Use the following set of variables to calculate transition distances.
{e} | The equilibrium cant for the curve. This value is determined from the Equilibrium Cant formula that is specified in the Calculate Cant Wizard - Attainment Method Page. |
{a} | The applied cant for the curve. |
{u} | The cant deficiency for the curve. |
{t} | The transition length value that is read from the transition length table, based on the design speed and the curve radius. |
{l} | The length of the spiral, if a spiral is involved in the transition. This is the actual length of the spiral element in the curve group. |
{s} | The track width value that is defined on the Rail Parameters tab of the Alignment Properties dialog box. |
{g} | The gravitational acceleration. |
{r} | The radius of the curve. This is the actual radius of the curve element. |
{v} | The design speed at the alignment station. |
{p} | The fractional part of the transition length achieved before the BC point. This value is specified as either % On Tangent for Tangent-Curve or % On Spiral for Spiral-Curve in the Calculate Cant Wizard - Attainment Method Page. |
{d} | Maximum applied cant on tangent for tangent-curve. This value is specified in the Calculate Cant Wizard - Attainment Method Page. |
{m} | Maximum allowable cant deficiency. This value is determined from the Maximum Allowable Cant Deficiency formula that is specified in the Calculate Cant Wizard - Attainment Method Page. |
The variables in the previous table are used to calculate the following:
XML Code | Description |
---|---|
LR | Level Rail |
FC | Full Cant |
BC | Begin Curve |
EC | End Curve |
The following table describes the formulas:
XML Code | Description |
---|---|
LRtoFC | The distance from the Level Rail Station to the Full Cant station is the value {t}, which is read from the selected transition length table. The formula assumes that the transition length table defines the transition length. |
LRtoBC | The distance from the Level Rail station to the Beginning of Curve station is a percentage of the transition length {t} based on the variable {p}. |