石灰-偏高岭土改良滨海盐渍土力学性能研究

Experimental study on physical and mechanical properties of coastal saline soil improved by lime-metakaolin

滨海地区分布大量盐渍土,为解决盐渍土用作路基填料时产生盐胀、腐蚀、溶陷等不良工程特性,通过掺入偏高岭土替代部分石灰改良盐渍土,进行室内击实试验和无侧限抗压强度试验,分析其击实特性和强度特性的影响规律,以期为滨海地区盐渍土路基工程应用提供理论依据。试验结果表明:掺入偏高岭土可使盐渍土的最大干密度呈逐渐减小的趋势,最佳含水量呈逐渐增大的趋势;当偏高岭土掺量从0增加至3%时,其无侧限抗压强度从0.96 MPa增加到1.19 MPa,相比未掺加偏高岭土的石灰改良土强度增加了24%。在一定掺量范围内,偏高岭土可替代部分石灰,以减少环境污染,提高石灰改良土强度。

A large amount of saline soil is distributed in coastal areas.In order to solve the adverse engineering characteristics such as salt expansion,corrosion and collapsibility when saline soil is used as roadbed filler,this study improves saline soil by adding metakaolin instead of part of lime,and carries out indoor compaction test and unconfined compressive strength test.The influence of compaction characteristics and strength characteristics is analyzed in order to provide theoretical basis for the application of saline soil roadbed engineering in coastal areas.The results show that the maximum dry density of saline soil decreases gradually and the optimum water content increases gradually with the addition of metakaolin.When the content of metakaolin increases from 0 to 3%,the unconfined compressive strength increases from 0.96 MPa to 1.19 MPa,which is 24%higher than that of lime-improved soil without metakaolin.In a certain range of dosage,metakaolin can replace part of lime to reduce environmental pollution and improve the strength of lime improved soil.