中文摘要：

根据静力触探探头和静压桩贯入软土时的特点，采用柱孔扩张理论来模拟圆锥锥身和桩身贯入过程中应力场的变化，采用球孔扩张理论分析锥尖和桩端的挤土受力情况，推导出该条件下柱孔扩张和球孔扩张的极限扩孔压力理论解，在此基础上，对静力触探探头和静压桩进行受力对比分析，推导出利用波速孔压静力触探试验成果估算静压桩极限承载力的理论表达式。理论计算值与现场试验桩的静载荷试验结果较为吻合，说明该理论解具有一定的实用价值。

英文摘要：

According to the characteristics of installation of seismic piezocone penetration test （SCPTu） penetrometers and jacked-in piles, the penetration process is simulated by means of the cavity expansion theory. Based on this evaluation, the analytical solutions of the limit pressure of spherical and cylindrical cavities are presented. According to the analytical solutions and comparison of forces between SCPTu penetrometers and the piles, an analytical relationship between the data measured from SCPTu and the ultimate bearing capacity of a single pile is established. Compared with the axial load tests on a single pile in the field, the value of the new analytical solution which is used to predict the ultimate bearing capacity of jacked-in piles by utilizing the SCPTu data is verified.