96
D0;10.7672/sgjx2013150096
工技术施
CONSTRUCTION TECHNOLOGY
2013年8月上第42卷第15期
松散回填土场地柔性墩强夯置换法地基处理
何国富，张玲云，韩根荣
200120）
（中石化上海工程有限公司，上海
【摘要】我国南方沿海地区大面积高填方多采用砂砾质残积黏性土作为国填材料，辅助强夯进行地基处理。天然残积黏性土本身具有孔腺比大、压缩性低、遇水软化和易扇解的特点，而经搬运后用作大面积回填时，其孔隙比更大，压缩性增大，虽经分层碾压，但土层颗粒仍为松散状态。由于南方地区多为晴热干早和多雨的气候条件，土的饱和度变化较大，造成强夯法地基施工时，极易形成或竭孔或吸锤等施工间题的不断转换，严重影响地基加固效果。为此，在普通强夯法施工工艺加固地基的基础上，提出了在强夯夯坑内回填同类残积土，经二次复夯形成柔性置换夯墩的地基处理方法，并采用多避点夯之间回填、休止、复夯逐步递进的特定施工工艺流程，解决了此类场地强夯施工困难、处理效果差的间题。工程实践表明，采用该方法进行地基处理，施工方便，消除了端孔、吸锤等现
象；处理后的地基场地均匀，承载力大幅提高，变形小，能有效满足工程设计要求。【关键词】地基；回填；强夯；柔性墩；处理
【中图分类号】TU472
【文献标识码］A
【文章编号】1002-8498（2013)15-0096-04
DynamicCompactionReplacementwithFlexibleEarth ColumnforSoilTreatmentinLooseBackfillGround
He Guofu,Zhang Lingyun,Han Genrong
(Sinopec Shanghai Engineering Co., Ld., Shanghai 200120, China)
Abstract; Residual sandy clay soil is normally used for large area leveling backfill material with dynamic compaction in coastal region in south of China. Natural residual clay soil have characteristics of big pore ratio, low compressive, soften and disintegration encountering water. When used for large area backfilling after transportation, its pore ratio become bigger, and its compressibility increased. Despite of be rolled, eeease degree of change bigger, and easily to cause allernative happening for soil collapse and hammer absorption during construction. The effect of soil treatment is seriously decreased. Whereas based on the construction processing of commonly used dynamic compaction methods to consolidate subgrade, the ieronaaenaeaesoea make backfill in tramping excavation with same backfill materials and to be compacted in double times, meanwhile the special processing procedure have been adopted in cyclic backfill, rest, re-tramp step by step forward between multi-times tramping. Thereby the problems of construction difficulties and low efficient of treatment have been solved. The engineering practice indicated this method is easily to construct, and avoid soil collapse and hammer absorption during construction. The subgrade after treated is uniform, and bearing capacity increasing, deformation reducing, the parameter can satisfy the requirements of engineering design effectively.
Key words:foundations; backfill; dynamic compaction; flexible earth columns; treatment
我国南方沿海地区多为丘陵地貌，地层主要以
，中石化上海工程有限公司课题：海南洋浦地区更新世特殊地层研究
【作者简介】何国富，教授级高级工程师，E-mail：beguofa.ssee@ sinopee. com
【收稿日期】2013-01-15 万方数据
砂砾质残积土覆盖为主。在大面积高程填方时多以残(坡)积土作为回填材料，并采用强夯法进行地基处理。天然残积土本身具有孔融比大、压缩性低、遇水软化和易崩解的特点“1】，经搬运后用作大