The geometry of the arch section is actually very non-standard. It seems that there is not single equation governing the design of arch pipe. All manufactures tend to vary the specific dimensions of the various arch dimensions. To provide an approximate solution to arch shaped sections, the program relies on a set of table provided in Modern Sewer Design, American Iron and Steel Institute, 1995 for guidance.
Hydraulic Properties of Arch Conduits Flowing Part Full
Determination of Arch Area
|
Determination of Area |
|
|
Values of A/BD |
|
Y/D |
0 |
0.01 |
0.02 |
0.03 |
0.04 |
0.05 |
0.06 |
0.07 |
0.08 |
0.09 |
|
0.1 |
|
0.072 |
0.081 |
0.09 |
0.1 |
0.109 |
0.119 |
0.128 |
0.138 |
0.148 |
|
0.2 |
0.157 |
0.167 |
0.177 |
0.187 |
0.197 |
0.207 |
0.217 |
0.227 |
0.237 |
0.247 |
|
0.3 |
0.257 |
0.267 |
0.0277 |
0.287 |
0.297 |
0.307 |
0.316 |
0.326 |
0.336 |
0.346 |
|
0.4 |
0.365 |
0.356 |
0.375 |
0.385 |
0.394 |
0.404 |
0.413 |
0.423 |
0.432 |
0.442 |
|
0.5 |
0.451 |
0.46 |
0.47 |
0.479 |
0.488 |
0.497 |
0.506 |
0.515 |
0.524 |
0.533 |
|
0.6 |
0.541 |
0.55 |
0.559 |
0.567 |
0.576 |
0.584 |
0.592 |
0.6 |
0.608 |
0.616 |
|
0.7 |
0.624 |
0.632 |
0.64 |
0.647 |
0.655 |
0.662 |
0.67 |
0.677 |
0.684 |
0.69 |
|
0.8 |
0.697 |
0.704 |
0.71 |
0.716 |
0.722 |
0.728 |
0.734 |
0.74 |
0.745 |
0.75 |
|
0.9 |
0.755 |
0.76 |
0.764 |
0.769 |
0.772 |
0.776 |
0.78 |
0.783 |
0.785 |
0.787 |
|
1.0 |
0.788 |
|
|
|
|
|
|
|
|
|
Determination of Hydraulic Radius
|
Determination of Hydraulic Radius |
|
|
Values of R/D |
|
Y/D |
0 |
0.01 |
0.02 |
0.03 |
0.04 |
0.05 |
0.06 |
0.07 |
0.08 |
0.09 |
|
0.1 |
|
0.078 |
0.086 |
0.094 |
0.102 |
0.110 |
0.118 |
0.126 |
0.133 |
0.141 |
|
0.2 |
0.148 |
0.156 |
0.163 |
0.170 |
0.177 |
0.184 |
0.191 |
0.197 |
0.204 |
0.210 |
|
0.3 |
0.216 |
0.222 |
0.228 |
0.234 |
0.240 |
0.245 |
0.25 |
0.256 |
0.261 |
0.266 |
|
0.4 |
0.271 |
0.275 |
0.28 |
0.284 |
0.289 |
0.293 |
0.297 |
0.301 |
0.305 |
0.308 |
|
0.5 |
0.312 |
0.315 |
0.319 |
0.322 |
0.325 |
0.328 |
0.331 |
0.334 |
0.337 |
0.339 |
|
0.6 |
0.342 |
0.344 |
0.346 |
0.348 |
0.350 |
0.352 |
0.354 |
0.355 |
0.357 |
0.358 |
|
0.7 |
0.360 |
0.361 |
0.362 |
0.363 |
0.363 |
0.364 |
0.364 |
0.365 |
0.365 |
0.365 |
|
0.8 |
0.365 |
0.365 |
0.364 |
0.364 |
0.363 |
0.362 |
0.361 |
0.360 |
0.359 |
0.357 |
|
0.9 |
0.355 |
0.353 |
0.350 |
0.348 |
0.344 |
0.341 |
0.337 |
0.332 |
0.326 |
0.318 |
|
1.0 |
0.299 |
|
|
|
|
|
|
|
|
|
Determination of Arch Top Width
|
Determination of Top Width |
|
|
Values of T/B |
|
Y/D |
0 |
0.01 |
0.02 |
0.03 |
0.04 |
0.05 |
0.06 |
0.07 |
0.08 |
0.09 |
|
0.1 |
|
0.9 |
0.914 |
0.927 |
0.938 |
0.948 |
0.956 |
0.964 |
0.971 |
0.976 |
|
0.2 |
0.982 |
0.986 |
0.99 |
0.993 |
0.995 |
0.997 |
0.998 |
0.998 |
0.998 |
0.999 |
|
0.3 |
0.997 |
0.996 |
0.995 |
0.993 |
0.991 |
0.989 |
0.987 |
0.985 |
0.982 |
0.979 |
|
0.4 |
0.976 |
0.971 |
0.967 |
0.964 |
0.96 |
0.956 |
0.951 |
0.947 |
0.942 |
0.937 |
|
0.5 |
0.932 |
0.927 |
0.921 |
0.916 |
0.91 |
0.904 |
0.897 |
0.891 |
0.884 |
0.877 |
|
0.6 |
0.87 |
0.863 |
0.855 |
0.847 |
0.839 |
0.83 |
0.822 |
0.813 |
0.803 |
0.794 |
|
0.7 |
0.784 |
0.773 |
0.763 |
0.752 |
0.741 |
0.729 |
0.717 |
0.704 |
0.691 |
0.678 |
|
0.8 |
0.664 |
0.649 |
0.634 |
0.618 |
0.602 |
0.585 |
0.567 |
0.548 |
0.528 |
0.508 |
|
0.9 |
0.486 |
0.462 |
0.437 |
0.41 |
0.381 |
0.349 |
0.313 |
0.272 |
0.223 |
0.158 |