scholarly journals Estimating of Maximum Groundwater Level to Trigger Landslide in Batu Hijau Open Pit Mine, West Nusa Tenggara, Indonesia

2021 ◽  
Vol 5 (2) ◽  
pp. 113
Author(s):  
Amirul Aiman Abd Karim ◽  
Wahyu Wilopo ◽  
I Gde Budi Indrawan ◽  
Yan Adriansyah

The safety of the employees is essential in the mining activity area. Thus, the sloping wall of the pit needs to evaluate from time to time to avoid any loss due to landslide. One of the essential parameters to lead to slope failure is groundwater. Therefore, this paper highlights the limitations of the groundwater for the existing slope mine by analyzing it for several groundwater levels until it reached a safety factor below 1.2. The analysis was done using a finite element method for slope stability and finite element analysis for groundwater seepage for groundwater modeling. The results show that the safety factor of the slope showing a linearly decreasing trend and safety factor reached below 1.2 when 70 m increment in groundwater level from the original groundwater level model.

2021 ◽  
Vol 16 (4) ◽  
pp. 485-494
Author(s):  
Akihiko Wakai ◽  
Akino Watanabe ◽  
Nguyen Van Thang ◽  
Takashi Kimura ◽  
Go Sato ◽  
...  

Numerous annual slope failures are induced by heavy rainfall during the monsoons, especially in developing countries in Asia. The authors have developed a simple method to predict rising groundwater levels in natural slopes at a relatively shallow depth based on parametric studies conducted using the finite element method. An assumption of a semi-infinite homogeneous slope was adopted in the analysis. Addtionally, the authors numerically modelled the vertical infiltration and the lateral seepage flow. Using this method implies that the finite element analysis is not mandatory in the evaluations of practical slopes. Such a simplified approach helps avoid time-consuming tasks in rigorous computations. However, a semi-infinite assumption used in the developed method may provide us with unsuitable solutions, particularly in cases where the slopes include heavily terraced topography with local small cliffs, because theoretically, the first slope failure tends to occur in steep slopes, like the edge of a rice terrace, even though they are very small cliffs. Nevertheless, these local solutions do not affect the conclusions for disaster risk reduction. Moreover, such unsuitable alternatives must be eliminated during analysis. To address this matter, the current study proposes a novel concept of specific lengths. This procedure provides a representative length within the specified length range. The averaged slope gradient is defined by focusing on the secant lines between each topographical grid, while those defined outside the specified range – for example, local cliff angles – are ignored in the slope stability calculation. Consequently, the proposed concept was confirmed to be efficient and can be applied to evaluate the terraced rice fields in Sapa, northern Vietnam. In the past, this area had experienced rainfall-induced slope failures; hence, the proposed method may be able to simulate these occurences. The proposed concept’s effectiveness when applied to terraced fields should continue to be verified through case studies conducted in areas with extensive smallterraced topography.


2021 ◽  
Vol 11 (13) ◽  
pp. 5782
Author(s):  
Harutus Phoban ◽  
Uma Seeboonruang ◽  
Prateep Lueprasert

Behaviors of the pile foundation due to groundwater level rising were analyzed by a series two-dimensional finite element analyses with fully coupled flow-deformation analysis. The different numerical models of single bore pile depth and diameter in Bangkok subsoil were represented with the parametric study. The pile–soil movement due to groundwater levels rising between numerical simulation and a previous experiment of the centrifuge test as the same condition are in good agreement. With rising groundwater level, the reduction of pile capacity can be evidently performed by the increase of pile settlement relative to soil surface. Moreover, the development of the plastic point captured by the finite element analysis revealed the mechanism behind the reduction of pile capacity. In this study, the evaluation of pile stability due to groundwater level rising for preliminary guidelines to protect existing structures are proposed.


2015 ◽  
Vol 1090 ◽  
pp. 233-237
Author(s):  
Ji Jun Miao ◽  
Ri Sheng Long

In order to solve the cracking and poor reliability problems of motor box of Horizontal Roadheader, the static structural FEA (Finite Element Analysis) of cutting arm & motor box of the EBH160 Horizontal Roadheader was conducted, and the stress and strain contours of FEA were obtained. By comparing the calculated results, the safety factor of cutting arm & motor box was 1.36, which provides a reference for the optimal design of cutting arm & motor box.


Jurnal METTEK ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Angga Restu Pahlawan ◽  
Rizal Hanifi ◽  
Aa Santosa

Frame adalah salah satu komponen yang sangat penting dalam sebuah kendaraan, yang berfungsi sebagai penopang penumpang, mesin, suspensi, sistem kelistrikan dan lain-lain. Melihat fungsi dari frame sangat penting, maka dalam merancang sebuah frame harus diperhitungkan dengan baik. Banyak sekali jenis pengujian yang sering dipakai dalam perancangan sebuah struktur frame, salah satunya adalah digunakannya metode komputasi dengan menggunakan metode Finite Element Analysis (FEA). Tujuan dari penelitian ini adalah untuk mengetahui distribusi tegangan, regangan, displacement, dan safety factor dari hasil pembebanan statis pada frame gokar. Struktur frame didesain dan dianalisis menggunakan software Solidworks 2016. Material yang digunakan frame adalah baja AISI 1045 hollow tube 273,2 mm, dengan menggunakan pembebanan pengendara sebesar 50 kg dan 70 kg. Hasil dari perhitungan manual didapatkan tegangan maksimum sebesar 4,735  107 N/m2, sedangkan dari simulasi didapatkan sebesar 4,516  107 N/m2. Regangan maksimum didapatkan dari perhitungan manual sebesar 2,310  10-4. Displacement maksimum didapatkan dari perhitungan manual sebesar 1,864  108 mm, sedangkan dari simulasi didapatkan sebesar 1,624  108 mm. Safety factor minimum didapatkan dari perhitungan manual sebesar 11,193, dan perhitungan simulasi didapatkan sebesar 11,736. The frame is one of the most important components in a vehicle, which functions as a support for passengers, engines, suspensions, electrical systems and others. Seeing the function of the frame is very important, so designing a frame must be taken into account well. There are many types of tests that are often used in the design of a frame structure, one of which is the use of computational methods using the Finite Element Analysis (FEA) method. The purpose of this study was to determine the distribution of stress, strain, displacement, and safety factor from the results of static loading on the kart frame. The frame structure was designed and analyzed using Solidworks 2016 software. The material used in the frame is steel AISI 1045 hollow tube 27  3,2 mm, using a rider load of 50 kg and 70 kg. The result of manual calculation shows that the maximum stress is 4,735  107 N/m2, while the simulation results are 4,516  107 N/m2. The maximum strain is obtained from manual calculation of 2,310  10-4. The maximum displacement is obtained from manual calculations of 1,864  108 mm, while the simulation results are 1,624  108 mm. The minimum safety factor obtained from manual calculation is 11,193, and the simulation calculation is 11,736.


Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 697 ◽  
Author(s):  
Klemen Kenda ◽  
Matej Čerin ◽  
Mark Bogataj ◽  
Matej Senožetnik ◽  
Kristina Klemen ◽  
...  

In this study a thorough analysis is conducted concerning the prediction of groundwater levels of Ljubljana polje aquifer. Machine learning methodologies are implemented using strongly correlated physical parameters as input variables. The results show that data-driven modelling approaches can perform sufficiently well in predicting groundwater level changes. Different evaluation metrics confirm and highlight the capability of these models to catch the trend of groundwater level fluctuations. Despite the overall adequate performance, further investigation is needed towards improving their accuracy in order to be comprised in decision making processes.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Rui Zhang ◽  
Jie Zhao ◽  
Guixuan Wang

Under the condition of the plane strain, finite element limit equilibrium method is used to study some key problems of stability analysis for anchored slope. The definition of safe factor in slices method is generalized into FEM. The “true” stress field in the whole structure can be obtained by elastic-plastic finite element analysis. Then, the optimal search for the most dangerous sliding surface with Hooke-Jeeves optimized searching method is introduced. Three cases of stability analysis of natural slope, anchored slope with seepage, and excavation anchored slope are conducted. The differences in safety factor quantity, shape and location of slip surface, anchoring effect among slices method, finite element strength reduction method (SRM), and finite element limit equilibrium method are comparatively analyzed. The results show that the safety factor given by the FEM is greater and the unfavorable slip surface is deeper than that by the slice method. The finite element limit equilibrium method has high calculation accuracy, and to some extent the slice method underestimates the effect of anchor, and the effect of anchor is overrated in the SRM.


Author(s):  
Mosfequr Rahman ◽  
Gustavo Molina ◽  
Sirajus Salekeen ◽  
Ana Dungan ◽  
Isaac Hyers ◽  
...  

Finite Element Analysis (FEA) has been performed on variety of a driveshaft and universal joints based on different shaft materials and shaft different operating angles. A driveshaft is particularly useful in applications such as taking of transferring torque from one piece of equipment to the other such as in vehicle of all kinds. A driveshaft transfers torque from the transmission to the rear end differential since these two pieces of equipment cannot be connected directly. The driveshaft has universal joints located on both ends of the shaft to allow for fluctuations in the angle of the transmission and rear differential. The driveshaft alone is composed of two parts, a female and male end, connected by a spline to allow changes in the length during operation. The driveshaft must be able to withstand the constant torque that is being applied throughout operation in order to increase safety for the operator and machine. Having a lower polar moment of inertia allows the driveshaft to turn with a lower torque value compared to a driveshaft with a higher moment of inertia. It is noted that driveshaft can be manufactured into a variety of lengths and diameters depending on the use and equipment it will be supporting. This paper describes a method of finite element implemented on variations of driveshaft and universal joints. Effect of material properties, geometry and operating angle of the driveshaft were considered for this numerical investigation. Five different materials such as structural steel, aluminum alloy, polyethylene, titanium, and carbon fiber with an outer diameter of 1.5 in of the driveshaft was used for this analysis. The effect of both metals and composite materials was observed. Based on the analysis it was found that a 15° operating angle allowed for the longest life cycle of the driveshaft, while the carbon fiber composite presented the highest stress resistance and safety factor, approximately 6 GPa of yield tensile strength and a safety factor of 15. It was also found that titanium had an equivalent safety factor of 15. However, the tensile yield strength of titanium was much lower than that of its composite counterpart. All of the numerical experimentation was done using the Finite Element Analysis software ANSYS. Material properties for all materials were preset in the software except the composite carbon fiber whose properties were easily found from other research papers and experiments. Based on the data collected and the general assumptions that the most effective drive shaft is the one that lasts the longest. It can be concluded that a driveshaft made of carbon fiber operating at an angle of 15° presents the optimum driveshaft design.


2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Meri Rahmi ◽  
Delffika Canra ◽  
Suliono Suliono

Valve (katup) sebagai salah satu produk industri, sangat dibutuhkan oleh perusahaan yang bergerak mengontrol aliran cairan untuk efisiensi. Kebutuhan tentang ini banyak digunakan oleh perusahaan makanan, obat-obatan, minuman, pembangkit listrik dan industri minyak dan gas. Tujuan penggunaan valve adalah untuk membatasi dan mengontrol cairan pada kondisi tekanan tinggi. Salah satu katup yang sering digunakan adalah ball valve, yaitu katup dengan tipe gerak memutar. Adanya permintaan ball valve ini, dibutuhkan produk dengan spesifikasi tertentu memiliki rancangan dengan tingkat kekuatan yang baik. Dengan kata lain, produk valve (katup) yang baik, harus memiliki kekuatan yang baik, aman dan sesuai dengan kebutuhan dilakukan pengujian. Penelitian ini bertujuan untuk melakukan analisis terhadap ball valve 4 inch ANSI 300 untuk memastikan katup yang diproduksi sesuai spesifikasi, kuat dan tahan terhadap tekanan fluida. Metode yang digunakan adalah Finite Element Analysis (FEA) dengan software Solidworks. Analisis dilakukan pada ball valve 4 inch ANSI 300 dengan keadaan full open, hall open dan full closed serta dengan pembebanan 725 psi dan 1087.5 psi hasil dari Computational Fluid Dynamics (CFD). Analisis dilakukan pada temperatur -29.50C, 250C dan 4250C. Berdasarkan hasil analisis dengan FEA, dinyatakan bahwa ball valve 4 inch ANSI 300 kuat dan aman untuk digunakan. Nilai faktor keamanan (safety factor), signifikan lebih tinggi dari nilai safety factor minimum yang diizinkan.


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