腹式三角桁架模拟地下大跨度大腋角可行性分析  

Feasibility Analysis of Adding Web Members in Triangular Truss to Imitate the Big Axillary Angle in Large-span Underground RC Structure

作　　者：刘建辉 郭乾坤 LIU Jianhui;GUO Qiankun(Guangzhou Municipal Engineering Design&Research Institute Guangzhou 510060,China)

机构地区：[1]广州市市政工程设计研究总院有限公司,广州510060

出　　处：《广东土木与建筑》2022年第9期52-55,共4页Guangdong Architecture Civil Engineering

摘　　要：地下工程中,梁端、柱端、板墙交接部位加腋,是一种常见的结构受力形式。加腋可以减少应力集中,增加截面抗弯抗压承载能力。工程中,对于小腋角不参与结构受力计算,只作为安全储备;对于大腋角的结构受力计算,偏向采用变截面梁单元模拟,忽略的大腋角的刚度对结构的正向有利作用,此算法偏保守,不经济。在钢筋混凝土牛腿的“三角桁架计算模型”基础上,提出增加水平、竖向腹杆的三角桁架计算模型,用以模拟大腋角。通过分析对比,增加水平、竖向腹杆的三角桁架计算模型模拟大腋角合理可行,并且比有限元板单元模拟腋角计算模型更简便读取内力和弯矩进行设计,在工程中具有一定的参考意义。In underground engineering,laying the axillary angle at the beam end,column end,and at the junction of floor and wall is a common form of RC structural stress.Laying the axillary angle can reduce stress concentration and increase the flexural and compressive bearing capacity of the section.In underground engineering,the small axillary angle is not involved in the structural stress calculation and is only used as a safety reserve.For the structural stress calculation of big axillary angle,the variable cross-section beam element simulation is preferred,and the positive beneficial effect of the stiffness of big axillary angle on the structure is ignored.This algorithm is conservative and uneconomical.Based on the“triangular truss calculation model”of reinforced concrete corbel,this paper proposes a triangular truss calculation model with horizontal and vertical web members to imitate big axillary angle.Through analysis and comparison,the triangular truss calculation model with horizontal and vertical web members is reasonable and feasible to imitate big axillary angle,and it is more intuitive to read the internal force and bending moment for design than the plate element to imitate big axillary angle calculation model,which has a certain reference significance in engineering.

关 键 词：地下大跨度结构 大腋角 三角桁架模型 有限元计算 

分 类 号：TU473[建筑科学—结构工程]