海泥海砂混合料最大干密度确定方法研究

The Method of Maximum Dry Density Determining of the Mix of Sea Mud and Sea Sand

海泥海砂混合料能否作为海堤填料,很大程度上取决于混合料的最大干密度。因此,如何准确确定最大干密度就显得至关重要。通过轻型击实试验、相对密实度试验、振动台试验等室内试验对海砂海泥混合料最大干密度确定方法进行比较分析研究,得出以下结论:当海泥含量比较多时,击实法得到的干密度大于振动台法,这主要是由于击实试验采用的为干法;在粉碎过筛的过程中,土体结构遭到破坏,土体中的含水率明显变小;而振动台法则直接采用原样土进行试验,更符合现场施工情况。从不同比例掺合料的含水率来看,当海砂海泥比例小于1.5∶1时,此时的掺合料处于饱和状态,采用振动台法更加适合;当海砂海泥比例大于1.5∶1时,混合料含水率小于饱和含水率,相对密实度法得到的结果较振动台法更加准确,此时应采用相对密实度法确定最大干密度。

Whether the mixture of sea mud and sea sand can be used as a filler of seawall,it depends largely on the maximum dry density of the mixture. So,how to accurately determine the maximum dry density is critical. The laboratory tests（ such as the light compaction test,the relative density test,the shaking table test,etc） are carried out to compare the determining method of the mixture of sea sand and sea mud,the results show that： when the content of sea mud is relatively large,the dry density measured by compaction method is larger than shaking table test,this is mainly due to the method compaction test used was dry method. In the process of crushing sieving,the soil structure was destroyed,the water content was significantly smaller,however,the soil samples in the shaking table test are undisturbed soil,which is more aligned with the practical construction conditions. From the point of the moisture content of admixtures in different proportions,when the ratio of sea sand and sea mud is less than1. 5∶ 1,the admixture is saturated,which is more suitable to use shaking table test; when the ratio is greater than1. 5∶ 1,the mixture moisture content is less than the saturated water content,the results conducted by relative density method turns out to be more accurate than shaking table test,it is suggested to determine the maximum dry density using relative density method.