged by reservoir water in the front of the slope fractured, and the failure of the slope occurred.

scholarly journals Experimental investigation on the deformation and failure mechanism of slope with interbedding soft and hard rocks under rainfall infiltration

2020 ◽  
Vol 194 ◽  
pp. 04056
Author(s):  
Yafen Song ◽  
Li Chen ◽  
Xiaotao Zhang ◽  
Qian Zhao ◽  
Linlin Yu ◽  
...  
Keyword(s):  
Failure Mechanism ◽  
Hard Rock ◽  
Similarity Theory ◽  
Soft Rock ◽  
Deformation Mode ◽  
Rainfall Infiltration ◽  
Water Infiltration ◽  
Deformation And Failure ◽  
Hard Rocks ◽  
Softening Process

Taking Peng Jiawan slope in Yiba expressway as the project background, the deformation and failure mechanism of slope with interbedding of soft and hard rocks was studied on the basis of geological analysis and similarity theory. In geomechanical model test, the water infiltration softening process is used to simulate the rainfall infiltration. The result indications showed as follows: under the condition, the deformation mode of the slope is the previous sliding-tension and upper overall creep-slip, and the failure mode is overall slip failure in the sliding zone of deep soft rock. Strictly speaking, the deformation of hard rock differs from the deformation of soft rock, hard rock deforms mainly on sliding-tension and soft rock deforms mainly on overall creep-slippage. Changes of the condition of deep soft rock affect the total stability of the interbedded slope mostly.

scholarly journals Estimasi dan Evaluasi Debit Rembesan pada Bendungan Urugan Batu Zonal Inti Tegak

2019 ◽  
Vol 4 (2) ◽  
pp. 53
Author(s):  
Siswanto Siswanto ◽  
Suprapto Suprapto ◽  
Sri Sangkawati Sachro
Keyword(s):  
Finite Element ◽  
Water Level ◽  
Complex Geometry ◽  
Coefficient Of Determination ◽  
Seepage Discharge ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Discharge Data ◽  
Linear Pattern ◽  
Rockfill Dam

Bendungan urugan batu zonal inti tegak mempunyai geometri yang lebih kompleks dibandingkan dengan bendungan tanah homogen. Banyaknya bentuk geometri dan material yang digunakan menyebabkan prediksi dan perhitungan yang lebih rumit. Pemodelan finite element (FEM) sering digunakan untuk menghitung perilaku rembesan yang terjadi. Tujuan dari penelitian ini adalah untuk mendapatkan model numeris yang dapat digunakan sebagai estimasi debit rembesan sekaligus sebagai validasi pemodelan rembesan pada bendungan urugan batu inti tegak. Evaluasi debit berdasarkan pengukuran instrumen diperlukan untuk validasi pemodelan numeris yang dilakukan. Hukum Darcy dan Casagrande dapat digunakan untuk mengevaluasi pola debit terukur. Debit rembesan berbanding lurus dengan ketinggian muka air waduk dan berbanding terbalik dengan panjang lintasan rembesan. Metode statistik dan regresi digunakan untuk mendapatkan pola rembesan berdasarkan akuisisi data rembesan melalui V-Notch. Estimasi dan pola rembesan ini penting untuk diketahui, sehubungan dengan kinerja electronic instrument yang berpotensi mengalami kerusakan dan sulitnya akses pada gallery karena suatu keadaan. Studi kasus pada paper ini dilakukan pada Bendungan Jatibarang (Semarang), dimana bendungan ini mulai beroperasi penuh pada tahun 2015. Inkonsistensi data debit rembesan terjadi sampai dengan 3 tahun setelah penggenangan bendungan dilakukan. Pola linier hubungan debit rembesan (q) berdasarkan ketinggian muka air waduk (h) yaitu q = 0.5221h - 68.958. Koefisien determinasi pada model tersebut sebesar 78.5%, nilai ini mengindikasikan bahwa model tersebut sudah cukup baik untuk digunakan. Pendekatan ini dapat digunakan sebagai validasi data pada semua jenis pemodelan sesuai dengan tujuan pemodelan tersebut akan dilakukan. Kata Kunci : rembesan; bendungan urugan batu; v-notch ABSTRACTVertical zoned rockfill dam has a more complex geometry compared to a homogeneous earthfill dam. The many geometric shapes and materials used to cause more complex predictions and calculations. Finite element (FEM) modeling is often used to calculate seepage behavior. The purpose of this study is to obtain a numerical model that can be used to estimate of seepage discharge and as validation of seepage modeling on zoned vertical rockfill dam. Seepage evaluation based on instrument measurements is needed for validation of numerical modeling performed. Darcy's and Casagrande's Law can be used to evaluate the measured discharge pattern. The seepage discharge is directly proportional to the height of the reservoir water level and inversely proportional to the length of the seepage path. Statistical and regression methods are used to obtain the seepage pattern based on seepage data acquisition using V-Notch. Estimation and seepage pattern is important to know due to the performance of electronic instruments that have apotential damage and difficult access to the gallery. The case study in this paper was carried out at the Jatibarang Dam (Semarang), where the dam began full operation in 2015. The inconsistency of seepage discharge data occurred up to 3 years after the impounding of the dam. The linear pattern of seepage discharge relationship (q) based on reservoir water level (h) is q = 0.5221h - 68.958. The coefficient of determination in the model is 78.5%, this value indicates that the model is good enough to be used. This approach can be used for data validation on all types of modeling in accordance with the purpose of the modeling will be carried out.

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