Very very thank you sir I can't find the how to run kgp back software after watching your video I am able to use kgp back software thankyou sir god bless you and keep uploaded this wonderful knowledgeable vidios. Thank you sir
Thank you sir, very useful video. Can you do another presentation showing how to distinguish between different layers of flexible pavement in a test pit and how to evaluate strength of each layer.
Please note that IRC 115(2014) states that the subgrade modulus is 59.6 and the corresponding ranges selected for subgrade modulus are 57.2 to 83.4. But upon calculation the lower bound value comes out to be 1.2*59.6*0.8= 57.2 and the upper bound value comes out to be 1.2*59.6*1.2= 85.82 instead of 83.4 as mentioned in IRC 115(2014) pg 32. Please clarify
It does not matter whether it is 85 or 83. This range is given to the software to start the iteration and the final value will depend on the deflection values and layer thicknesses. The software has some weakness and I am sure these will be removed in the next revision.
There is no other procedure for Rigid Pavements. An FWD is used on rigid pavement to evaluate the load transfer across slabs and can be used to detect large voids when significant erosion of the base material has occurred under the slab joints. An FWD is commonly used to determine the variability of overall deflection along the roadway alignment. The test pocedure is same.
Sir i would request you please kindly provide a lecture on FWD data collection for Airfield Pavements and Back calculation of material properties and over lay design If possible please
Design Life in IRC 37: 2019 is 20 years for flexible pavement and in IRC 115 : 2014 it is suggested for 10 to 15 years for design of overlay, basically my question is if we are going to widen existing two lane carriageway to2 Lane + PS, which traffic calculation will govern design either IRC 37 or IRC 115. Other query is if in widening for 30 MSA traffic and 8% Subgrade CBR crust thickness is 200 mm GSB + 250 mm WMM+ 95 MM DBM + 40 MM BC and overlay thickness by FWD test we are getting 90 mm BC over 120 mm existing Bituminous part, how layers will match in this case? Kindly explain my query
IRC 115 is for the purpose of overlay design only, not for the design of pavements. Layers must be matched from subgrade level. You need to dig the side so that base course layers in two pavements is at the same level.
Nice video Sir. Our company has an almost identical KUAB in Bolivia, so it's good to see a similar FWD in other countries. I just want to know why you have two rows of buffers below the weights. Is it something related to the pulse duration? Thank you
Sir, Can milling is permitted for overlay of bituminous surface after FWD test.Miling out existing bituminous surface may reduce the strength of pavement.sir,pl clarify this
Sir In IRC 2015 given example so many problems... so i confused. Because 1st problem is poisonous ratio new payment of BT layer we take as par new pavement design is 0.35 as per IRC 37 andIRC 115 given 0.5. 2) 2nd problem is Va-Vb we can change va-vb in different different project y we take Va 3.5 and Vb 11.5 as per IRC 115 example. 3) in IIT PAVE how many analysis point use and how much radius use in road project? . Because in IRC 37-2018 IIT PAVE USE DIFFERENCE PARAMETERS AND IRC 115 USE DIFFERENCE PARAMETERS SO CAN U suggest me which can we used .
Yes, there is a confusion in Poisson ratio as suggested in IRC 115 and IRC 37. You can take any. There is very little effect of Poisson ratio on results. Generally we take 4 points for analysis. one at the depth of bituminous layer and radial distance zero, Two at same depth but radial distance 155 mm. three at the top of subgrade layer and radial distance zero, fourth, at top of subgrade layer and radial distance 155 mm. I have explained in my video on Design of Flexible pavement aslo. It is available in Hindi and English both. Watch it once.
Sir I would request you to please provide videos on various pavement compositions. Like CTB, CTSB, RAP. Also sir please cover how we can convert different layer thickness into equivalent bituminous layer thickness.
You wrote same in both cases. The Poisson ratio of bitumnous layer will increase with temperature. Test temp in FWD is higher than what we take in pavement design.
15th percentile value of any data set is the value above which 85 percent data would lie. So if you a series of data (for example Mr values estimated at different locations of a highway) then arrange them in decreasing order and locate the value below which only 15 % values lie. This can also be done by making a frequency table and plotting cumulative frequency curve in excel sheet.
Dear Sir, I would like to get clarity on the Remaining fatigue life, in your video it comes out as 11.07 msa which is less than 100 msa (design life). So if I have similar case where my remaining fatigue life is 17.1 MSA and 19 MSA (design) then, whether this will also require the overlay to match the design MSA 19 requirement?
Sir F.W.D. The value of deflection is obtained from the test. Then how is the modulus value of each layer obtained? Sir please explain. It will be so kind of you. Thank you
Modulus of eavh layer is obtained using KGPBACK software. It is a program based on Genetic Algorithm and comes with the IRC code. I have explained this method in the video also.
Unfortunately, I also do not have it. I made this video when I was in CRRI and took the help of one scientist there. Will try to get it for you, if possible.
Sir, if the existing Pavement has stabilized layers like BSM, or CTB/CTSB then during the use of KGPBACK software in which layer type should these layers be considered? Either Bituminous layer or Granular layer.. Especially incase of BSM with foamed bitumen?
The second deformation modulus EV2 is a very popular index of compaction standard of soil foundation in Germany, France and other European countries, but not in India. I will certainly make a video on Effective Modulus of Subgrade Reaction (K).
Thank you so much sir Sir, if i have deflection data at 200 m interval for a 4 km stretch , then should I input the deflection data at each interval one by one in KGPBACK or is there any other way to get the output from KGPBACK by giving deflections along the chainage at a time?
Sir, 1. Can we put 40mm BC and 55 mm DBM over existing BC. 2. Can we lay DBM over existing BC being inferior grade. 3. Or we have to mill the existing BC before laying 55m DBM and 40 mm BC.
Arun Ji, It is always good to mill the existing BC if you can. It will save both natural resources and environment. If not possible, you can certainly put DBM layer over existing BC. Remember, you need overlay on a road because the existing structure has become weak. So BC is now a weak layer.
please explin the normaliseation of fwd ಡಾಟಾ for standard load on rigid pavement with a set of data ! I it's only the you for correct person to solve my problem so I am requesting you sir please explin me !
There are no Excel sheets for this analysis. It is done through a software, which is provided by the IRC alongwith the code. You can download it www.geotran.in/back-calculation-software
@@SatishIITR As per code r is average of radial distances and w is average of surface deflections measured at 1200 mm, 1500 mm and 1800 mm. My question is by using parameters for calculating subgrade modulus range Im getting the answer as 66.67 MPa
KGPBACK demo and overlay design procedure in one video...Excellent and very useful....
Glad to know that you liked it. Please share with others also.
Thank you Sir for providing a detailed presentation.
You are most welcome, keep watching. Share the link with your friends also.
Very useful and informative presentation on FWD..
Thanks.
Another very informative lecture.
Thanks again. Keep circulating among your colleagues and students.
@@SatishIITR Sure Sir.
Sir, Thank you very much for sharing valuable information regarding overlay.
Thanks. Keep watching
Sir, thank you very much. Excellent educative ppt
Most welcome. Please send the link to your known contacts
Sir, very informative and useful lecture. Thank you for providing clear concept on pavement evaluation by FWD.
Thanks, share with your friends and students.
Very very thank you sir I can't find the how to run kgp back software after watching your video I am able to use kgp back software thankyou sir god bless you and keep uploaded this wonderful knowledgeable vidios. Thank you sir
You are welcome. Please share the link in your groups also.
can you please share KGP BACK software
Superb, very informative video.
Thanks Vishal ji, please share the link to your known contacts.
very informative
Glad you think so! Keep watching
@@SatishIITR sir try kijiye iska hindi video dene ke liye
@@swabhimaansahu OK. sure
@@SatishIITR tq so much sir ..bahht help hoga hamko
Thank you so much sir for this well explained video
Please share the link with your friends also. If possible, post it on your LinkedIn page so that many others can also be benefitted.
Great sir thank you very much I appreciate your efforts.
Thanks a lot. Keep watching.
Sir very informative lecture
Thanks, keep watching other videos also.
Very well explained sir
Can you please share KgpBack software
Thanks. You can download the KGPBACK geotran.in/backcalculation-software
Thank You 💖 SIR 💕
Most welcome
Need for Overlays, Overlays design methods for Flexible and Rigid Pavements please make a video on this topic sir🙏🙏
all these points have been discussed in different videos. Watch overlay by Benkelman Beam method, and thin white topping
Thank you sir, very useful video. Can you do another presentation showing how to distinguish between different layers of flexible pavement in a test pit and how to evaluate strength of each layer.
Great suggestion! will try to do it.
Please note that IRC 115(2014) states that the subgrade modulus is 59.6 and the corresponding ranges selected for subgrade modulus are 57.2 to 83.4. But upon calculation the lower bound value comes out to be 1.2*59.6*0.8= 57.2 and the upper bound value comes out to be 1.2*59.6*1.2= 85.82 instead of 83.4 as mentioned in IRC 115(2014) pg 32. Please clarify
It does not matter whether it is 85 or 83. This range is given to the software to start the iteration and the final value will depend on the deflection values and layer thicknesses. The software has some weakness and I am sure these will be removed in the next revision.
Please make a video on rigid pavement also sir.
There is no other procedure for Rigid Pavements. An FWD is used on rigid pavement to evaluate the load transfer across slabs and can be used to detect large voids when
significant erosion of the base material has occurred under the slab joints. An FWD is commonly used to determine the
variability of overall deflection along the roadway alignment. The test pocedure is same.
Sir, what is the moduli values consider for flexible pavement with CTB & CTSB layer for FWD analysis
In the FWD analysis, you can take initail value of moduli as suggested in IRC 37. The program will calculate it.
Sir i would request you please kindly provide a lecture on FWD data collection for Airfield Pavements and Back calculation of material properties and over lay design
If possible please
will try. However, the method of data collection remains same at airfield pavements also.
Design Life in IRC 37: 2019 is 20 years for flexible pavement and in IRC 115 : 2014 it is suggested for 10 to 15 years for design of overlay, basically my question is if we are going to widen existing two lane carriageway to2 Lane + PS, which traffic calculation will govern design either IRC 37 or IRC 115.
Other query is if in widening for 30 MSA traffic and 8% Subgrade CBR crust thickness is 200 mm GSB + 250 mm WMM+ 95 MM DBM + 40 MM BC and overlay thickness by FWD test we are getting 90 mm BC over 120 mm existing Bituminous part, how layers will match in this case?
Kindly explain my query
IRC 115 is for the purpose of overlay design only, not for the design of pavements.
Layers must be matched from subgrade level. You need to dig the side so that base course layers in two pavements is at the same level.
Sir, how can we decide the range of moduli for granular layer if the granular layer is made up of WMM + CTSB.......Please guide
You can refer IRC 37 in such cases. It gives a procedure for such layers also
Nice video Sir. Our company has an almost identical KUAB in Bolivia, so it's good to see a similar FWD in other countries. I just want to know why you have two rows of buffers below the weights. Is it something related to the pulse duration? Thank you
Thanks for watching.
@@SatishIITR Can you explain why this FWD has 2 rows of buffers, please?
Sir,
Can milling is permitted for overlay of bituminous surface after FWD test.Miling out existing bituminous surface may reduce the strength of pavement.sir,pl clarify this
Yes, milling should be preferred. Mill top 50 - 90 mm of bituminous layer and recycle it. Design the pavement as per IRC 37
Sir
In IRC 2015 given example so many problems... so i confused. Because 1st problem is poisonous ratio new payment of BT layer we take as par new pavement design is 0.35 as per IRC 37 andIRC 115 given 0.5.
2) 2nd problem is Va-Vb we can change va-vb in different different project y we take Va 3.5 and Vb 11.5 as per IRC 115 example.
3) in IIT PAVE how many analysis point use and how much radius use in road project? . Because in IRC 37-2018 IIT PAVE USE DIFFERENCE PARAMETERS AND IRC 115 USE DIFFERENCE PARAMETERS SO CAN U suggest me which can we used .
Yes, there is a confusion in Poisson ratio as suggested in IRC 115 and IRC 37. You can take any. There is very little effect of Poisson ratio on results.
Generally we take 4 points for analysis. one at the depth of bituminous layer and radial distance zero, Two at same depth but radial distance 155 mm. three at the top of subgrade layer and radial distance zero, fourth, at top of subgrade layer and radial distance 155 mm.
I have explained in my video on Design of Flexible pavement aslo. It is available in Hindi and English both. Watch it once.
Ok thank you sir
Sir,
Please help in calculations of lower bound of subgrade it is not coming as given in irc 115
How can I help you remotely??
@@SatishIITR sir the values are not coming as per the solved example
Sir in overlay design, we're the tensile strains considered under bottom of overlay or bottom of existing bituminous layer?
bottom of the existing bituminous layer only.
@@SatishIITR thanks sir
Sir I would request you to please provide videos on various pavement compositions. Like CTB, CTSB, RAP. Also sir please cover how we can convert different layer thickness into equivalent bituminous layer thickness.
There is no such technically sound method that can convert a layer into equivalent thickness of bituminous layer.
Sir, why VG30 moduli take as 1695 MPA instead 2000 MPA for overlay ?
This is just an example problem. You can take 2000 MPa. No issues
What if the 15th percentile of SG moduli is more than 100 MPa, shall we the same for overlay design or limited to 100 MPa,
Pls tell us.
Limit it to 100 MPa
Sir please make one more video on evaluation of rigid pavement by FWD
OK.
Sir, please guide about fwd for rigid pavement as per IRC 117-2015
Ok, will make one video on this topic also
@@SatishIITR thank u sir
Fwd se gsb ya wmm ka thikness pata kar sakte hai kya
I think Yes
In kgpback we took poisson ratio of existing bituminous as 0.4 and in iitpave we took it as 0.4. Why
You wrote same in both cases. The Poisson ratio of bitumnous layer will increase with temperature. Test temp in FWD is higher than what we take in pavement design.
Can you please share KGPBACK SOFTWARE
Sir why do we calculate temperature below 40 mm from the top ?
Pavement temperature is not at the surface, it is inside the layer.
In iitpave the poisson ratio is taken 0.5, 0.4, 0.4, and 0.4.
But generally we take these as 0.35. Pls explain why we took different
There is hardly any effect of Poisson ratios on stress calculations.
@@SatishIITR Thanks sir.
Sir can u explain how to calculate the 15th percentile module values?
15th percentile value of any data set is the value above which 85 percent data would lie. So if you a series of data (for example Mr values estimated at different locations of a highway) then arrange them in decreasing order and locate the value below which only 15 % values lie. This can also be done by making a frequency table and plotting cumulative frequency curve in excel sheet.
@@SatishIITR Thank u for ur valuable information sir...
Sir...please share one on CRCP design
OK. Thanks
Sir do you have any literature or something for design of bus/ truck lay byes
There is an IRC code on this subject
Dear Sir,
I would like to get clarity on the Remaining fatigue life, in your video it comes out as 11.07 msa which is less than 100 msa (design life). So if I have similar case where my remaining fatigue life is 17.1 MSA and 19 MSA (design) then, whether this will also require the overlay to match the design MSA 19 requirement?
Yes, you need overlay on this road so that pavement lasts its design life.
Does poor pavement conditions need FWD? As normally such stretches are taken for reconstruction
Yes, the decision of reconstruction will be taken based on FWD data
Sir
F.W.D. The value of deflection is obtained from the test. Then how is the modulus value of each layer obtained? Sir please explain.
It will be so kind of you.
Thank you
Modulus of eavh layer is obtained using KGPBACK software. It is a program based on Genetic Algorithm and comes with the IRC code. I have explained this method in the video also.
Thank you sir
@@SatishIITRHow to get
KGPBACK Software?
you can download it from internet@@parasmanisindhia4493
Sir, please provide the download link.
Hello Sir,
can you provide me excel sheet of CC pavement for FWD? for find Radius of Relative stiffness?
There are no such excel sheets
Overlay is 95mm BC in example. Can this be put as 30BC and 65 DBM?
Probably yes, will need to check.
Sir, Can you please share the KGPBACK moduli please
Will see if I have it.
@@SatishIITR Sir please share KGPBACK
@@manasswain5450 sorry, i do not have it. My file got corrupted.
Sir I can't find the KGPBACK software. Can you share the link please.
Unfortunately, I also do not have it. I made this video when I was in CRRI and took the help of one scientist there. Will try to get it for you, if possible.
@@SatishIITR That would be a great help sir. Please let me know if you find it somehow.
Sir, if the existing Pavement has stabilized layers like BSM, or CTB/CTSB then during the use of KGPBACK software in which layer type should these layers be considered? Either Bituminous layer or Granular layer.. Especially incase of BSM with foamed bitumen?
stabilized layers are more close to granular layers.
@@SatishIITR Thank you so much Sir..
Sir how to download KGP BACK Software?
It comes with IRC code. Not available for download
Sir how to select the poisson's ratio?
There is hardly any effect of Poisson Ratio on stresses. Take as per guidelines given in IRC 37
Sir can u make a concept video on EV2 test ?
The second deformation modulus EV2 is a very popular index of compaction standard of soil foundation in Germany, France and other European countries, but not in India. I will certainly make a video on Effective Modulus of Subgrade Reaction (K).
Thank you so much sir
Sir, if i have deflection data at 200 m interval for a 4 km stretch , then should I input the deflection data at each interval one by one in KGPBACK or is there any other way to get the output from KGPBACK by giving deflections along the chainage at a time?
you need input the data at each location
Thank you sir
Sir, while calculating remaining fatigue life , what about the C value in the equation, factor C of volumetrics?
How can we get C value sir?
@@saitharun9585 In the same manner as you take in the design of a new pavement.
@@SatishIITR okay sir
Thank you sir
Sir,
1. Can we put 40mm BC and 55 mm DBM over existing BC.
2. Can we lay DBM over existing BC being inferior grade.
3. Or we have to mill the existing BC before laying 55m DBM and 40 mm BC.
Arun Ji, It is always good to mill the existing BC if you can. It will save both natural resources and environment. If not possible, you can certainly put DBM layer over existing BC. Remember, you need overlay on a road because the existing structure has become weak. So BC is now a weak layer.
sir please help from where we can get this software
This software is freely available for download on internet. Try
Sir I wanted to ask you some questions
sure,. you can write either here or you can send me an email.
@@SatishIITR ok sir
@@SatishIITR I wanted to ask you that it is possible to suggest reconstruction of the pavement section after performing the FWD test.
After analyzing the data..after calculating the overlay required can we suggest this?
Or else how can we analyze that the granular layer n subgrade are not sufficient enough to carry the design MSA
please explin the normaliseation of fwd ಡಾಟಾ for standard load on rigid pavement with a set of data !
I it's only the you for correct person to solve my problem so I am requesting you sir please explin me !
Normalization here means extrapolation only. If deflection value for a load of 39 kN is 0.234, then for 40 kN it will be 0.234*(40/39).
Kindly, provide excel sheets in the video if possible sir!..Thanks
There are no Excel sheets for this analysis. It is done through a software, which is provided by the IRC alongwith the code. You can download it www.geotran.in/back-calculation-software
m 0.4
P 40000
r 1500 (1200+1500+1800)/3
w 0.107 (0.134+0.107+0.08)/3
E 66.67
53.34 66.67*0.8
80.00 66.67*1.2
Im getting E value as 66.67 by using above parameters. Can you please tell me what I did wrong
I did not understand these calculations and your question. Why did you take average of r and w?
@@SatishIITR As per code r is average of radial distances and w is average of surface deflections measured at 1200 mm, 1500 mm and
1800 mm. My question is by using parameters for calculating subgrade modulus range Im getting the answer as 66.67 MPa
@@BHARATKUMAR-zf4co a subgrade modulus of 66 looks fine
Sir value is differ with the given example in Appendix iv of irc115@@SatishIITR
@@GoutamChatterjee-w4j which value?? Value of subgrade modulus?
kgpback software link plz
There is no link available for this software. It comes with IRC code.
Sir, can you upload link of this pdf ?
will see
Fugro India is going to start FWD in India
That's very great.