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.

DG Set foundation Daily Digest Wed Aug 18 23:00:02 2004

 
This forum is locked: you cannot post, reply to, or edit topics.This topic is locked: you cannot edit posts or make replies.    www.sefindia.org Forum Index -> Past Discussions Year 2004
View previous topic :: View next topic  
Author Message
cdeshpan
SEFI Member
SEFI Member


Joined: 26 Jan 2003
Posts: 6

PostPosted: Wed Aug 18, 2004 8:20 pm    Post subject: DG Set foundation Daily Digest Wed Aug 18 23:00:02 2004 Reply with quote

Hi Snehal,

Would you be able to let us know the approx. size and
pattern of cracks if possible, and also the kind of
grout that has been used.  Also how long has the
foundation been in service?  Also, if there is any
significant temperature differential possible, and any
other relevant details you may observe/know.  For
example: you have observed vibrations in one set, then
any available measurements of the same.  


-Chitra


----------------------------------------------------------
Message From  JVCSNL@ltecd.ltindia.com
Subject: DG Set foundation
Date: 18/08/04
Time: 17:18:46
----------------------------------------------------------
Dear Snehal,

It is difficult to judge the cause of the vibration
problem in one of
the DG set foundation based on the information
provided.  However,
assuming the same quality of reinforced concrete for
all 5 foundation
blocks,  verify following conditions to assess the
reason for the
vibration problem.

1.  At a first glance, I guess, the problem could be
the misalignment
of the rotating parts of the DG showing vibration
problem.  This may
induce larger Unbalance forces, leading to larger
amplitudes.  

Also, can you check whether all DG Sets are operating
at the same
speed?  This information may guide you to assess the
resonance criteria
at the operating speed (I guess it may be different
from normal
operating speed for other DGs) which may not have been
considered in
the
Dynamic analysis of the block foundation.

2.  Though, the foundation block size for all DG sets
is same, the soil
beneath each block may not have same properties.
Hence, if the soil
properties below each foundation vary from one block
to other, the
performance of block foundation will also be
different.  

You may have to carry out detailed analysis to examine
the causes of
the problem based on the machine's actual operating
conditions, in-situ
soil and reinforced concrete properties.

Regards,

Jignesh Chokshi



Quote:
Quote:
Quote:
snehal.bhatt@mottmac-india.com 17-08-2004 >>>
Dear friends,
We have encoutered a problem in DG set foundation
block: The details
are as under:
1. There are 5 simillar DG sets with same details of
foundation block
at the same location:
2. In one of the DG set, there are vibrations and due
to that there are
lot of problems in DG set operation and were compelled
to detatch DG
set
from foundation.All other DG sets are OK.
3. There is no visible crack in the foundation
block.However some
cracks are found in the grout of the foundation bolts
at the
corners.There are 8 bolts in each side and other
pockets are OK.

Can anyone suggest the cause/ remedy for this type of
vibrations?
Snehal.






          
__________________________________

New and Improved Yahoo! Mail - Send 10MB messages!

Posted via Email
Back to top
View user's profile Send private message
Display posts from previous:   
This forum is locked: you cannot post, reply to, or edit topics.This topic is locked: you cannot edit posts or make replies.    www.sefindia.org Forum Index -> Past Discussions Year 2004 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 can 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