PHC与CFG桩复合地基在高速铁路基底中处理效果试验对比  

EXPERIMENTAL EFFECT CONTRAST BETWEEN PHC AND CFG PILE-RAFT COMPOSITE FOUNDATION IN HIGH SPEED RAILWAY BASE TREATMENT

作　　者：沈宇鹏[1,2] 毛远凤[1] 荆鹏[1] 程万慧[1] 田亚护[1,2] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]北京交通大学轨道工程北京市重点实验室,北京100044

出　　处：《岩石力学与工程学报》2014年第A02期4174-4180,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50908012;41271072);中央高校基本科研业务费专项资金(2011JBZ009)

摘　　要：以京津城际铁路2种不同桩筏复合地基处理形式为工程实例,对比分析PHC桩和CFG桩的单桩承载力、荷载桩–土分担、以及不同位置的荷载和沉降与时间的变化特征。结果表明,PHC桩的单桩承载力明显大于CFG桩,约为其1.33倍;PHC复合地基段路基的中心沉降量小于CFG桩复合地基段;PHC桩断面的桩–土应力比为17-47,荷载分担比为0.56-0.78,而CFG桩断面桩–土应力比为12-25,荷载分担比为0.42-0.59,说明PHC桩复合地基能尽量减小桩间土的荷载。认为在松软地基上采用PHC管桩不仅能保证复合地基中的成桩效果,也能减小桩间土的荷载承担,从而减小复合地基的总沉降量。Through analyzing the differences of bearing capacities of a single pile,pile-soil load distribution and variation characteristics of the load and settlement in the different times,PHC and CFG piles raft composite foundations are compared when applied to treat the foundations of Beijing-Tianjin intercity railway. The results show that PHCs bearing capacity of single pile is obvious higher than the CFGs,about 1.33 times,and the settlement in PHCs section is smaller than CFGs. The results appear that the pile-soil stress ratio is about 17–47,and load ratio is 0.56–0.78 in PHCs section. The pile-soil stress ratio is 12–25,and load ratio is 0.42–0.59 in CFGs section. It is said that the PHC piles can bear more load than the CFG,the soils in PHCs section will bear less load than CFGs. In summary,PHC piles are used to as a ground treatment not only to ensure pile-forming effect,but to reduce the load on soil between two piles in soft foundations,and to decrease the total settlement of composite.

关 键 词：复合地基 高速铁路 沉降 桩–土应力比 单桩承载力 

分 类 号：TU47[建筑科学—结构工程]