膨润土与黏性土复合改善沙土保水性的研究

目的]为了改善干旱少雨、水资源短缺地区土壤持水和保水能力。方法]以土壤干密度、膨润土掺叠和黏性土掺量为因素,设计正交试验研究膨润土与黏性土复合对沙土持水性和保水性的作用。结果]沙土持水率随干密度的增大而减小,随膨润土和黏性土掺量的增加而增大,最优组合为干密度1.30 g/cm3、膨润土掺量6%、黏性土掺量20%,各因素对持水率影响的主次顺序为干密度、黏性土掺量和膨润土掺量;总体上看,沙土保水性随干密度和膨润土掺量的增大而增大,随黏性土掺量的增加先增大后减小,黏性土最优掺量为15.0%,就保水性而言,最优组合为干密度1.50 g/cm3、膨润土掺量6%、黏性土掺量15%,各因素对保水性影响的主次顺序前期为膨润土掺量、干密度和黏性土掺量,后期为膨润土掺量、黏性土掺量和干密度;综合考虑持水率和保水性,最优组合为干密度1.40 g/cm3、膨润土掺量6.0%、黏性土掺量15.0%。结论]膨润土和黏性土能显著提高沙土的持水性和保水性。

Improvement of Water Retention of Sandy Soil by Bentonite and Cohesion Soil

Objective]The research aimed to improve the water holding power and water retention of sand in drought, water shortage area.Method]Dry density of soil, bentonite content and cohesion content were considered as factors, and the composite effect of bentonite and cohesion on water holding power and water retention of sand were studied by orthogonal test. Result]The water holding power of sand decreased with the increase of dry density, and increased with the increase of bentonite content or cohesion content. The optimum combination plan about water holding power was dry density 1.30 g/cm3, bentonite content 6%, cohesive-sand content 20%. The important order of the factors that affected the water holding power of sand was dry density, cohesion content, and bentonite content. As a whole, the water retention of sand increased with the increase of dry density and bentonite content first increased, then decreased with the increase of cohesion content. The optimum cohesion content was 15%. The optimum combination plan about water retention was dry density 1.50 g/cm3, bentonite content 6%, and cohesive-sand content 15%. The important order of the factors that affected the water retention of sand was bentonite content, dry density, cohesion content prophase. Comprehensive consideration of water holding power and water retention, the optimum combination plan was dry density 1.40 g/cm3, bentonite content 6%, and cohesion content 15%. Conclusion]Bentonite and cohesion could significantly increase the water retention of sand.