FILL HEIGHT TABLES
Fill Height Tables
The ACPA's Fill Height Tables have been developed using the indirect design method in accordance with Section 220.127.116.11 of the AASHTO LRFD Bridge Design Specification, 9th Edition.
To save the engineer the trouble of going through a design analysis per the AASHTO LRFD method, ACPA created the fill height tables to quickly and easy facilitate selection of the proper reinforced concrete pipe for a given installation condition. Once bedding type, pipe diameter and fill height are chosen, the fill height tables will provide the required D-Load and the corresponding required class of concrete pipe.
Fill Height tables are conservative to the extent that the pipe is assumed to be installed in a positive projecting embankment condition with a soil unit of 120 pounds per cubic foot, which this is rarely the case.
The fill height tables are based on the four types of Standard Installations, with a Type 1 Installation requiring the highest level of compaction and the highest quality of granular material and a Type 4 Installation requiring the lowest level of compaction and lowest quality material.
Pipes are categorized into five classes by color, along with a sixth category of pipe when the strength of the standard classes per ASTM C76 (AASHTO M170) are exceeded and a special design is required. The strength of the pipe increases with the class number, with Class V being the strongest standard classification of pipe per ASTM C76, and Class I the least strong.