Effect of cycling wetting and drying on suction variation under axial loading an experimental approach

الملخص EN

Disregarded the unsaturated soil behavior, like changes in volume and soil collapsing has caused a lot of damage to the foundations of the buildings and other structures.

These behaviors relate to drying and wetting phenomena.

An experimental study was carried out to investigate the variations of suction and stress - settlement relations under axial static loading on fine grain unsaturated soil (CL-ML) after 3 cycles wetting and drying.

A prototype foundation model (100×100×35mm) was used in the testing program.

Tests were carried out in a specially designed bearing capacity box (900×900×850) mm with soil suction measurements.

Results showed an increase in the applied failure stress of about 19%after an application of three wetting-drying cycles.

On the other hand, the sense record slight variation in amount of suction about 2 kPa (both recorded sensors S1,S2) during increasing axial load after wetting-drying cycles repetition.

While the variation coincide with first applied load increment (before moisturizing drying case), and sense readings showed continue change (from 12 to 15 at S1,from 7 to 0 kPa at S2) with increasing load limit till failure happened.

This could be attributed to the change in physical soil properties such as soil densification and hysteresis effects, consequently affected its ability on retention water in pore space.