The Research On The Research Of The Raw Lime Treatment For The Wet Ground Of The Jishu Highway

Relying on the program ‘Research on the Ground Treatment Technology of Over-wet Soil Highway',with the research of lime stabilized soil treatment technology,aiming to improve the construction technology on Ji-Shu expressway.The achievements of this study included:1.The liquid limit and plastic limit of lime stabilized soil increases with the increase of lime incorporation ratio,while the change of plastic index is opposite.With the lime mixed with the soil,the specific gravity of the soil particles increases gradually,and the particle size of the particles changes obviously.The content of granules and clay in soil decreases with the increase of lime content,but the change of clay is more obvious.2.With the increase of lime content,the optimum moisture content of lime treated soil gradually increased,while the maximum dry density showed a decreasing trend.The shear strength of lime treated soil showed a significant growth trend with the increase of lime content and compaction degree.3.By analyzing the influence of the strengthening layer on the soil strength,the compressive stress distribution on the top of the soil foundation,the dynamic stress of the soil foundation and the mechanical response of the pavement structure,It can be concluded that the thickness and modulus of the soil strengthening layer have a significant effect on the soil strength.However,in the case of poor soil strength,blindly increase the thickness and modulus of the strengthened layer can't improve the strength of the foundation.The compressive stress distribution of the over wet soil subgrade with the strengthened layer is reduced and the compressive stress distribution is more gentle.With the increase of the thickness and modulus of the strengthening layer,the compressive stress on the surface of the soil and the stress of the soil are gradually decreasing.At the same time,the flexural tensile stress and flexural-tensile strain at the bottom of the pavement and base are gradually decrease.And the greater the thickness and modulus,the greater the magnitude of the reduction.It can be said that the increase in lime treatment of wet soil reinforcement layer thickness and modulus is conducive to extend the service life of the pavement.4.With the increase of lime content,the height and volume of frost heave of lime treated soil decreased and tended to be stable.This indicates that the incorporation of lime can effectively improve the overall frost resistance of the roadbed.After several times of freeze-thaw cycle,the strength of the soil at the lime has been attenuated,but still far greater than the strength of soil;Both the soil and lime treated soil increased with the increase of the degree of compaction,It is proved that improving the compaction of subgrade is one of the most economical and effective measures to ensure the overall strength and stability of subgrade.Increasing the compaction degree of the roadbed can improve the CBR value of the soil after freezing and thawing,so as to ensure the carrying capacity of the subgrade after freeze and thaw action.Considering the economic factors,the study found that the ratio of lime to 3% ~ 5% is ideal.5.According to the monitoring data,it can be seen that the temperature inside the subgrade varies with the temperature of the atmosphere.The internal temperature of the subgrade is less affected by the atmospheric temperature.By comparing the daily temperature difference,it can be found that the range of temperature of the 5% lime stabilized soil is less than that of the replacement of mountain stone.The results show that lime treated soil roadbed has better thermal insulation performance,and its maximum frozen depth is small.In addition,under the same depth of embedding,the change of volumetric water content of the 5% lime stabilized soil is less than the replacement of the mountain stone,which indicating that it has a certain water separation performance.The study shows that it is technically feasible to deal with the construction of the roadbed with the lime in the Ji-Shu expressway.