scholarly journals Interpretasi Instrumentasi Piezometer Dalam Rangka Pemantauan Keamanan Bendungan Kedung Ombo

2021 ◽  
Vol 7 (2) ◽  
pp. 131-145
Author(s):  
Gerald Guntur Pandapotan Siregar ◽  
Fajar aldoko Kurniawan
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Level Fluctuations ◽  
Embankment Dam ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Embankment Dams ◽  
The World ◽  
Earthfill Dams

The embankment dam is the most widely built dam in the world, especially in Indonesia. However, embankment dams are also prone to collapse. Dam failures due to the piping process through the dam body account for 30.5% of the total dam collapses worldwide. Therefore, it is necessary to periodically monitor and evaluate the condition of pore water pressure and seepage in a dam which is usually carried out using installed instrumentation. Very little has been done on instrumentation interpretation of earthfill dams in Indonesia, which is a very worrying condition. It is possible that old or even new dams have shown behavior that leads to a decrease in safety. This condition can be monitored by instrumentation in the dam if interpreted properly. Kedung Ombo Dam as an old embankment dam but has a fairly complete instrumentation can be evaluated for safety related to pore water pressure and phreatic line (seepage line). Pore water pressure evaluation is carried out by collecting piezometer readings and reservoir water level fluctuations over a period of several years. The results of the research on the interpretation of piezometer readings indicate that the overall safety of the Kedung Ombo dam is still good in terms of pore water pressure conditions. However, there are some anomalous conditions that should be investigated further

scholarly journals Influence of pore water pressure to seepage and stability of embankment dam (case study of Sermo Dam Yogyakarta, Indonesia)

2017 ◽  
Vol 101 ◽  
pp. 05007
Author(s):  
Undayani Cita Sari ◽  
Sri Prabandiyani Retno Wardani ◽  
Suharyanto ◽  
Windu Partono
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Embankment Dam

scholarly journals Evaluasi Tekanan Air Pori dan Rembesan Pada Bendungan Panohan

2019 ◽  
Vol 4 (2) ◽  
pp. 26
Author(s):  
Adib Lathiful Huda ◽  
Sri Prabandiyani Retno Wardani ◽  
Suharyanto Suharyanto
Keyword(s):  
Finite Element ◽  
Water Level ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
The Body ◽  
Reservoir Water ◽  
Planning Stage ◽  
Fem Method ◽  
Comparison Results

Salah satu penyebab kegagalan struktur bendungan adalah terjadinya rembesan yang dipicu oleh tingginya tekanan air pori yang terjadi pada tubuh bendungan. Pada Bendungan Panohan, kebocoran rembesan terjadi hingga memotong lereng hilir bendungan yang dapat mengganggu stabilitas tubuh bendungan. Tujuan dari penelitian ini adalah untuk mengevaluasi tekanan air pori dan rembesan di tubuh Bendungan Panohan menggunakan metode analisis instrumentasi piezometer dan v-notch yang kemudian dibandingkan dengan analisis metode elemen hingga (finite element method / FEM) menggunakan program perangkat lunak SEEP/W. Metode FEM menggunakan parameter desain material selama tahap perencanaan bendungan. Kedua analisis dilakukan pada section C - C Bendungan Panohan menggunakan beberapa variasi ketinggian muka air waduk. Hasil perbandingan menunjukkan bahwa nilai tekanan air pori dan rembesan pada metode FEM lebih besar dari hasil analisis dengan metode pembacaan instrumentasi pada kondisi muka air minimal dan normal. Kondisi sebaliknya terjadi pada kondisi ketinggian air banjir, yaitu nilai tekanan air pori dan rembesan dari pembacaan instrumentasi lebih besar dari hasil analisis metode FEM. Seiring dengan naiknya ketinggian muka air waduk, terjadi kenaikan nilai tekanan air pori dan rembesan dari kedua hasil analisis. Kondisi rembesan yang terjadi pada  Bendungan Panohan saat ini tidak aman pada kondisi muka air banjir, karena memiliki nilai debit rembesan 0,38 ltr/det melebihi dari yang disyaratkan yaitu sebesar 0,35 ltr/det.Kata kunci : bendungan panohan; tekanan air pori; rembesan; FEM ABSTRACTOne of the causes of the failure of a dam structure is the occurrence of seepage triggered by high pore water pressure that occurs in the body of the dam. In the Panohan Dam, seepage occurs on the downstream slope of the dam which can disturb the stability of the dam body. The purpose of this research is to evaluate the pore water pressure and seepage in the Panohan Dam body using the piezometer and v-notch instrumentation reading method which is then compared with the finite element (FEM) method using SEEP/W software program. FEM method uses material parameters during the dam planning stage. Both analyses were carried out on the C – C section of the Panohan Dam using several variations of reservoir water level. The comparison results show that pore water pressure in the FEM method is greater than the pore water pressure value based on the piezometer method at the minimum and normal water level conditions. The opposite condition occurs in maximum water level conditions. The seepage value of the v-notch reading is greater than the seepage value from the FEM method. Seepage that occurs in the Panohan Dam is currently unsafe under the maximal water level conditions.

scholarly journals Experimental and numerical study of upstream slope stability in an earth dam reservoir under rapid drawdown conditions

2020 ◽  
Vol 8 (1) ◽  
pp. 1-15
Author(s):  
Seyed Habib Mousavi Jahromi ◽  
Mansour Pakmanesh ◽  
Amir Khosrojerdi ◽  
Hossein Hassanpour Darvishi ◽  
Hossein Babazadeh
Keyword(s):  
Water Level ◽  
Pore Water Pressure ◽  
Numerical Study ◽  
Water Pressure ◽  
Earth Dam ◽  
Dam Reservoir ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Seepage Analysis ◽  
Upstream Slope

The rapid ‎drawdown of the dam reservoir is one of the most common situations occurring in the lifetime of a dam. For this reason, one of the main factors in the design of the upstream slope is the rapid drainage of the reservoir. In this case, the upstream slope is in a critical condition and the slope may be unstable. When the water surface in the reservoir is drawdown suddenly, the water level in the dam body does not decrease at the same time as the reservoir water level. The analysis of seepage from the earth dam body and calculation of the water loss play an important role in calculating the amount of pore water pressure, and, consequently, the stability analysis of the dam body. In addition, any seepage analysis is dependent on the hydraulic properties of the dam materials. In order to investigate the effect of hydraulic conductivity on the rapid drawdown of water level and the seepage, an experimental model was constructed of an earth dam. By accurate measurement of hydraulic parameters of the materials in saturated and unsaturated media, the flow through this model was modeled using a disk penetrometer by seep/w software. The results were then compared with the observed data.

scholarly journals ANALISIS STABILITAS TIMBUNAN (MAINDAM) BERDASARKAN DATA INSTRUMEN GEOTEKNIK PADA BENDUNGAN SINDANG HEULA SERANG BANTEN

2021 ◽  
Vol 3 (1) ◽  
pp. 48-58
Author(s):  
Nanang Sutisna ◽  
M. Ichwanul Yusup ◽  
Euis Amilia Euis Amilia
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Field Studies ◽  
Internal Erosion ◽  
Embankment Dam ◽  
Support Tool ◽  
The Core ◽  
Conducting Research ◽  
The Stability

The development of science and technology has obtained supporting technology for monitoring the soil shear force and pore water pressure in the dam, the presence of shear forces against the landfill and pore water pressure through small cavities in the embankment soil in the dam body which can be detected by equipment such as inclinometer and piezometer that have been installed at predetermined points. The application of inclinometer and piezometer technology is used as a support tool for monitoring the movement of landfill and pore water pressure against dams. The embankment dam is the most complex of civilian structures and is very dangerous if damaged. When there is damage to a dam, it will cause a big disaster for the areas that are downstream of the dam. Damage or collapse of a dam can occur due to several things, including overtopping, sliding of the dam slopes (internal erosion or "piping"), and the occurrence of structural degradation of each zone. on the dam body. In the analysis of the stability of the embankment (maindam) which is based on geotechnical instrument data, it must be carried out as carefully and accurately as possible. The purpose of this analysis is to measure the early damage in the main dam (maindam). After conducting research and field studies at the Sindang Heula dam, there were several points of decline at the top of the core embankment (maindam). To find out the cause of the decline, data was taken from measuring geotechnical instruments.

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.

Reliability Analysis for Effects of Reservoir Water Level Change on Embankment Dam

2007 ◽  
Vol 340-341 ◽  
pp. 1327-1332 ◽  
Author(s):  
Bo Han ◽  
Hong Jian Liao ◽  
Kyoji Sassa ◽  
Fa Wu Wang
Keyword(s):  
Water Level ◽  
Reliability Analysis ◽  
Unsaturated Soils ◽  
Soil Parameters ◽  
Embankment Dam ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Seepage Analysis ◽  
Embankment Dams ◽  
Unsaturated Seepage

This paper is mainly concerned with the saturated-unsaturated seepage analysis of embankment dams based on unsaturated soil theory and the reliability analysis of embankment dam based on conception of reliability. The transient seepage due to change of the water level is calculated using the finite element method based on unifying saturated-unsaturated seepage governing equations. The transient pore water pressures are then used for stability analyses of embankment dam considering the effects of suction on shear strength of unsaturated soils. Meanwhile, combined with reliability computation, the Monte-Carlo stimulation method is used to calculate the corresponding reliability index dealing with the stochastic features of soil parameters. The reliability of different water level condition of embankment dams has been analyzed. The effects of different reservoir water level drawdown and raise speeds on reliability of embankment dam are discussed.

scholarly journals Mechanical Properties of Sandstone Roof and Surrounding-Rock Control of Mining Roadways Subject to Reservoir Water Disturbance

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Bin Ma ◽  
Zaiqiang Hu ◽  
Xingzhou Chen ◽  
Lili Chen ◽  
Wei Du
Keyword(s):  
Crack Initiation ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Surrounding Rock ◽  
Water Inflow ◽  
Reservoir Water ◽  
Deformation And Failure ◽  
Joint Dislocations ◽  
Rock Structure

Sandstone-roofed roadways are susceptible to deformation and failure caused by reservoir-water-induced disturbances, thereby compromising human safety. Using rock-mechanics testing techniques, numerical simulations, and engineering principles, this study investigates the strength, deformation, and pore-structure characteristics of sandstone roofs as well as means to support the surrounding rock structure. The results obtained in this study reveal that the residual strain is proportional to the pore-water pressure, which, in turn, causes a significant reduction in the elastic modulus during the unloading phase. Furthermore, an increase in the pore-water pressure causes the shear failure of specimens in compression. The delay between crack initiation and specimen-volume expansion decreases. Moreover, the specimen demonstrates increased deformation and failure responses to changes in the confining pressure, thereby resulting in accelerated conversion. Changes in water inflow can be correlated to crack initiation, propagation, and fracture. This water inflow gradually increases with an increase in the osmotic pressure. Correspondingly, the volumetric strain required for maximum water inflow undergoes a gradual decrease. The increased water inflow can be considered a precursor to specimen failure. In addition, fractures in the surrounding rock structures are mainly caused by joint dislocations. The increase in pore pressure promotes the development of dislocation fractures in the deep surrounding rocks. Subsequently, these fractures overlap with their open counterparts to form large fractures; this increases the roadway-roof subsidence and layer separation of the shallow surrounding rocks, thereby further increasing the fracture count. Lastly, the use of high-performance rock bolts, cable-bolt reinforcements, and W-shaped steel bands is expected to ensure the stability of rocks surrounding sandstone-roofed roadways subject to water-pressure disturbances.

The Analysis about Seepage of the Bank Slope under the Cycle Rising and Drawdown of Reservoir Water Level

2013 ◽  
Vol 353-356 ◽  
pp. 112-115
Author(s):  
Xiao Wen Liu ◽  
Wen Wan ◽  
Xi Zhong Shen
Keyword(s):  
Water Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Bank Slope ◽  
Saturation Region ◽  
Distribution Laws ◽  
Seepage Theory ◽  
Stabilization Period

Bank slope seepage field is analyzed by saturated-unsaturated seepage theory under the three times cycle conditions of water level rising and drawdown . The pore water pressure distribution laws of the water level rising period, the stabilization period, the period of decline and decline stable period for every cycle are researched. The result shows soil near slope region is saturated easily after many rounds of water level rising and drawdown, and saturation region gradually increases. Soil phreatic line near slope falls fastly in the drawdown period, away from the slope, phreatic line declines slowly.

scholarly journals ANALISIS REMBESAN TERHADAP KEAMANAN BENDUNGAN KEDUNG OMBO DI GROBOGAN, JAWA TENGAH

2021 ◽  
Vol 12 (2) ◽  
pp. 79-92
Author(s):  
Rais Buldan ◽  
Suharyanto Suharyanto ◽  
Najib Najib ◽  
Kresno Wikan Sadono
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Good Condition ◽  
Condition Index ◽  
The Body ◽  
Embankment Dam ◽  
Safety Level ◽  
Human Needs ◽  
The Stability

A dam, besides having a great benefits to meet human needs, it also can be a big disaster in addition to the dam collapsing. One of the main causes of failure of an embankment dam is the occurrence of excessive seepage which triggers piping events that can disturb the stability and safety of the dam. In general, the body of the Kedung Ombo Dam is in good condition, but there are several problems, such as the drain holes that are overgrown with dense grass which indicates that seepage has occurred. Therefore, it is necessary to evaluate the seepage to determine the safety level of the Kedung Ombo Dam. This study aims to analyze the condition of pore water pressure and seepage that occurs in the body of the Kedung Ombo Dam and to determine the level of safety of the dam body. The analyze was carried out using seepage monitoring instruments installed on the dam, namely the Piezometer and V-Notch at the Kedung Ombo Dam in 2021. Based on the results of the analysis, it was found that the pore water pressure and seepage discharge that occurred in the Kedung Ombo Dam were generally still within the permissible limits. According to the analysis results of the seepage index, the highest QI value is 0.09 at the maximum flood water level of +95 m, where the safety criteria for the seepage index is QI <1. Therefore it indicates that the seepage condition index at the Kedung Ombo Dam are still in a safe condition.Keywords: pore water pressure, seepage, piezometer, V-Notch, seepage index 

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