摘要
由于螺杆灌注桩下部的螺纹段可以与土体发生相互咬合,使得其桩土作用效果与传统直杆桩存在较大的差异性,本文为了研究螺杆灌注桩的竖向抗压承载性能,进行了一系列现场原位静载试验,得到了螺杆灌注桩与直杆桩的荷载沉降曲线,记录了各级荷载下试验桩桩身轴力分布情况,对比分析了螺杆灌注桩与直杆桩竖向抗压承载性能差异。研究结果表明:在本文地层条件下,螺杆灌注桩的承载力较直杆桩提升了26%—45%,对于类似地层,在良好土层施工螺纹段能取得较好经济效果;螺杆灌注桩在前几级荷载作用下,轴力沿深度呈线性衰减,随着荷载增大,桩体螺纹段侧阻优势开始发挥,轴力曲线呈明显折线状;荷载较大时,螺杆桩桩身侧摩阻力差异较直杆桩更为明显,其螺纹段能提供远大于直杆段的平均侧摩阻力。
Because the screw section at the lower part of the screw cast-in-place pile can occlude with the soil,which makes its pile-soil interaction effect different fro m that of the traditional straight rod pile.In order to study the vertical co mpressive bearing capacity of the screw cast-in-place pile,this paper conducted a series of in-situ static load tests,obtained the load settle ment curve of the screw cast-in-place pile and the straight rod pile,and recorded the axial force distribution of the test pile shaft under various loads,The difference of vertical co mpressive bearing capacity between screw cast-in-place pile and straight pile is analyzed.The results show that the bearing capacity of the screw cast-in-place pile is 26%-45%higher than that of the straight pole pile under the stratu m conditions in this paper;Under the action of the first several levels of load,the axial force of the screw cast-in-place pile decreases linearly along the depth.With the increase of load,the lateral resistance advantage of the screw section of the pile starts to play,and the axial force curve is obviously broken;When the load is large,the difference of side friction of screw pile is more obvious than that of straight rod pile,and the threaded section can provide much more average side friction than that of straight rod section.
作者
张午阳
李皓
高柏辉
陈放鸣
ZHANG Wu-yang;LI Hao;GAO Bai-hui;CHEN Fang-ming(Guangzhou municipal Engineering Testing Co.,Ltd.,Guangzhou 510520;Guangdong Provincial Research Center for Testing and monitoring Technology of Prefabricated Underground Structure,Guangzhou 510520;Zhuodian Gao mai High-Tech(Guangdong)Co.,Ltd.,Guangzhou 511450)
出处
《广州建筑》
2022年第6期61-64,共4页
GUANGZHOU ARCHITECTURE
关键词
螺杆灌注桩
抗压承载性能
原位试验
内力测试
screw cast-in-place pile
compressive bearing capacity
in situ test
internal force test
