上软下硬地层大断面类矩形顶管结构的力学特性分析

Mechanical Characteristics Analysis of Rectangular Top Pipe Structures with Large Cross-Sections in Upper Soft&Lower Hard Strata

以珠海市兴业快线(北段)下穿梅华东路隧道为工程背景,比对理论计算结果与工程监测数据,分析超大断面类矩形顶管管节在典型华南地区“上软下硬”地质条件下的力学特性。通过研究发现,该地质条件下结构受力形式并非理想状态下均匀且对称分布,常用的土压力计算理论更适用于上部软土地层,下部硬质地层土压力分布的离散性要大于上部软土地层,底部硬岩造成底部支座约束较强,导致结构两侧受力与理想状态的对称形态有所差异。

Taking the East Meihua Road Tunnel under the Xingye Express Line(North Section)in Zhuhai as the engineering background,the theoretical calculation results&engineering monitoring data are compared to analyze the mechanical characteristics of the ultra large cross-section rectangular top pipe joint under typical geological conditions of upper soft&lower hard in southern China.Through research,it has been found that the force distribution of the structure under this geological condition is not uniformly&symmetrically distributed under ideal conditions.The commonly used theory of soil pressure calculation is more suitable for upper soft soil strata.The discreteness of soil pressure distribution in lower hard strata is greater than that in upper soft soil strata.The bottom hard rock creates strong constraints on the bottom support,resulting in differences in the symmetrical shape of the force on both sides of the structure compared to the ideal state.