根式沉井基础群井效率系数现场水平试验研究  

Field test of lateral group efficiency of root-caisson foundations

作　　者：龚维明[1] 有智慧[1] 殷永高[2] 童小东[1] 

机构地区：[1]东南大学,南京210096 [2]安徽省高速公路总公司,合肥230051

出　　处：《土木工程学报》2010年第5期89-95,共7页China Civil Engineering Journal

基　　金：交通部和安徽省联合攻关课题(2006-353-334-120)

摘　　要：根式沉井基础是一种根据仿生学原理提出的新型基础,制作时先在沉井井壁预留顶推孔,待沉井下沉至设计标高后,通过千斤顶将预制根键顶推入土,挤密周围土体,最后通过混凝土封壁保证根键和沉井固接。该基础适用于承受较大竖向、水平荷载且需要巨大抗拔力的构筑物。本文结合锚锭根式沉井基础课题,采用慢速维持荷载法进行了三次现场水平静载试验,测试了带承台群井体系的水平承载力及变位情况,研究分析了根式沉井基础群井效率系数。试验结果表明,群井效率系数保守值约为1.35,承台约束效率系数约为1.49,两者均随沉井数量和基础顶部水平位移的增大而增加。Root-caisson foundation is based on the bionics principle.The construction procedure involves sinking a caisson with reserved holes in the sidewall,then pushing prefabricated rootstalks into the soil through the jack hole after the caisson has been sank to the design level,and casting concrete to make sure that rootstalks are fixed with the caisson.It suits well in structures with significant extraction-resistantce,and vertical and horizontal bearing capacity.For an anchorage foundation of the Changjiang River Bridge in Maanshan City,three field tests have been carried out using lateral static loading test method to acquire the horizontal displacement and bearing capacity of the group root-caisson foundation.The lateral group efficiency of the root-caisson foundation is analyzed.The result shows that a conservative value of lateral group efficiency is about 1.35,cap-restraint efficiency is about 1.49,and both could increase with the development of root-caisson quantity and the horizontal displacement.

关 键 词：根式沉井基础 群井效率系数 静载试验 水平承载力 

分 类 号：TU473.1[建筑科学—结构工程]