水泥搅拌桩固化土性能试验研究

Experimental Research on the Performance of Cement Mixing Pile’s Solidified Soil

我国沿海地区地基土多为软弱土质,为加强其承载能力,需要对软弱地基土进行处理加固,水泥搅拌桩为较为常见的一种处理方法。本文通过对两种初始含水率下,四种固化剂对固化土的加固作用的研究,对各个试块断裂面特征进行了观察,对各个养护龄期下试块的无侧限抗压强度、固结物含量以及固结物烧失量进行了分析,测定了固化剂水化产物的类型和含量,并对固化土试件进行了微观特征观测,分别探究了含水率和掺合料对水泥搅拌桩固化土强度的影响,发现了待加固软基土体的初始含水率对固化土强度的影响较大,高含水率既会产生较多的水化产物以加强水泥搅拌桩强度,也会在其内部产生孔隙而降低其强度,且使用掺入矿渣(Slag)的普通硅酸盐水泥的固化效果较其他固化剂明显。

Most of the foundation soil in coastal areas of our country is soft soil. In order to strengthen its bearing capacity,it is necessary to treat and strengthen the weak foundation soil. Cement mixing pile is a common treatment method. In this paper,by studying the reinforcement effect of four curing agents on the reinforced soil under two initial water contents,the characteristics of the fracture surface of each test block are observed,and the unconfined compressive strength of the test block under various curing ages is observed. Consolidation content and Consolidation loss on ignition were analyzed,the type and content of curing agent hydration products were determined,and the microscopic characteristics of the reinforced soil specimens were observed,and the influence of moisture content and admixtures on intensity of cement mixing pile strengthening soil were investigated respectively. It is found that the initial moisture content of the soil to be strengthened has a greater impact on the intensity of the strengthened soil. High moisture content will not only produce more hydration products to strengthen the intensity of the cement mixing pile,but also the porosity will be generated inside it to reduce its intensity,and the curing effect of ordinary Portland cement mixed with slag is more obvious than other curing agents.