钻孔埋入式后压浆管桩水平承载特性研究

针对大直径管桩不便于山区输电线路杆塔基础中推广应用等问题,提出了一种钻孔埋入式后压浆管桩技术,通过4根桩的水平静载试验及有限元模拟,对该新型桩的水平承载特性进行了研究。结果表明:(1)试桩的水平承载力极限值和特征值的平均值分别为542.3 kN和345.7 kN,高于同直径打入桩的水平承载力;(2)水平承载力特征值随着灌浆层厚度增大近似线性增大,灌浆层厚度为50～200 mm时,较等直径打入桩提高15.3%～62.4%;(3)桩身弯矩随灌浆层厚度增大而减小,50～200 mm厚灌浆层可减小桩身弯矩32.9%～60.8%;(4)桩身水平位移对土体水平位移的影响区域近似为倒锥形,水平位移影响区域范围随灌浆层厚度增大而增大,但其形状基本不变;(5)灌浆层与管桩间未出现脱离现象,两者始终作为一个整体共同承担水平荷载。本文研究成果对该桩型的研究及推广具有一定的参考价值。

The Horizontal Bearing Properties of Drilled and Post-Grouted Concrete Pipe Pile

In order to deal with the application problem that the large diameter pipe pile cosntructing in line tower foundation in mountainous area is not convenient, a Drilled and Post-Grouted Pipe pile was proposed. Its horizontal bearing characteristics were investigated with the horizontal static load tests of four piles and finite element simulation analysis. The results show that: (1) the average value of the horizontal ultimate bearing capacity and the characteristic value are 542.3 kN and 345.7 kN, respectively, which is higher than that of the driven pile with same diameter; (2) the characteristic value of horizontal bearing capacity of Drilled and Post-Grouted Concrete Pipe Pile increases approximate linearly with the increase of the thickness of the grouting layer, and when the grouting layer thickness is at the range of 50~100 mm, its bearing capacity is greater than driven pile with same diameter by 15.3%~62.4%; (3) the bending moment of the pile body decreases by 32.9%~60.8% with the increase of the grout layer thickness at the range of 50~100 mm; (4) the shape of soil horizontal displacement influenced areas is like an inverted cone, and with the thickness of the grouting layer increasing, the range of horizontal displacement affected area increases; (5) The grouting layer and the pipe pile are cemented together during the field tests and share the horizontal load as a whole structure. The research results of this paper have certain reference value for the research and popularization of this pile type.