高含水率回填土土质改良方法研究

Investigation on the Methods of Soil Improvement for High Water Content Backfill

为深入分析不同土体改良方式对高含水率回填土的改良效应,分别通过水泥改良法、石灰改良法和掺砂改良法不同土体改良方法对高含水率回填土进行改良处理。进一步针对改良后的土样进行不同含水率条件下的固结排水三轴试验,并以试样峰值强度作为改良评价指标对改良效应进行量化。结果表明:在利用石灰和水泥对回填土进行改良过程中,改良抗剪强度随固化剂含量增大而增大,大致呈现线性关系,采用掺砂法进行改良时,在较低含水率条件下,随着掺砂率的增加,试样峰值强度增加,当含水率较高时,试样强度几乎不随掺砂率的变化而变化,在较低含水率的条件下,石灰改良和掺砂改良的方式均可达到较好的改良效果,而当含水率较高时,则水泥改良方式具有显著优势。

In order to investigate the improvement effect of different soil improvement methods on high water content backfill,three different soil improvement methods,namely,cement modification,lime modification,and sand-improvement,were used to improve the high water content backfill.Under the condition of different water content,the improved soil samples were subjected to consolidated drained triaxial tests,and the peak strength of sample was used as an improved evaluation index to quantify the improvement effects.Improvement effects of different soil improvement methods were obtained.The results show that:when lime and cement were used to improve the backfill,there is a linear relationship between the improvement effect of the soil and the content of the curing agent,and the shear strength increases with the increase of the content of the curing agent.In addition,when the sand is used for the improvement,the peak strength of the sample increases with the increase of the sand content when the water content is relatively low.However,when the water content is high,the strength of the sample hardly changes with the sand content.Furthermore,under the condition of low water content,both of the lime and sand would achieve better improvement effect,and when the water content is higher,the cement modification method has significant advantages.