Study On Settlement And Stability Of Vertical Drains Improved Roadbed

Preloading with vertical drains is an effective technique of the soft ground treatment under highway embankment. And preloading with sand wick is one of most commonly used technique at present. As the requirement of controlling post-construction settlement and settlement and stability during construction is more and more strict, it's necessary to study deformation characteristic of sand drains improved soft ground under highway embankment.This paper introduces the current situation of consolidation theory of sand drains improved subsoil. Then, the characteristic of deformation and stability of soft ground under highway embankment were discussed thoroughly according to large amounts of in-site observation data in JiangZhong highway. The elaborate work involves several aspects as follow:(1) Basing on the project, the article discuses the calculating of consolidation of sand drains improved ground, and compares consolidation settlement of sand drains area and substratum, studies on increase of strength of soft soil during consolidation, and their effect to safety coefficient.(2)Use finite element analysis software ADINA, Analysis the highway embankment with sand drains improved ground. With the method of equivalent vertical hydraulic conductivity, analysis of sand drains improved subsoil can be treated the same as that of unimproved case.(3) In-site observation is discussed thoroughly in this paper according to large amounts of in-site observation data in JiangZhong highway. And the forecast of the settlement of subsoil under highway embankment with Grey Model is discussed in this paper.(4) Comparing the results with the results of finite element analysis and in-site observation, some useful suggest is proposed in this paper.(5) Stability analysis of embankment is discussed, and the effect of settlement, increase of strength and effect of geotextile is taken into account.