Civil Engineering Association

Its quite easy, make one unit width box section with springs on bottom and soil trapozidol loads on walls as per soil mechanics, and top slab load with taking in accout arch action of soil. Analyse and design.

in a newbie to sap2000....can anyone guide me on how to create the box section and the loadings input?

Using software is depend on the type and importance of box culvert. i have also model same in staad pro and sap 200 both are giving same result. but remember, both these are small culverts. if required let me know i will send u both files.

(03-27-2010, 07:26 AM)fazilat Wrote: [ -> ]Using software is depend on the type and importance of box culvert. i have also model same in staad pro and sap 200 both are giving same result. but remember, both these are small culverts. if required let me know i will send u both files.

Appreciate it very much if you could provide me a link to the files.

There are two methods to model any type of culvert, small or large.

1. Unit strip method. (2-D Model)

In this method one ft or one meter portion of culvert is modeled using beam-column members. This method is same like analysis of one-way slab with the exception that in one-way slab only beam member is required while in culvert top slab of unit width is modeled as beam and walls of unit width are modeled as columns.

For this method any software (STRAP, SAP2000, Etabs, StaadPro, Visualanalysis etc) can be used.

2. 3-D Model.

In this method, 3-d model of culvert is made using shell elements.

For this method only those software can be used which give results for moments as well as in-plane forces. STRAP is the software that not only gives results for in-plane forces but also designs reinforcement taking into account in-plane forces. Other software like SAP2000, Etabs, StaadPro, Visualanalysis etc. cannot be used.

Similarly, for analysis and design of over-head water tanks (using shell elements) software like SAP2000, Etabs, StaadPro, Visualanalysis etc. must not be used because these give results without in-plane forces.

Hi Techno,

I've been design box culvert for runway in airport, from my experience you much collect the bigger load from aircraft, in this case, impact load from aircraft so important to consider. For earthquake load or snow load, i think depend on your case and your location. Back to your question, you can use SAP2000 because that software more complete than ETABS (usually for building design). In initial design, consider loading data using AASHTO, ACI and ASCE, for you input data in SAP2000 modeling. I agree to Mr. Djulaiman for using spring value from Bowles, but if you've soil data, you must calculate from that soil information. For SAP2000 modeling, you can combine 2D frame model and shell model for more accurate calculation. Hopefully this note help u to solve your project.

Best Regards,


Zamil.EC

box culvert can also be analysed by STAAD considering unit width of Box.

I believe ETABS can do well in box culvert because i have been using it to design ranging from small and big culvert. So far, everything all right..

ETABS doesn't have tool to analyze vehicular load, but SAP2000 has.