scholarly journals Investigation and Monitoring of Groundwater Level: Building Crack Near to IIUM Kuantan

2018 ◽  
Vol 5 (3) ◽  
pp. 51-56
Author(s):  
M.F. Ishak ◽  
Koay B.K ◽  
M.S.I. Zaini ◽  
M.F. Zolkepli
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Groundwater Level ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
High Concentration ◽  
Monitoring Equipment ◽  
Bottom Part ◽  
Level Building

The objective of this study is to analyze groundwater level on slope that effect the slope stability. In this research, the instrumentation monitoring equipment were applied to investigate the groundwater due to the rainfalls that effected to slope stability. Groundwater level were related to rainfall intensity and pore water pressure as the simulation of behavior of the groundwater pattern through slope model were produced. The result indicates that the pore water pressure and groundwater level are facilitated to be fluctuated by heavy rainfall. Moreover, the different part of slopes need to be compared and it was found that the bottom part of the slope has high concentration of groundwater and pore water pressure due to the rainfall cumulative effects. The result also indicates that the bottom slope is worse when it is subjected to a high groundwater level. Thus, the rising of groundwater level due to rainfall was the main reason for the slope resulted in unstable condition.

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 STUDI GEOTEKNIK PENGARUH MUKA AIR TANAH TERHADAP KESTABILAN LERENG TAMBANG BATUBARA

2020 ◽  
Vol 1 (1) ◽  
pp. 475-488
Author(s):  
Jioni Santo Frans ◽  
Muhammad Hafizh Nurfalaq
Keyword(s):  
Rock Mass ◽  
Slope Stability ◽  
Ground Water ◽  
Water Level ◽  
Pore Water ◽  
Groundwater Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Slope Angle ◽  
Ground Water Level

ABSTRAK Dalam keadaan normal, suatu massa batuan memiliki kesetimbangan gaya yang bekerja. Kesetimbangan gaya yang bekerja tersebut bisa terganggu akibat terjadinya perubahan kondisi massa batuan, baik secara alamiah (erosi, patah, peningkatan muka air tanah) maupun aktivitas manusia (pengupasan, pengangkutan, penggalian, penimbunan). Respon dari perubahan tersebut, massa batuan dapat mengalami ketidakstabilan sebagai usaha untuk mencapai kondisi kesetimbangan baru. Hal ini akan memicu gerakan massa batuan akibat lereng yang tidak stabil dan terjadinya longsor. Lereng yang tidak stabil akan berdampak terhadap faktor keselamatan, ekonomi, dan sosial. Air tanah memiliki permasalahan tersendiri dalam pengelolaan tambang. Tekanan air pori (pore water pressure) dari air tanah dapat menimbulkan gaya angkat (uplift force) dan menurunkan kekuatan suatu massa batuan penyusun lereng, yang mana akan mempengaruhi kestabilan suatu lereng. Karakteristik daerah penelitian yang memiliki muka air tanah relatif dekat dengan permukaan, menyebabkan lereng berada dalam kondisi hampir jenuh. Penelitian ini bertujuan untuk melakukan studi pengaruh muka air tanah terhadap kestabilan lereng tambang batubara di daerah penelitian. Metode penelitian yang digunakan meliputi pengumpulan data primer melalui observasi lapangan untuk mengumpulkan data-data teknis terkait dan pengumpulan data sekunder melalui studi literatur. Analisa kestabilan lereng dilakukan untuk mendapatkan rekomendasi dengan nilai Faktor Keamanan minimum 1,30. Hasil penelitian menunjukkan muka air tanah memiliki hubungan berbanding terbalik terhadap nilai Faktor Keamanan. Rekomendasi yang dihasilkan yaitu melakukan dewatering dengan menggunakan drain hole. Target penurunan muka air tanah pada dinding tambang daerah penelitian adalah RL+40 pada area sidewall dan RL+65 pada area highwall. Altenatif lain yang diajukan oleh penulis adalah dengan melandaikan sudut lereng keseluruhan (overall slope angle) pada dinding tambang di daerah penelitian. Dinding tambang daerah penelitian direkomendasikan untuk dilakukan pelandaian dengan sudut lereng keseluruhan berkisar 24°. Kata kunci: kestabilan lereng, muka air tanah, longsor, dewatering, sudut lereng keseluruhan  ABSTRACT Under normal circumstances, a rock mass has an equilibrium of working forces. The equilibrium of these working forces can be disrupted due to changes in rock mass conditions, both naturally (erosion, broken, increased ground water level) and human activities (stripping, loading, excavation, backfill). In response to these changes, rock mass can have instability issue as an effort to reach new equilibrium conditions. This  condition will trigger rock mass movements and slope failure due to unstable slopes. Unstable slopes will affect the safety, economic and social factors. Groundwater has its own problems in mining activities. Pore water pressure from ground water can cause uplift force and decrease the strength of a rock mass forming a slope, which will affect the slope stability. Characteristics of the study area which has groundwater level relatively close to surface, causes the slope to be in nearly saturated condition. This research aims to study the effect of groundwater level on the stability of coal mine slopes in the study area. The research method used includes collecting primary data through field observations to collect related technical data and secondary data collection through literature studies. Slope stability analysis is carried out to obtain recommendations with a minimum Safety Factor value of 1.30. The results showed the ground water level has an inverse relationship to the value of the Safety Factor. The recommendations are dewatering using drain holes. The target of groundwater level reduction in the mine wall of the study area is RL+40 in the sidewall area and RL+65 in the highwall area. Another alternative proposed by the author is by resloping the overall slope angle of the mine wall in the study area. The mining wall of the study area is recommended for alignment with an overall slope angle of around 24 °. Keywords: slope stability, ground water level, landslides, dewatering, overall slope angle

scholarly journals Characteristics of Rainfall-Induced Slope Instability in Cisokan Region, Indonesia

2021 ◽  
Vol 53 (5) ◽  
pp. 210504
Author(s):  
Sugeng Krisnanto ◽  
Harianto Rahardjo
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Groundwater Level ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Matric Suction ◽  
Slope Instability ◽  
Access Road ◽  
Level Increase ◽  
Long Access

A 25.5 km long access road has been constructed in a hilly area in Cisokan region. Several slope instabilities occurred during the rainy season, particularly at the end of heavy rainfall. A comprehensive study was performed to understand the characteristics of rainfall-induced slope instability. The study consisted of field observation, analyses of field and laboratory test data, and numerical analyses. The study revealed that in general there were two categories of slopes with instability characteristics: (i) slopes with a significant groundwater level increase during rainfall; (ii) slopes with an insignificant groundwater level increase during rainfall. In the first category, the slope instability was caused by a loss of matric suction and eventually the pore-water pressure, uw became positive as indicated by an increase of the groundwater level. In the second category, the slope instability was caused by a loss of matric suction without a rise in pore-water pressure, uw, to a positive magnitude. Two empirical curves of slope stability were developed as a preliminary guidance to assess slope stability during rainfall in the region.

Study on Slope Instability Disciplinarian on the Condition of Rainfall

2013 ◽  
Vol 353-356 ◽  
pp. 654-658
Author(s):  
Nan Tong Zhang ◽  
Xiao Chun Zhang ◽  
Hua Rong Wang ◽  
Chen Yan
Keyword(s):  
Slope Stability ◽  
Tensile Stress ◽  
Rainfall Intensity ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Road Construction ◽  
Slope Instability ◽  
Slope Surface ◽  
Large Area ◽  
Break Zone

Slope stability is one of the problems of road construction which should be faced with and solve. Rainfall can reduce the shear strength of slope soil and raise the underground water level which can lead to increase slope soil pore water pressure. The influence of rainfall infiltration on slop is mainly to change the slope seepage field, increase dynamic and hydrostatic water load on the slope soil and decrease of soil shear parameters. More abundant rainfall of typhoon area could make the road slope stability more fragile. Based on Matoushan Mountain along 104 state roads in Taizhou city, Zhejiang province, slope instability disciplinarian on the condition of rainfall is studied using the method of numerical simulation in this paper. As the results, when the rainfall intensity was 0.006 m/h and continuous rain was in 24 hours, the slope surface compressive stress tends to zero which began to appear tensile stress area on the condition of self-weight. And when the rainfall intensity was 0.01 m/h and continuous rain was in 24 hours, the large area of the slope surface was tensile stress area which means to appear break zone in slope surface and likely to landslide at the same time.

Influences on Liquefaction-Induced Damage of Pore Water Seepage into an Unsaturated Surface Layer

2020 ◽  
Vol 15 (6) ◽  
pp. 754-764
Author(s):  
Yohsuke Kawamata ◽  
Hiroshi Nakazawa ◽  
◽  
Keyword(s):  
Surface Layer ◽  
Pore Water ◽  
Groundwater Level ◽  
Water Movement ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Lateral Spreading ◽  
Soil Liquefaction ◽  
Water Seepage ◽  
Long Duration

Various studies have examined soil liquefaction and the resultant structure damage. The 1995 Southern Hyogo Prefecture Earthquake, a near-field earthquake, caused significant damage when the ground was liquified due to the rapidly increased pore water pressure in several cycles of major motions. Therefore, the effect of pore water movement during earthquakes has been assumed to be limited, and liquefaction has mainly been evaluated in undrained conditions. Additionally, the ground and building settlement or inclination caused by liquefaction are deemed to result from pore water drainage after earthquakes. Meanwhile, in the 2011 Tohoku Earthquake, off the Pacific Coast, a subduction-zone earthquake, long-duration motions were observed for over 300 s with frequent aftershocks. Long-duration motions with frequent aftershocks are also anticipated in a future Nankai Trough Earthquake. The effect of pore water movement not only after but during an earthquake should be considered in cases where pore water pressure gradually increases in long-duration motion. The movement of pore water during and after an earthquake typically results in simultaneous dissipation and buildup of water pressure, as well as volumetric changes associated with settlement and lateral spreading. Such effects must reasonably be considered in liquefaction evaluation and building damage prediction. This research focuses on pore water seepage into the unsaturated surface layer caused by the movement of pore water. Seepage experiments were performed based on parameters such as height of test ground, ground surface permeability, and liquefaction duration. In the tests, water pressure when the saturated ground below the groundwater level is fully liquified was applied to the bottom of the specimen representing an unsaturated surface layer. Seepage behaviors into the unsaturated surface layer were then evaluated based on the experiment data. The results show that the water level rises due to pore water seepage from the liquefied ground into the unsaturated surface layer right above the liquefied ground. For this reason, a ground shallower than the original groundwater level can be liquified.

Analyses for the stability of potash tailings piles

1993 ◽  
Vol 30 (3) ◽  
pp. 491-505 ◽  
Author(s):  
Delwyn G. Fredlund ◽  
Zai Ming Zhang ◽  
Karen Macdonald
Keyword(s):  
Slope Stability ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Field Studies ◽  
Equilibrium Analysis ◽  
Limit Equilibrium Analysis ◽  
Dissipation Model ◽  
The Stability

The stability of potash tailings piles is investigated using a pore-water pressure generation and dissipation model together with a limit equilibrium analysis. It is found that a shallow toe failure mode is generally the most applicable and that the stability may be influenced by pore-water pressure migration below the pile. It is suggested that field studies would be useful in evaluating stability in the toe region of the pile. Key words : potash tailings, slope stability, pore pressure dissipation, solutioning.

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