Sensitive use analysis DG11
The vibration check calculations can be performed for sensitive equipment & occupancy if required.
These calculations make use of Chapter 6 of DG11 2nd Edition (2016) with revisions and errata of 27 July 2018. They only cover ⅓ octave spectral velocity and acceleration.
For these calculations the mode shape factors ɸ_{E} and ɸ_{W} are taken as 1.0. i.e. it is conservatively assumed that the walker and sensitive equipment or sensitive occupant are both at midbay.
Use Case  Sensitive Equipment If walking speed = Very Slow , 

f_{step}  =  1.25 Hz  [Table 61] 
V_{1/3}  =  (250 * 10^{6}) / (β * W) * (f_{step}^{2.43} / f_{n}^{1.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 63a] 
A_{1/3}/g  =  (100 * 4.2) / (β * W) * (f_{step}^{2.43} / f_{n}^{0.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 68a] 
Else if walking speed = Slow , or Moderate or Fast 

f_{step} , f_{L} , f_{U} and γ as appropriate to selected walking speed  [Table 61]  
If f_{n} ≤ f_{L} 

V_{1/3}  =  (175 * 10^{6}) / (β * W * f_{n}^{0.5}) * (e^{γ*fn})  [Eqn 63b]^{1} 
A_{1/3}/g  =  (100 * 6.4) / (β * W) * (e^{γ*fn})  [Eqn 68b]^{1} 
If f_{n} ≥ f_{U} 

V_{1/3}  =  (250 * 10^{6}) / (β * W) * (f_{step}^{2.43} / f_{n}^{1.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 63b]^{2} 
A_{1/3}/g  =  (100 * 4.2) / (β * W) * (f_{step}^{2.43} / f_{n}^{0.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 68b]^{2} 


Else if f_{L} < f_{n} < f_{U} For V_{1/3}
For A_{1/3}/ g

Use Case  Sensitive Occupancy DG11 2nd Edn does not provide explicit ⅓ octave spectral Acceleration equations for Sensitive Occupancy, so in Tekla Structural Designer these equations have been derived from the ⅓ octave spectral Acceleration equations for Sensitive Equipment by ‘modifying’ them by factors 200/250 (for very slow walking) and 120/175 (for other walking speeds).These modification factors are derived from consideration of the differences between ⅓ octave spectral Velocity equations for Sensitive Equipment and Sensitive Occupancy, which are given explicitly in DG11 2nd Edn. 

If walking speed = Very Slow , 

f_{step}  =  1.25 Hz  [Table 61] 
V_{1/3}  =  (200 * 10^{6}) / (β * W) * (f_{step}^{2.43} / f_{n}^{1.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 69a] 
A_{1/3}/g  =  (200/250)*(100 * 4.2) / (β * W) * (f_{step}^{2.43} / f_{n}^{0.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 68a] modified 

Else if walking speed = Slow , or Moderate or Fast 

f_{step} , f_{L} , f_{U} and γ as appropriate to selected walking speed [Table 61]  
If f_{n} ≤ f_{L} 

V_{1/3}  =  (120 * 10^{6}) / (β * W * f_{n}^{0.5}) * (e^{γ*fn})  [Eqn 69b]^{1} 
A_{1/3}/g  =  (120/175)*(100 * 6.4) / (β * W) * (e^{γ*fn})  [Eqn 68b]^{1} modified 
If f_{n} ≥ f_{U} 

V_{1/3}  =  (200 * 10^{6}) / (β * W) * (f_{step}^{2.43} / f_{n}^{1.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 69b]^{2} 
A_{1/3}/g  =  (200/250)*(100 * 4.2) / (β * W) * (f_{step}^{2.43} / f_{n}^{0.8}) * (1  e^{2*π*β*fn / fstep})  [Eqn 68b]^{2} modified 

Else if f_{L} < f_{n} < f_{U} For V_{1/3}
For A_{1/3}/ g
