Study On The Experiment Of Dynamic Characteristics Of Subgrade Soil

Subgrade is an important structure of road, when earthquake take place, its damage will be very serious. Therefore, in order to lower or reduce the roadbed damage caused by the earthquake, study on the earthquake resistance of subgrade appears to be particularly urgent.In order to study the earthquake resistance of subgrade, the first and foremost issue is to study on the dynamic characteristics of subgrade earth soil.In this paper, using dynamic triaxial test, studying the dynamic characteristics of typical subgrade soil of the western region——the filler of red layer soft clay. A transient limit equilibrium theory was used for study the impact of confining pressure, consolidation stress ratio on dynamic strength of filler, of the packing stress than the impact of dynamic strength, and be verified through testing. Based on the dynamic strength test results, analysis the influence of the moisture content, the degree of compaction and stone content on dynamic strength of filler, then determine the dynamic strength of filler and intensity indicators. Through the dynamic elasitic modulus and damping ratio test, determine the relation curve between dynamic elastic modulus and dynamic strain , and determine the relation curve between damping ratio and dynamic strain, the curves obtained its maximum dynamic elastic modulus and the largest damping ratio, based on the test results, analysis the influence of moisture content, confining pressure, and the degree of compaction and stone content on dynamic elastic modulus and dynamic strain of filler, presented the statistical relationship among aximum dynamic elastic modulus, the largest damping ratio and confining pressure.It is important to study on the dynamic characteristics of subgrade earth fill, because it can perfect the design methods earthquake resistance of subgrade, improving the earthquake resistance ability of subgrade, preventing the economic losses for earthquake damage of road and Protection and ensure the road open and operational safety.