螺杆锚桩反力法在大吨位桩基检测中的应用研究

Study on theApplication of Screw Anchor Pile Reaction Method in Large Tonnage Pile Foundation Detection

螺杆桩作为一种新型预制挤土桩具有承载力高、使用土层广、工程造价低等技术优势,被广泛应用于多种工程建筑领域,现阶段对其竖向荷载作用下的承载机理方向的研究已日趋成熟,但是将其作为锚桩应用于桩基检测中却鲜有报道。考虑到堆载法的高运输成本及传统锚桩法的高时间成本,本文通过常用桩基检测方法的比选,利用螺杆桩充当锚桩配合反力装置提出了一种新型螺杆锚桩反力法,并总结了施工工艺流程与技术特点,最后基于抗拔力测试试验完成了工程应用;研究结果表明;螺杆锚桩反力法可以有效地避免了堆载法与传统锚桩法的土体换填、现场浇注等技术缺点,具有装配式施工、可回收利用、对试验场地要求低等诸多技术优势,通过静载试验的顺利进行,证明螺杆锚桩反力法可以用于大吨位静载试验,相比传统检测方法节约成本70%,现有专用螺母与垫片可以有效地保证静载试验的安全。研究结果对于螺杆桩的工程应用与技术推广具有积极的意义。

Screwpile as a newtype of prefabricated pile,it has the advantages of high bearing capacity,wide soil layer adaptation and lowengineering cost,thus it is widely used in many engineering construction fields.At present,the research on the direction of the bearing mechanism of screw pile under vertical load has become increasingly mature,but it has rarely been used as an anchor pile in pile foundation detection.Considering the high transportation cost of the stowagemethod and the high time cost of the traditional anchor pilemethod,the paper proposes a new type of screw anchor pile reaction method,by comparing and selecting common pile foundation detection methods,using screw piles as the anchor pile and reaction force devices,further the construction process and technical characteristics is summarized.In the end of the paper based on the test results of pullout resistance the engineering application has been completed.The research results show that the reaction method of screw anchor pile can effectively avoid the technical shortcomings of soil replacement and field pouring of the stowage method and traditional anchor pile method.Meanwhile,it has many technical advantages such as assembly-type construction,recyclable and low requirement on test site.Through the smooth running of the static load test,it is proved that the reaction method of screw anchor pile can be used for the static load test of large tonnage,the cost can be reduced by 70% compared with the traditional test method,and the existing special nut and gasket can effectively guarantee the safety of the static load test.The research results have positive significance for the engineering application and technology promotion of screwpiles.