悬挑式卸料平台主梁抗弯受力分析研究

Flexural Stress Analysis of Main Beam of Overhanging Unloading Platform

近年来悬挑式卸料平台在超高层施工中的应用越来越普遍,在传统悬挑式卸料平台主梁抗弯受力分析中,钢丝绳以等效为铰支座的计算方式为主,计算精度有所不足。本文提出直接对钢丝绳建立有限元模型,并进行悬挑式卸料平台主梁的抗弯受力计算。通过对6个在建工程的8种常用悬挑式卸料平台案例分别采用有限元模型方法和传统连续梁方法进行对比计算,探究悬挑式卸料平台主梁的抗弯受力性能。研究结果表明:(1)在考虑外拉吊钢丝绳时,采用有限元建模计算方法得到的主梁工字钢最大弯矩比传统连续梁计算所得到的结果偏大,比值在1.07~1.25范围之内,但钢丝绳拉力则小于传统连续梁计算结果,比值在0.85~0.98范围之内;(2)在考虑内拉吊钢丝绳时,采用有限元建模计算得到的主梁工字钢最大弯矩与传统连续梁计算结果相同,钢丝绳拉力同样小于传统连续梁计算结果,比值在0.90~0.97范围之内。本文提出对钢丝绳直接建立有限元模型的计算方法更接近于悬挑式卸料平台主梁实际受力情况,研究结果可对传统连续梁计算结果进行校正和补充。

Overhanging unloading platforms have been widely used in super high-rise construction in recent years.In the traditional analysis of flexure force of main beam of cantilevered unloading platform,the wire rope is mainly considered equivalent to hinge support,and the calculation accuracy is insufficient.In this paper,finite element model of steel wire rope is established directly,and the bending force of main beam of overhanging unloading platform is calculated.The bending behaviors of eight commonly used overhanging unloading platforms in six under-construction projects were calculated using both finite element modeling and traditional continuous beam methods.The calculated results were compared and investigated.The results show that:(1)when considering the external pulling wire rope,the maximum bending moment of I-beam obtained by finite element modeling method is higher than that obtained by traditional method(the ratio within the range of 1.07~1.25),but the tension force in wire rope is lower than that obtained by traditional method(the ratio within the range of 0.85~0.98);(2)when considering the internal pulling wire rope,the maximum bending moment of I-beam calculated by finite element modeling method is the same as that calculated by traditional method,and the tension force in wire rope is lower than that calculated by traditional method(the ration within the range of 0.90~0.97).The proposed calculation method of directly establishing finite element model for wire rope is more close to the actual stress of main beam of overhanging unloading platform,and the research results can be used to correct and supplement the calculation results of traditional continuous beam method.