3D numerical investigation of the coupled interaction behavior between mechanized twin tunnels and groundwater – A case study: Shiraz metro line 2

2020 ◽  
Vol 103 ◽  
pp. 103458 ◽  
Author(s):  
Sina Shivaei ◽  
Nader Hataf ◽  
Keivan Pirastehfar
Keyword(s):  
Numerical Investigation ◽  
Interaction Behavior ◽  
Twin Tunnels

scholarly journals EVOLUTIONARY ALGORITHMS FOR RESOURCE CONSTRAINED NON-SERIAL MIXED FLOW SHOPS

2003 ◽  
Vol 03 (04) ◽  
pp. 411-435 ◽  
Author(s):  
ROBERT L. BURDETT ◽  
ERHAN KOZAN
Keyword(s):  
Evolutionary Algorithms ◽  
Numerical Investigation ◽  
Flow Shop ◽  
Resource Constrained ◽  
Mixed Flow ◽  
Flow Shops ◽  
Constrained Flow

In this paper the resource-constrained flow shop (RCF) problem is addressed. A number of realistic extensions are incorporated, including non-serial precedence requirements, mixed flow shop situations, and the distribution of the human workforce among a number of pre-determined groups. The RCF is then solved by meta-heuristics, primarily of the evolutionary type. An extensive numerical investigation, including a case study of a particular industrial situation, details the implementation and execution of the heuristics, and the efficiency of the proposed algorithms.

Solving Downslope Pipeline Walking on Non-Linear Soil With Brittle Peak Strength and Strain Softening

2017 ◽  
Author(s):  
Adriano Castelo ◽  
David White ◽  
Yinghui Tian
Keyword(s):  
Finite Element ◽  
Strain Softening ◽  
Peak Strength ◽  
Design Stage ◽  
Rigid Plastic ◽  
Soil Model ◽  
Interaction Behavior ◽  
Study Results ◽  
Non Linear

In 2000 the first case of pipeline walking (PW) was properly documented when this phenomenon seriously impacted a North Sea high pressure and high temperature (HP/HT) pipeline (Tornes et al. 2000). By then, the main drivers of this problem were accordingly identified for the case studied. On the other hand, to study other aspects related not only to PW, the industry joined forces in the SAFEBUCK Joint Industry Project (JIP) with academic partners. As a result, other drivers, which lead a pipeline to walk, have been identified (Bruton et al. 2010). Nowadays, during the design stage of pipelines, estimates are calculated for pipeline walking. These estimates often use a Rigid-Plastic (RP) soil idealization and the Coulomb friction principle (Carr et al. 2006). Unfortunately, this model does not reflect the real pipe-soil interaction behavior, and in practice time consuming finite element computations are often performed using an Elastic-Perfectly-Plastic (EPP) soil model. In reality, some observed axial pipe-soil responses are extremely non-linear and present a brittle peak strength before a strain softening response (White et al. 2011). This inaccuracy of the soil representation normally overestimates the Walking Rate (WR) (a rigid plastic soil model leads to greater walking). A magnified WR invariably leads to false interpretations besides being unrealistic. Finally, a distorted WR might also demand mitigating measures that could be avoided if the soil had been adequately treated. Unnecessary mitigation has a very strong and negative effect on the project as whole. It will require more financial and time investments for the entire development of the project — from design to construction activities. Therefore, having more realistic and pertinent estimates becomes valuable not only because of budgetary issues but also because of time frame limits. The present paper will show the results of a set of Finite Element Analyses (FEA) performed for a case-study pipeline. The analyses — carried out on ABAQUS software — used a specific subroutine code prepared to appropriately mimic Non-Linear Brittle Peak with Strain Softening (NLBPSS) axial pipe-soil interaction behavior. The specific subroutine code was represented in the Finite Element Models (FEMs) by a series of User Elements (UELs) attached to the pipe elements. The NLBPSS case is a late and exclusive contribution from the present work to the family of available pipeline walking solutions for different forms of axial pipe-soil interaction model. The parametric case-study results are benchmarked against theoretical calculations of pipeline walking showing that the case study results deliver a reasonable accuracy level and are reliable. The results are then distilled into a simplified method in which the WR for NLBPSS soil can be estimated by adjusting a solution derived for RP and EPP soil. The key outcome is a genuine method to correct the WR resultant from a RP soil approach to allow for peak and softening behaviour. It provides a design tool that extends beyond the previously-available solutions and allows more rapid and efficient predictions of pipeline walking to be made. This contribution clarifies, for the downslope walking case, what is the most appropriate basis to incorporate or idealize the soil characteristics within the axial Pipe-Soil Interaction (PSI) response when performing PW assessments.

Numerical investigation on the sliding process and deposit feature of an earthquake-induced landslide: a case study

Landslides ◽  
2020 ◽  
Vol 17 (11) ◽  
pp. 2671-2682 ◽  
Author(s):  
Huanling Wang ◽  
Shiqi Liu ◽  
Weiya Xu ◽  
Long Yan ◽  
Xiao Qu ◽  
...  
Keyword(s):  
Numerical Investigation

Mathematical modeling and numerical investigation of carbon capture by adsorption: Literature review and case study

2018 ◽  
Vol 221 ◽  
pp. 437-449 ◽  
Author(s):  
Shuangjun Li ◽  
Shuai Deng ◽  
Li Zhao ◽  
Ruikai Zhao ◽  
Meng Lin ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Literature Review ◽  
Numerical Investigation ◽  
Carbon Capture

Numerical investigation of thermal discharge to coastal areas: A case study in South Italy

2020 ◽  
Vol 124 ◽  
pp. 104596
Author(s):  
Maria Gabriella Gaeta ◽  
Achilleas G. Samaras ◽  
Renata Archetti
Keyword(s):  
Numerical Investigation ◽  
Coastal Areas ◽  
Thermal Discharge ◽  
South Italy
Sign in / Sign up

Export Citation Format

Share Document