水泥土复合管桩复合地基技术及应用

Technology of pipe pile embedded in cement soil composite foundation and its application

水泥土复合管桩复合地基是一种新的地基形式,其兼具水泥土桩与预应力高强混凝土管桩的优点,有利于实现其与地基土的变形耦合,达到共同承担上部荷载的目的。文章结合山东聊城金柱大学城A区工程实例,提出了水泥土复合管桩复合地基的施工技术;并通过桩身质量与桩位偏差、静荷载试验,对水泥土复合管桩复合地基的应用进行研究。结果表明:采用的施工机械具有施工速度快、水泥土桩搅拌均匀、钻头故障率低等优点,满足加固深度范围内土体搅拌次数要求,其施工工艺能够较好的指导施工;水泥土芯样立方体抗压强度大于3.5 MPa,桩位偏差小于110 mm,满足设计和规范要求;复合地基承载力特征值为330 k Pa,单桩承载力特征值为1050 k N,满足设计要求;水泥土复合管桩复合地基比原桩基础节约资金11.1%~12.7%。

Composite foundation of pipe pile embedded in cement soil is a new type of foundation, and it has the advantages of cement soil pile and pipe pile, can be deformed with the foundation soil at the same time, and can bear the upper load together with the foundation soil. By combining with the Shandong Liaocheng Jinzhu University town area as an engineering example, the construction technology of composite foundation of pipe pile embedded in cement soil is proposed. Through the quality of pile and the deviation of pile and static load test, the application of cement soil composite pipe pile composite foundation is studied. The results show that the construction machinery used has the advantages of fast construction speed, uniform mixing of cement soil pile and low failure rate of drill bit. It can meet the requirement of soil mixing in strengthening depth range, and according to the construction characteristics of this type of mechanical technology, it can better guide the construction. The compressive strength of cement soil sample is more than 3. 5 MPa, which meets the design requirements; the deviation of pile position is less than ll0mm, which meets the requirement of the code. The characteristic value of bearing capacity of composite foundation is 330 kPa. The characteristic value of single pile bearing capacity is 1050 kN, its index meets the design requirements, and compared with the pile foundation, composite foundation of pipe pile embedded in cement soil saving is 11.1% - 12.7% , which has achieved good results.