Experimental Study On Cement-Soil Strength Properties Of Silt Soil In Dongting Lake Area

The soil-cement construction parameters meet the engineering need, which obtained through indoor experiment using silt soil in Dongting Lake area as the raw material and by using the theory of soft soil reinforcement technology. That provide the basis for engineering practice. The main research works in this paper as follows:Firstly, through cement-soil mixed design and experiment, studies several main factors which influence of cement-soil unconfined compressive strength, obtains the rule about the unconfined compressive strength of cement-soil with cement ratio, moisture content, sand ratio and cement grade change.Secondly, through triaxial test of the cement-soil, the stress strain curve under different cement ratio, curing age and confining pressure of cement-soil has researched, obtains the rules of cement-soil strength change with cement ratio, curing age and the confining pressure. The cement-soil damage model is brittle failure.Thirdly, a embankment foundation has been designed according to the results of laboratory test in Dongting Lake area, using field load test to check the foundation treatment, the results show that the design parameters of this study provide, can guide the engineering practice, the foundation bearing capacity meet the requirements after be treated.According to the laboratory experiment, the main results as follows:Firstly, the silt soil unconfined compressive strength of the cement ratio increases linearly approximately when the cement ratio is 6% ~ 16%, the strength increases from 56 kPa to 87 kPa with the increase of the ratio per 1%, The strength of cement-soil increases slowly if cement ratio is less than 10% or more than 14%, then increase quickly else. Cement ratio have a significant effect on cement-soil strength, no significant influence of other factors.Secondly, the peak strength of cement-soil increases with the cement ratio increase, the peak strength of cement-soil increase between 60 k Pa to 360 kPa as a 3%increase(cement ratio).Under the same cement ratio. The peak strength of cement-soil increases with the increase of confining pressure, its value is between 170 k Pa to 120 k Pa. The strain value along with stress peak appears is at 2.1% ~ 3.6%.Thirdly, confining pressure has significant effect on cement-soil strength with long curing age. The influence of the strength of cement-soil pile is closely related to surrounding soils provide confining pressure, the greater the confining pressure, the more capable of cement-soil strength.