Construction Technology Research of Deep Foundation Excavation in Deep Soft Clay Layer
Taking the civil air defense underground material storage project of Experimental Middle School in Beichen District of Tianjin as an example,the corresponding foundation excavation design and excavation scheme are put forward,and the deformation and internal force of foundation excavation enclosure structure under deep soft clay geological conditions are analyzed by field measurement method.The results show that the deformation of foundation excavation enclosure structure shows significant time-space effect and size effect.The deeper the excavation is,the greater the maximum horizontal displacement rate is.The creep effect of deep soft clay aggravates the deflection change rate of foundation excavation enclosure structure.When the excavation depth of foundation excavation is small,the maximum horizontal displacement value of bored pile is more concentrated.With the increase of excavation depth,the dispersion degree of maximum horizontal displacement value increases.It is proposed that the upper limit of deformation control in this area is 0.75% H and the lower limit is 0.30% H.The coefficient of static earth pressure corresponding to the measured earth pressure gradually decreases with the increase of depth.The horizontal earth pressure of soft clay layer increases linearly with the increase of depth and tends to converge.
deep foundation excavationsupportsenclosure structurebored pilesmonitoringdisplacementearth pressure
万方数据
维普
