This document is the TN 2.05 Minimum Maximum Cover Heights for SaniTite HP for Sanitary Sewer. Minimum and maximum cover in traffic applications explained.

The information in this document is designed to provide answers to general cover height questions; the data provided is not intended to be used for project design. The design procedure described in the Structures section (Section 2) of the Drainage Handbook provides detailed information for analyzing most common installation conditions. This procedure should be utilized for project specific designs.

The two common cover height concerns are minimum cover in areas exposed to vehicular traffic and maximum cover heights. Either may be considered "worst case" scenario from a loading perspective, depending on the project conditions.

Minimum Cover in Traffic Applications are pipe diameters from 12- through 48-inch (300-1200 mm) installed in traffic areas (AASHTO H-20, H-25, or HL-93 loads) must have at least one foot (0.3m) of cover over the pipe crown, while 60-inch (1500 mm) pipes must have at least 24 inches (0.6m) of cover. The backfill envelope must be constructed in accordance with the Installation section (Section 5) of the Drainage Handbook and the requirements of ASTM D2321.

Table 1 shows the values for Minimum Cover Requirements for ADS SaniTite HP with AASHTO H-20, H-25, or HL-93 Load.

For maximum cover, wall thrust generally governs the maximum cover a pipe can withstand and conservative maximum cover heights will result when using the information presented in the Structures section (Section 2) of the Drainage Handbook.

The maximum burial depth is highly influenced by the type of backfill and level of compaction around the pipe. Table 2 shows the values for the ADS SaniTite HP Mechanical Properties.

Figure 1 is the ADS SaniTite HP Pipe Trench Detail (Sanitary Sewer), Table 3 shows the values for Maximum Cover for ADS SaniTite HP Pipe for Sanitary Sewer, ft (m).