大型油库储罐桩基础差异沉降处理有限元分析

Finite element analysis of differential settlement treatment for pile foundation of large oil storage tank

宁波某油库15#储罐地基原采用预制钢筋混凝土方桩进行地基加固,油罐运行过程中基础周边不均匀沉降(非平面倾斜)超出规范限值。为减少大型储油罐桩基的差异沉降,拟采用截桩方案进行处理,由此可能给油罐带来一定的风险。本文以该项工程为依托,针对截桩方案建立基础板+桩+地基土的有限元模型,预测了截桩方案对差异沉降的调节效果及系统的应力场分布和发展情况。结果表明:截桩可导致明显的剪切应力集中效应,但油罐地基系统处于稳定状态,截桩附近(5倍桩间距范围)的差异沉降调节效果较明显,为油库储罐桩基础差异沉降处理设计和施工提供了参考。

In the 15#storage tank foundation of certain oil depot in Ningbo,the precast reinforced concrete square piles were used to reinforce the foundation.During the operation of the oil tank,the uneven settlement around the foundation(non-planar slope)exceeded the standard limit.In order to reduce the differential settlement of the pile foundation of the large oil storage tank,it is planned to adopt the interception pile scheme for the treatment,which may bring certain risks to the tank.Based on this project,the finite element model with the foundation plate+pile+foundation soil for the pile-cutting scheme is established,and the differential settlement adjustment effect of the interception piles and the distribution and development of the stress field are predicted.The results show that the interception piles can lead to obvious shear stress concentration effects,but the tank foundation system is in a stable state,and the differential settlement adjustment effect near the intercepted piles(5 times pile spacing range)is obvious,which provides the reference for the design and construction of the differential settlement treatment of the oil tank foundation.