Compressible Clay Soil As Backfill Material:Problems And Remedial Measures

Soil is the most abundantly available construction material on the earth. At places, it is found to be the only locally available construction material. Backfilling of utility trenches is done with the soli available from the excavation of the trenches. Properties of this backfill soil vary from site to site depending upon the material available from excavation. Many times due to use of poor soils or due to improper compaction, settlement of the backfill material due to the loss of strength in the backfill soil results in the hindrance to the traffic crossing the utility trenches and may also cause damage to the utility. Sometimes it becomes difficult to compact the backfill properly in the confined areas due to various site constraints such as backfilling around or beneath the concrete or steel structures or in the narrow trenches of the underground utilities. To avoid inconvenience to the road users and damage to the underlaid pipes etc. proper care should be taken during the backfilling operations. For this in addition to imparting the required compaction to the backfill, the properties of soil available should also be improved by using various techniques of soil stabilization. The modified material should then be used in the backfilling operations.

Stabilization of yellow clays obtained from the excavation of the trench, having high to moderate compressibility, can be done with locally available sand. This may be one of the cost-effective and quick methods of improving the properties of such soils.