福建莆田软土区桩-土相互作用原位试验研究

Study on Pile-soil Interaction of Soft Soil Area in Putian City,Fujian Province

软土区桥头路堤填筑会给下卧软土层带来一定的位移场,导致典型的软土-桩基相互作用,会威胁到桥梁的建设与正常使用。研究开展了软土-桩基相互作用的1∶1原位试验,根据桩顶偏移、桩身拉压应变、桩身弯矩、桩侧土抗力和桩周孔隙水压力等监测数据,对路堤填筑引发的软土-桩基相互作用进行了深入分析。研究得出,在相同大小的堆载作用下,桩径越大,桩身抗弯刚度越大,桩身最大拉压应变越小,桩身最大弯矩越小,最大应变和最大弯矩的位置越深,抗裂性能越强,桩侧土抗力越大,桩身与软土间的相互作用效果越好。

The filling of bridgehead embankment in soft soil area will bring a certain displacement field to the underlying soft soil layer,which will lead to the interaction of typical soft soil pile foundation and threaten the construction and normal use of bridges.The 1:1 in situ test of pile foundation interaction in soft soil was carried out.Based on the monitoring data of pile top deviation,pile tension strain,pile bending moment,pile side soil pressure and pore water pressure around pile,the interaction of soft soil pile foundation caused by embankment filling is analyzed in depth.It is concluded that under the action of the same size,the larger the pile diameter,the greater the bending stiffness of the pile body,the smaller the maximum tensile strain,the smaller the maximum bending moment,the deeper the position of the maximum strain and the maximum bending moment,the stronger the crack resistance.