预应力管桩穿过中密粉砂夹细砂层的静力压桩法施工技术

通过对预应力管桩桩端进行特殊处理,在既满足设计要求,又不影响周边居民正常生活的情况下,进行桩径为600mm、桩长53m、设计单桩极限承载力标准值7 850kN的预应力管桩施工,预应力管桩通过5 100kN的静压力顺利穿过双桥静力触探锥头阻力平均值为9.2MPa,标准贯入锤击数平均值为25.2击,厚度约9m的中密粉砂夹细砂层。

Static Pressed Pile Technology on Prestressed Pipe Pile Drilling Through Fine-sand-mingled Medium-compacted Silty Sand Layer

To meet the design requirements without impacts on normal life of surrounding residents,the prestressed pipe pile is driven after special pile-tip treatment,which is designed as 600mm in diameter,53m in length, and(7 850)kN in standard value of ultimate bearing capacity.Under the static pressure of(5 100)kN,the pipe pile can be successfully drilled through the fine-sand-mingled medium-compacted silty sand layer characterized as 9.2 MPa in average resistance value by double-bridge static cone penetration,25.2 in mean standard penetration blow-count,and 9 meter in thickness.