The changes of the soil physical properties due to the influence of seawater and differences in clay mineral composition.

Climate change influences urban conditions on the north coast of Java island causes changes in coastlines and catastrophic tidal flooding that harmed infrastructures, i.e. cracks, tilts, and sank, and damage on roads and waterways. Semarang is one of the cities that always experiences flood problems; it reduces bearing capacity due to the swelling-shrinking and consolidation behaviour on unconsolidated clay materials. This research was intended to reveal the changes in the soil properties due to seawater contact. The method used was the immersion model and mineral composition of XRD results. Statistical tests were conducted on the immersion and mineral composition results to obtain correlations between seawaters and changes in clay soils. The F-count value of 3.897 is more significant than F-table, indicating clay soil is strongly influenced by seawater. The statistical test resulting in the clay minerals and volume changes show the t-count value of the Montmorillonite has a value of 3.303 or greater than the t-table value. Hence, the Montmorillonite has the most influence on changes in sample volume when immersed in seawater. This research is expected to provide an understanding of the seawater impact on clay, building, and infrastructure in Semarang city. [ABSTRACT FROM AUTHOR]