真空预压卸载时间预测方法研究及应用  

Prediction process of unloading time for vacuum preloading and its application

作　　者：张明[1] 闫伟峰 

机构地区：[1]中国铁道科学研究院深圳研究设计院,广东深圳518034 [2]河南金建建设有限公司,河南平顶山467000

出　　处：《工程勘察》2009年第9期13-18,共6页Geotechnical Investigation & Surveying

摘　　要：真空预压法相关规范把固结度和沉降速率作为软基处理卸载的重要标准。由于有些工程采用不同的预压工法,同时又有工期上的搭接和严格限定的工期,最关心的问题是何时能卸载。基于一维固结理论和Voigt-Kelvin粘弹性模型一维流变方程,揭示了主固结阶段与次固结阶段沉降速率与沉降近似呈线性关系的规律。运用双曲线沉降拟合法和Asaoka法预测达到设计固结度的卸荷时间;在三点法预测最终沉降量的基础上,运用沉降速率与剩余主固结沉降的关系,可以推算卸载时的沉降速率,确定卸荷时间。在深圳华侨城欢乐海岸软基处理一期工程中这些方法应用效果较好。The settlement rate and consolidation degree are considered as the very important unloading criterion in soft foundation treatment by using vacuum preloading method in relative codes. Because different preloading methods are used in some projects, the most concerned problem is when to unload owing to the overlap on construction time limit. Based on one-dimensional consolidation theory and one-dimensional theological equation of Voigt-Kelvin viscoelastic model, the results show that the relationship between the settlement rate and the settlement of ground is approximately linear at the primary and secondary consolidation phases. The unloading time for the design consolidation degree could be predicted by using hyperbolic settlement fitting method and Asaoka method. The settlement rate could be computed and the unloading time could also be confirmed through the relationship between the settlement rate and the residual primary settlement based on the three-point method for forecasting the final settlement. The said methods are effective to the soft foundation treatment called the joy coast project in Shenzhen Overseas Chinese Town, which may have the preferable application value.

关 键 词：真空预压法 卸载时间 沉降速率 固结度 Asaoka 三点法 

分 类 号：TU472[建筑科学—结构工程]