ANS:D - all the above.

A sewer running partially full and hurried with backfill may fail in compression due to various factors, including:

• Weight of the pipe: The weight of the sewer pipe itself contributes to the overall load on the sewer system. The weight of the pipe can exert downward pressure on the backfill material and the surrounding soil.
• Weight of the backfill: The backfill material placed around the sewer pipe exerts lateral and vertical pressure on the pipe. If the backfill material is too heavy or inadequately compacted, it can lead to excessive pressure on the pipe, potentially causing compression failure.
• Superimposed traffic loads: If the sewer is located beneath roadways or areas subject to vehicular traffic, the additional weight and dynamic loading from vehicles can further stress the sewer system. The combination of traffic loads and the weight of the backfill can contribute to compression failure.

Therefore, the correct statement is: all the above. Each of these factors - the weight of the pipe, the weight of the backfill, and superimposed traffic loads - can individually or collectively contribute to compression failure in a sewer running partially full and hurried with backfill.