Impact factor for ALL Model 1 loading of CS 454

Creation date: 7/23/2020 9:29 PM    Updated: 7/24/2020 7:02 AM    all model 1 all model 2 cs 454
Question:

Hi,


I am doing a bridge assessment in accordance with new DMRB assessment codes. I have a question regarding the impact factor to ALL Model 1 loading. I have a vehicle defined as shown in the screenshot below, you can see that the weight critical axel 3 does not seem to have included the impact factor 1.62 or 1.8 depending on the road surface. Could you clarify if the impactor is included in the analysis automatically or not based on the condition of the road surface specified?


Kind regards,






Answer:

Hi,

The values of axle loads in the vehicle dialog box represent the static effect without impact factor included. The impact factor will be determined based on the loading case and road surface option and applied during the analysis automatically.

Regards,
DK Lee
Technical Manager

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DK LEE,


Thank you very much for your help. Now I have another question, I need to apply ALL Model 2 together HB Loading (or any of the SV vehicles). Should I use moving load optimisation or should I use traffic line/surface lane? Sometimes, I could not find the vehicles I defined when generating the moving load cases. I defined ALL M2 with SV 80, SV 100 , SV 150 and SV 196 respectively. They all give me the same results, why? Please find the attached model for your information.


Kind regards,





Hi,

I need to apply ALL Model 2 together HB Loading (or any of the SV vehicles). Should I use moving load optimisation or should I use traffic line/surface lane?
For the grillage model like your model, traffic line lane is preferred. 

Sometimes, I could not find the vehicles I defined when generating the moving load cases. 
Certain options in the moving load case cannot apply to some vehicle type. If you let me know a specific case, I could explain better.

I defined ALL M2 with SV 80, SV 100 , SV 150 and SV 196 respectively. They all give me the same results, why?
I will look into this and get back to you.

Regards,
DK Lee
Technical Manager

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DK LEE,

Thank you very much for the quick reply. when I am trying to apply ALL M2 with HB vehicles (or SVs) with possibility of HB straddling two lanes in accordance with assessment code. The program does not allow me to do it, why? See screenshot below: I untick the moving load optimisation box and tick the Auto live load combination box.



When I untick the Auto live load combination box at the same time, I got another error message. show screenshot below:



I remember that I used to be able to use lane straddling option in the previous verison of MIDAS Civil. Could you let me know how should I do the lane straddling as it is required in the code as shown in sketch below:



Kind regards,





Hi,

1. Straddling option in the moving load case cannot be used with the 'Transverse Lane Optimisation'. If you check off this option in the lane 1, 2 and 3 definition, the first message will not appear.

2. We have blocked the combination of two vehicles unless Auto Live Load Combination is not used. Thus, only one type of vehicle can be applied as shown below.
   

Regards,
DK Lee
Technical Manager

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Hi,

Thank you very much for your help once again. I have unticked "Transverse Lane Optimisation" and I am able to stradde the spectial vehical. However I started to analyse the model; I got the error messages shown in the screenshot below. Please find the attached my new model for your information. Could you advise me what to do next ASAP please? Thank you! 


Kind regards,







Element 786 is missing in the Lane 2. That is the reason.
    

Regards,
DK Lee
Technical Manager

Click here to give FEEDBACK


DK LEE,


Thank you so much for your quick reply. I correct the Lane 2 and It is analysing now.


Kind regards,




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