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水泥改良土是高速铁路路基工程中广泛使用的一种重要填料。本文通过固结不排水三轴剪切试验,在实验室内模拟环境条件的变化,研究了循环失水过程与水泥土强度变化之间的关系。结果表明,循环失水后水泥土的静强度都有一定程度的降低,特别是粉质粘土,经历一次失水饱和后其静强度降低了36%左右;环境变化的影响主要集中在前两次循环失水过程,两次之后强度基本稳定。本文还通过在改良土中置换一定比例的砂土来改善土料的颗粒级配,以降低循环失水对水泥土强度的影响。试验结果表明,这一措施对水泥土绝对强度的提高有一定程度的改善作用。
Cement-modified soil is an important filler widely used in high-speed railway subgrade engineering. In this paper, the relationship between the cyclic loss of water and the change of cement soil strength was studied through the consolidation of undrained triaxial shear tests in a laboratory to simulate the change of environmental conditions. The results show that the static strength of cement soil decreases to a certain degree after cyclic loss of water, especially silty clay, the static strength of which decreases about 36% after a loss of water saturation; the influence of environmental change mainly focuses on the first two times The cycle of water loss, after two times the basic strength and stability. In this paper, we also improve the particle size distribution of the soil by replacing a certain proportion of sand in the modified soil to reduce the impact of cyclic loss of water on the strength of cement soil. Test results show that this measure to improve the absolute strength of cement soil to a certain extent, improve the role.