P pinkpig Active member Joined Aug 5, 2008 Messages 43 Reaction score 0 Sep 16, 2008 #1 How to calculate a critical length of grade for a vertical curve?
N nomind New member Joined Sep 10, 2008 Messages 1 Reaction score 0 Sep 16, 2008 #2 pinkpig said: How to calculate a critical length of grade for a vertical curve? Click to expand... I found the answer from Green Book Page 240. Critical Length of Grade derived as tangent grade. where vertical curve is part of critical Length of grade, an approximate equivalent tangent grade should be used. Refer to Exhibit 3-69 Vertical curve Type II and IV, the grade algebraic difference is not too great, critical length of grade maybe measured as between VPI. I would think it is measure btw PVC and PVT For Vertical Curve Type I and III, one-quarter of vertical curve length is considered as part of critical length of grade. If anything wrong, please point it out. Thanks
pinkpig said: How to calculate a critical length of grade for a vertical curve? Click to expand... I found the answer from Green Book Page 240. Critical Length of Grade derived as tangent grade. where vertical curve is part of critical Length of grade, an approximate equivalent tangent grade should be used. Refer to Exhibit 3-69 Vertical curve Type II and IV, the grade algebraic difference is not too great, critical length of grade maybe measured as between VPI. I would think it is measure btw PVC and PVT For Vertical Curve Type I and III, one-quarter of vertical curve length is considered as part of critical length of grade. If anything wrong, please point it out. Thanks