生物酶改性膨胀土室内三轴试验研究

Study on bio-enzyme-treated expansive soil by laboratory triaxial test

采用室内三轴试验,研究了生物酶、石灰、水泥改良膨胀土的应力-应变曲线及强度特性,探讨了生物酶、石灰、水泥含量对改良膨胀土强度影响的变化规律。试验结果表明:1)改良膨胀土的偏应力随轴向应变的增加而增加,掺生物酶改性膨胀土的试验曲线表现为硬化型,掺石灰、水泥改性膨胀土试验曲线表现为软化型;2)掺生物酶、石灰、水泥能提高膨胀土体承受偏应力的强度,相同围压下,掺1∶300(酶与水的质量比)生物酶试样承受的偏应力最大,掺7%的石灰次之,最后为掺9%的水泥;3)通过比较分析强度提高系数R可知,掺1∶300(酶与水的质量比)生物酶对提高膨胀土抗剪强度效果最佳。以上研究结果为娄益高速处置膨胀土路基提供量化资料,同时也为其他膨胀土工程提供参考。

Laboratory triaxial tests were carried out in order to understand the stress-strain relationship and strength property of bio-enzyme-treated,lime-treated and cement-treated expansive soil.The effect change of biological enzyme,lime and cement content on the strength of expansive soil was studied.The laboratory test results show as follows：1）With the increase in axial strain,the deviator stress increases,and the bio-enzyme-treated expansive soil relation curves of deviator stress and axial strain present as hardening type.The lime-treated and cement-treated expansive soil relation curves show softening type.2）The deviator stress of bio-enzyme-treated expansive soil,lime-treated expansive soil and cement-treated expansive soil is increased.Under the same confining pressure,the destructed deviator stress of 1∶300bio-enzyme-treated sample is the biggest,the 7%lime-treated sample is middle and 9% cement-treated sample is the least.3）By analysis and comparison,the strength of mid-expansive soil after 1∶300（enzyme to water mass ratio）bio-enzyme-treated is largely increased and 1∶300（enzyme to water mass ratio）bio-enzyme is optimum added quantity.All results can provide the quantitative information for Louyi expansive soil,at the same time,it can also be used as p the necessary reference for other expansive soil area.