Study On Strength And Deformation Of Compacted Loess And Its Microstructure For Highway Engineering

The paper presents tests of the best water conten and the largest dry desity for loess under the vibration compaction condition with a vibration compactor used in lab designed by ourselves.The influence regularity of vibratory parameters such as amplitude,frequency,centrifugal force,intensity of pressure,time of vibratory and material factors such water content is studied.Vibration parameters for loess under the good compaction condition are given.It is concluded that internal factors such as granulometric composition,microstructure and external factors such compaction methods,water content,compaction power are the main factors influencing loess compacting.Based on tests of CBR,moudulus of resilience,shearing intensity,the relationship between intensity indexes and physical properties is analyzed.According to the compression tests,deformation properties of compaction loess is studied,and the results of compression tests can be given with stress-strain methods.The paper establishes the reinforcing consititutive model,the mostening and drying consititutive model of compacted loess.The collapsibility of compacted loess which is related with water content,dry density and age is studied,which is contrasted with that of original state loess.Based on referring architecture specifications of collapsibility loess area,making use of experience for highway project established or establishing,according to highway foundations' characteristic,the paper put forward some suggestion of evaluation methods for collapsibility loess foudation in highway engineering,which is proposed from testing pressures of collapsible coefficient, construction's classification, estimation of collapsible sort and collapsible grade for building sites.The influence of water content,dry density and pressure on shearing strength,collapsibility and compression is discussed. Futhermore the contributions of these factors and their reciprocal actions affecting strength,collapsibility and compression are ascertained so as to give a reference to control construction quality and improve properties of loess. Aimed at the disadvantages of compaction quality control methods of soil subgrade,suggetions of compaction quality control methods of soil subgrade are put forward. On analysis of the applications of digital image...