Research On Settlement And Deformation Of Swampy Soil Roadbed In Yuhui Railroad

Swampy soil has high moisture content, high organiccontent, big void ratio, high compressibility and low intensity etcbad engineering properties. Swampy soil exists in china northeast,south and southwest, its worse engineering properties bring manygeological engineering problems to regional highway andrailway construction. By far, there is little research on theengineering properties of swampy soil and roadbed soilsettlement inland and abroad, neither is sophisticated experience.Generally, the following measures are adopted during thedisposal course of special soils, such as dig-exchange,jackstone-piling silt and counter pressure berm etc, which have amarked effect on the thin swampy soil, but lookstime-consuming and hard sledding to the thick. Hence, it is verynecessary to study swampy soil on it's settlement deformationand measurement. Based on the scientific research items:research on seepage consolidation and compression deformationof Jingyu-Huinan railroad swampy soil roadbed, this papermakes a detailed analysis on swampy soil and emphasizes on itsengineering properties, the rule of roadbed sedimentation anddeformation, the effects of the method drainage consolidationand composite foundation.First, the roadbed settlement consolidation theory. Referringto Osterberg method of superposition to get the subsidiary stress,this paper calculates the settlement and deformation of theroadbed. Then it analyzes the internal and external factors,especially the organic content and resolution to the compressiondeformation of swampy soil. Besides, it dissertates Terzaghione-dimensional consolidation theory, the well roadbedconcretion theory and the design calculation method ofcomposite foundation. Analyzes and discusses the applicabilityof this method to instantaneous settlement and secondaryconsolidation settlement of the swampy soil roadbed. Second, based on analysis on swampy soil engineeringproperties of Yuhui railway and combined with roadbedsettlement consolidated theory, this paper studies in the naturalcharacters of swampy soil roadbed settlement and deformation inYuhui railroad. In the early loading step, turfy soil subsides faster,with large coefficient of compressibility, it controls the totalsettlement, but time of the consolidation is determined by thesettlement of the clay. Then, there is an analysis on the relatedproblem of turfy soil between the immediate settlement andsecondary consolidation settlement; Additionally, during the timelimit for the project, the secondary consolidation settlement ofswampy soil, especially high organic content turfy soil must beconsidered, which accounts for above 10 percent in the endconsolidation settlement. Third, this paper studies the effective measure to deal withswampy soil, based on the foundation treatment theory ofroadbed soft soil. It indicates that the method of drainage andconsolidation can improve effectively the consolidation rate ofYuhui railway swampy soil; the settlement of turfy soil is themajor in the end settlement and the consolidation rate of clay hasa determinant effect on the time limit for the project. Theprefabricated drains method is feasible for foundation treatment...