Experimental Study On Cement/Lime Modified Loess And Its Engineering Application

Loess in China has a more widely distributed,its distribution in the thickness,degree of development,size,complexity and other aspects of the more prominent features.Collapsibility is considered to be the biggest characteristic of loess,which leaves a certain degree of instability in engineering practice.At present,China is vigorously promoting the strategic theme of the new Silk Road economic zone.In the northwest region where the loess is widely distributed,a new wave of road transportation facilities will be launched.This will put forward the service function of loess in engineering construction.A high degree of demand.In the current industry,a variety of methods are used to optimize the loess and improve its stability.In this paper,lime improvement and cement improvement of the indoor test,including liquid-plastic limit test,compaction test,unconfined compressive strength,collapsibility test,CBR test,rebound modulus test,direct shear test,Through these experiments to explore the modified loess mechanical parameters of the law.(1)after the loess improved by the cement,with the increase of cement content,the limit of plasticity increases;the plastic index decreases;the optimal moisture content and the maximum dry density increase;the cohesion and internal friction angle increase,and the cohesion increases With the increase of cement mixing ratio,the unconfined compressive strength of modified loess increased obviously.The compressive strength of modified loess increased with age.When the cement mixing ratio is 6%,the improvement of the engineering performance of the improved loess is the most significant.It is suggested that the cement mix ratio of the loess embankment is 6%.(2)After the lime was improved,the plastic index decreased with the increase of lime content,the maximum dry density decreased,the optimum water content increased,and the range of water content increased.The strength of lime soil is obviously increased with the increase of the ratio of dust,and the peak value is higher than the peak value and the strength decreases.The other properties of the loess are also affected by the project.The elastic modulus increases significantly.With the increase of the ash content,the elastic modulus increases slowly and the speed increases from fast to slow.(2)The loess is not easy to compaction Difficult to compaction changes;(3)CBR sharply increased,with the increase in ash,increased to a certain value and gradually reduced.Combined with the actual construction of highway engineering,introduces the construction technology of Improved Loess process,key process and quality assurance points,combined with the construction site test section,experimental study was carried out on the degree of compaction,foundation coefficient,the number of degree of compaction and foundation system improvement test section two methods that can meet the requirements of the highway construction.In order to accumulate some data for Highway Loess improvement roadbed in the future.