机场软土地基变截面双向水泥土搅拌桩应用

Application of Variable Bi-directional Deep Mixed Pile in Soft Soil Foundation of an Airport

结合某机场地基软土分布特点,选择典型场地开展变截面双向搅拌桩加固软弱地基的现场试验,进行桩身强度检测、单桩荷载试验及单桩复合地基荷载试验、地基反应模量试验和沉降观测,以检验变截面双向搅拌桩加固机场软土地基的效果。试验结果表明,变截面双向搅拌桩成桩质量可靠,桩身强度沿深度分布均匀;变截面双向搅拌桩具有良好的承载性能,地基反应模量及复合地基工后沉降满足设计要求;变截面双向搅拌桩能根据土层分布特点合理设计桩间距,减少桩数,从而大大降低工程造价。

In this paper,combined with the distribution characteristics of soft soil layer of an airport foundation,field test of variable bi-directional deep mixed column in soft foundation was carried out on typical site. With the pile strength detection,single pile load test,load test of single pile composite foundation,foundational response modulus test and settlement observation conducted, the effect of variable bi-directional deep mixed pile strengthening airport soft soil foundation was tested. Test studies show that,the quality of variable bi-directional deep mixed pile is reliable and the strength of pile is distributed evenly along the depth; the pile has good bearing capacity,the foundational response modulus and the post-construction settlement of composite foundation can meet the design requirements; the pile spacing can be reasonably designed according to the soil layer distribution characteristics,reducing the pile number,and thus it greatly reduces the project cost.