Research Of Correlativity Between Subgrade Compacting Parameters And The Control Indexes To Improved Soil

The principal work of the paper includes: (1) In view of the feature——the current domestic ballastless track subgrade compaction control indexes and the many different international compaction standard system using different compaction indexes, launched the field test study of correlativity between subgrade compaction parameters;(2)Through laboratory modulus of resilience and shear wave tests, established the prior estimate to subgrade fill compaction indexes——K₃₀ and E_v2;(3)Combining the select of subgrade fill to high-speed railway, launched the study of characteristics and control indexes to improved soil.Based on the above issues, through field tests, laboratory tests and theoretical analysis, the following conclusions is gained:(1) Subgrade compaction parameters mechanical indexes have some relevance, physical indexes have higher relevance. However, mechanical and physical indicators correlation is very low. Through the analysis of correlation about the mechanical indexes E_vd,E_v2,K₃₀ , can be drawn from them that they are controlled by medium modulus and the relevance between them is the best and we can also see they are basically the same in subgrade compaction quality control standards.(2) Through the analysis to the correlativity of E_v2,K₃₀ and the distribution of K₃₀/E_v2 value, China is generally equivalent with German in subgrade compaction standard.(3) With the same fill, we can choose a two-species mechanical indexes and one physical index as the subgrade fill compaction indexes.(4) E_v2 is more suitable for subgrade evaluation capacity. E_v2 has smaller effect to interference, in E_v2/E_v1 meeting certain conditions circumstances, proposed to use E_v2 value as subgrade evaluation criteria.(5) Theoretically ,modulus of resilience E_e and v_s² seperatly exists in a strictly linear relationship with K₃₀, actual laboratory test results also showed that a good linear relationship exists between them. laboratory modulus of resilience and shear wave tests can be used as the prior estimate of foundation coefficient K₃₀, Reusing the correlativity between E_v2 and K₃₀, but also to achieve prior estimate to deformation modulus E_v2. thus can avoid blindness in fill choice. Contrast resilient modulus test, shear wave test is simpler and faster, and there is no contact interface problems.(6) Improved soil control indexes will have to consider in line with the general fill in the conventional indexes, as well as those of their special characteristics of its indexes request.(7)Against improved soil, the paper presents : K will be as compaction control index; K₃₀,E_v2,E_vd,CBR as modulus and deformation control index; Unconfined compressive strength, shear strength index C,Φvalue as its intensity control index; slaking loss rate of quality, wash loss rate of quality, swelling rate in loading as water rate stability control index; Critical stress, the wet and dry cycles quality loss rate as its durability control index.(8) Compaction coefficient K, foundation coefficient K₃₀, deformation modulus E_v2,dynamic modulus of deformation E_vd, unconfined compressive strength are as the basic control indexes to improved soil. According to the actual situation, the importance of construction and design requirements , Other indexes are selected. Thus improved soil properties should not be lower than that intended for use in the group A and B fill performance.