土与小型钢管抗滑桩群复合结构模型试验研究

为揭示滑坡体在地震动力作用下微型钢管抗滑桩群与土形成的复合结构中桩的内力沿桩身的分布、土的内部压力变化、复合结构的耗能性能及动力特性,在参考Thompson研究方法并考虑土拱效应的基础上,自主研发了直剪式小型抗滑桩土群的低周往复模型试验装置,确定了小型钢管抗滑桩的合理桩间距,并依据相似理论设计了三排小型钢管抗滑桩模型并对其进行低周往复加载试验,通过试验研究了土与抗滑桩群复合结构的力学响应、动力特性、强度规律及破坏形态等主要性状。试验结果表明,桩前被动土压力呈梯形分布,桩后主动土压力呈三角形分布,桩身弯矩呈抛物线形分布,承台板起到桩身弯矩重分布的重要作用,土与抗滑桩复合结构在低周往复荷载作用下的滞回性能良好,刚度退化小,塑性变形性能优良,有良好的耗能能力。

Model test of composite structure of soil and small steel pipe anti-slide piles

On the basis of Thompson's research method and considering soil arching effect，a low-cycle reciprocating model test device for small direct shear anti-slide piles was developed independently，and the reasonable pile spacing of small steel tube anti-slide piles was determined． Based on similarity theory，three rows of small steel tube anti-slide piles were designed and tested under low-cycle reciprocating loading． The test results show that the passive earth pressure in front of the pile is trapezoidal distribution，the active earth pressure behind the pile is triangular distribution，the bending moment of the pile is circular arc distribution，the cap plate plays an important role in the redistribution of the bending moment of the pile，and the hysteretic behavior of the composite structure of soil and anti-slide pile under low cyclic reciprocating load． It has good performance，small stiffness degradation，excellent plastic deformation performance and good energy dissipation capacity．