Variation among Working stress method and Limit state method

This construction video shows the variation among working stress method and limit state method.

The basic variance among Working state method (WSM) and Limit State method (LSM) is that WSM stands for an elastic design method while LSM stands for a plastic design method.

In elastic design method, the design strength is estimated in such a manner that the stress in material is controlled with its yield limit, under which the material adheres to Hooke's law, and therefore, the word "elastic" is utilized. This method is used to produce cost-effective design of simple beam, or other structural elements where the standard for evaluating the design is stress (static). But, in case of changing the evaluation standard to other factors like fatigue stress, both the methods will give similar design. Also, WSM substantially reduces the calculation efforts.

In plastic design method the stress in material is permitted to go outside the yield limit and move into the plastic zone to attain extreme strength. Therefore, the "moment-rotation" power of beam, as for instance, is applied for creating more cost-effective design. However, because of the deployment of the non-linear zone, this method comprises laborious calculation.

Given below, some other general differences:

1) Serviceability check if LSM is necessary since after the elastic region strain is greater, it leads to more deformation, therefore a check is required.

2) LSM refers to strain based method while WSM is stress based method.

3) LSM refers to non-deterministic method while WSM is deterministic approach.

4) Partial safety factor is applied in LSM while Safety factor is applied in WSM.

5) Characteristic values (resulting from probabilistic approach) are applied in case of LSM while Average or statistic values are applied in WSM.

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Published By

Rajib Dey

www.constructioncost.co

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How to use Tekla Structure 2016 for bridge pier reinforcement

This construction video briefly shows how to use Tekla Structure 2016 to perform bridge pier reinforcement.

Concrete piers stand for vertical structural elements that support the weight of a building or structure. The role of the concrete piers is similar to the table legs. If they are designed properly, and arranged on solid ground or to a depth that the friction on the sides of the pier is exceeding the load placed on the pier, the piers and the structure will be immovable.

Most concrete piers applied over the average home for a deck or other structures are generally lower than 24 or so inches in diameter at the base of the pier. As the pier increases and out of the ground, it can be minimized in size to as small as 10 inches in diameter. The bottom of the pier should always remain under the frost line in the area.

The bottom of the pier should be broader as compared to the top. The wider base facilitates allocating the weight of the structure over more soil. Thus the design becomes stable enough.

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Published By

Rajib Dey

www.constructioncost.co

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SCAD Office 21.1 is useful for perfect structural design

SCAD Soft launched SCAD Office 21.1 to simplify structural design process. This construction program only supports windows platform. With integrated graphics environment useful for developing a design as well as evaluating its analysis results, the users will be able to model any simple or complicated structure.

Superior processing core facilitates the users to find out solutions concerning large dimension (hundreds of thousands freedom degrees) in linear and geometric non-linear formation.

There is an extensive library containing finite elements for modeling bar, plate, solid and combined structures, modules of stability analysis, building design stress combinations, verifying stressed state of structural elements in accordance with several failure theories, determining forces through which a fragment provides an effect the complete structure, measuring forces and displacement due to loading combinations. The system also takes in routines for selecting reinforcement for ferroconcrete structural elements and for validating cross-sections of steelwork structural elements.

Program-satellites for analysis and design of structural elements

COMET – design of joints of steel structures based on SNiP and DBN

• KRISTALL – assessment and analysis of steel structural elements based on SNiP, DBN, Eurocode 3 (together with the analysis of the damaged structures)

• ARBAT – Analysis and reinforcement selection for reinforced concrete structural elements based on SNiP

• COMEIN – Analysis of masonry and reinforced masonry structural elements according to SNiP and DBN.

• MONOLIT – Design of in-situ ribbed floors

• WEST (wind, snow, temperature) – analysis based on SNiP and DBN

• CROSS – Calculation of subsoil parameters on the basis of geotechnical investigations

• ZAPROS – Analysis of soil and foundation members based on SNiP and DBN

• DECOR – Assessment of timber structural elements based on SNiP and DBN

• SLOPE – Stability analysis of slopes.

Link for download An Integrated System For Finite Element Structural Analysis

Programs for building cross-sections and the analysis of their geometrical characteristics

• Section Builder – Development of built-up cross-sections and the analysis of their characteristics

• CONSUL – Creation and analysis of arbitrary cross-sections of bar elements

• SEZAM – equivalent cross-section selection

• TONUS – Development of thin-wall cross-sections and the analysis of their characteristics.

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Published By

Rajib Dey

www.constructioncost.co

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How to generate reinforcement drawing in Autodesk Advance Concrete 2016

Md Humayun Kabir has made this nice tutorial for construction professionals. In this tutorial, Kabir shows some useful tips for creating reinforcement drawing in Advance Concrete 2016 developed by Autodesk. Advance Concrete 2016 is used to model reinforced concrete structures instantly. It supports Windows 7 64-bit and Windows 8 64-bit.

This construction program contains the following features :-

• Modeling structural elements like Column, Beam, Slab, Isolated footing, Continuous footing, Pile as well as Stairs, Roofs.

• Contain material & section libraries with several concrete, masonry and full bricks materials as well as parametric sections.

• Create view automatically that includes plan views, elevation views, cross section views, isometric views, reinforcement views etc.

• Create reinforcement drawing efficiently for manual reinforcement like stirrups, straight bars, polygonal bars, meshes etc.

• Create documents like organizing drawings on layout, inserting frame & title block, generating BOM for concrete volume & formwork area.

• BIM integration with Graitec compatible software and Revit, IFC 2x3 export/import.

• Structural analysis for finite element.

Download a free trial Autodesk Advance Concrete 2016

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Published By

Rajib Dey

www.constructioncost.co

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Build a concrete slab footing of modern buildings

A concrete slab is a common structural element of modern buildings. Horizontal slabs of steel reinforced concrete, typically between 100 and 500 millimeters thick, are most often used to construct floors and ceilings, while thinner slabs are also used for exterior paving.

In many domestic and industrial buildings a thick concrete slab, supported on foundations or directly on the subsoil, is used to construct the ground floor of a building. In high rise buildings and skyscrapers, thinner, pre-cast concrete slabs are slung between the steel frames to form the floors and ceilings on each level.

On the technical drawings, reinforced concrete slabs are often abbreviated to "r.c.slab" or simply "r.c.".

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Published By

Rajib Dey

www.quantity-takeoff.com

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