(宁波市城建设计研究院  315012)
【提要】  在预应力混凝土管桩基础设计实践中，发现一些工程中采用静压法沉桩时，管桩的终压标准同《宁波市建筑桩基设计与施工细则》(2001甬DBJ02—12)推荐值相差较多，通过增加设计试桩并结合静载荷试验、高应变动测等检测和分析，提出了合理的终压标准。针对预应力混凝土薄壁管桩抗水平变形能力弱，在软土地基中应用极易产生偏位、折断等现象进行分析探讨，通过减少土体扰动、增强管桩基础刚度等方法，总结出一套措施，经实际工程检验，以上措施对提高薄壁管桩抗水平变形能力及预防折断等有较好的效果。
【关键词】  预应力混凝土管桩  软土地基  压桩力  水平变形能力  断桩预防
Some Practical Issues for Using Prestressed Concrete Tubular Piles in Softsoil Ground/Wu Chunfei,Zheng Shuiqiang(Ningbo Urban Construction Design and Research Institute,Ningbo 315012,China)
Abstract:While using static pressure method to sink the piles in some project,it is found
that the final pressure value for prestressed concrete tubular pile has more diffe
rence compared with the recommend value given by Design and Construction Details for Pile Foundations in Ningbo (2001 Yong DBJ02—12).By using the method of increasing the number of test piles combind with the static loading tests and high strain dynamic tests,a re
asonable final pressure value is given after the analysis.A discussion is made to the condition of pile shift and pile break due to the weakness of the resistant to thehorizontal deformation for prestressed concrete thinwalled tubular piles in soft soils.A set of method is concluded by using the principles of reducing the disturb to the soil and increasing the rigidity of the tubular piles. In practical projects, the good results have got to increase the
resistant to the horizontal deformation and prevent the pile break off.
Keywords:prestressed concrete tubular pile; soft soil ground; pressure force; horizontal deformation; break prevention