scholarly journals Analysis of the mechanical behavior of adobe walls without reinforcement through computational modelling

2022 ◽  
Vol 2159 (1) ◽  
pp. 012006
Author(s):  
P A Ospina Henao ◽  
R D Oñate Ballesteros ◽  
J S Peñaranda Vega
Keyword(s):  
Finite Elements ◽  
Limit State ◽  
Computational Modelling ◽  
Developed Countries ◽  
Civil Structures ◽  
Safety Standards ◽  
Stress Studies ◽  
Service Limit State ◽  
Raw Earth ◽  
Pressure Analysis

Abstract The construction of civil structures on land has played an important role for centuries, however, due to the seismic requirements and the minimum safety standards that are currently required for any structure, this type of construction has been lagged, it is denoted that the related regulations they are widely dispersed and in most cases. In developed countries, numerous technical and legal problems arise to carry out construction with these materials. In relation to this work, a set of models of raw earth type walls are presented, through the SAP 2000 software, having as a supply of the mechanical properties of this material the Peruvian regulation E.080. For the analysis of these models, a static linear analysis for finite elements and a stress analysis of the service limit state concept were studied. Finally, the models with their respective stress studies, management and design recommendations are presented under the criteria of the analyses carried out, leaving open the possibility of both carrying out an experimental phase to develop the analogy with the postulates and proposed results, as well as such as the option to perform a static pressure analysis by finite elements in order to achieve greater precision and calibration of the model with respect to what can be evidenced in laboratory tests.

Food Safety Standards, Trade & WTO

2008 ◽  
Vol 43 (3) ◽  
pp. 3-20 ◽  
Author(s):  
Khushdeep Dharni ◽  
Sonika Sharma
Keyword(s):  
Developing Countries ◽  
Food Safety ◽  
Fruits And Vegetables ◽  
Developed Countries ◽  
Safety Standards ◽  
Food Items ◽  
Food Borne ◽  
Marine Products ◽  
The Developed Countries ◽  
Food Safety Standards

With incidence of food-borne diseases, consumers have become more conscious of food safety. Share of high value food items in the export bounty from developing countries like India is on the rise. These high value food items such as fresh & processed fruits and vegetables, marine products, meat and its preparations are highly income elastic as well as sensitive from the viewpoint of food safety. Article 20 of GATT allows governments to act on trade in order to protect human, animal or plant life or health, provided they do not discriminate or use this as disguised protectionism. SPS Agreement sets out the basic rules concerning food safety and animal & plant health standards. It allows countries to set their own standards but also says that regulations must be based on science. With increased retail concentration ratio, large retailers in the developed countries are enforcing their own food safety standards and these standards are stringent as compared to standards of standard setting bodies of WTO. At times these standards are used for discrimination in international trade and are telling upon the exports from developing countries in terms of additional costs of compliance and lack of “harmonization” and difficulties in establishing “equivalence”. For the benefit of exporters from the developing countries and consumers of the developed countries, efforts must be made for encouraging harmonization in these private standards and reducing the resulting discrimination.

scholarly journals Evaluating the operational resilience of small and medium-sized enterprises to flooding using a computational modelling and simulation approach: a case study of the 2007 flood in Tewkesbury

2020 ◽  
Vol 378 (2168) ◽  
pp. 20190210 ◽  
Author(s):  
Graham Coates ◽  
Meshal Alharbi ◽  
Chunhui Li ◽  
Sangaralingam Ahilan ◽  
Nigel Wright
Keyword(s):  
Relative Effectiveness ◽  
Computational Modelling ◽  
Developed Countries ◽  
Modelling And Simulation ◽  
Mitigation Measures ◽  
Simulation Approach ◽  
Structured Interviews ◽  
Urban Flood ◽  
Geographical Environment

The resilience of small and medium-sized enterprises (SMEs) to disruptive events is significant as this highly prevalent category of business forms the economic backbone in developed countries. This article provides an overview of the application of a computational modelling and simulation approach to evaluate SMEs' operational resilience to flooding based on combinations of structural and procedural mitigation measures that may be implemented to improve their premises' resistance to flooding and safeguard their business continuity. The approach integrates flood modelling and simulation with agent-based modelling and simulation (ABMS) within a modelled geographical environment. SMEs are modelled as agents based on findings of semi-structured interviews with SMEs that have experienced flooding or are at risk of flooding. In this paper, the ABMS has been applied to a new case study of the major flood event of 2007 in Tewkesbury. Furthermore, to enable an evaluation of the operational resilience of manufacturing SMEs in terms of the relative effectiveness of flood mitigation measures, a new coefficient based on production loss is introduced. Results indicate structural mitigation measures are more effective than procedural measures. While this result is intuitive, the approach provides a means of evaluating the relative effectiveness of combinations of mitigation measures that SMEs may implement to enhance their operational resilience to flooding. This article is part of the theme issue ‘Urban flood resilience’.

Investigation of Ultimate Limit State Safety Margins in the Structural Design Rules

2017 ◽  
Author(s):  
Kristoffer Lofthaug ◽  
Lars Brubak ◽  
Åge Bøe ◽  
Eivind Steen
Keyword(s):  
Finite Elements ◽  
Safety Factor ◽  
Limit State ◽  
Load Level ◽  
Structural Safety ◽  
Ultimate Limit State ◽  
Structural Members ◽  
Safety Margins ◽  
Non Linear ◽  
Ultimate Limit

A study to document the Ultimate Limit State (ULS) safety margins built into the DNV GL rules for Bulk and Tanker is presented. Critical structural members were identified together with the load level at which these members start to develop permanent buckling sets exceeding normal fabrication tolerances. These critical load levels are then compared with the local ULS rule strength limits in order to have a measure for the structural safety margins and hull redundancy. Non-linear finite element (NFLE) analyses were performed to estimate the structural response for different focus areas (critical structural members). Typically, critical members in bottom, deck, transverse bulkhead and hopper were chosen. Cargo hold models were developed both with linear finite elements, [1,2] and non-linear finite elements, [3]. In the non-linear FE analysis, the structural safety factor for ULS was defined as the load level giving permanent plastic deformation equal to the permissible distortion (production tolerances) for structural members. The non-linear FE results were compared with the maximum permissible load level with respect to buckling and yielding according to DNV GL Ship rules [1] inclusive Common Structural Rules for BC&OT (CSR) [4]. The structural safety factor shows a typical value of 1.2–1.4, and for most cases the plate is governing dimensioning structural member. This study has identified significant structural safety margins, typically 20–40% above rule acceptance level for typical highly utilized local areas in Bulk and Tanker hulls. It is to be noted that global Hull Girder Capacity is not addressed in present paper.

scholarly journals Upper Bound Method for Yield Design of Reinforced Concrete Slabs Using Conic Programming and an Adaptive Remeshing Strategy

2019 ◽  
Author(s):  
Hector Andres Tinoco
Keyword(s):  
Reinforced Concrete ◽  
Finite Elements ◽  
Upper Bound ◽  
Limit State ◽  
Standard Form ◽  
Numerical Procedure ◽  
Concrete Slabs ◽  
Flow Rule ◽  
Adaptive Remeshing ◽  
Reinforced Concrete Slabs

This study presents a numerical procedure for the analysis of reinforced concrete slabs (RCS) that obey Nielsen's yield criterion (slabs orthogonally reinforced). An upper bound formulation combined with finite elements was established to solve the kinematic theorem as a conic optimization problem with the aim to determine the maximum bearing capacity of RCS. Discrete Kirchhoff finite elements were implemented and adapted to establish a limit state problem for the yield design. By using Nielsen´s criterion, a kinematic criterion was established applying the flow rule of plasticity. The kinematic criterion was included in the upper bound formulation with the aim to constraint the curvatures of the slab. The upper bound formulation was organized in the standard form of a second order cone programming (SOCP) problem since the kinematic criterion was formulated in conic form. Numerical examples were proposed to test the accuracy of the method including the adaptive remeshing strategy.

scholarly journals Load and resistance factor design of drilled shafts subjected to lateral loading at service limit state

2018 ◽  
Author(s):  
◽  
Minh Dinh Uong
Keyword(s):  
Limit State ◽  
Design Procedure ◽  
Drilled Shafts ◽  
Resistance Factor ◽  
Lateral Loading ◽  
Drilled Shaft ◽  
Resistance Factors ◽  
Service Limit State ◽  
Load And Resistance Factor ◽  
Aashto Lrfd

Since 2007, the American Association of State Highway Administration Officials (AASHTO) has made utilization of Load and Resistance Factor Design (LRFD) mandatory on all federally-funded new bridge projects (AASHTO, 2007). However, currently, there are no guidelines implementing LRFD techniques for design of drilled shaft subjected to lateral loads using reliability-based analysis. On a national level, the AASHTO LRFD Bridge Design Specifications (AASHTO, 2012) specify that a resistance factor of 1.0 be used for design of drilled shafts subjected to lateral loading at service limit state, which means reliability-based analyses for calibration of resistance factors have not been performed. Therefore, there is a need to create a LRFD procedure for drilled shafts subjected to lateral loading at service limit state that has reliability-based calibrated resistance factors applicable for future projects. The research focuses on the reliability-based analysis of drilled shaft subjected to lateral loading, characterize lateral load transfer model of drilled shafts in shale, probabilistic calibrate resistance factor and contribute to the development of design procedure using LRFD. The objective of this work is to improve the design of drilled shaft subjected to lateral loading using LRFD at service limit state by providing a more reliable design procedure than the current AASHTO LRFD procedure for drilled shafts subjected to lateral loading at service limit state.

scholarly journals Experimental Study and Numerical Simulation on Mechanical Properties of the Bottom Plate in the Assembled Composite Slab with Additional Steel Trusses

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Xiuying Yang ◽  
Yuzhuo Wang ◽  
Yongxin Liu ◽  
Zhenyu Wei
Keyword(s):  
Crack Resistance ◽  
Limit State ◽  
Load Level ◽  
Bottom Plate ◽  
Composite Slab ◽  
Static Test ◽  
Service Limit State ◽  
New Type ◽  
Transverse Steel ◽  
Steel Trusses

The composite slab with steel trusses is composed of precast bottom plate and cast-in-place concrete. In engineering applications, cracks often appear in the bottom plate before casting the upper concrete, which even leads to the failure of the composite slab. To improve the crack resistance of the slab, a composite slab with additional steel trusses is proposed; that is, on the basis of the original longitudinal steel trusses, the transverse steel trusses are added. Static test and numerical analysis were carried out on the bottom plate of the new type of composite slab with the additional transverse steel trusses. The experimental and analytical results show that the load level of the plate with additional steel trusses can be increased by 33% under the normal service limit state; the deflection of the plate is significantly reduced and the crack development is effectively controlled, which illustrates that the new type of composite slab can improve the bearing capacity, increase the bending stiffness, and enhance the crack resistance effectively.

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