摘要
利用真空预压法处理吹填土时,细颗粒常堵塞排水管,导致土体排水不畅。为提高吹填土固结效率,采用自重沉淤排水与加负压排水固结相结合的方式在室内进行吹填土固结试验。试验第一阶段用排水管作为吹填土自重沉淤的竖向排水通道;第二阶段以装入中粗砂的排水管作吹填土排水通道,同时也是压力传递通道。试验监测到吹填土固结过程中不同位置孔隙水压力的变化,通过监测数据着重研究自重沉淤排水阶段吹填土的固结规律。借助渗流平衡方程确定吹填土在自重沉淤阶段孔隙水压力变化主要由排水管中水位、单位土面积控制,解释自重沉淤阶段孔隙水压力变化机理。同时,为了减小由于排水距离远近造成的固结不均,利用自重沉淤与加压固结结合的方法使吹填土达到较为理想的固结效果,将砂井设计理论与孔隙水压力变化曲线相结合确定排水管有效排水范围等效直径,为实际工程提供排水管间距的设计参数。
The drain pipes,which were applied to treat the dredger fill by vacuum preloading,were always plugged by fine particles. It is essential to keep out of construction period for delay to improve the efficiency of the dredger fill consolidation.The test of dead-weight sludging drainage plus a combination of vacuum method of drainage in the laboratory was carried out.As vertical drainage channels,the drain pipes were experimentally used during the first-stage called dead-weight sludging drainage.Then the drain pipes were filled with medium-coarse sand to consolidate the dredger fill by vacuum method.The pore water pressure of varied depths and ranges were continuously observed especially to approach the primary-stage consolidation law.On account for the balance equation of water in the soil seepage,the major changes of pore water pressure were dominated.The mechanism of the pore water pressure changes during the first stage was explained accordingly.In order to fine consolidation the equivalence circle diametric was determined by sand drain theory and the pore water pressure curves.So drainpipe spacing to achieve the same desired effect of consolidation was determined under different circumstances whether the soil is near or far from the drain for the actual project design parameters.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2010年第9期2935-2940,共6页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.40372122
No.40672180)
国家自然科学基金国际合作项目(No.40911120044)
成都理工大学地质灾害防治与地质环境保护国家专业实验室开放基金(No.GZ2004-08)
关键词
自重沉淤固结
孔隙水压力变化机制
渗流力
排水管间距
dead-weight sludging drainage
mechanism of pore water pressure changes
seepage force
drainpipe spacing
