5572

5206

كارشناسي ارشد

خاك و پي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده عمران

1389

نه،145ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

فرهاد بهنام فر، محمود وفائيان

امير مهدي حلبيان

5/10/89

بيژن برومند، محمود هاشمي اصفهانيان

مهندسي عمران

ID5206

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Dynamic Analysis of Buried Steel Pipelines with Elbow Under Wave Propagation Miad Sabery m sabery@cv iut ac ir June 22 2010 Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Farhad Behnamfar Farhad@cc iut ac ir Mahmood Vafaeian mahmood@cc iut ac ir Abstract Pipelines are often referred to as lifelines and this demonstrates they play an role for human life and safety If such facilities are damaged in an earthquake it will result in both spoiling of products and services and also threatening health and environment Due to considerable length and wide geographical distribution of pipelines in comparison to other types of structures they are subjected to different seismic hazards and various soil conditions As a result evaluation of pipeline plays a key role in engineering Seismic wave propagations and its incidence affect operation of buried pipelines which influences safety of pipeline systems during and after earthquakes This subject has been studied in the presented research For this purpose shell and beam models have been employed and connector elements are used for simulation of buried pipelines and soils respectively The connector elements are employed due to their more accuracy in simulation of soil hardening behavior in cyclic loadings in comparison with spring elements Moreover a boundary condition has been used at the end of each branch of pipe that simulates their infinite length more closely Also spatial variation of the incident waves was regarded as a certain incidence angle causing time lag in vibration of different points and it was studied as an influencing parameter on pipeline system The elbow angle is an important factor in response of pipeline systems Generally elbow angles in the range of 112 5 and 157 5 degrees are subjected to higher strains The horizontal propagation of waves and parallel to one of branches has the most influence on response of pipelines Thickness and buried depth of pipes are other important parameters that influence the elbow strain However soil type should be considered as a factor which could increase or decrease the effect of thickness and buried depth Pipelines in condensed soil have less slippage and higher axial strain Results of shell models do not have a significant difference with beam models however shell models are preferred because of their ability to show response changes in cross section of pipes Finally maximum strain in buried pipeline as a result of wave propagation leads to plastic deformations and local buckling that are not as much to reach the failure point Key Words Buried Pipeline Wave Propagation Elbow Numerical Model Pipe Soil Interaction

فرهاد بهنام فر، محمود وفائيان

امير مهدي حلبيان

بيژن برومند، محمود هاشمي اصفهانيان