scholarly journals Analisis Stabilitas Lereng Menggunakan Model Numerik 3 Dimensi Studi Kasus Lereng Sekolah Terpadu di Kecamatan Jonggol Bogor

Author(s):  
Desti Santi Pratiwi ◽  
Nirpan Lesmana ◽  
Indra Noer Hamdhan

<p class="BodyAbstract">Slope is the surface of the earth that forms an inclination angle, that it has the potential for landslides. Landslide will be occurred by several factors, such as steep slopes, large loads, high rain intensity, poor drainage systems, high ground water levels and others. Therefore, slope stability analysis is needed to ensured that the slopes are safe from landslides potential which injured many people. As for the prevention and handling of landslides that can be done, such as changing the geometry of the slopes, improving the drainage system, providing slope reinforcement such as gabions, retaining walls, poles and others. This study aims to determine the effect of water level on the stability of the existing slope and which has been reinforced by bored piles using a 3-dimensional numerical model. The case study reviewed is the slope in the Integrated School in Bendungan Village, Jonggol District, Bogor Regency. The results of the analysis show that in the existing conditions with a normal water level, the value of the safety factor (SF) is 1.16, and when the water level is critical, the SF value is 1.14. Whereas in slope conditions with the reinforcement of the bored pile, the analysis results show that the SF value with normal water level is 2.33 and when the water level is critical is 1.58. The results of the analysis with the reinforcement of the drill pile show that the SF value is more than 1.5 so that the slope is safe from landslide based on SNI 8460 of 2017.</p>

1997 ◽  
Vol 24 ◽  
pp. 288-292 ◽  
Author(s):  
Andrew P. Barrett ◽  
David N. Collins

Combined measurements of meltwater discharge from the portal and of water level in a borehole drilled to the bed of Findelengletscher, Switzerland, were obtained during the later part of the 1993 ablation season. A severe storm, lasting from 22 through 24 September, produced at least 130 mm of precipitation over the glacier, largely as rain. The combined hydrological records indicate periods during which the basal drainage system became constricted and water storage in the glacier increased, as well as phases of channel growth. During the storm, water pressure generally increased as water backed up in the drainage network. Abrupt, temporary falls in borehole water level were accompanied by pulses in portal discharge. On 24 September, whilst borehole water level continued to rise, water started to escape under pressure with a resultant increase in discharge. As the drainage network expanded, a large amount of debris was flushed from a wide area of the bed. Progressive growth in channel capacity as discharge increased enabled stored water to drain and borehole water level to fall rapidly. Possible relationships between observed borehole water levels and water pressures in subglacial channels are influenced by hydraulic conditions at the base of the hole, distance between the hole and a channel, and the nature of the substrate.


2020 ◽  
Vol 223 (2) ◽  
pp. 1288-1303
Author(s):  
K Strehlow ◽  
J Gottsmann ◽  
A Rust ◽  
S Hautmann ◽  
B Hemmings

Summary Aquifers are poroelastic bodies that respond to strain by changes in pore pressure. Crustal deformation due to volcanic processes induces pore pressure variations that are mirrored in well water levels. Here, we investigate water level changes in the Belham valley on Montserrat over the course of 2 yr (2004–2006). Using finite element analysis, we simulate crustal deformation due to different volcanic strain sources and the dynamic poroelastic aquifer response. While some additional hydrological drivers cannot be excluded, we suggest that a poroelastic strain response of the aquifer system in the Belham valley is a possible explanation for the observed water level changes. According to our simulations, the shallow Belham aquifer responds to a steadily increasing sediment load due to repeated lahar sedimentation in the valley with rising aquifer pressures. A wholesale dome collapse in May 2006 on the other hand induced dilatational strain and thereby a short-term water level drop in a deeper-seated aquifer, which caused groundwater leakage from the Belham aquifer and thereby induced a delayed water level fall in the wells. The system thus responded to both gradual and rapid transient strain associated with the eruption of Soufrière Hills Volcano (Montserrat). This case study gives field evidence for theoretical predictions on volcanic drivers behind hydrological transients, demonstrating the potential of hydrological data for volcano monitoring. Interrogation of such data can provide valuable constraints on stress evolution in volcanic systems and therefore complement other monitoring systems. The presented models and inferred results are conceptually applicable to volcanic areas worldwide.


1997 ◽  
Vol 24 ◽  
pp. 288-292 ◽  
Author(s):  
Andrew P. Barrett ◽  
David N. Collins

Combined measurements of meltwater discharge from the portal and of water level in a borehole drilled to the bed of Findelengletscher, Switzerland, were obtained during the later part of the 1993 ablation season. A severe storm, lasting from 22 through 24 September, produced at least 130 mm of precipitation over the glacier, largely as rain. The combined hydrological records indicate periods during which the basal drainage system became constricted and water storage in the glacier increased, as well as phases of channel growth. During the storm, water pressure generally increased as water backed up in the drainage network. Abrupt, temporary falls in borehole water level were accompanied by pulses in portal discharge. On 24 September, whilst borehole water level continued to rise, water started to escape under pressure with a resultant increase in discharge. As the drainage network expanded, a large amount of debris was flushed from a wide area of the bed. Progressive growth in channel capacity as discharge increased enabled stored water to drain and borehole water level to fall rapidly. Possible relationships between observed borehole water levels and water pressures in subglacial channels are influenced by hydraulic conditions at the base of the hole, distance between the hole and a channel, and the nature of the substrate.


2013 ◽  
Vol 16 (1) ◽  
pp. 218-230 ◽  
Author(s):  
Gooyong Lee ◽  
Sangeun Lee ◽  
Heekyung Park

This paper proposes a practical approach of a neuro-genetic algorithm to enhance its capability of predicting water levels of rivers. Its practicality has three attributes: (1) to easily develop a model with a neuro-genetic algorithm; (2) to verify the model at various predicting points with different conditions; and (3) to provide information for making urgent decisions on the operation of river infrastructure. The authors build an artificial neural network model coupled with the genetic algorithm (often called a hybrid neuro-genetic algorithm), and then apply the model to predict water levels at 15 points of four major rivers in Korea. This case study demonstrates that the approach can be highly compatible with the real river situations, such as hydrological disturbances and water infrastructure under emergencies. Therefore, proper adoption of this approach into a river management system certainly improves the adaptive capacity of the system.


2020 ◽  
Vol 33 (02) ◽  
pp. 737-745
Author(s):  
Amir Behshad

Installation and monitoring of instrumentation is one of the practical methods for controlling safety and stability of earth dams. Piezometers existing in dam body and dam abutments are one of the various types of precision instruments used in dams, which indicate the height of water level in different parts of the dam. In order to evaluate the performance of piezometers of Shah Qasim Dam in Kohgiluyeh and Boyerahmad province (in south east of Iran), we compare water level changes in piezometer and water level changes in the dam lake over time. In this paper, the above mentioned dam is modelled using the SEEP/W software, then after imposing boundary conditions, water levels are computed at various points. For more accurate comparison, water level changes are plotted in transverse and longitudinal piezometers over time. The results of analysis indicate significant increase of permeability in vicinity of some piezometers. The piezometers BX4, BX14, BX13 and SP6, and the region near them, as well as piezometers SP24 and SP18 and their surrounding area, have critical conditions which should be inspected as soon as possible.


2021 ◽  
Vol 10 (1) ◽  
pp. 1-8
Author(s):  
Dyah Pratiwi Kusumastuti ◽  
Husna Alghoida

Abstract Dams have many benefits such as irrigation, flood prevention, power generation and even tourism, especially in areas where the dam is located. So that the benefits received can last a long time, in the planning, it must be analyzed for stability, seepage discharge that occurs and the safety of the piping. The piping hazard safety figures in this study were calculated using the Harza method for maximum water level conditions, normal water levels, fast receding and empty dams at sta 0 + 150, sta 0 + 200, sta 0 + 250 and sta 0 + 300. Based on the calculation results, it is found that the safety of piping hazards without filters with the grouting method do not meet the requirements safety factor, especially in conditions of maximum water level, normal water level and fast receding. In order for the safety of piping hazard in order to meet the requirements, a filter is applied under the dams. The filter is applied so that the piping hazard safety figure meets the requirements of all water level conditions and all station is 80 cm deep.   Keywords: safety factor, piping, Harza method, filter   ABSTRAK Bendungan memiliki banyak manfaat seperti irigasi, pencegah banjir, pembangkit listrik bahkan pariwisata khususnya pada wilayah dimana bendungan tersebut berada. Agar manfaat yang diterima dapat berlangsung lama maka dalam perencanaannya wajib dianalisis terhadap stabilitas, debit rembesan yang terjadi maupun keamanan dari piping. Angka keamanan bahaya piping pada penelitian ini dihitung dengan menggunakan metode Harza untuk kondisi muka air maksimum, muka air normal, surut cepat dan bendungan kosong di sta 0+150, sta 0+200, sta 0+250 serta sta 0+300. Berdasarkan hasil perhitungan didapatkan bahwa angka keamanan bahaya piping tanpa penggunaan filter dengan metode grouting tidak memenuhi persyaratan angka keamanan khususnya pada kondisi muka air maksimum, muka air normal dan surut cepat. Agar angka keamanan bahaya piping memenuhi persyaratan maka diaplikasikan filter dibawah tubuh bendungan. Filter yang diaplikasikan agar angka keamanan bahaya piping memenuhi persyaratan diseluruh kondisi muka air dan seluruh sta adalah dengan kedalaman 80 cm.   Kata kunci: angka keamanan, piping, metode Harza, filter Abstract Dams have many benefits such as irrigation, flood prevention, power generation and even tourism, especially in areas where the dam is located. So that the benefits received can last a long time, in the planning, it must be analyzed for stability, seepage discharge that occurs and the safety of the piping. The piping hazard safety figures in this study were calculated using the Harza method for maximum water level conditions, normal water levels, fast receding and empty dams at sta 0 + 150, sta 0 + 200, sta 0 + 250 and sta 0 + 300. Based on the calculation results, it is found that the safety of piping hazards without filters with the grouting method do not meet the requirements safety factor, especially in conditions of maximum water level, normal water level and fast receding. In order for the safety of piping hazard in order to meet the requirements, a filter is applied under the dams. The filter is applied so that the piping hazard safety figure meets the requirements of all water level conditions and all station is 80 cm deep.   Keywords: safety factor, piping, Harza method, filter   ABSTRAK Bendungan memiliki banyak manfaat seperti irigasi, pencegah banjir, pembangkit listrik bahkan pariwisata khususnya pada wilayah dimana bendungan tersebut berada. Agar manfaat yang diterima dapat berlangsung lama maka dalam perencanaannya wajib dianalisis terhadap stabilitas, debit rembesan yang terjadi maupun keamanan dari piping. Angka keamanan bahaya piping pada penelitian ini dihitung dengan menggunakan metode Harza untuk kondisi muka air maksimum, muka air normal, surut cepat dan bendungan kosong di sta 0+150, sta 0+200, sta 0+250 serta sta 0+300. Berdasarkan hasil perhitungan didapatkan bahwa angka keamanan bahaya piping tanpa penggunaan filter dengan metode grouting tidak memenuhi persyaratan angka keamanan khususnya pada kondisi muka air maksimum, muka air normal dan surut cepat. Agar angka keamanan bahaya piping memenuhi persyaratan maka diaplikasikan filter dibawah tubuh bendungan. Filter yang diaplikasikan agar angka keamanan bahaya piping memenuhi persyaratan diseluruh kondisi muka air dan seluruh sta adalah dengan kedalaman 80 cm.   Kata kunci: angka keamanan, piping, metode Harza, filter


2016 ◽  
Vol 47 (S1) ◽  
pp. 69-83 ◽  
Author(s):  
Bing Li ◽  
Guishan Yang ◽  
Rongrong Wan ◽  
Xue Dai ◽  
Yanhui Zhang

Modeling of hydrological time series is essential for sustainable development and management of lake water resources. This study aims to develop an efficient model for forecasting lake water level variations, exemplified by the Poyang Lake (China) case study. A random forests (RF) model was first applied and compared with artificial neural networks, support vector regression, and a linear model. Three scenarios were adopted to investigate the effect of time lag and previous water levels as model inputs for real-time forecasting. Variable importance was then analyzed to evaluate the influence of each predictor for water level variations. Results indicated that the RF model exhibits the best performance for daily forecasting in terms of root mean square error (RMSE) and coefficient of determination (R2). Moreover, the highest accuracy was achieved using discharge series at 4-day-ahead and the average water level over the previous week as model inputs, with an average RMSE of 0.25 m for five stations within the lake. In addition, the previous water level was the most efficient predictor for water level forecasting, followed by discharge from the Yangtze River. Based on the performance of the soft computing methods, RF can be calibrated to provide information or simulation scenarios for water management and decision-making.


2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Wenchen Fan ◽  
Ping Cao ◽  
Ke Zhang ◽  
Kaihui Li ◽  
Chong Chen

Chengmenshan copper mine, located at Jiujiang city in the Jiangxi Province, is a rarely lakeside open-pit mine in China. Since the open-pit is very close to Sai Lake, the seasonally changed water level and the distance between lake and slope have great influence to the stability of open-pit slope. Based on the drill data and geological sections, a numerical model of the slope is built. With the fluid-mechanical interaction associated, the stability of the slopes is numerically analyzed, in which different lake water levels and lake-slope distances are taken into consideration. The comparative analysis shows that a larger lake-slope distance can promise better slope stability and weaken the sensitivity of slope stability to water. The stability of slopes with different heights is analyzed to find that the stability weakens and the sensitivity is enhanced with the height increasing. To the most serious situation, the slope height and the lake water level being 238 m and 17.2 m, respectively, theFsvalue equals 1.18945 which is extremely closed to the allowable safety factor of 1.20 for slope design. According to the minimumFsfor slope design, the minimum distance between lake and open-pit slope is found to be 60 m.


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