Abstract:

Turfy soil is a humus soil which is formed at lowland with the characteristics of high organic matter content, large void ratio, high compressibility and different decomposition degree. The variation characteristics of structural strength with different decomposition degrees of turfy soil are researched through indoor tests. It is studied on the characteristic of microstructure with the change of decomposition degree of turfy soil. Then, the unconfined compressive strength and the variation of stress-strain with different decomposition degrees are determined by sensitivity tests and triaxial tests for undisturbed and disturbed soils. The variation features of sensitivity and structural strength with different decomposition degrees are tested by compression experiments and analysed from its structure and mechanism. The results show that turfy soil is a soil with high decomposition degree. With the increase of decomposition degree, the structure of the specimens changes from framework structure to flocculated structure, the pore volume becomes small and the structural sensitivity decreases from 2.029 to 1.075. The structural strength of specimens 1^#,2^#,3^# are 17 kPa, 15 kPa and 9 kPa respectively.

Key words: turfy soil, decomposition, microstructure, structural analysis