Abstract:

Inferior strength and more deformation resulted from salt expansion, dissolution and water absorption, are overcome by means of reinforcement with wheat straw. Reinforced ratio, reinforced length and water content of soil influence the compressive strength of heavy compaction specimen and its stress-strain. It has been proved that (1)compressive strength of reinforced soil with 0.25% ratio is the best, those with 0.2% and 0.3% are better, peak of stress-strain curve of reinforced soil with 0.25% is remarkable; (2)effect of reinforced ratio on stress-strain is more and more weaker with the increase of reinforced length;(3)type of stress-strain curve changes gradually from strain softening to strain hardening with the increase of reinforced length, in which that with 70 mm is obvious; and (4)there is a peak in stress-strain curve of reinforced soils below optimum water content, and that above optimum water content display gently plasticity. Analysis on regulation of unconfined compressive strength and stress-strain will provide some directions for studying triaxial shear strength of reinforced soils with wheat straw and its deviator stress-strain in next stage.

Key words: compressive strength, stress-strain, reinforcement condition, water content, wheat straw, saline soil, heavy compaction