scholarly journals PREDIKSI KELONGSORAN LERENG ALAM TANGSE-GEUMPANG DALAM PERSPEKTIF GEOTEKNIK

2019 ◽  
Vol 9 (1) ◽  
pp. 25-30
Author(s):  
Abdul Jalil
Keyword(s):  
Safety Factor

Hujan deras yang terjadi di bulan Nopember 2016 telah menyebabkan longsor lereng alam dan terputusnya jalan raya yang menghubungkan Tangse dan Geumpang. Labilnya tanah lereng alam yang tidak mempunyai perkuatan dan air hujan infiltrasi kedalam tanah dan menjadi saturated. Kondisi ini menyebabkan kehilangan tegangan tanah efektif pada lereng dan terjadinya longsor. Untuk mengatasi kejadian ini perlu melakukan analisis stabilitas lereng alam dengan perkuatan lereng. Perkuatan lereng dapat dikerjakan secara mekanik dan kimiawi. Analisis lereng dapat digunakan metoda morgenstern-Price, Fellenius. Dengan mengetahui gaya yang menahan dan gaya menggulingkan tanah lereng, maka nilai safety factor lereng dapat diketahui. Stabilitas lereng  diharapkan dengan nilai SF > 1,5 maka lereng akan stabil.

Modeling drive wheels of hoisting machines with rubber cables

2020 ◽  
pp. 105-114
Author(s):  
V. E. Perekutnev ◽  
V. V. Zotov
Keyword(s):  
Stress State ◽  
Safety Factor ◽  
Numerical Models ◽  
Design Parameters ◽  
Potential Range ◽  
Capital Costs ◽  
Reducing Gear ◽  
Reduce Risk ◽  
Steel Cables ◽  
Sidewall Surface

Upgrading of hoisting machines aims to improve their performance, to reduce risk of accidents, and to cut down operational and capital costs. One of the redesign solutions is replacement of steel cables by rubber cables. This novation can extend life of pulling members, decrease diameters of drive and guide wheels and, consequently, elements of the whole hoisting machines: rotor, reducing gear, motor. This engineering novation needs re-designing of hoisting machines; thus, the new design should be validated, in particular, strength characteristics of the machine members. This article considers a drive wheel of a hoisting machine with a pulling belt. In order to justify the potential range of design parameters with regard to safety factor, the numerical models of different-design drive wheels are developed and their operation with pulling belt (rubber cable) is simulated in the SolidWorks environment. The data on the stress state of the wheel elements are analyzed, the most loaded points are identified, and the maximal stresses on the sidewall surface and in the spokes of wheels of different designs are plotted.

Integrating Safety-II into Safety Management

2021 ◽  
Author(s):  
Toni Wäfler ◽  
Rahel Gugerli ◽  
Giulio Nisoli
Keyword(s):  
Risk Factor ◽  
Safety Factor ◽  
Safety Management ◽  
Management Systems ◽  
Safety Management Systems ◽  
Safety Science ◽  
Human Failure ◽  
The Given ◽  
Freedom Of Action

We all aim for safe processes. However, providing safety is a complex endeavour. What is it that makes a process safe? And what is the contribution of humans? It is very common to consider humans a risk factor prone to errors. Therefore, we implement sophisticated safety management systems (SMS) in order to prevent potential "human failure". These SMS provide an impressive increase of safety. In safety science this approach is labelled "Safety-I", and it starts to be questioned because humans do not show failures only. On the contrary, they often actively contribute to safety, sometimes even by deviating from a procedure. This "Safety-II" perspective considers humans to be a "safety factor" as well because of their ability to adjust behaviour to the given situation. However, adaptability requires scope of action and this is where Safety-I and Safety-II contradict each other. While the former restricts freedom of action, the latter requires room for manoeuvring. Thus, the task of integrating the Safety-II perspective into SMS, which are traditionally Safety-I based, is difficult. This challenge was the main objective of our project. We discovered two methods that contribute to the quality of SMS by integrating Safety-II into SMS without jeopardizing the Safety-I approach.

Evaluation of Hydraulic Fracturing Models and Their Limitations to Predict No-Drill Zones for Horizontal Directional Drilling

2018 ◽  
Author(s):  
Saeed Delara ◽  
Kendra MacKay
Keyword(s):  
Hydraulic Fracturing ◽  
Safety Factor ◽  
Standard Procedure ◽  
Accurate Determination ◽  
Strength Properties ◽  
Analytical Models ◽  
Alternative Methods ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
The Impact

Horizontal directional drilling (HDD) has become the preferred method for trenchless pipeline installations. Drilling pressures must be limited and a “no-drill zone” determined to avoid exceeding the strength of surrounding soil and rock. The currently accepted industry method of calculating hydraulic fracturing limiting pressure with application of an arbitrary safety factor contains several assumptions that are often not applicable to specific ground conditions. There is also no standard procedure for safety factor determination, resulting in detrimental impacts on drilling operations. This paper provides an analysis of the standard methods and proposes two alternative analytical models to more accurately determine the hydraulic fracture point and acceptable drilling pressure. These alternative methods provide greater understanding of the interaction between the drilling pressures and the surrounding ground strength properties. This allows for more accurate determination of horizontal directional drilling limitations. A comparison is presented to determine the differences in characteristics and assumptions for each model. The impact of specific soil properties and factors is investigated by means of a sensitivity analysis to determine the most critical soil information for each model.

scholarly journals Analysis of the influence of asymmetric geological conditions on stability of high arch dam

2021 ◽  
Vol 28 (1) ◽  
pp. 426-436
Author(s):  
Zelin Ding ◽  
Xuanyi Zhu ◽  
Hongyang Zhang ◽  
Hanlin Ban ◽  
Yuan Chen
Keyword(s):  
Safety Factor ◽  
Negative Impact ◽  
Decisive Role ◽  
Arch Dam ◽  
Test Method ◽  
Stable Operation ◽  
High Arch Dam ◽  
Reinforcement Scheme ◽  
Structural Plane ◽  
Geological Conditions

Abstract Geological conditions play a decisive role in the stability of arch dam engineering, and the asymmetric geological conditions of the abutment have a very negative impact on the safety of the arch dam. This article takes Lizhou arch dam as the research object, and determines that the arch dam is preliminarily affected by the geological asymmetric characteristics. Through the geomechanical model test method, the overload failure test of the Lizhou arch dam was carried out, and the resistance body, the instability deformation of the structural plane of the two dam abutments, and the influence of each structural plane on the dam body are obtained, and the safety factor is determined. According to the test results under the condition of asymmetric foundation of arch dam, for the structural plane which affects the geological asymmetry of the arch dam, the corresponding reinforcement measures are carried out. The feasibility of the reinforcement scheme is verified by the finite element method, and the safety factor after reinforcement is obtained. According to the results, it is suggested that some engineering measures can be taken to reduce the geological asymmetry between the two banks and ensure the safe and stable operation of the arch dam in the future.

scholarly journals The effect of fillet radius and length of the thick-walled cylinder on Von Mises stress and safety factor for rocket motor case

2020 ◽  
Author(s):  
Lasinta Ari Nendra Wibawa ◽  
Kuncoro Diharjo ◽  
Wijang Wisnu Raharjo ◽  
Bagus Hayatul Jihad
Keyword(s):  
Safety Factor ◽  
Rocket Motor ◽  
Von Mises Stress ◽  
Fillet Radius ◽  
Von Mises ◽  
Walled Cylinder

Limit State Philosophy in Pipeline Design

1987 ◽  
Vol 109 (1) ◽  
pp. 9-22 ◽  
Author(s):  
C. P. Ellinas ◽  
P. W. J. Raven ◽  
A. C. Walker ◽  
P. Davies
Keyword(s):  
Structural Analysis ◽  
Safety Factor ◽  
Current Knowledge ◽  
Limit State ◽  
Structural Behavior ◽  
Major Conclusion ◽  
Safety Factors ◽  
Suitable Framework ◽  
General Aspects ◽  
Pipeline Design

This paper considers the application of the limit state philosophy of structural analysis to pipeline design. General aspects of the philosophy are discussed and the approach to the evaluation of safety factors is reviewed. The paper further considers the various limit and serviceability states which would be relevant to a pipeline and reviews the various factors which may require consideration, before a code embodying the limit state philosophy could be formulated. A review of the state of current knowledge on various aspects of geometry and material characteristics, loading and structural behavior is presented. It is intended that such a review can be used as the basis for a larger study to provide guidance and data for the evaluation of rational levels of safety factor. The major conclusion reached by the authors is that a limit state philosophy would be valuable in providing a suitable framework, which may highlight the significant aspects of pipeline design and which can most easily accommodate new requirements and results obtained from research.

Finite Element Analysis of Motor Box for EBZ160 Horizontal Roadheader

2015 ◽  
Vol 1090 ◽  
pp. 233-237
Author(s):  
Ji Jun Miao ◽  
Ri Sheng Long
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Safety Factor ◽  
Stress And Strain ◽  
Element Analysis

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.

Redistribution of Internal Force under Structural Defect and Non-Linear Spatial Stability under Live Load and Wind of Tied-Arch Bridge

2013 ◽  
Vol 477-478 ◽  
pp. 640-645
Author(s):  
Qian Hui Pu ◽  
Hu Zhao
Keyword(s):  
Safety Factor ◽  
Mechanical Performance ◽  
Influence Factors ◽  
Internal Force ◽  
Structural Defects ◽  
Live Load ◽  
Positive Contribution ◽  
Arch Bridge ◽  
Initial Defect ◽  
Tied Arch Bridge

To study the mechanical performance and stability of tied-arch bridge under structural defects and damages, limited element modal of Panzhihua Luoguo Jinshajiang Bridge was established and analyzed. Firstly, some typical damage models and their influence factors were presented. Then, based on the model established, change of suspender force caused by arch rib lineation defect, hanger lineation defect and boom failure was calculated respectively. The stability safety factor under the load group composed of dead load, live load and wind was calculated as well as the second-class nonlinear stability safety factor under structural initial defect. Calculation results shows that, suspender forces were more sensitive to archs vertical defect than to transverse defect. While, short hangers were more sensitive to lineation defect than long ones, and secondary inner force in short booms were bigger than in long ones. The result also tells that lateral wind is bad to lateral stability. Lift wind, somehow, makes positive contribution to structures in-plane stability. Structural initial defect can draw down the second-class stability safety factor under geometric nonlinear condition.

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