Abstract: This paper deals with simulating the regimes of drilling deep curvilinear bore - holes with presc ribed geometrical imperfections of their axial lines. The interpolation techniques (spline approximation) are used for the well shape representation. On the basis of the theory of curvilinear flexible elastic rods, the 3D “stiff - string” drag and torque mod el of the drill string bending is elaborated. With its application it is shown that the contact and friction forces generated by interaction of the drill string with the bore - hole surface can be calculated and regulate, after their analysis, the regimes of buckling and dead lock states of drill strings in the curvilinear cavities of the bore - holes are simulated.

• Publication Date: 03-Sep-2017
• DOI: 10.15224/978-1-63248-132-0-33
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Abstract: One of the critical issues for a long suspension bridge is the vibration induced by wind. The excessive vibration on long suspension bridge owing to bridge flexibility may cause the bridge ’s aerodynamic instability and vehicle accidents. Therefore, in the present study, the optimum ratio for the span and turning angle to bridge width was investigated. The analysis was carried out on bridge with total span of 470m, main span 270m and side span 100m, using variations of bridges width ranging from 9 m to 22m. SAP2000 program was used to analyze the stability behavior of the suspension bridge under wind load at speed of 35m/s. The results of analysis shows that the optimum ratio of spa n to width bridge is 0.034L or L= 29.375b . When the turning angle was taken into consideration in the analysis , it will result in increasing the bridge’s stability , decreasing natural freq uency of the structure a nd increasing stress es on the cable s . Further , it was a lso found that the deflection a

• Publication Date: 03-Sep-2017
• DOI: 10.15224/978-1-63248-132-0-34
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