Abstract

In geotechnical projects involving soft soils, cement-mixed soils are an excellent way to improve the mechanical behaviour and engineering performance of soils. The water-to-cement ratio, cement content, and porosity are the most critical parameters impacting the strength of cement-mixed soils, but their effects are less well understood. The proportional influence of cement amount, porosity, and moisture content on cement-mixed soil strength is investigated in this research. The results showed that as the water-to-cement ratio increases, the influence of cementation and porosity on unconfined compressive strength decreases. The blended volume ratio is proposed as a new and adequate index for evaluating cement-mixed soil strength based on the experimental results. The blended volume ratio is the product of the void/cement volume ratio and the water/cement volume ratio. While the current index has not fully addressed the important effects of the water-to-cement ratio and porosity, the blended volume ratio allows describing the concurrent influences of porosity, cement amount, and water amount on the strength development. The experimental results showed that the cement-mixed soil strength is a function of the blended volume ratio. An empirical equation based on the blended volume ratio was then proposed for predicting the strength of cement-mixed soils. The validation of the proposed equation is verified by strength analysis for several different test data sets. A good agreement between measured and predicted results indicated that the proposed model is applicable to predict well the strength of cement-mixed soils.

摘要

在涉及软土的岩土工程中，水泥混合土是改善土的力学性能和工程性能的极好方法。水灰比、水泥含量和孔隙率是影响水泥混合土强度的最关键参数，但它们的影响却鲜为人知。本研究研究了水泥用量、孔隙率和含水率对水泥土强度的影响比例。结果表明，随着水灰比的增加，胶结作用和孔隙率对无侧限抗压强度的影响减小。根据试验结果，提出混合体积比作为评价水泥土强度的新指标。混合体积比是空隙/水泥体积比和水/水泥体积比的乘积。虽然目前的指数没有完全解决水灰比和孔隙率的重要影响，但混合体积比可以描述孔隙率、水泥用量和水用量对强度发展的同时影响。试验结果表明，水泥混合土的强度是混合体积比的函数。然后提出了基于混合体积比的经验方程来预测水泥混合土的强度。通过对几个不同测试数据集的强度分析来验证所提出方程的有效性。