Show the limitations of grillage analysis, Civil Engineering

Assignment Help:

Q. Show the Limitations of grillage analysis?

In designing the number of cells for concrete box girder bridges, in case depth of a box girder bridge exceeds 1/6 or 1/5 of bridge width then it is recommended to be designed as a single cell box girder bridge. Though if the bridge depth is smaller than 1/6 of bridge width then a twin-cell or multiple cell is a better.Though one should note that even for wider bridges with small depths, number of cells must be minimized since there isn't much improvement in transverse load distribution when number of cells of box girder is increased to three or more.

For structural analysis of bridges, grillage analysis that involves the structure to be modelled as a series of transverse and longitudinal elements that are interconnected at nodes is normally adopted. 

Grillage analysis suffers from the following limitations:

(i)  For coarse mesh, torques may not be identical in orthogonal directions. In the same way twists may differ in orthogonal directions.

(ii)  Moment in any beams is primarily proportional to its curvature only. Though moment in an element depends on curvatures in the beam's direction and its orthogonal direction. 

Grillage analysis can't be used to determine the effect of distortion and warping. Furthermore the effect of shear lag may hardly be assessed by using grillage analysis. By employing fine mesh of elements, local effects may be determined with a grillage. On the other hand, local effects can be assessed separately and put in the results of grillage analysis.


Related Discussions:- Show the limitations of grillage analysis

Corrosion, Distinguish between dry and wet corrosion

Distinguish between dry and wet corrosion

Reasons of ground heaving during pipe-jacking, Reasons of ground heaving du...

Reasons of ground heaving during pipe-jacking It is commonly recognized that ground settlement is one of the significant concern in pipe jacking operation. Though engineer mus

Calculate the total labor cost per cubic yard, A contractor will place 90-c...

A contractor will place 90-cubic yards of concrete for a housekeeping pad on the rooftop of a 36-ft tall building. Site conditions dictate that the safest and best method of placem

Explain the installation of shock transmission unit, Explain the Installati...

Explain the Installation of Shock Transmission Unit? It is not always necessary to install STUs while a structure is under construction but the holding down anchor bolts and th

Meaning of driving succession of driven piles, Question What is meaning...

Question What is meaning of driving succession of driven piles? Answer In Basement construction, if piles are driven from centre to perimeter, there is a propensity o

Dam, Check for stability in a dam

Check for stability in a dam

Explain the shrink factor of soil, Explain the Shrink Factor of Soil In...

Explain the Shrink Factor of Soil In addition to the swell factor and its associated load factor, soil also has a shrink factor. While the first two relate the volume of an equ

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd