新近吹填淤泥现行真空预压技术加固效果不佳原因分析

发布时间：2018-06-03 13:46

本文选题：新近吹填淤泥 + 现行真空预压技术　；参考：《水运工程》2015年11期

【摘要】：为探讨现行真空预压技术加固新近吹填淤泥地基时效果不理想的原因,首先分析新近吹填淤泥的工程特性,然后开展不同含水率下新近吹填淤泥的室内真空固结足尺单井模型试验研究。研究结果表明:1)新近吹填淤泥主要由较细颗粒物质和极细颗粒物质组成,其中黏粒含量(黏粒+胶粒)和强亲水矿物含量(伊利石+蒙脱石)均较高;孔隙特征主要以孤立孔隙和粒间孔隙为主;含水率基本在100%以上、均大于1.5倍的液限,孔隙比均大于2.5,塑性指数基本在20以上,液性指数基本大于2.0。2)新近吹填淤泥采用现行真空预压技术加固时,膜下真空度损失程度可高达20%以上;真空度从排水板向周围土体中传递时的径向损失程度严重,真空压力的径向作用范围仅局限于直径约为40 cm的土柱范围内:土柱范围内土体的无侧限抗压强度值不超过35 kPa;土体的有效加固深度和强度增长幅度均较小。这两方面是新近吹填淤泥采用现行真空预压技术进行处理时效果不理想的主要原因,因此,有必要结合新近吹填淤泥的工程特性研发出一种新型加固技术或对现行真空预压技术加以改进。
[Abstract]:In order to discuss the causes of the unsatisfactory effect of the current vacuum preloading technology in strengthening the newly filled silt foundation, the engineering characteristics of the newly filled silt foundation are analyzed. Then the model study on vacuum consolidation of full-scale single well under different water cut is carried out. The results show that the newly filled silt is mainly composed of fine particles and very fine particles. The clay content (clay colloid) and strong hydrophilic mineral content (Illite montmorillonite) are both higher. The pore characteristics are mainly isolated pores and intergranular pores, the water content is more than 100%, the liquid limit is more than 1.5 times, the porosity ratio is more than 2.5, and the plasticity index is above 20. The hydraulic index is more than 2.0.2) the degree of vacuum loss under the film can be more than 20% when the new filling silt is strengthened by the current vacuum preloading technology, and the radial loss of vacuum degree is serious when the vacuum degree is transferred from the drainage plate to the surrounding soil. The radial action range of vacuum pressure is limited to the soil column with a diameter of about 40 cm. The unconfined compressive strength of the soil in the soil column is not more than 35 KPA, and the effective reinforcement depth and strength increase range of the soil are smaller. These two aspects are the main reasons for the unsatisfactory effect of the current vacuum preloading technology in the treatment of the newly filled silt. It is necessary to develop a new reinforcement technology or to improve the existing vacuum preloading technology combined with the engineering characteristics of the newly filled silt.
【作者单位】：广州港股份有限公司;中交四航工程研究院有限公司;中交交通基础工程环保与安全重点实验室;
【基金】：中交交通基础工程环保与安全重点实验室科研资助项目(院科Y2013D27)
【分类号】：TU472.33

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