Study On Stabilization Of Muddy Soil And Mechanical Properties Of Stabilized Soil

Cemented soil has been widely used in ground treatment, however, engineering experiences suggested that strength of cemented soil is very slower when the cement is used to treat the muddy soil riched in organica matter and water. Cement mixed pile is difficult to be formed in this kind of ground. The cost of ground treatment is largely increased, so it is necessary to choose the proper material added into the cement to improve the effect of soil stabilization. This paper is based on the project of "Research on the organic matter soil stabilization and the physical and mechanical properties of stabilized soil" (authorized number: 50675155), which is sponsored by National Nature Science Foundation of China. The present state and perspectives of stabilization agent has been generalized. The influence mechanism of humic acid on the process of cement stabilization was analysed, and treating techinique was put forward; The optimum mixture ratio of stabilization agent was determined based on the indoor single-mixed and orthogonal experiment; Strength prediction model for the stabilized soil was established based on the analysing the influence of factors on the development of stabilized soil. The nonlinear empirical constitutive model was built up based on data obtained from triaxial tests. The curves of triaxial tests simulated for the stabillized soil by the FLAC software. The main contents of this paper are as follows:(1)The influence mechanism of humic acid on the process of cement stabilization was analysed, and treating techinique was put forward;(2)Stabilization effect and mixture reference range of several additives on the strength development of stabilized soil was obtained by the single mixed test. These additives include hydrate of sodium, triethanolamine, high efficiency water reducing agent, sodium silicate, gypsum, kalli permangana, quicklime.(3)The optimum mixture ratio of stabilization agent GX07 was made based on the orthogonal experiment. Compared with other stabilizers, GX07 has advantage in improving strength.(4) Strength prediction model for the stabilized soil was established by regression analysis for the data obtained from unconfined compression tests. This model considered the influnce of content of humic acid, stabilizer, cement, water and curing time on the strength development of stabilized soil.(5) Regularity considering the influence regularity of confined pressure on the mechanical property of muddy soil treated with stabilizer was obtained from triaxial tests. At the same time, the relation between the index of shear strength resistance and the strength of stabilized soil has also been analysed.(6) Nonlinear. fitting was done on the stress-strain curves obtained from the unconfined compression tests and triaxial tests. The nOnlinear empirical constitutive model was built up based on experiment data.(7) Disturbance evolution regularity of shear strength resistance index was derived from the results of tests. The strain soften and harden character of curves has been simulated by the FLAC software.