地下空间巨型型钢混凝土斜柱的受力性能及参数化仿真分析

Mechanical Properties and Parametric Simulation Analysis of Giant Steel Reinforced Concrete Inclined Column in Underground Space

针对深圳黄木岗地下综合交通枢纽的巨型型钢混凝土斜柱结构,基于钢材的双线性本构模型和混凝土塑性损伤模型,采用ABAQUS有限元软件建立了22根不同倾角巨型型钢混凝土足尺斜柱的仿真模型。通过不同倾角下巨型型钢混凝土足尺斜柱在竖向荷载作用下的受力全过程分析,研究对比了不同倾角对其荷载-位移曲线和峰值承载力的影响规律,同时对不同倾角试件受力全过程中混凝土和型钢的荷载分配进行了分析,从而揭示了巨型型钢混凝土斜柱受压承载机理。在该基础上,以混凝土强度、型钢含钢率、型钢屈服强度和纵筋配筋率为主要参数,进一步分析各参数对试件荷载-位移曲线以及峰值承载力的影响规律。研究结果表明:随着倾角的增大,试件初始刚度逐渐降低,且试件峰值承载力显著减小,呈“饱缩”现象,混凝土受压损伤区域和型钢屈服区域逐渐由腹中向斜柱两端转移且范围不断减小;随着混凝土强度、型钢含钢率、型钢屈服强度和纵筋配筋率的提高,试件的峰值荷载均有所提高。该研究结果可为进一步明确该类斜柱在地下枢纽工程中的设计应用提供理论参考。

The giant steel concrete inclined column structure of the Huangmugang underground integrated hub in Shenzhen was taken as an example. Based on the bilinear constitutive model of steel and the plastic damage model of concrete, the simulation models of 22 giant steel concrete inclined columns(GSRIC) with different angles were established by ABAQUS. Under vertical load, the whole pressure process of the GSRCIC with different inclination angles was analyzed. The influence of different angles on the load-displacement curves and peak bearing capacity of the inclined column was compared. And the load distribution of concrete and steel sections was analyzed during the whole loading process of specimens with different dip angles to reveal the mechanism of compressive bearing of GSRCIC. On this basis, the influence of each parameter on the load-displacement curve and peak bearing capacity of the specimens were further analyzed by the main parameters of the concrete strength, steel content ratio, steel yield strength and longitudinal reinforcement ratio. The results show that the initial stiffness of specimens decreases gradually with the increase of inclination angle. The peak bearing capacity of specimens decreases significantly which showed “saturation”. With the increase of the inclination angle, the compression damage area of the concrete and the yield area of the steel gradually shift from the middle of the web to the two ends of the inclined column and the range decreases;With the increase of concrete strength, steel content ratio, steel yield strength and longitudinal reinforcement ratio, the peak load of the specimen increases. The results can provide a theoretical reference for further clarifying the design and application of the same column in underground hub projects.