Characterizations of Soil Collapsibility: Effect of Salts Dilution

Abstract

Collapsibility of soils is the large change in volume of soil upon saturation or wetting.  This change may or may not be the result of the application of additional load.  Soil at a construction site may not always be suitable for supporting structures such as buildings, bridges, highways, and dams.  For example, if soil is placed in a certain none desire density, a large settlement will occur either due to loading or wetting of soil deposits.  Hence, a collapse will occur which will create a large subsidence or a sinkhole.

In this study, soil samples of CL-ML soil were modified by adding different amounts of brine.  The main goal of which was to examine the effect of brine presence on the collapse potential of the soil.  Soil index properties, compaction characteristics, and a collapse potential were evaluated according to ASTM standards.  The test includes Atterberg's limit, Harvard miniature compaction, and double oedometer tests.

It has been shown that brine additive has pronounced effect on the Atterberg’s limits; it is clearly shown that as the amount of brine increases both liquid limit and plastic limit decrease.  Compaction curve characteristics of soil were altered by the presence of brine, the maximum dry density, obtained using Harvard miniature device, increased as brine percentage increased, however, the optimum moisture content showed substantial decrease with increasing the amount of brine.