www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

Angle of internal friction

 
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> Engineering Marvels
View previous topic :: View next topic  
Author Message
saikiran gone
General Sponsor
General Sponsor


Joined: 22 Apr 2016
Posts: 217

PostPosted: Sat Nov 12, 2016 6:31 am    Post subject: Angle of internal friction Reply with quote

Dear Engineers,

Please explain what exactly angle of  internal friction means with practical examples, if possible with images . I can visualize in my mind what is cohesion (c) . But I unable to visualize what is the angle of internal friction (phi).

I know it is related to shear strength property of cohesionless soil . How it will help in resisting the skin friction forces (i.e uplift).I know that cohesion value is more in sands but how it will help in resisting the uplift by skin friction I am not understanding.

Thanks,

Regards,
Saikiran.
Back to top
View user's profile Send private message
saikiran gone
General Sponsor
General Sponsor


Joined: 22 Apr 2016
Posts: 217

PostPosted: Tue Nov 15, 2016 6:51 am    Post subject: Reply with quote

Dear Engineer,

Waiting for experts to comment on the above query.

Thanks,

Regards,
Saikiran.
Back to top
View user's profile Send private message
mallan
SEFI Member
SEFI Member


Joined: 17 Mar 2016
Posts: 19

PostPosted: Wed Nov 16, 2016 6:06 pm    Post subject: Reply with quote

Dear Er. Gone,

Im in no way an expert, but would like to contribute to this discussion.

The physical phenomenon involved is basically micro-level interlock between particles of soil.

When two surfaces slide over each other, the friction between them is a function of a co-efficient of friction and the normal force b/w them. In case shear in soils also it is similar, wherein the normal force is replaced by the effective stress in the soil. This is evident from the failure envelope of a triaxial shear graph.  http://www.geocities.ws/dominic_trani/paper4j.jpg

This coefficient of friction can be expressed in terms of an angle such that Tan-1 θ = coefficient of friction. This θ is the angle of internal friction.
Angle of internal friction is also equal to angle of repose. The angle of repose of a soil is the steepest angle of descent to which a soil can be heaped without collapsing/slumping. https://en.wikipedia.org/wiki/Angle_of_repose


Now, when the two sliding surfaces are both soil, such as the case of Terzhagi's derivation of shear strength of a soil, then the friction between the surfaces is a function of angle of internal friction, which is cohesive in nature. When the sliding surfaces are of different material such as concrete piles and soil, then angle of adhesive friction should be investigated. In the absence of investigation, it is taken as (2/3) times the angle of internal friction of soil.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> Engineering Marvels All times are GMT
Page 1 of 1

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy