挤密桩对大厚度黄土地基浸水沉降的影响  

Influence of Compaction Piles on the Immersion Settlement of Large⁃thickness Loess Foundations

作　　者：王亚军 白晨帆 蒋应军[2] 李瀚盛 范江涛 袁可佳 WANG Yajun;BAI Chenfan;JIANG Yingjun;LI Hansheng;FAN Jiangtao;YUAN Kejia(Shaanxi Xihan Intercity Railway Co.Ltd.,Xi’an 710054,China;School of Highway,Chang’an University,Xi’an 710064,China;School of Automobile and Transportation,Xihua University,Chengdu 610039,China)

机构地区：[1]陕西西韩城际铁路有限公司,西安710054 [2]长安大学公路学院,西安710064 [3]西华大学汽车与交通学院,成都610039

出　　处：《铁道建筑》2025年第2期126-133,共8页Railway Engineering

基　　金：陕西省交通运输厅科技项目(19-27K);长安大学中央高校科技专项(300102218212)。

摘　　要：为明确挤密桩对大厚度黄土地基的处理效果,开展了天然黄土地基和挤密桩复合地基的现场浸水试验,对比分析了挤密桩处理前后黄土地基入渗特性和湿陷变形的差异,并探讨了桩间距及桩长对沉降变形的影响。结果表明:挤密桩处理显著增强了黄土地基的抗渗性,浸水作用下地基的日均入渗量从150.3 m^(3)降至52.0 m^(3)。此外,挤密桩有效控制了黄土地基的地表湿陷变形,未对湿陷下限深度产生影响。挤密桩处理后黄土地基的地表湿陷变形降低约61.8%,影响范围由40.0 m降至29.5 m。挤密桩复合地基的沉降变形受桩长和桩间距影响,桩间距每增加0.1 m,水泥土挤密桩复合地基的地表沉降增加约10.1%,柱锤冲扩桩复合地基的地表沉降增加约25.6%;桩长每增加1 m,水泥土挤密桩复合地基的地表沉降减少约14.8%,柱锤冲扩桩复合地基的地表沉降减少约9.7%。To clarify the effectiveness of compaction piles in improving thick loess foundations,field immersion tests of natural loess foundation and composite foundation of compaction piles were conducted.The differences in infiltration characteristics and collapsible deformation of loess foundation before or after treatment with compaction piles were compared and analyzed,and the influence of pile spacing and pile length on settlement deformation was discussed.The results show that treatment with compaction piles significantly enhances the impermeability of the loess foundation,reducing the average daily infiltration volume of the foundation from 150.3 m^(3)to 52.0 m^(3)under immersion.In addition,the compaction piles effectively control the surface collapsible deformation of loess foundation,but have no influence on the depth of the lower limit of collapsibility.After the treatment with compaction piles,the surface collapsible deformation of loess foundation is reduced by about 61.8%,and the influence range is reduced from 40.0 m to 29.5 m.The settlement deformation of the composite foundation of compaction piles is affected by pile length and pile spacing.For every 0.1 m increase in pile spacing,the surface settlement of the composite foundation of cement-soil compaction piles increases by about 10.1%,and the surface settlement of the composite foundation of the deep dynamic compaction piles increases by about 25.6%.For every 1 m increase in pile length,the surface settlement decreases by approximately 14.8%for the composite foundation of cement-soil compaction piles and 9.7%for the composite foundation of deep dynamic compaction piles.

关 键 词：大厚度黄土地基 挤密桩 浸水试验 桩参数 沉降变形 入渗特性 

分 类 号：U213.15[交通运输工程—道路与铁道工程]