Effects Of Gypsum On Loess Collapsibility In Tongxin District Of Ningxia

According to the collapsible loess of Ningxia Tongxin area is Loess soluble salt content is high, especially for high dissolved salt content, the characteristics of large collapsible and building foundation cracking and subsidence engineering problems, Therefore,in view of characteristics of loess and the existing problems on engineering,combined with the research situation,put forward the research on the loess collapsibility Gypsum.with the representative loess of Ningxia Tongxin County as research object, gypsum content G,the age a,dry density ρd,water content W,soluble salt content as factor,coefficient of collapsibility δs, design the single factor experiment,mixing evenly in order to investigate the preparation parameters,structural remodeling soil samples of collapsible deformation experiment research. Application of the least squares method to establish a relationship model, by dimension reduction, reduced order and coupled analysis,and the role of law reveals the principle, Study concluded that:(1) the loess collapsibility coefficient decreases with the increase of the content of gypsum, moisture content, dry density. (2) age, density, water content and gypsum respectively coupling conditions conducive to reducing the collapsibility of loess, the soluble salts of calcium chloride,soluble salt of sodium sulfate and gypsum coupling condition is advantageous to increase the collapsibility of loess. (3) calcium chloride and sodium sulfate and gypsum respectively coupling conditions of loess collapsibility coefficient increases with increasing chloride calcium and sodium sulfate content.The results contributed to a better awareness of the loess collapsible mechanism, with reference to the loess foundation design, handling and construction.