【摘要】 水泥土搅拌桩周围环境中的Mg2+和SO42-对水泥土及其桩体的力学性能具有很大的影响。通过模拟试验的方法探讨了在不同硫酸镁溶液环境下不同龄期的水泥土表观和抗压强度变化规律,得出了水泥土表面腐蚀程度随着腐蚀时间的增长和硫酸镁浓度的增大而增加,水泥土抗压强度随硫酸镁浓度的增大而减小;分析了硫酸镁溶液的Mg2+浓度和SO42-浓度随时间的变化关系,得出随着时间的增长Mg2+浓度呈减小趋势,而SO42-浓度则呈抛物线型。研究认为:水泥土强度改变与环境中的Mg2+浓度和SO42-浓度密切相关。在此基础上建立了水泥土环境下考虑Mg2+浓度和SO2-4浓度相互影响的水泥土强度模型,经对比预测值与实测值,证明两者比较接近,该关系具有一定的可行性,可供工程设计参考。更多还原

【Abstract】 The Mg2+ and SO42-in the surrounding environment of soil-cement piles may affect the mechanical properties of cement soil in turn to cause some serious damage to structures.In order to simulate and study the erosion effect process such as the changes of corrosive degree of surface,compression strength of cement soil samples and Mg2+ concentration and SO42-concentration of corrosive solutions,a series of tests are conducted on the cement soil blocks cured in different concentrations of MgSO4 solutions,including taking photos,compressive strength tests,and measuring Mg2+ and SO42-concentrations.The test results show that the corrosive degree of the sample surface increases while the compression strength decreases with the increase of the corrosive solution concentration at the same erosion time,and that the corrosive degree increases with the corrosive time.Chemical analysis of corrosive environment indicates that the Mg2+ concentration decreases and the SO42-concentration shows a parabolic trend with the corrosive time.So it is concluded that the compressive strength is closely related with the Mg2+ concentration and SO42-concentration of MgSO4 corrosive environment.Finally,a strength model of cement soil is set up based on the relationship of compressive strength and Mg2+ concentration and SO42-concentration.The predicted and measured values agree well so that the accuracy of the formula is rather high and the model may be used in practical design.更多还原