Improvement of sabkha soil by using geomesh and addition of polycoat

Abstract EN

Sabkha soil is a rich soil with salt deposited which result from evaporation of water, it is one of the many types of collapsible soils and in turn is one of the many types of problematic soils.

This soil totally has good engineering properties when dry , i.

e, moderately bearing capacity with low settlement.

But once is wetted it loses its entire structure (collapse) and undergoes very large instantaneous settlement.

A laboratory model test consists of a cylindrical steel container of 270 mm diameter and 300 mm height, the soil is brought from Al-Khalis discrete.

The density of soil is controlled by placing the required weight inside the container of known volume, to the required height.

A square footing 40mmx40mm makes from steel is used.

The stress is applied from a fixed loading system designed especially for model tests.

In this study two types of improvement are used, the first improvement consists of fine geomesh under footing at different depth (0.5B, B, 2B),the second improvement is the addition of polycoat with different concentration to surface of soil.

The first method do not give good results of improvement but the second method gives good improvement which reduces the collapsibility to 62 % at stress level of 50 kPa.