风化岩地基微型抗浮桩承载性能原位试验研究  

IN-SITU TEST STUDY ON BEARING BEHAVIOR OF ANTI-FLOATING MICROPILE IN WEATHERED ROCK SITE

作　　者：白晓宇[1] 张明义[1] 刘鹤 

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033 [2]青岛市户外广告与亮化管理办公室,山东青岛266071

出　　处：《工业建筑》2014年第2期94-97,共4页Industrial Construction

基　　金：国家自然科学基金项目(51278261);青岛地铁集团有限公司资助项目(SDSITC-0108310)

摘　　要：微型抗浮桩具有地层适应性强、布置形式灵活、成孔快、施工占用场地小、施工机械小型化及经济环保等优点。基于中风化花岗岩地层8根微型抗浮桩现场静载荷试验，研究青岛风化岩地基微型抗浮桩的竖向抗拔承载性状。试验结果表明：试桩Q—s曲线为缓变型，极限荷载作用下桩长为4．2～5．1m的微型抗浮桩总上拔量不超过7．0mm，极限抗拔承载力高达1700kN，承载力较高，满足设计要求；单桩单位平均极限侧摩阻力为0．307～0．425MPa；在其他条件均不变的情况下，微型抗浮桩的单位平均极限侧摩阻力随桩径的增加而减小。Anti-floating micropile has the virtue of strong strata adaptability, flexible layout, economical construction, quick hole forming, environmental protection and machinery miniaturization. Based on the static load test of eight anti-floating micropiles, the vertical pull-out bearing properties of anti-floating micropile in Qingdao weathered rock site have been studied. The test results show that the Q - s curves of the testing piles are of slow change type, ultimate uplift capacity of pile length with 4.2 - 5. 1 m are 1 700 kN under the ultimate load, which can meet the design demands ; the unit average ultimate side friction of single pile is 0. 307 - 0. 425 MPa under the ultimate load ; with other conditions being unchanged, the unit average ultimate side friction of anti-floating micropile reduces with the increase in pile diameter.

关 键 词：风化岩地基 微型抗浮桩 极限抗拔承载力 单位平均极限侧摩阻力 

分 类 号：TU473.1[建筑科学—结构工程]