双排门式抗滑桩的空间计算模型

Spatial calculation model for portal double row anti-slide piles

滑坡推力大时单排抗滑桩不能产生良好的抗滑效果,而抵抗力大、桩顶位移小的双排门架式抗滑桩能有效地限制支挡结构的变形。目前的计算方法忽略了双排抗滑桩间联系梁和圈梁所起的变形协调及桩梁岩土间的相互作用,具有一定的局限性。针对这一问题,将双排门架式抗滑桩视为桩梁岩土共同作用的单层多跨框架结构,综合考虑桩间土拱效应、框梁及联系梁对双排门架式抗滑桩的空间协同作用,提出了桩梁土空间协同作用下的双排门架式抗滑桩受力模型;基于静力平衡及变形协调原理,建立了双排门架式抗滑桩受力模型的变形方程;采用有限元理论编制了双排门架式抗滑桩的有限元程序,计算内力和变形特性;最后在三峡库区防治工程中对研究成果进行了验证,计算结果及对比分析表明该模型符合于抗滑桩的特性。

Since single row anti-slide piles is not capable of providing efficient bracing structure under larger sliding-force, portal double row anti-slide piles, which have the advantages of less displacement in the top of the piles and large anti-force, can be used to reduce the piles deformation. However, the calculation models of double row piles in prior ignore the interaction features of piles, beams and soils; and the calculation results based on the models are not accurate enough. Taking portal double row anti-slide pile as a single-layer multi-span frame affected by piles, beams and soils, and analyzing spatial coordinative interaction between top ring beam and link beam, as well as the affection of soil arch effect on the flame, a spatial forces model of the portal double row anti-slide piles is presented. A deformation equation is established by using pile lead border condition, continuous deformation of strong point, static force balance and deformation compatibility between top ring beam and pile lead. A program is developed by finite element method and Winkler beam on elastic foundation method. Finally, the model is applied to the test of the Three Gorges reservoir area prevention and curing project; and the result shows it is suitable for similar engineering.