摘要
以延安新区综合管廊项目中挤密桩处理地基为背景,为了研究挤密桩对高填方的湿陷性黄土地基承载力和消除湿陷性的处理效果问题,进行了现场试验段的分析。首先,在试验场地设计了7个实验组,分析了桩心距、桩孔填料、处理深度、处理范围等因素的影响,处理后测得了两桩间和三桩间各个实验点的地基密实度变化值;其次,进行了现场的静载试验、桩体取样试验、小面积浸水和大面积浸水试验,测量得到了在不同情况下的浸水试验的各组湿陷沉降量。结果表明:桩心距在2.5d范围内基本上不仅可以解决承载力问题还可以完全消除回填黄土的湿陷性;桩孔填料为灰土时的处理效果明显优于素土,灰土配合比为3∶7时能满足要求;小面积浸水试验消除的湿陷性为外荷载湿陷性,大面积浸水可以完全释放地基的湿陷性。
In order to study the effect of compaction pile on the bearing capacity of high embankment backfilled collapsible loess foundation and the effect of eliminating collapsibility,a discussion about the field test was conducted based on the project of foundation treatment with compaction piles in Yan＇an new district. Firstly,seven experimental sites were designed in the field to study the effects of pile center distance,pile filling,treatment depth,treatment range and other factors. After treatment,the change of ground compaction was measured at each experimental point between two and three piles. Secondly,static load test,pile sampling test,small-area immersion test and large-area immersion test were carried out. The settlement of each point in immersion testsunder different conditions was measured. The results show that pile center distance less than 2. 5 times of pile diameter can not only solve the problem of bearing capacity but also completely eliminate the collapsibility of backfilled loess. The treatment effect of gray soil as pile filler is obviously better than that of vegetarian soil. The pile with gray soil of 3 ∶ 7 can meet the requirements; small area immersion test eliminates collapsibility due to the external load,and large area immersion test can completely release the collapsibility of the foundation.
出处
《广西大学学报（自然科学版）》
CAS
北大核心
2018年第1期197-204,共8页
Journal of Guangxi University（Natural Science Edition）
基金
国家自然科学基金资助项目(51174038)
辽宁省教育厅项目(L2014693)
关键词
挤密桩
湿陷性黄土
地基处理
浸水试验
compaction pile
collapsible loess
foundation treatment
immersion test
